[llvm] [ELFObject] Added conditions to print removed symbols and removed sections (PR #124692)
Kshitij Paranjape via llvm-commits
llvm-commits at lists.llvm.org
Thu May 15 21:40:06 PDT 2025
https://github.com/kshitijvp updated https://github.com/llvm/llvm-project/pull/124692
>From 718edfee71e995ab4fbee442af7b92a0c15cee65 Mon Sep 17 00:00:00 2001
From: Kshitij Paranjape <kshitijvparanjape at gmail.com>
Date: Mon, 27 Jan 2025 21:19:33 +0530
Subject: [PATCH 1/5] [ELFObject] Added dbgs() statement in removeSections()
This patch adds dbgs() statement inside removeSections()
and removeSymbol() function to print the removed sections
and symbols.
Fixes: #123041
---
llvm/lib/ObjCopy/ELF/ELFObject.cpp | 26 ++++++++++++++++++++------
llvm/tools/llvm-objcopy/CommonOpts.td | 2 ++
2 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/llvm/lib/ObjCopy/ELF/ELFObject.cpp b/llvm/lib/ObjCopy/ELF/ELFObject.cpp
index 45c7ea49b5d93..94c73b62de12e 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObject.cpp
+++ b/llvm/lib/ObjCopy/ELF/ELFObject.cpp
@@ -766,8 +766,14 @@ Error SymbolTableSection::removeSymbols(
function_ref<bool(const Symbol &)> ToRemove) {
Symbols.erase(
std::remove_if(std::begin(Symbols) + 1, std::end(Symbols),
- [ToRemove](const SymPtr &Sym) { return ToRemove(*Sym); }),
- std::end(Symbols));
+ [ToRemove](const SymPtr &Sym) {
+ if (ToRemove(*Sym)) {
+ dbgs()<<"Symbols Removed:"<<Sym->Name<< "\n";
+ return true;
+ }
+ return false;
+ }));
+
auto PrevSize = Size;
Size = Symbols.size() * EntrySize;
if (Size < PrevSize)
@@ -2249,10 +2255,18 @@ Error Object::removeSections(
// Transfer removed sections into the Object RemovedSections container for use
// later.
- std::move(Iter, Sections.end(), std::back_inserter(RemovedSections));
- // Now finally get rid of them all together.
- Sections.erase(Iter, std::end(Sections));
- return Error::success();
+ for(auto &KeepSec : make_range(std::begin(Sections) , Iter))
+ {
+
+ if (Error E = KeepSec->removeSectionReferences(
+ AllowBrokenLinks, [&RemoveSections](const SectionBase *Sec) {
+ return RemoveSections.find(Sec) != RemoveSections.end();
+ }))
+ std::move(Iter, Sections.end(), std::back_inserter(RemovedSections));
+ dbgs()<<"Sections Removed:"<<KeepSec->Name<<'\n';
+ Sections.erase(Iter, std::end(Sections));
+ return Error::success();
+ }
}
Error Object::replaceSections(
diff --git a/llvm/tools/llvm-objcopy/CommonOpts.td b/llvm/tools/llvm-objcopy/CommonOpts.td
index c247c93f6e0f2..5b15191f54605 100644
--- a/llvm/tools/llvm-objcopy/CommonOpts.td
+++ b/llvm/tools/llvm-objcopy/CommonOpts.td
@@ -117,6 +117,8 @@ def regex
def version : Flag<["--"], "version">,
HelpText<"Print the version and exit.">;
+def verbose : Flag<["--"], "verbose">,
+ HelpText<"Prints the removed symbols and sections">;
def V : Flag<["-"], "V">,
Alias<version>,
HelpText<"Alias for --version">;
>From 02fb5c0b003a99cdbd36c47c2ffd1ca95ab5db85 Mon Sep 17 00:00:00 2001
From: Kshitij Paranjape <kshitijvparanjape at gmail.com>
Date: Sat, 8 Feb 2025 14:59:42 +0530
Subject: [PATCH 2/5] Made Changes
---
llvm/include/llvm/ObjCopy/CommonConfig.h | 1 +
llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp | 1 +
llvm/lib/ObjCopy/ELF/ELFObject.cpp | 27 +++++++++++-----------
llvm/lib/ObjCopy/ELF/ELFObject.h | 1 +
llvm/tools/llvm-objcopy/ObjcopyOptions.cpp | 2 ++
5 files changed, 18 insertions(+), 14 deletions(-)
diff --git a/llvm/include/llvm/ObjCopy/CommonConfig.h b/llvm/include/llvm/ObjCopy/CommonConfig.h
index aea9cd6f9a9c7..83ad4590d9c72 100644
--- a/llvm/include/llvm/ObjCopy/CommonConfig.h
+++ b/llvm/include/llvm/ObjCopy/CommonConfig.h
@@ -274,6 +274,7 @@ struct CommonConfig {
bool StripNonAlloc = false;
bool StripSections = false;
bool StripUnneeded = false;
+ bool Verbose = false;
bool Weaken = false;
bool DecompressDebugSections = false;
diff --git a/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp b/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
index 5aa0079f3fbc7..ad3a2135d23a7 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
+++ b/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
@@ -782,6 +782,7 @@ static Error verifyNoteSection(StringRef Name, endianness Endianness,
// system. The only priority is that keeps/copies overrule removes.
static Error handleArgs(const CommonConfig &Config, const ELFConfig &ELFConfig,
ElfType OutputElfType, Object &Obj) {
+ Obj.isVerboseEnabled = Config.Verbose;
if (Config.OutputArch) {
Obj.Machine = Config.OutputArch->EMachine;
Obj.OSABI = Config.OutputArch->OSABI;
diff --git a/llvm/lib/ObjCopy/ELF/ELFObject.cpp b/llvm/lib/ObjCopy/ELF/ELFObject.cpp
index 94c73b62de12e..c9a090cdea517 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObject.cpp
+++ b/llvm/lib/ObjCopy/ELF/ELFObject.cpp
@@ -768,7 +768,7 @@ Error SymbolTableSection::removeSymbols(
std::remove_if(std::begin(Symbols) + 1, std::end(Symbols),
[ToRemove](const SymPtr &Sym) {
if (ToRemove(*Sym)) {
- dbgs()<<"Symbols Removed:"<<Sym->Name<< "\n";
+ llvm::outs() << "Symbols Removed:" << Sym->Name<< "\n";
return true;
}
return false;
@@ -2236,6 +2236,9 @@ Error Object::removeSections(
for (auto &RemoveSec : make_range(Iter, std::end(Sections))) {
for (auto &Segment : Segments)
Segment->removeSection(RemoveSec.get());
+ if (isVerboseEnabled) {
+ llvm::outs() << "Removed Section: " << (RemoveSec.get()->Name);
+ }
RemoveSec->onRemove();
RemoveSections.insert(RemoveSec.get());
}
@@ -2255,18 +2258,10 @@ Error Object::removeSections(
// Transfer removed sections into the Object RemovedSections container for use
// later.
- for(auto &KeepSec : make_range(std::begin(Sections) , Iter))
- {
-
- if (Error E = KeepSec->removeSectionReferences(
- AllowBrokenLinks, [&RemoveSections](const SectionBase *Sec) {
- return RemoveSections.find(Sec) != RemoveSections.end();
- }))
- std::move(Iter, Sections.end(), std::back_inserter(RemovedSections));
- dbgs()<<"Sections Removed:"<<KeepSec->Name<<'\n';
- Sections.erase(Iter, std::end(Sections));
- return Error::success();
- }
+ std::move(Iter, Sections.end(), std::back_inserter(RemovedSections));
+ // Now finally get rid of them all together.
+ Sections.erase(Iter, std::end(Sections));
+ return Error::success();
}
Error Object::replaceSections(
@@ -2296,8 +2291,12 @@ Error Object::replaceSections(
Error Object::removeSymbols(function_ref<bool(const Symbol &)> ToRemove) {
if (SymbolTable)
for (const SecPtr &Sec : Sections)
- if (Error E = Sec->removeSymbols(ToRemove))
+ if (Error E = Sec->removeSymbols(ToRemove)){
+ if (isVerboseEnabled){
+ llvm::outs() << "Removed Symbols:" << Sec->Name;
+ }
return E;
+ }
return Error::success();
}
diff --git a/llvm/lib/ObjCopy/ELF/ELFObject.h b/llvm/lib/ObjCopy/ELF/ELFObject.h
index d8f79a4b1a3cc..4ec1f7188ef88 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObject.h
+++ b/llvm/lib/ObjCopy/ELF/ELFObject.h
@@ -1195,6 +1195,7 @@ class Object {
uint32_t Flags;
bool HadShdrs = true;
+ bool isVerboseEnabled = true;
bool MustBeRelocatable = false;
StringTableSection *SectionNames = nullptr;
SymbolTableSection *SymbolTable = nullptr;
diff --git a/llvm/tools/llvm-objcopy/ObjcopyOptions.cpp b/llvm/tools/llvm-objcopy/ObjcopyOptions.cpp
index 0d209590655ef..7a0d719756081 100644
--- a/llvm/tools/llvm-objcopy/ObjcopyOptions.cpp
+++ b/llvm/tools/llvm-objcopy/ObjcopyOptions.cpp
@@ -1103,6 +1103,7 @@ objcopy::parseObjcopyOptions(ArrayRef<const char *> ArgsArr,
OBJCOPY_verify_note_sections, OBJCOPY_no_verify_note_sections, true);
Config.OnlyKeepDebug = InputArgs.hasArg(OBJCOPY_only_keep_debug);
+ Config.Verbose = InputArgs.hasArg(OBJCOPY_verbose);
ELFConfig.KeepFileSymbols = InputArgs.hasArg(OBJCOPY_keep_file_symbols);
MachOConfig.KeepUndefined = InputArgs.hasArg(OBJCOPY_keep_undefined);
Config.DecompressDebugSections =
@@ -1586,6 +1587,7 @@ objcopy::parseStripOptions(ArrayRef<const char *> RawArgsArr,
Config.StripAllGNU = InputArgs.hasArg(STRIP_strip_all_gnu);
MachOConfig.StripSwiftSymbols = InputArgs.hasArg(STRIP_strip_swift_symbols);
Config.OnlyKeepDebug = InputArgs.hasArg(STRIP_only_keep_debug);
+ Config.Verbose = InputArgs.hasArg(STRIP_verbose);
ELFConfig.KeepFileSymbols = InputArgs.hasArg(STRIP_keep_file_symbols);
MachOConfig.KeepUndefined = InputArgs.hasArg(STRIP_keep_undefined);
>From 76ccb5731498b389f6c3511dfd0ec09eae36505b Mon Sep 17 00:00:00 2001
From: Kshitij Paranjape <kshitijvparanjape at gmail.com>
Date: Tue, 11 Mar 2025 12:29:29 +0530
Subject: [PATCH 3/5] Made Changes
---
llvm/docs/CommandGuide/llvm-objcopy.rst | 4 +++
llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp | 6 ++---
llvm/lib/ObjCopy/ELF/ELFObject.cpp | 33 ++++++++++++-------------
llvm/lib/ObjCopy/ELF/ELFObject.h | 7 ++++--
4 files changed, 28 insertions(+), 22 deletions(-)
diff --git a/llvm/docs/CommandGuide/llvm-objcopy.rst b/llvm/docs/CommandGuide/llvm-objcopy.rst
index 8dc1357635e1b..b90a5a4ddb0b5 100644
--- a/llvm/docs/CommandGuide/llvm-objcopy.rst
+++ b/llvm/docs/CommandGuide/llvm-objcopy.rst
@@ -178,6 +178,10 @@ multiple file formats.
specified ``<flag>`` values. Can be specified multiple times to update multiple
sections.
+.. option:: --verbose
+
+ List all object files modified.
+
Supported flag names are `alloc`, `load`, `noload`, `readonly`, `exclude`,
`debug`, `code`, `data`, `rom`, `share`, `contents`, `merge`, `strings`, and
`large`. Not all flags are meaningful for all object file formats or target
diff --git a/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp b/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
index ad3a2135d23a7..6cf42ea0e0303 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
+++ b/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
@@ -546,7 +546,7 @@ static Error replaceAndRemoveSections(const CommonConfig &Config,
};
}
- if (Error E = Obj.removeSections(ELFConfig.AllowBrokenLinks, RemovePred))
+ if (Error E = Obj.removeSections(ELFConfig.AllowBrokenLinks, RemovePred, Config.Verbose))
return E;
if (Error E = Obj.compressOrDecompressSections(Config))
@@ -782,7 +782,7 @@ static Error verifyNoteSection(StringRef Name, endianness Endianness,
// system. The only priority is that keeps/copies overrule removes.
static Error handleArgs(const CommonConfig &Config, const ELFConfig &ELFConfig,
ElfType OutputElfType, Object &Obj) {
- Obj.isVerboseEnabled = Config.Verbose;
+ Obj.VerboseOutput = Config.Verbose;
if (Config.OutputArch) {
Obj.Machine = Config.OutputArch->EMachine;
Obj.OSABI = Config.OutputArch->OSABI;
@@ -791,7 +791,7 @@ static Error handleArgs(const CommonConfig &Config, const ELFConfig &ELFConfig,
if (!Config.SplitDWO.empty() && Config.ExtractDWO) {
return Obj.removeSections(
ELFConfig.AllowBrokenLinks,
- [&Obj](const SectionBase &Sec) { return onlyKeepDWOPred(Obj, Sec); });
+ [&Obj](const SectionBase &Sec) { return onlyKeepDWOPred(Obj, Sec); }, Config.Verbose);
}
// Dump sections before add/remove for compatibility with GNU objcopy.
diff --git a/llvm/lib/ObjCopy/ELF/ELFObject.cpp b/llvm/lib/ObjCopy/ELF/ELFObject.cpp
index c9a090cdea517..8976612d5e67e 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObject.cpp
+++ b/llvm/lib/ObjCopy/ELF/ELFObject.cpp
@@ -766,10 +766,11 @@ Error SymbolTableSection::removeSymbols(
function_ref<bool(const Symbol &)> ToRemove) {
Symbols.erase(
std::remove_if(std::begin(Symbols) + 1, std::end(Symbols),
- [ToRemove](const SymPtr &Sym) {
+ [&](const SymPtr &Sym) {
if (ToRemove(*Sym)) {
- llvm::outs() << "Symbols Removed:" << Sym->Name<< "\n";
- return true;
+ if(VerboseOutput)
+ outs() << "Symbols Removed:" << Sym->Name<< "\n";
+ return true;
}
return false;
}));
@@ -779,7 +780,6 @@ Error SymbolTableSection::removeSymbols(
if (Size < PrevSize)
IndicesChanged = true;
assignIndices();
- return Error::success();
}
void SymbolTableSection::replaceSectionReferences(
@@ -2201,7 +2201,7 @@ Error Object::updateSectionData(SectionBase &S, ArrayRef<uint8_t> Data) {
}
Error Object::removeSections(
- bool AllowBrokenLinks, std::function<bool(const SectionBase &)> ToRemove) {
+ bool AllowBrokenLinks, std::function<bool(const SectionBase &)> ToRemove, bool VerboseOutput) {
auto Iter = std::stable_partition(
std::begin(Sections), std::end(Sections), [=](const SecPtr &Sec) {
@@ -2236,8 +2236,8 @@ Error Object::removeSections(
for (auto &RemoveSec : make_range(Iter, std::end(Sections))) {
for (auto &Segment : Segments)
Segment->removeSection(RemoveSec.get());
- if (isVerboseEnabled) {
- llvm::outs() << "Removed Section: " << (RemoveSec.get()->Name);
+ if (VerboseOutput) {
+ outs() << "removed section: " << (RemoveSec.get()->Name);
}
RemoveSec->onRemove();
RemoveSections.insert(RemoveSec.get());
@@ -2282,21 +2282,20 @@ Error Object::replaceSections(
if (Error E = removeSections(
/*AllowBrokenLinks=*/false,
- [=](const SectionBase &Sec) { return FromTo.count(&Sec) > 0; }))
+ [=](const SectionBase &Sec) { return FromTo.count(&Sec) > 0; }, false))
return E;
llvm::sort(Sections, SectionIndexLess);
return Error::success();
}
Error Object::removeSymbols(function_ref<bool(const Symbol &)> ToRemove) {
- if (SymbolTable)
- for (const SecPtr &Sec : Sections)
- if (Error E = Sec->removeSymbols(ToRemove)){
- if (isVerboseEnabled){
- llvm::outs() << "Removed Symbols:" << Sec->Name;
- }
+ if (SymbolTable){
+ for (const SecPtr &Sec : Sections){
+ if (Error E = Sec->removeSymbols(ToRemove))
return E;
- }
+ outs() << "removed symbols:" << Sec->Name;
+ }
+ }
return Error::success();
}
@@ -2583,7 +2582,7 @@ static Error removeUnneededSections(Object &Obj) {
: Obj.SymbolTable->getStrTab();
return Obj.removeSections(false, [&](const SectionBase &Sec) {
return &Sec == Obj.SymbolTable || &Sec == StrTab;
- });
+ }, false);
}
template <class ELFT> Error ELFWriter<ELFT>::finalize() {
@@ -2637,7 +2636,7 @@ template <class ELFT> Error ELFWriter<ELFT>::finalize() {
if (Error E = Obj.removeSections(false /*AllowBrokenLinks*/,
[this](const SectionBase &Sec) {
return &Sec == Obj.SectionIndexTable;
- }))
+ }, false))
return E;
}
}
diff --git a/llvm/lib/ObjCopy/ELF/ELFObject.h b/llvm/lib/ObjCopy/ELF/ELFObject.h
index 4ec1f7188ef88..bcda100343813 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObject.h
+++ b/llvm/lib/ObjCopy/ELF/ELFObject.h
@@ -814,6 +814,8 @@ class SymbolTableSection : public SectionBase {
void setStrTab(StringTableSection *StrTab) { SymbolNames = StrTab; }
void assignIndices();
+private:
+ bool VerboseOutput;
protected:
std::vector<std::unique_ptr<Symbol>> Symbols;
StringTableSection *SymbolNames = nullptr;
@@ -856,6 +858,7 @@ class SymbolTableSection : public SectionBase {
static bool classof(const SectionBase *S) {
return S->OriginalType == ELF::SHT_SYMTAB;
}
+ bool getVerboseOutput() { return VerboseOutput; }
};
struct Relocation {
@@ -1195,7 +1198,7 @@ class Object {
uint32_t Flags;
bool HadShdrs = true;
- bool isVerboseEnabled = true;
+ bool VerboseOutput;
bool MustBeRelocatable = false;
StringTableSection *SectionNames = nullptr;
SymbolTableSection *SymbolTable = nullptr;
@@ -1225,7 +1228,7 @@ class Object {
ConstRange<Segment> segments() const { return make_pointee_range(Segments); }
Error removeSections(bool AllowBrokenLinks,
- std::function<bool(const SectionBase &)> ToRemove);
+ std::function<bool(const SectionBase &)> ToRemove, bool VerboseOutput);
Error compressOrDecompressSections(const CommonConfig &Config);
Error replaceSections(const DenseMap<SectionBase *, SectionBase *> &FromTo);
Error removeSymbols(function_ref<bool(const Symbol &)> ToRemove);
>From 378fadbfe355d61b0fd538346fbf758244ff1433 Mon Sep 17 00:00:00 2001
From: Kshitij Paranjape <kshitijvparanjape at gmail.com>
Date: Sat, 12 Apr 2025 23:18:56 +0530
Subject: [PATCH 4/5] Informal Change(Testing)
---
.../InstCombine/InstCombineAndOrXor.cpp | 28 ++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index ca8a20b4b7312..6feadb5f2a3eb 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -2854,7 +2854,33 @@ Instruction *InstCombinerImpl::visitAnd(BinaryOperator &I) {
simplifyAndOrWithOpReplaced(Op1, Op0, Constant::getAllOnesValue(Ty),
/*SimplifyOnly*/ false, *this))
return BinaryOperator::CreateAnd(Op0, V);
-
+ // I is the 'and' instruction
+if (auto *Add = dyn_cast<BinaryOperator>(I.getOperand(0))) {
+ if (Add->getOpcode() == Instruction::Add) {
+ Value *LHS = Add->getOperand(0); // should be shl
+ ConstantInt *AddConst = dyn_cast<ConstantInt>(Add->getOperand(1));
+ ConstantInt *AndConst = dyn_cast<ConstantInt>(I.getOperand(1));
+ if (AddConst && AndConst) {
+ // check if AddConst is 47 and AndConst is -32
+ if (AddConst->equalsInt(47) && AndConst->getSExtValue() == -32) {
+ // Check if LHS is shl i64 %a, 5
+ if (auto *Shl = dyn_cast<BinaryOperator>(LHS)) {
+ if (Shl->getOpcode() == Instruction::Shl) {
+ ConstantInt *ShlConst = dyn_cast<ConstantInt>(Shl->getOperand(1));
+ if (ShlConst && ShlConst->equalsInt(5)) {
+ // You've matched the pattern!
+ // Replace with: shl i64 (add i64 %a, 1), 5
+ IRBuilder<> Builder(&I);
+ Value *NewAdd = Builder.CreateAdd(Shl->getOperand(0), ConstantInt::get(I.getType(), 1));
+ Value *NewShl = Builder.CreateShl(NewAdd, ShlConst);
+ I.replaceAllUsesWith(NewShl);
+ }
+ }
+ }
+ }
+ }
+ }
+}
return nullptr;
}
>From ac9040802ce64ae7eb7ca4e56129837f88ed5340 Mon Sep 17 00:00:00 2001
From: Kshitij Paranjape <kshitijvparanjape at gmail.com>
Date: Fri, 16 May 2025 10:09:56 +0530
Subject: [PATCH 5/5] Delete
llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
---
.../InstCombine/InstCombineAndOrXor.cpp | 5023 -----------------
1 file changed, 5023 deletions(-)
delete mode 100644 llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
deleted file mode 100644
index 6feadb5f2a3eb..0000000000000
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ /dev/null
@@ -1,5023 +0,0 @@
-//===- InstCombineAndOrXor.cpp --------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the visitAnd, visitOr, and visitXor functions.
-//
-//===----------------------------------------------------------------------===//
-
-#include "InstCombineInternal.h"
-#include "llvm/Analysis/CmpInstAnalysis.h"
-#include "llvm/Analysis/InstructionSimplify.h"
-#include "llvm/IR/ConstantRange.h"
-#include "llvm/IR/Intrinsics.h"
-#include "llvm/IR/PatternMatch.h"
-#include "llvm/Transforms/InstCombine/InstCombiner.h"
-#include "llvm/Transforms/Utils/Local.h"
-
-using namespace llvm;
-using namespace PatternMatch;
-
-#define DEBUG_TYPE "instcombine"
-
-/// This is the complement of getICmpCode, which turns an opcode and two
-/// operands into either a constant true or false, or a brand new ICmp
-/// instruction. The sign is passed in to determine which kind of predicate to
-/// use in the new icmp instruction.
-static Value *getNewICmpValue(unsigned Code, bool Sign, Value *LHS, Value *RHS,
- InstCombiner::BuilderTy &Builder) {
- ICmpInst::Predicate NewPred;
- if (Constant *TorF = getPredForICmpCode(Code, Sign, LHS->getType(), NewPred))
- return TorF;
- return Builder.CreateICmp(NewPred, LHS, RHS);
-}
-
-/// This is the complement of getFCmpCode, which turns an opcode and two
-/// operands into either a FCmp instruction, or a true/false constant.
-static Value *getFCmpValue(unsigned Code, Value *LHS, Value *RHS,
- InstCombiner::BuilderTy &Builder, FMFSource FMF) {
- FCmpInst::Predicate NewPred;
- if (Constant *TorF = getPredForFCmpCode(Code, LHS->getType(), NewPred))
- return TorF;
- return Builder.CreateFCmpFMF(NewPred, LHS, RHS, FMF);
-}
-
-/// Emit a computation of: (V >= Lo && V < Hi) if Inside is true, otherwise
-/// (V < Lo || V >= Hi). This method expects that Lo < Hi. IsSigned indicates
-/// whether to treat V, Lo, and Hi as signed or not.
-Value *InstCombinerImpl::insertRangeTest(Value *V, const APInt &Lo,
- const APInt &Hi, bool isSigned,
- bool Inside) {
- assert((isSigned ? Lo.slt(Hi) : Lo.ult(Hi)) &&
- "Lo is not < Hi in range emission code!");
-
- Type *Ty = V->getType();
-
- // V >= Min && V < Hi --> V < Hi
- // V < Min || V >= Hi --> V >= Hi
- ICmpInst::Predicate Pred = Inside ? ICmpInst::ICMP_ULT : ICmpInst::ICMP_UGE;
- if (isSigned ? Lo.isMinSignedValue() : Lo.isMinValue()) {
- Pred = isSigned ? ICmpInst::getSignedPredicate(Pred) : Pred;
- return Builder.CreateICmp(Pred, V, ConstantInt::get(Ty, Hi));
- }
-
- // V >= Lo && V < Hi --> V - Lo u< Hi - Lo
- // V < Lo || V >= Hi --> V - Lo u>= Hi - Lo
- Value *VMinusLo =
- Builder.CreateSub(V, ConstantInt::get(Ty, Lo), V->getName() + ".off");
- Constant *HiMinusLo = ConstantInt::get(Ty, Hi - Lo);
- return Builder.CreateICmp(Pred, VMinusLo, HiMinusLo);
-}
-
-/// Classify (icmp eq (A & B), C) and (icmp ne (A & B), C) as matching patterns
-/// that can be simplified.
-/// One of A and B is considered the mask. The other is the value. This is
-/// described as the "AMask" or "BMask" part of the enum. If the enum contains
-/// only "Mask", then both A and B can be considered masks. If A is the mask,
-/// then it was proven that (A & C) == C. This is trivial if C == A or C == 0.
-/// If both A and C are constants, this proof is also easy.
-/// For the following explanations, we assume that A is the mask.
-///
-/// "AllOnes" declares that the comparison is true only if (A & B) == A or all
-/// bits of A are set in B.
-/// Example: (icmp eq (A & 3), 3) -> AMask_AllOnes
-///
-/// "AllZeros" declares that the comparison is true only if (A & B) == 0 or all
-/// bits of A are cleared in B.
-/// Example: (icmp eq (A & 3), 0) -> Mask_AllZeroes
-///
-/// "Mixed" declares that (A & B) == C and C might or might not contain any
-/// number of one bits and zero bits.
-/// Example: (icmp eq (A & 3), 1) -> AMask_Mixed
-///
-/// "Not" means that in above descriptions "==" should be replaced by "!=".
-/// Example: (icmp ne (A & 3), 3) -> AMask_NotAllOnes
-///
-/// If the mask A contains a single bit, then the following is equivalent:
-/// (icmp eq (A & B), A) equals (icmp ne (A & B), 0)
-/// (icmp ne (A & B), A) equals (icmp eq (A & B), 0)
-enum MaskedICmpType {
- AMask_AllOnes = 1,
- AMask_NotAllOnes = 2,
- BMask_AllOnes = 4,
- BMask_NotAllOnes = 8,
- Mask_AllZeros = 16,
- Mask_NotAllZeros = 32,
- AMask_Mixed = 64,
- AMask_NotMixed = 128,
- BMask_Mixed = 256,
- BMask_NotMixed = 512
-};
-
-/// Return the set of patterns (from MaskedICmpType) that (icmp SCC (A & B), C)
-/// satisfies.
-static unsigned getMaskedICmpType(Value *A, Value *B, Value *C,
- ICmpInst::Predicate Pred) {
- const APInt *ConstA = nullptr, *ConstB = nullptr, *ConstC = nullptr;
- match(A, m_APInt(ConstA));
- match(B, m_APInt(ConstB));
- match(C, m_APInt(ConstC));
- bool IsEq = (Pred == ICmpInst::ICMP_EQ);
- bool IsAPow2 = ConstA && ConstA->isPowerOf2();
- bool IsBPow2 = ConstB && ConstB->isPowerOf2();
- unsigned MaskVal = 0;
- if (ConstC && ConstC->isZero()) {
- // if C is zero, then both A and B qualify as mask
- MaskVal |= (IsEq ? (Mask_AllZeros | AMask_Mixed | BMask_Mixed)
- : (Mask_NotAllZeros | AMask_NotMixed | BMask_NotMixed));
- if (IsAPow2)
- MaskVal |= (IsEq ? (AMask_NotAllOnes | AMask_NotMixed)
- : (AMask_AllOnes | AMask_Mixed));
- if (IsBPow2)
- MaskVal |= (IsEq ? (BMask_NotAllOnes | BMask_NotMixed)
- : (BMask_AllOnes | BMask_Mixed));
- return MaskVal;
- }
-
- if (A == C) {
- MaskVal |= (IsEq ? (AMask_AllOnes | AMask_Mixed)
- : (AMask_NotAllOnes | AMask_NotMixed));
- if (IsAPow2)
- MaskVal |= (IsEq ? (Mask_NotAllZeros | AMask_NotMixed)
- : (Mask_AllZeros | AMask_Mixed));
- } else if (ConstA && ConstC && ConstC->isSubsetOf(*ConstA)) {
- MaskVal |= (IsEq ? AMask_Mixed : AMask_NotMixed);
- }
-
- if (B == C) {
- MaskVal |= (IsEq ? (BMask_AllOnes | BMask_Mixed)
- : (BMask_NotAllOnes | BMask_NotMixed));
- if (IsBPow2)
- MaskVal |= (IsEq ? (Mask_NotAllZeros | BMask_NotMixed)
- : (Mask_AllZeros | BMask_Mixed));
- } else if (ConstB && ConstC && ConstC->isSubsetOf(*ConstB)) {
- MaskVal |= (IsEq ? BMask_Mixed : BMask_NotMixed);
- }
-
- return MaskVal;
-}
-
-/// Convert an analysis of a masked ICmp into its equivalent if all boolean
-/// operations had the opposite sense. Since each "NotXXX" flag (recording !=)
-/// is adjacent to the corresponding normal flag (recording ==), this just
-/// involves swapping those bits over.
-static unsigned conjugateICmpMask(unsigned Mask) {
- unsigned NewMask;
- NewMask = (Mask & (AMask_AllOnes | BMask_AllOnes | Mask_AllZeros |
- AMask_Mixed | BMask_Mixed))
- << 1;
-
- NewMask |= (Mask & (AMask_NotAllOnes | BMask_NotAllOnes | Mask_NotAllZeros |
- AMask_NotMixed | BMask_NotMixed))
- >> 1;
-
- return NewMask;
-}
-
-// Adapts the external decomposeBitTestICmp for local use.
-static bool decomposeBitTestICmp(Value *Cond, CmpInst::Predicate &Pred,
- Value *&X, Value *&Y, Value *&Z) {
- auto Res = llvm::decomposeBitTest(Cond, /*LookThroughTrunc=*/true,
- /*AllowNonZeroC=*/true);
- if (!Res)
- return false;
-
- Pred = Res->Pred;
- X = Res->X;
- Y = ConstantInt::get(X->getType(), Res->Mask);
- Z = ConstantInt::get(X->getType(), Res->C);
- return true;
-}
-
-/// Handle (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E).
-/// Return the pattern classes (from MaskedICmpType) for the left hand side and
-/// the right hand side as a pair.
-/// LHS and RHS are the left hand side and the right hand side ICmps and PredL
-/// and PredR are their predicates, respectively.
-static std::optional<std::pair<unsigned, unsigned>>
-getMaskedTypeForICmpPair(Value *&A, Value *&B, Value *&C, Value *&D, Value *&E,
- Value *LHS, Value *RHS, ICmpInst::Predicate &PredL,
- ICmpInst::Predicate &PredR) {
-
- // Here comes the tricky part:
- // LHS might be of the form L11 & L12 == X, X == L21 & L22,
- // and L11 & L12 == L21 & L22. The same goes for RHS.
- // Now we must find those components L** and R**, that are equal, so
- // that we can extract the parameters A, B, C, D, and E for the canonical
- // above.
-
- // Check whether the icmp can be decomposed into a bit test.
- Value *L1, *L11, *L12, *L2, *L21, *L22;
- if (decomposeBitTestICmp(LHS, PredL, L11, L12, L2)) {
- L21 = L22 = L1 = nullptr;
- } else {
- auto *LHSCMP = dyn_cast<ICmpInst>(LHS);
- if (!LHSCMP)
- return std::nullopt;
-
- // Don't allow pointers. Splat vectors are fine.
- if (!LHSCMP->getOperand(0)->getType()->isIntOrIntVectorTy())
- return std::nullopt;
-
- PredL = LHSCMP->getPredicate();
- L1 = LHSCMP->getOperand(0);
- L2 = LHSCMP->getOperand(1);
- // Look for ANDs in the LHS icmp.
- if (!match(L1, m_And(m_Value(L11), m_Value(L12)))) {
- // Any icmp can be viewed as being trivially masked; if it allows us to
- // remove one, it's worth it.
- L11 = L1;
- L12 = Constant::getAllOnesValue(L1->getType());
- }
-
- if (!match(L2, m_And(m_Value(L21), m_Value(L22)))) {
- L21 = L2;
- L22 = Constant::getAllOnesValue(L2->getType());
- }
- }
-
- // Bail if LHS was a icmp that can't be decomposed into an equality.
- if (!ICmpInst::isEquality(PredL))
- return std::nullopt;
-
- Value *R11, *R12, *R2;
- if (decomposeBitTestICmp(RHS, PredR, R11, R12, R2)) {
- if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
- A = R11;
- D = R12;
- } else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) {
- A = R12;
- D = R11;
- } else {
- return std::nullopt;
- }
- E = R2;
- } else {
- auto *RHSCMP = dyn_cast<ICmpInst>(RHS);
- if (!RHSCMP)
- return std::nullopt;
- // Don't allow pointers. Splat vectors are fine.
- if (!RHSCMP->getOperand(0)->getType()->isIntOrIntVectorTy())
- return std::nullopt;
-
- PredR = RHSCMP->getPredicate();
-
- Value *R1 = RHSCMP->getOperand(0);
- R2 = RHSCMP->getOperand(1);
- bool Ok = false;
- if (!match(R1, m_And(m_Value(R11), m_Value(R12)))) {
- // As before, model no mask as a trivial mask if it'll let us do an
- // optimization.
- R11 = R1;
- R12 = Constant::getAllOnesValue(R1->getType());
- }
-
- if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
- A = R11;
- D = R12;
- E = R2;
- Ok = true;
- } else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) {
- A = R12;
- D = R11;
- E = R2;
- Ok = true;
- }
-
- // Avoid matching against the -1 value we created for unmasked operand.
- if (Ok && match(A, m_AllOnes()))
- Ok = false;
-
- // Look for ANDs on the right side of the RHS icmp.
- if (!Ok) {
- if (!match(R2, m_And(m_Value(R11), m_Value(R12)))) {
- R11 = R2;
- R12 = Constant::getAllOnesValue(R2->getType());
- }
-
- if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
- A = R11;
- D = R12;
- E = R1;
- } else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) {
- A = R12;
- D = R11;
- E = R1;
- } else {
- return std::nullopt;
- }
- }
- }
-
- // Bail if RHS was a icmp that can't be decomposed into an equality.
- if (!ICmpInst::isEquality(PredR))
- return std::nullopt;
-
- if (L11 == A) {
- B = L12;
- C = L2;
- } else if (L12 == A) {
- B = L11;
- C = L2;
- } else if (L21 == A) {
- B = L22;
- C = L1;
- } else if (L22 == A) {
- B = L21;
- C = L1;
- }
-
- unsigned LeftType = getMaskedICmpType(A, B, C, PredL);
- unsigned RightType = getMaskedICmpType(A, D, E, PredR);
- return std::optional<std::pair<unsigned, unsigned>>(
- std::make_pair(LeftType, RightType));
-}
-
-/// Try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E) into a single
-/// (icmp(A & X) ==/!= Y), where the left-hand side is of type Mask_NotAllZeros
-/// and the right hand side is of type BMask_Mixed. For example,
-/// (icmp (A & 12) != 0) & (icmp (A & 15) == 8) -> (icmp (A & 15) == 8).
-/// Also used for logical and/or, must be poison safe.
-static Value *foldLogOpOfMaskedICmps_NotAllZeros_BMask_Mixed(
- Value *LHS, Value *RHS, bool IsAnd, Value *A, Value *B, Value *D, Value *E,
- ICmpInst::Predicate PredL, ICmpInst::Predicate PredR,
- InstCombiner::BuilderTy &Builder) {
- // We are given the canonical form:
- // (icmp ne (A & B), 0) & (icmp eq (A & D), E).
- // where D & E == E.
- //
- // If IsAnd is false, we get it in negated form:
- // (icmp eq (A & B), 0) | (icmp ne (A & D), E) ->
- // !((icmp ne (A & B), 0) & (icmp eq (A & D), E)).
- //
- // We currently handle the case of B, C, D, E are constant.
- //
- const APInt *BCst, *DCst, *OrigECst;
- if (!match(B, m_APInt(BCst)) || !match(D, m_APInt(DCst)) ||
- !match(E, m_APInt(OrigECst)))
- return nullptr;
-
- ICmpInst::Predicate NewCC = IsAnd ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE;
-
- // Update E to the canonical form when D is a power of two and RHS is
- // canonicalized as,
- // (icmp ne (A & D), 0) -> (icmp eq (A & D), D) or
- // (icmp ne (A & D), D) -> (icmp eq (A & D), 0).
- APInt ECst = *OrigECst;
- if (PredR != NewCC)
- ECst ^= *DCst;
-
- // If B or D is zero, skip because if LHS or RHS can be trivially folded by
- // other folding rules and this pattern won't apply any more.
- if (*BCst == 0 || *DCst == 0)
- return nullptr;
-
- // If B and D don't intersect, ie. (B & D) == 0, try to fold isNaN idiom:
- // (icmp ne (A & FractionBits), 0) & (icmp eq (A & ExpBits), ExpBits)
- // -> isNaN(A)
- // Otherwise, we cannot deduce anything from it.
- if (!BCst->intersects(*DCst)) {
- Value *Src;
- if (*DCst == ECst && match(A, m_ElementWiseBitCast(m_Value(Src))) &&
- !Builder.GetInsertBlock()->getParent()->hasFnAttribute(
- Attribute::StrictFP)) {
- Type *Ty = Src->getType()->getScalarType();
- if (!Ty->isIEEELikeFPTy())
- return nullptr;
-
- APInt ExpBits = APFloat::getInf(Ty->getFltSemantics()).bitcastToAPInt();
- if (ECst != ExpBits)
- return nullptr;
- APInt FractionBits = ~ExpBits;
- FractionBits.clearSignBit();
- if (*BCst != FractionBits)
- return nullptr;
-
- return Builder.CreateFCmp(IsAnd ? FCmpInst::FCMP_UNO : FCmpInst::FCMP_ORD,
- Src, ConstantFP::getZero(Src->getType()));
- }
- return nullptr;
- }
-
- // If the following two conditions are met:
- //
- // 1. mask B covers only a single bit that's not covered by mask D, that is,
- // (B & (B ^ D)) is a power of 2 (in other words, B minus the intersection of
- // B and D has only one bit set) and,
- //
- // 2. RHS (and E) indicates that the rest of B's bits are zero (in other
- // words, the intersection of B and D is zero), that is, ((B & D) & E) == 0
- //
- // then that single bit in B must be one and thus the whole expression can be
- // folded to
- // (A & (B | D)) == (B & (B ^ D)) | E.
- //
- // For example,
- // (icmp ne (A & 12), 0) & (icmp eq (A & 7), 1) -> (icmp eq (A & 15), 9)
- // (icmp ne (A & 15), 0) & (icmp eq (A & 7), 0) -> (icmp eq (A & 15), 8)
- if ((((*BCst & *DCst) & ECst) == 0) &&
- (*BCst & (*BCst ^ *DCst)).isPowerOf2()) {
- APInt BorD = *BCst | *DCst;
- APInt BandBxorDorE = (*BCst & (*BCst ^ *DCst)) | ECst;
- Value *NewMask = ConstantInt::get(A->getType(), BorD);
- Value *NewMaskedValue = ConstantInt::get(A->getType(), BandBxorDorE);
- Value *NewAnd = Builder.CreateAnd(A, NewMask);
- return Builder.CreateICmp(NewCC, NewAnd, NewMaskedValue);
- }
-
- auto IsSubSetOrEqual = [](const APInt *C1, const APInt *C2) {
- return (*C1 & *C2) == *C1;
- };
- auto IsSuperSetOrEqual = [](const APInt *C1, const APInt *C2) {
- return (*C1 & *C2) == *C2;
- };
-
- // In the following, we consider only the cases where B is a superset of D, B
- // is a subset of D, or B == D because otherwise there's at least one bit
- // covered by B but not D, in which case we can't deduce much from it, so
- // no folding (aside from the single must-be-one bit case right above.)
- // For example,
- // (icmp ne (A & 14), 0) & (icmp eq (A & 3), 1) -> no folding.
- if (!IsSubSetOrEqual(BCst, DCst) && !IsSuperSetOrEqual(BCst, DCst))
- return nullptr;
-
- // At this point, either B is a superset of D, B is a subset of D or B == D.
-
- // If E is zero, if B is a subset of (or equal to) D, LHS and RHS contradict
- // and the whole expression becomes false (or true if negated), otherwise, no
- // folding.
- // For example,
- // (icmp ne (A & 3), 0) & (icmp eq (A & 7), 0) -> false.
- // (icmp ne (A & 15), 0) & (icmp eq (A & 3), 0) -> no folding.
- if (ECst.isZero()) {
- if (IsSubSetOrEqual(BCst, DCst))
- return ConstantInt::get(LHS->getType(), !IsAnd);
- return nullptr;
- }
-
- // At this point, B, D, E aren't zero and (B & D) == B, (B & D) == D or B ==
- // D. If B is a superset of (or equal to) D, since E is not zero, LHS is
- // subsumed by RHS (RHS implies LHS.) So the whole expression becomes
- // RHS. For example,
- // (icmp ne (A & 255), 0) & (icmp eq (A & 15), 8) -> (icmp eq (A & 15), 8).
- // (icmp ne (A & 15), 0) & (icmp eq (A & 15), 8) -> (icmp eq (A & 15), 8).
- if (IsSuperSetOrEqual(BCst, DCst)) {
- // We can't guarantee that samesign hold after this fold.
- if (auto *ICmp = dyn_cast<ICmpInst>(RHS))
- ICmp->setSameSign(false);
- return RHS;
- }
- // Otherwise, B is a subset of D. If B and E have a common bit set,
- // ie. (B & E) != 0, then LHS is subsumed by RHS. For example.
- // (icmp ne (A & 12), 0) & (icmp eq (A & 15), 8) -> (icmp eq (A & 15), 8).
- assert(IsSubSetOrEqual(BCst, DCst) && "Precondition due to above code");
- if ((*BCst & ECst) != 0) {
- // We can't guarantee that samesign hold after this fold.
- if (auto *ICmp = dyn_cast<ICmpInst>(RHS))
- ICmp->setSameSign(false);
- return RHS;
- }
- // Otherwise, LHS and RHS contradict and the whole expression becomes false
- // (or true if negated.) For example,
- // (icmp ne (A & 7), 0) & (icmp eq (A & 15), 8) -> false.
- // (icmp ne (A & 6), 0) & (icmp eq (A & 15), 8) -> false.
- return ConstantInt::get(LHS->getType(), !IsAnd);
-}
-
-/// Try to fold (icmp(A & B) ==/!= 0) &/| (icmp(A & D) ==/!= E) into a single
-/// (icmp(A & X) ==/!= Y), where the left-hand side and the right hand side
-/// aren't of the common mask pattern type.
-/// Also used for logical and/or, must be poison safe.
-static Value *foldLogOpOfMaskedICmpsAsymmetric(
- Value *LHS, Value *RHS, bool IsAnd, Value *A, Value *B, Value *C, Value *D,
- Value *E, ICmpInst::Predicate PredL, ICmpInst::Predicate PredR,
- unsigned LHSMask, unsigned RHSMask, InstCombiner::BuilderTy &Builder) {
- assert(ICmpInst::isEquality(PredL) && ICmpInst::isEquality(PredR) &&
- "Expected equality predicates for masked type of icmps.");
- // Handle Mask_NotAllZeros-BMask_Mixed cases.
- // (icmp ne/eq (A & B), C) &/| (icmp eq/ne (A & D), E), or
- // (icmp eq/ne (A & B), C) &/| (icmp ne/eq (A & D), E)
- // which gets swapped to
- // (icmp ne/eq (A & D), E) &/| (icmp eq/ne (A & B), C).
- if (!IsAnd) {
- LHSMask = conjugateICmpMask(LHSMask);
- RHSMask = conjugateICmpMask(RHSMask);
- }
- if ((LHSMask & Mask_NotAllZeros) && (RHSMask & BMask_Mixed)) {
- if (Value *V = foldLogOpOfMaskedICmps_NotAllZeros_BMask_Mixed(
- LHS, RHS, IsAnd, A, B, D, E, PredL, PredR, Builder)) {
- return V;
- }
- } else if ((LHSMask & BMask_Mixed) && (RHSMask & Mask_NotAllZeros)) {
- if (Value *V = foldLogOpOfMaskedICmps_NotAllZeros_BMask_Mixed(
- RHS, LHS, IsAnd, A, D, B, C, PredR, PredL, Builder)) {
- return V;
- }
- }
- return nullptr;
-}
-
-/// Try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E)
-/// into a single (icmp(A & X) ==/!= Y).
-static Value *foldLogOpOfMaskedICmps(Value *LHS, Value *RHS, bool IsAnd,
- bool IsLogical,
- InstCombiner::BuilderTy &Builder,
- const SimplifyQuery &Q) {
- Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr, *E = nullptr;
- ICmpInst::Predicate PredL, PredR;
- std::optional<std::pair<unsigned, unsigned>> MaskPair =
- getMaskedTypeForICmpPair(A, B, C, D, E, LHS, RHS, PredL, PredR);
- if (!MaskPair)
- return nullptr;
- assert(ICmpInst::isEquality(PredL) && ICmpInst::isEquality(PredR) &&
- "Expected equality predicates for masked type of icmps.");
- unsigned LHSMask = MaskPair->first;
- unsigned RHSMask = MaskPair->second;
- unsigned Mask = LHSMask & RHSMask;
- if (Mask == 0) {
- // Even if the two sides don't share a common pattern, check if folding can
- // still happen.
- if (Value *V = foldLogOpOfMaskedICmpsAsymmetric(
- LHS, RHS, IsAnd, A, B, C, D, E, PredL, PredR, LHSMask, RHSMask,
- Builder))
- return V;
- return nullptr;
- }
-
- // In full generality:
- // (icmp (A & B) Op C) | (icmp (A & D) Op E)
- // == ![ (icmp (A & B) !Op C) & (icmp (A & D) !Op E) ]
- //
- // If the latter can be converted into (icmp (A & X) Op Y) then the former is
- // equivalent to (icmp (A & X) !Op Y).
- //
- // Therefore, we can pretend for the rest of this function that we're dealing
- // with the conjunction, provided we flip the sense of any comparisons (both
- // input and output).
-
- // In most cases we're going to produce an EQ for the "&&" case.
- ICmpInst::Predicate NewCC = IsAnd ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE;
- if (!IsAnd) {
- // Convert the masking analysis into its equivalent with negated
- // comparisons.
- Mask = conjugateICmpMask(Mask);
- }
-
- if (Mask & Mask_AllZeros) {
- // (icmp eq (A & B), 0) & (icmp eq (A & D), 0)
- // -> (icmp eq (A & (B|D)), 0)
- if (IsLogical && !isGuaranteedNotToBeUndefOrPoison(D))
- return nullptr; // TODO: Use freeze?
- Value *NewOr = Builder.CreateOr(B, D);
- Value *NewAnd = Builder.CreateAnd(A, NewOr);
- // We can't use C as zero because we might actually handle
- // (icmp ne (A & B), B) & (icmp ne (A & D), D)
- // with B and D, having a single bit set.
- Value *Zero = Constant::getNullValue(A->getType());
- return Builder.CreateICmp(NewCC, NewAnd, Zero);
- }
- if (Mask & BMask_AllOnes) {
- // (icmp eq (A & B), B) & (icmp eq (A & D), D)
- // -> (icmp eq (A & (B|D)), (B|D))
- if (IsLogical && !isGuaranteedNotToBeUndefOrPoison(D))
- return nullptr; // TODO: Use freeze?
- Value *NewOr = Builder.CreateOr(B, D);
- Value *NewAnd = Builder.CreateAnd(A, NewOr);
- return Builder.CreateICmp(NewCC, NewAnd, NewOr);
- }
- if (Mask & AMask_AllOnes) {
- // (icmp eq (A & B), A) & (icmp eq (A & D), A)
- // -> (icmp eq (A & (B&D)), A)
- if (IsLogical && !isGuaranteedNotToBeUndefOrPoison(D))
- return nullptr; // TODO: Use freeze?
- Value *NewAnd1 = Builder.CreateAnd(B, D);
- Value *NewAnd2 = Builder.CreateAnd(A, NewAnd1);
- return Builder.CreateICmp(NewCC, NewAnd2, A);
- }
-
- const APInt *ConstB, *ConstD;
- if (match(B, m_APInt(ConstB)) && match(D, m_APInt(ConstD))) {
- if (Mask & (Mask_NotAllZeros | BMask_NotAllOnes)) {
- // (icmp ne (A & B), 0) & (icmp ne (A & D), 0) and
- // (icmp ne (A & B), B) & (icmp ne (A & D), D)
- // -> (icmp ne (A & B), 0) or (icmp ne (A & D), 0)
- // Only valid if one of the masks is a superset of the other (check "B&D"
- // is the same as either B or D).
- APInt NewMask = *ConstB & *ConstD;
- if (NewMask == *ConstB)
- return LHS;
- if (NewMask == *ConstD)
- return RHS;
- }
-
- if (Mask & AMask_NotAllOnes) {
- // (icmp ne (A & B), B) & (icmp ne (A & D), D)
- // -> (icmp ne (A & B), A) or (icmp ne (A & D), A)
- // Only valid if one of the masks is a superset of the other (check "B|D"
- // is the same as either B or D).
- APInt NewMask = *ConstB | *ConstD;
- if (NewMask == *ConstB)
- return LHS;
- if (NewMask == *ConstD)
- return RHS;
- }
-
- if (Mask & (BMask_Mixed | BMask_NotMixed)) {
- // Mixed:
- // (icmp eq (A & B), C) & (icmp eq (A & D), E)
- // We already know that B & C == C && D & E == E.
- // If we can prove that (B & D) & (C ^ E) == 0, that is, the bits of
- // C and E, which are shared by both the mask B and the mask D, don't
- // contradict, then we can transform to
- // -> (icmp eq (A & (B|D)), (C|E))
- // Currently, we only handle the case of B, C, D, and E being constant.
- // We can't simply use C and E because we might actually handle
- // (icmp ne (A & B), B) & (icmp eq (A & D), D)
- // with B and D, having a single bit set.
-
- // NotMixed:
- // (icmp ne (A & B), C) & (icmp ne (A & D), E)
- // -> (icmp ne (A & (B & D)), (C & E))
- // Check the intersection (B & D) for inequality.
- // Assume that (B & D) == B || (B & D) == D, i.e B/D is a subset of D/B
- // and (B & D) & (C ^ E) == 0, bits of C and E, which are shared by both
- // the B and the D, don't contradict. Note that we can assume (~B & C) ==
- // 0 && (~D & E) == 0, previous operation should delete these icmps if it
- // hadn't been met.
-
- const APInt *OldConstC, *OldConstE;
- if (!match(C, m_APInt(OldConstC)) || !match(E, m_APInt(OldConstE)))
- return nullptr;
-
- auto FoldBMixed = [&](ICmpInst::Predicate CC, bool IsNot) -> Value * {
- CC = IsNot ? CmpInst::getInversePredicate(CC) : CC;
- const APInt ConstC = PredL != CC ? *ConstB ^ *OldConstC : *OldConstC;
- const APInt ConstE = PredR != CC ? *ConstD ^ *OldConstE : *OldConstE;
-
- if (((*ConstB & *ConstD) & (ConstC ^ ConstE)).getBoolValue())
- return IsNot ? nullptr : ConstantInt::get(LHS->getType(), !IsAnd);
-
- if (IsNot && !ConstB->isSubsetOf(*ConstD) &&
- !ConstD->isSubsetOf(*ConstB))
- return nullptr;
-
- APInt BD, CE;
- if (IsNot) {
- BD = *ConstB & *ConstD;
- CE = ConstC & ConstE;
- } else {
- BD = *ConstB | *ConstD;
- CE = ConstC | ConstE;
- }
- Value *NewAnd = Builder.CreateAnd(A, BD);
- Value *CEVal = ConstantInt::get(A->getType(), CE);
- return Builder.CreateICmp(CC, CEVal, NewAnd);
- };
-
- if (Mask & BMask_Mixed)
- return FoldBMixed(NewCC, false);
- if (Mask & BMask_NotMixed) // can be else also
- return FoldBMixed(NewCC, true);
- }
- }
-
- // (icmp eq (A & B), 0) | (icmp eq (A & D), 0)
- // -> (icmp ne (A & (B|D)), (B|D))
- // (icmp ne (A & B), 0) & (icmp ne (A & D), 0)
- // -> (icmp eq (A & (B|D)), (B|D))
- // iff B and D is known to be a power of two
- if (Mask & Mask_NotAllZeros &&
- isKnownToBeAPowerOfTwo(B, /*OrZero=*/false, /*Depth=*/0, Q) &&
- isKnownToBeAPowerOfTwo(D, /*OrZero=*/false, /*Depth=*/0, Q)) {
- // If this is a logical and/or, then we must prevent propagation of a
- // poison value from the RHS by inserting freeze.
- if (IsLogical)
- D = Builder.CreateFreeze(D);
- Value *Mask = Builder.CreateOr(B, D);
- Value *Masked = Builder.CreateAnd(A, Mask);
- return Builder.CreateICmp(NewCC, Masked, Mask);
- }
- return nullptr;
-}
-
-/// Try to fold a signed range checked with lower bound 0 to an unsigned icmp.
-/// Example: (icmp sge x, 0) & (icmp slt x, n) --> icmp ult x, n
-/// If \p Inverted is true then the check is for the inverted range, e.g.
-/// (icmp slt x, 0) | (icmp sgt x, n) --> icmp ugt x, n
-Value *InstCombinerImpl::simplifyRangeCheck(ICmpInst *Cmp0, ICmpInst *Cmp1,
- bool Inverted) {
- // Check the lower range comparison, e.g. x >= 0
- // InstCombine already ensured that if there is a constant it's on the RHS.
- ConstantInt *RangeStart = dyn_cast<ConstantInt>(Cmp0->getOperand(1));
- if (!RangeStart)
- return nullptr;
-
- ICmpInst::Predicate Pred0 = (Inverted ? Cmp0->getInversePredicate() :
- Cmp0->getPredicate());
-
- // Accept x > -1 or x >= 0 (after potentially inverting the predicate).
- if (!((Pred0 == ICmpInst::ICMP_SGT && RangeStart->isMinusOne()) ||
- (Pred0 == ICmpInst::ICMP_SGE && RangeStart->isZero())))
- return nullptr;
-
- ICmpInst::Predicate Pred1 = (Inverted ? Cmp1->getInversePredicate() :
- Cmp1->getPredicate());
-
- Value *Input = Cmp0->getOperand(0);
- Value *Cmp1Op0 = Cmp1->getOperand(0);
- Value *Cmp1Op1 = Cmp1->getOperand(1);
- Value *RangeEnd;
- if (match(Cmp1Op0, m_SExtOrSelf(m_Specific(Input)))) {
- // For the upper range compare we have: icmp x, n
- Input = Cmp1Op0;
- RangeEnd = Cmp1Op1;
- } else if (match(Cmp1Op1, m_SExtOrSelf(m_Specific(Input)))) {
- // For the upper range compare we have: icmp n, x
- Input = Cmp1Op1;
- RangeEnd = Cmp1Op0;
- Pred1 = ICmpInst::getSwappedPredicate(Pred1);
- } else {
- return nullptr;
- }
-
- // Check the upper range comparison, e.g. x < n
- ICmpInst::Predicate NewPred;
- switch (Pred1) {
- case ICmpInst::ICMP_SLT: NewPred = ICmpInst::ICMP_ULT; break;
- case ICmpInst::ICMP_SLE: NewPred = ICmpInst::ICMP_ULE; break;
- default: return nullptr;
- }
-
- // This simplification is only valid if the upper range is not negative.
- KnownBits Known = computeKnownBits(RangeEnd, /*Depth=*/0, Cmp1);
- if (!Known.isNonNegative())
- return nullptr;
-
- if (Inverted)
- NewPred = ICmpInst::getInversePredicate(NewPred);
-
- return Builder.CreateICmp(NewPred, Input, RangeEnd);
-}
-
-// (or (icmp eq X, 0), (icmp eq X, Pow2OrZero))
-// -> (icmp eq (and X, Pow2OrZero), X)
-// (and (icmp ne X, 0), (icmp ne X, Pow2OrZero))
-// -> (icmp ne (and X, Pow2OrZero), X)
-static Value *
-foldAndOrOfICmpsWithPow2AndWithZero(InstCombiner::BuilderTy &Builder,
- ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
- const SimplifyQuery &Q) {
- CmpPredicate Pred = IsAnd ? CmpInst::ICMP_NE : CmpInst::ICMP_EQ;
- // Make sure we have right compares for our op.
- if (LHS->getPredicate() != Pred || RHS->getPredicate() != Pred)
- return nullptr;
-
- // Make it so we can match LHS against the (icmp eq/ne X, 0) just for
- // simplicity.
- if (match(RHS->getOperand(1), m_Zero()))
- std::swap(LHS, RHS);
-
- Value *Pow2, *Op;
- // Match the desired pattern:
- // LHS: (icmp eq/ne X, 0)
- // RHS: (icmp eq/ne X, Pow2OrZero)
- // Skip if Pow2OrZero is 1. Either way it gets folded to (icmp ugt X, 1) but
- // this form ends up slightly less canonical.
- // We could potentially be more sophisticated than requiring LHS/RHS
- // be one-use. We don't create additional instructions if only one
- // of them is one-use. So cases where one is one-use and the other
- // is two-use might be profitable.
- if (!match(LHS, m_OneUse(m_ICmp(Pred, m_Value(Op), m_Zero()))) ||
- !match(RHS, m_OneUse(m_c_ICmp(Pred, m_Specific(Op), m_Value(Pow2)))) ||
- match(Pow2, m_One()) ||
- !isKnownToBeAPowerOfTwo(Pow2, Q.DL, /*OrZero=*/true, /*Depth=*/0, Q.AC,
- Q.CxtI, Q.DT))
- return nullptr;
-
- Value *And = Builder.CreateAnd(Op, Pow2);
- return Builder.CreateICmp(Pred, And, Op);
-}
-
-/// General pattern:
-/// X & Y
-///
-/// Where Y is checking that all the high bits (covered by a mask 4294967168)
-/// are uniform, i.e. %arg & 4294967168 can be either 4294967168 or 0
-/// Pattern can be one of:
-/// %t = add i32 %arg, 128
-/// %r = icmp ult i32 %t, 256
-/// Or
-/// %t0 = shl i32 %arg, 24
-/// %t1 = ashr i32 %t0, 24
-/// %r = icmp eq i32 %t1, %arg
-/// Or
-/// %t0 = trunc i32 %arg to i8
-/// %t1 = sext i8 %t0 to i32
-/// %r = icmp eq i32 %t1, %arg
-/// This pattern is a signed truncation check.
-///
-/// And X is checking that some bit in that same mask is zero.
-/// I.e. can be one of:
-/// %r = icmp sgt i32 %arg, -1
-/// Or
-/// %t = and i32 %arg, 2147483648
-/// %r = icmp eq i32 %t, 0
-///
-/// Since we are checking that all the bits in that mask are the same,
-/// and a particular bit is zero, what we are really checking is that all the
-/// masked bits are zero.
-/// So this should be transformed to:
-/// %r = icmp ult i32 %arg, 128
-static Value *foldSignedTruncationCheck(ICmpInst *ICmp0, ICmpInst *ICmp1,
- Instruction &CxtI,
- InstCombiner::BuilderTy &Builder) {
- assert(CxtI.getOpcode() == Instruction::And);
-
- // Match icmp ult (add %arg, C01), C1 (C1 == C01 << 1; powers of two)
- auto tryToMatchSignedTruncationCheck = [](ICmpInst *ICmp, Value *&X,
- APInt &SignBitMask) -> bool {
- const APInt *I01, *I1; // powers of two; I1 == I01 << 1
- if (!(match(ICmp, m_SpecificICmp(ICmpInst::ICMP_ULT,
- m_Add(m_Value(X), m_Power2(I01)),
- m_Power2(I1))) &&
- I1->ugt(*I01) && I01->shl(1) == *I1))
- return false;
- // Which bit is the new sign bit as per the 'signed truncation' pattern?
- SignBitMask = *I01;
- return true;
- };
-
- // One icmp needs to be 'signed truncation check'.
- // We need to match this first, else we will mismatch commutative cases.
- Value *X1;
- APInt HighestBit;
- ICmpInst *OtherICmp;
- if (tryToMatchSignedTruncationCheck(ICmp1, X1, HighestBit))
- OtherICmp = ICmp0;
- else if (tryToMatchSignedTruncationCheck(ICmp0, X1, HighestBit))
- OtherICmp = ICmp1;
- else
- return nullptr;
-
- assert(HighestBit.isPowerOf2() && "expected to be power of two (non-zero)");
-
- // Try to match/decompose into: icmp eq (X & Mask), 0
- auto tryToDecompose = [](ICmpInst *ICmp, Value *&X,
- APInt &UnsetBitsMask) -> bool {
- CmpPredicate Pred = ICmp->getPredicate();
- // Can it be decomposed into icmp eq (X & Mask), 0 ?
- auto Res =
- llvm::decomposeBitTestICmp(ICmp->getOperand(0), ICmp->getOperand(1),
- Pred, /*LookThroughTrunc=*/false);
- if (Res && Res->Pred == ICmpInst::ICMP_EQ) {
- X = Res->X;
- UnsetBitsMask = Res->Mask;
- return true;
- }
-
- // Is it icmp eq (X & Mask), 0 already?
- const APInt *Mask;
- if (match(ICmp, m_ICmp(Pred, m_And(m_Value(X), m_APInt(Mask)), m_Zero())) &&
- Pred == ICmpInst::ICMP_EQ) {
- UnsetBitsMask = *Mask;
- return true;
- }
- return false;
- };
-
- // And the other icmp needs to be decomposable into a bit test.
- Value *X0;
- APInt UnsetBitsMask;
- if (!tryToDecompose(OtherICmp, X0, UnsetBitsMask))
- return nullptr;
-
- assert(!UnsetBitsMask.isZero() && "empty mask makes no sense.");
-
- // Are they working on the same value?
- Value *X;
- if (X1 == X0) {
- // Ok as is.
- X = X1;
- } else if (match(X0, m_Trunc(m_Specific(X1)))) {
- UnsetBitsMask = UnsetBitsMask.zext(X1->getType()->getScalarSizeInBits());
- X = X1;
- } else
- return nullptr;
-
- // So which bits should be uniform as per the 'signed truncation check'?
- // (all the bits starting with (i.e. including) HighestBit)
- APInt SignBitsMask = ~(HighestBit - 1U);
-
- // UnsetBitsMask must have some common bits with SignBitsMask,
- if (!UnsetBitsMask.intersects(SignBitsMask))
- return nullptr;
-
- // Does UnsetBitsMask contain any bits outside of SignBitsMask?
- if (!UnsetBitsMask.isSubsetOf(SignBitsMask)) {
- APInt OtherHighestBit = (~UnsetBitsMask) + 1U;
- if (!OtherHighestBit.isPowerOf2())
- return nullptr;
- HighestBit = APIntOps::umin(HighestBit, OtherHighestBit);
- }
- // Else, if it does not, then all is ok as-is.
-
- // %r = icmp ult %X, SignBit
- return Builder.CreateICmpULT(X, ConstantInt::get(X->getType(), HighestBit),
- CxtI.getName() + ".simplified");
-}
-
-/// Fold (icmp eq ctpop(X) 1) | (icmp eq X 0) into (icmp ult ctpop(X) 2) and
-/// fold (icmp ne ctpop(X) 1) & (icmp ne X 0) into (icmp ugt ctpop(X) 1).
-/// Also used for logical and/or, must be poison safe if range attributes are
-/// dropped.
-static Value *foldIsPowerOf2OrZero(ICmpInst *Cmp0, ICmpInst *Cmp1, bool IsAnd,
- InstCombiner::BuilderTy &Builder,
- InstCombinerImpl &IC) {
- CmpPredicate Pred0, Pred1;
- Value *X;
- if (!match(Cmp0, m_ICmp(Pred0, m_Intrinsic<Intrinsic::ctpop>(m_Value(X)),
- m_SpecificInt(1))) ||
- !match(Cmp1, m_ICmp(Pred1, m_Specific(X), m_ZeroInt())))
- return nullptr;
-
- auto *CtPop = cast<Instruction>(Cmp0->getOperand(0));
- if (IsAnd && Pred0 == ICmpInst::ICMP_NE && Pred1 == ICmpInst::ICMP_NE) {
- // Drop range attributes and re-infer them in the next iteration.
- CtPop->dropPoisonGeneratingAnnotations();
- IC.addToWorklist(CtPop);
- return Builder.CreateICmpUGT(CtPop, ConstantInt::get(CtPop->getType(), 1));
- }
- if (!IsAnd && Pred0 == ICmpInst::ICMP_EQ && Pred1 == ICmpInst::ICMP_EQ) {
- // Drop range attributes and re-infer them in the next iteration.
- CtPop->dropPoisonGeneratingAnnotations();
- IC.addToWorklist(CtPop);
- return Builder.CreateICmpULT(CtPop, ConstantInt::get(CtPop->getType(), 2));
- }
-
- return nullptr;
-}
-
-/// Reduce a pair of compares that check if a value has exactly 1 bit set.
-/// Also used for logical and/or, must be poison safe if range attributes are
-/// dropped.
-static Value *foldIsPowerOf2(ICmpInst *Cmp0, ICmpInst *Cmp1, bool JoinedByAnd,
- InstCombiner::BuilderTy &Builder,
- InstCombinerImpl &IC) {
- // Handle 'and' / 'or' commutation: make the equality check the first operand.
- if (JoinedByAnd && Cmp1->getPredicate() == ICmpInst::ICMP_NE)
- std::swap(Cmp0, Cmp1);
- else if (!JoinedByAnd && Cmp1->getPredicate() == ICmpInst::ICMP_EQ)
- std::swap(Cmp0, Cmp1);
-
- // (X != 0) && (ctpop(X) u< 2) --> ctpop(X) == 1
- Value *X;
- if (JoinedByAnd &&
- match(Cmp0, m_SpecificICmp(ICmpInst::ICMP_NE, m_Value(X), m_ZeroInt())) &&
- match(Cmp1, m_SpecificICmp(ICmpInst::ICMP_ULT,
- m_Intrinsic<Intrinsic::ctpop>(m_Specific(X)),
- m_SpecificInt(2)))) {
- auto *CtPop = cast<Instruction>(Cmp1->getOperand(0));
- // Drop range attributes and re-infer them in the next iteration.
- CtPop->dropPoisonGeneratingAnnotations();
- IC.addToWorklist(CtPop);
- return Builder.CreateICmpEQ(CtPop, ConstantInt::get(CtPop->getType(), 1));
- }
- // (X == 0) || (ctpop(X) u> 1) --> ctpop(X) != 1
- if (!JoinedByAnd &&
- match(Cmp0, m_SpecificICmp(ICmpInst::ICMP_EQ, m_Value(X), m_ZeroInt())) &&
- match(Cmp1, m_SpecificICmp(ICmpInst::ICMP_UGT,
- m_Intrinsic<Intrinsic::ctpop>(m_Specific(X)),
- m_SpecificInt(1)))) {
- auto *CtPop = cast<Instruction>(Cmp1->getOperand(0));
- // Drop range attributes and re-infer them in the next iteration.
- CtPop->dropPoisonGeneratingAnnotations();
- IC.addToWorklist(CtPop);
- return Builder.CreateICmpNE(CtPop, ConstantInt::get(CtPop->getType(), 1));
- }
- return nullptr;
-}
-
-/// Try to fold (icmp(A & B) == 0) & (icmp(A & D) != E) into (icmp A u< D) iff
-/// B is a contiguous set of ones starting from the most significant bit
-/// (negative power of 2), D and E are equal, and D is a contiguous set of ones
-/// starting at the most significant zero bit in B. Parameter B supports masking
-/// using undef/poison in either scalar or vector values.
-static Value *foldNegativePower2AndShiftedMask(
- Value *A, Value *B, Value *D, Value *E, ICmpInst::Predicate PredL,
- ICmpInst::Predicate PredR, InstCombiner::BuilderTy &Builder) {
- assert(ICmpInst::isEquality(PredL) && ICmpInst::isEquality(PredR) &&
- "Expected equality predicates for masked type of icmps.");
- if (PredL != ICmpInst::ICMP_EQ || PredR != ICmpInst::ICMP_NE)
- return nullptr;
-
- if (!match(B, m_NegatedPower2()) || !match(D, m_ShiftedMask()) ||
- !match(E, m_ShiftedMask()))
- return nullptr;
-
- // Test scalar arguments for conversion. B has been validated earlier to be a
- // negative power of two and thus is guaranteed to have one or more contiguous
- // ones starting from the MSB followed by zero or more contiguous zeros. D has
- // been validated earlier to be a shifted set of one or more contiguous ones.
- // In order to match, B leading ones and D leading zeros should be equal. The
- // predicate that B be a negative power of 2 prevents the condition of there
- // ever being zero leading ones. Thus 0 == 0 cannot occur. The predicate that
- // D always be a shifted mask prevents the condition of D equaling 0. This
- // prevents matching the condition where B contains the maximum number of
- // leading one bits (-1) and D contains the maximum number of leading zero
- // bits (0).
- auto isReducible = [](const Value *B, const Value *D, const Value *E) {
- const APInt *BCst, *DCst, *ECst;
- return match(B, m_APIntAllowPoison(BCst)) && match(D, m_APInt(DCst)) &&
- match(E, m_APInt(ECst)) && *DCst == *ECst &&
- (isa<PoisonValue>(B) ||
- (BCst->countLeadingOnes() == DCst->countLeadingZeros()));
- };
-
- // Test vector type arguments for conversion.
- if (const auto *BVTy = dyn_cast<VectorType>(B->getType())) {
- const auto *BFVTy = dyn_cast<FixedVectorType>(BVTy);
- const auto *BConst = dyn_cast<Constant>(B);
- const auto *DConst = dyn_cast<Constant>(D);
- const auto *EConst = dyn_cast<Constant>(E);
-
- if (!BFVTy || !BConst || !DConst || !EConst)
- return nullptr;
-
- for (unsigned I = 0; I != BFVTy->getNumElements(); ++I) {
- const auto *BElt = BConst->getAggregateElement(I);
- const auto *DElt = DConst->getAggregateElement(I);
- const auto *EElt = EConst->getAggregateElement(I);
-
- if (!BElt || !DElt || !EElt)
- return nullptr;
- if (!isReducible(BElt, DElt, EElt))
- return nullptr;
- }
- } else {
- // Test scalar type arguments for conversion.
- if (!isReducible(B, D, E))
- return nullptr;
- }
- return Builder.CreateICmp(ICmpInst::ICMP_ULT, A, D);
-}
-
-/// Try to fold ((icmp X u< P) & (icmp(X & M) != M)) or ((icmp X s> -1) &
-/// (icmp(X & M) != M)) into (icmp X u< M). Where P is a power of 2, M < P, and
-/// M is a contiguous shifted mask starting at the right most significant zero
-/// bit in P. SGT is supported as when P is the largest representable power of
-/// 2, an earlier optimization converts the expression into (icmp X s> -1).
-/// Parameter P supports masking using undef/poison in either scalar or vector
-/// values.
-static Value *foldPowerOf2AndShiftedMask(ICmpInst *Cmp0, ICmpInst *Cmp1,
- bool JoinedByAnd,
- InstCombiner::BuilderTy &Builder) {
- if (!JoinedByAnd)
- return nullptr;
- Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr, *E = nullptr;
- ICmpInst::Predicate CmpPred0, CmpPred1;
- // Assuming P is a 2^n, getMaskedTypeForICmpPair will normalize (icmp X u<
- // 2^n) into (icmp (X & ~(2^n-1)) == 0) and (icmp X s> -1) into (icmp (X &
- // SignMask) == 0).
- std::optional<std::pair<unsigned, unsigned>> MaskPair =
- getMaskedTypeForICmpPair(A, B, C, D, E, Cmp0, Cmp1, CmpPred0, CmpPred1);
- if (!MaskPair)
- return nullptr;
-
- const auto compareBMask = BMask_NotMixed | BMask_NotAllOnes;
- unsigned CmpMask0 = MaskPair->first;
- unsigned CmpMask1 = MaskPair->second;
- if ((CmpMask0 & Mask_AllZeros) && (CmpMask1 == compareBMask)) {
- if (Value *V = foldNegativePower2AndShiftedMask(A, B, D, E, CmpPred0,
- CmpPred1, Builder))
- return V;
- } else if ((CmpMask0 == compareBMask) && (CmpMask1 & Mask_AllZeros)) {
- if (Value *V = foldNegativePower2AndShiftedMask(A, D, B, C, CmpPred1,
- CmpPred0, Builder))
- return V;
- }
- return nullptr;
-}
-
-/// Commuted variants are assumed to be handled by calling this function again
-/// with the parameters swapped.
-static Value *foldUnsignedUnderflowCheck(ICmpInst *ZeroICmp,
- ICmpInst *UnsignedICmp, bool IsAnd,
- const SimplifyQuery &Q,
- InstCombiner::BuilderTy &Builder) {
- Value *ZeroCmpOp;
- CmpPredicate EqPred;
- if (!match(ZeroICmp, m_ICmp(EqPred, m_Value(ZeroCmpOp), m_Zero())) ||
- !ICmpInst::isEquality(EqPred))
- return nullptr;
-
- CmpPredicate UnsignedPred;
-
- Value *A, *B;
- if (match(UnsignedICmp,
- m_c_ICmp(UnsignedPred, m_Specific(ZeroCmpOp), m_Value(A))) &&
- match(ZeroCmpOp, m_c_Add(m_Specific(A), m_Value(B))) &&
- (ZeroICmp->hasOneUse() || UnsignedICmp->hasOneUse())) {
- auto GetKnownNonZeroAndOther = [&](Value *&NonZero, Value *&Other) {
- if (!isKnownNonZero(NonZero, Q))
- std::swap(NonZero, Other);
- return isKnownNonZero(NonZero, Q);
- };
-
- // Given ZeroCmpOp = (A + B)
- // ZeroCmpOp < A && ZeroCmpOp != 0 --> (0-X) < Y iff
- // ZeroCmpOp >= A || ZeroCmpOp == 0 --> (0-X) >= Y iff
- // with X being the value (A/B) that is known to be non-zero,
- // and Y being remaining value.
- if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_NE &&
- IsAnd && GetKnownNonZeroAndOther(B, A))
- return Builder.CreateICmpULT(Builder.CreateNeg(B), A);
- if (UnsignedPred == ICmpInst::ICMP_UGE && EqPred == ICmpInst::ICMP_EQ &&
- !IsAnd && GetKnownNonZeroAndOther(B, A))
- return Builder.CreateICmpUGE(Builder.CreateNeg(B), A);
- }
-
- return nullptr;
-}
-
-struct IntPart {
- Value *From;
- unsigned StartBit;
- unsigned NumBits;
-};
-
-/// Match an extraction of bits from an integer.
-static std::optional<IntPart> matchIntPart(Value *V) {
- Value *X;
- if (!match(V, m_OneUse(m_Trunc(m_Value(X)))))
- return std::nullopt;
-
- unsigned NumOriginalBits = X->getType()->getScalarSizeInBits();
- unsigned NumExtractedBits = V->getType()->getScalarSizeInBits();
- Value *Y;
- const APInt *Shift;
- // For a trunc(lshr Y, Shift) pattern, make sure we're only extracting bits
- // from Y, not any shifted-in zeroes.
- if (match(X, m_OneUse(m_LShr(m_Value(Y), m_APInt(Shift)))) &&
- Shift->ule(NumOriginalBits - NumExtractedBits))
- return {{Y, (unsigned)Shift->getZExtValue(), NumExtractedBits}};
- return {{X, 0, NumExtractedBits}};
-}
-
-/// Materialize an extraction of bits from an integer in IR.
-static Value *extractIntPart(const IntPart &P, IRBuilderBase &Builder) {
- Value *V = P.From;
- if (P.StartBit)
- V = Builder.CreateLShr(V, P.StartBit);
- Type *TruncTy = V->getType()->getWithNewBitWidth(P.NumBits);
- if (TruncTy != V->getType())
- V = Builder.CreateTrunc(V, TruncTy);
- return V;
-}
-
-/// (icmp eq X0, Y0) & (icmp eq X1, Y1) -> icmp eq X01, Y01
-/// (icmp ne X0, Y0) | (icmp ne X1, Y1) -> icmp ne X01, Y01
-/// where X0, X1 and Y0, Y1 are adjacent parts extracted from an integer.
-Value *InstCombinerImpl::foldEqOfParts(Value *Cmp0, Value *Cmp1, bool IsAnd) {
- if (!Cmp0->hasOneUse() || !Cmp1->hasOneUse())
- return nullptr;
-
- CmpInst::Predicate Pred = IsAnd ? CmpInst::ICMP_EQ : CmpInst::ICMP_NE;
- auto GetMatchPart = [&](Value *CmpV,
- unsigned OpNo) -> std::optional<IntPart> {
- assert(CmpV->getType()->isIntOrIntVectorTy(1) && "Must be bool");
-
- Value *X, *Y;
- // icmp ne (and x, 1), (and y, 1) <=> trunc (xor x, y) to i1
- // icmp eq (and x, 1), (and y, 1) <=> not (trunc (xor x, y) to i1)
- if (Pred == CmpInst::ICMP_NE
- ? match(CmpV, m_Trunc(m_Xor(m_Value(X), m_Value(Y))))
- : match(CmpV, m_Not(m_Trunc(m_Xor(m_Value(X), m_Value(Y))))))
- return {{OpNo == 0 ? X : Y, 0, 1}};
-
- auto *Cmp = dyn_cast<ICmpInst>(CmpV);
- if (!Cmp)
- return std::nullopt;
-
- if (Pred == Cmp->getPredicate())
- return matchIntPart(Cmp->getOperand(OpNo));
-
- const APInt *C;
- // (icmp eq (lshr x, C), (lshr y, C)) gets optimized to:
- // (icmp ult (xor x, y), 1 << C) so also look for that.
- if (Pred == CmpInst::ICMP_EQ && Cmp->getPredicate() == CmpInst::ICMP_ULT) {
- if (!match(Cmp->getOperand(1), m_Power2(C)) ||
- !match(Cmp->getOperand(0), m_Xor(m_Value(), m_Value())))
- return std::nullopt;
- }
-
- // (icmp ne (lshr x, C), (lshr y, C)) gets optimized to:
- // (icmp ugt (xor x, y), (1 << C) - 1) so also look for that.
- else if (Pred == CmpInst::ICMP_NE &&
- Cmp->getPredicate() == CmpInst::ICMP_UGT) {
- if (!match(Cmp->getOperand(1), m_LowBitMask(C)) ||
- !match(Cmp->getOperand(0), m_Xor(m_Value(), m_Value())))
- return std::nullopt;
- } else {
- return std::nullopt;
- }
-
- unsigned From = Pred == CmpInst::ICMP_NE ? C->popcount() : C->countr_zero();
- Instruction *I = cast<Instruction>(Cmp->getOperand(0));
- return {{I->getOperand(OpNo), From, C->getBitWidth() - From}};
- };
-
- std::optional<IntPart> L0 = GetMatchPart(Cmp0, 0);
- std::optional<IntPart> R0 = GetMatchPart(Cmp0, 1);
- std::optional<IntPart> L1 = GetMatchPart(Cmp1, 0);
- std::optional<IntPart> R1 = GetMatchPart(Cmp1, 1);
- if (!L0 || !R0 || !L1 || !R1)
- return nullptr;
-
- // Make sure the LHS/RHS compare a part of the same value, possibly after
- // an operand swap.
- if (L0->From != L1->From || R0->From != R1->From) {
- if (L0->From != R1->From || R0->From != L1->From)
- return nullptr;
- std::swap(L1, R1);
- }
-
- // Make sure the extracted parts are adjacent, canonicalizing to L0/R0 being
- // the low part and L1/R1 being the high part.
- if (L0->StartBit + L0->NumBits != L1->StartBit ||
- R0->StartBit + R0->NumBits != R1->StartBit) {
- if (L1->StartBit + L1->NumBits != L0->StartBit ||
- R1->StartBit + R1->NumBits != R0->StartBit)
- return nullptr;
- std::swap(L0, L1);
- std::swap(R0, R1);
- }
-
- // We can simplify to a comparison of these larger parts of the integers.
- IntPart L = {L0->From, L0->StartBit, L0->NumBits + L1->NumBits};
- IntPart R = {R0->From, R0->StartBit, R0->NumBits + R1->NumBits};
- Value *LValue = extractIntPart(L, Builder);
- Value *RValue = extractIntPart(R, Builder);
- return Builder.CreateICmp(Pred, LValue, RValue);
-}
-
-/// Reduce logic-of-compares with equality to a constant by substituting a
-/// common operand with the constant. Callers are expected to call this with
-/// Cmp0/Cmp1 switched to handle logic op commutativity.
-static Value *foldAndOrOfICmpsWithConstEq(ICmpInst *Cmp0, ICmpInst *Cmp1,
- bool IsAnd, bool IsLogical,
- InstCombiner::BuilderTy &Builder,
- const SimplifyQuery &Q) {
- // Match an equality compare with a non-poison constant as Cmp0.
- // Also, give up if the compare can be constant-folded to avoid looping.
- CmpPredicate Pred0;
- Value *X;
- Constant *C;
- if (!match(Cmp0, m_ICmp(Pred0, m_Value(X), m_Constant(C))) ||
- !isGuaranteedNotToBeUndefOrPoison(C) || isa<Constant>(X))
- return nullptr;
- if ((IsAnd && Pred0 != ICmpInst::ICMP_EQ) ||
- (!IsAnd && Pred0 != ICmpInst::ICMP_NE))
- return nullptr;
-
- // The other compare must include a common operand (X). Canonicalize the
- // common operand as operand 1 (Pred1 is swapped if the common operand was
- // operand 0).
- Value *Y;
- CmpPredicate Pred1;
- if (!match(Cmp1, m_c_ICmp(Pred1, m_Value(Y), m_Specific(X))))
- return nullptr;
-
- // Replace variable with constant value equivalence to remove a variable use:
- // (X == C) && (Y Pred1 X) --> (X == C) && (Y Pred1 C)
- // (X != C) || (Y Pred1 X) --> (X != C) || (Y Pred1 C)
- // Can think of the 'or' substitution with the 'and' bool equivalent:
- // A || B --> A || (!A && B)
- Value *SubstituteCmp = simplifyICmpInst(Pred1, Y, C, Q);
- if (!SubstituteCmp) {
- // If we need to create a new instruction, require that the old compare can
- // be removed.
- if (!Cmp1->hasOneUse())
- return nullptr;
- SubstituteCmp = Builder.CreateICmp(Pred1, Y, C);
- }
- if (IsLogical)
- return IsAnd ? Builder.CreateLogicalAnd(Cmp0, SubstituteCmp)
- : Builder.CreateLogicalOr(Cmp0, SubstituteCmp);
- return Builder.CreateBinOp(IsAnd ? Instruction::And : Instruction::Or, Cmp0,
- SubstituteCmp);
-}
-
-/// Fold (icmp Pred1 V1, C1) & (icmp Pred2 V2, C2)
-/// or (icmp Pred1 V1, C1) | (icmp Pred2 V2, C2)
-/// into a single comparison using range-based reasoning.
-/// NOTE: This is also used for logical and/or, must be poison-safe!
-Value *InstCombinerImpl::foldAndOrOfICmpsUsingRanges(ICmpInst *ICmp1,
- ICmpInst *ICmp2,
- bool IsAnd) {
- CmpPredicate Pred1, Pred2;
- Value *V1, *V2;
- const APInt *C1, *C2;
- if (!match(ICmp1, m_ICmp(Pred1, m_Value(V1), m_APInt(C1))) ||
- !match(ICmp2, m_ICmp(Pred2, m_Value(V2), m_APInt(C2))))
- return nullptr;
-
- // Look through add of a constant offset on V1, V2, or both operands. This
- // allows us to interpret the V + C' < C'' range idiom into a proper range.
- const APInt *Offset1 = nullptr, *Offset2 = nullptr;
- if (V1 != V2) {
- Value *X;
- if (match(V1, m_Add(m_Value(X), m_APInt(Offset1))))
- V1 = X;
- if (match(V2, m_Add(m_Value(X), m_APInt(Offset2))))
- V2 = X;
- }
-
- if (V1 != V2)
- return nullptr;
-
- ConstantRange CR1 = ConstantRange::makeExactICmpRegion(
- IsAnd ? ICmpInst::getInverseCmpPredicate(Pred1) : Pred1, *C1);
- if (Offset1)
- CR1 = CR1.subtract(*Offset1);
-
- ConstantRange CR2 = ConstantRange::makeExactICmpRegion(
- IsAnd ? ICmpInst::getInverseCmpPredicate(Pred2) : Pred2, *C2);
- if (Offset2)
- CR2 = CR2.subtract(*Offset2);
-
- Type *Ty = V1->getType();
- Value *NewV = V1;
- std::optional<ConstantRange> CR = CR1.exactUnionWith(CR2);
- if (!CR) {
- if (!(ICmp1->hasOneUse() && ICmp2->hasOneUse()) || CR1.isWrappedSet() ||
- CR2.isWrappedSet())
- return nullptr;
-
- // Check whether we have equal-size ranges that only differ by one bit.
- // In that case we can apply a mask to map one range onto the other.
- APInt LowerDiff = CR1.getLower() ^ CR2.getLower();
- APInt UpperDiff = (CR1.getUpper() - 1) ^ (CR2.getUpper() - 1);
- APInt CR1Size = CR1.getUpper() - CR1.getLower();
- if (!LowerDiff.isPowerOf2() || LowerDiff != UpperDiff ||
- CR1Size != CR2.getUpper() - CR2.getLower())
- return nullptr;
-
- CR = CR1.getLower().ult(CR2.getLower()) ? CR1 : CR2;
- NewV = Builder.CreateAnd(NewV, ConstantInt::get(Ty, ~LowerDiff));
- }
-
- if (IsAnd)
- CR = CR->inverse();
-
- CmpInst::Predicate NewPred;
- APInt NewC, Offset;
- CR->getEquivalentICmp(NewPred, NewC, Offset);
-
- if (Offset != 0)
- NewV = Builder.CreateAdd(NewV, ConstantInt::get(Ty, Offset));
- return Builder.CreateICmp(NewPred, NewV, ConstantInt::get(Ty, NewC));
-}
-
-/// Ignore all operations which only change the sign of a value, returning the
-/// underlying magnitude value.
-static Value *stripSignOnlyFPOps(Value *Val) {
- match(Val, m_FNeg(m_Value(Val)));
- match(Val, m_FAbs(m_Value(Val)));
- match(Val, m_CopySign(m_Value(Val), m_Value()));
- return Val;
-}
-
-/// Matches canonical form of isnan, fcmp ord x, 0
-static bool matchIsNotNaN(FCmpInst::Predicate P, Value *LHS, Value *RHS) {
- return P == FCmpInst::FCMP_ORD && match(RHS, m_AnyZeroFP());
-}
-
-/// Matches fcmp u__ x, +/-inf
-static bool matchUnorderedInfCompare(FCmpInst::Predicate P, Value *LHS,
- Value *RHS) {
- return FCmpInst::isUnordered(P) && match(RHS, m_Inf());
-}
-
-/// and (fcmp ord x, 0), (fcmp u* x, inf) -> fcmp o* x, inf
-///
-/// Clang emits this pattern for doing an isfinite check in __builtin_isnormal.
-static Value *matchIsFiniteTest(InstCombiner::BuilderTy &Builder, FCmpInst *LHS,
- FCmpInst *RHS) {
- Value *LHS0 = LHS->getOperand(0), *LHS1 = LHS->getOperand(1);
- Value *RHS0 = RHS->getOperand(0), *RHS1 = RHS->getOperand(1);
- FCmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
-
- if (!matchIsNotNaN(PredL, LHS0, LHS1) ||
- !matchUnorderedInfCompare(PredR, RHS0, RHS1))
- return nullptr;
-
- return Builder.CreateFCmpFMF(FCmpInst::getOrderedPredicate(PredR), RHS0, RHS1,
- FMFSource::intersect(LHS, RHS));
-}
-
-Value *InstCombinerImpl::foldLogicOfFCmps(FCmpInst *LHS, FCmpInst *RHS,
- bool IsAnd, bool IsLogicalSelect) {
- Value *LHS0 = LHS->getOperand(0), *LHS1 = LHS->getOperand(1);
- Value *RHS0 = RHS->getOperand(0), *RHS1 = RHS->getOperand(1);
- FCmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
-
- if (LHS0 == RHS1 && RHS0 == LHS1) {
- // Swap RHS operands to match LHS.
- PredR = FCmpInst::getSwappedPredicate(PredR);
- std::swap(RHS0, RHS1);
- }
-
- // Simplify (fcmp cc0 x, y) & (fcmp cc1 x, y).
- // Suppose the relation between x and y is R, where R is one of
- // U(1000), L(0100), G(0010) or E(0001), and CC0 and CC1 are the bitmasks for
- // testing the desired relations.
- //
- // Since (R & CC0) and (R & CC1) are either R or 0, we actually have this:
- // bool(R & CC0) && bool(R & CC1)
- // = bool((R & CC0) & (R & CC1))
- // = bool(R & (CC0 & CC1)) <= by re-association, commutation, and idempotency
- //
- // Since (R & CC0) and (R & CC1) are either R or 0, we actually have this:
- // bool(R & CC0) || bool(R & CC1)
- // = bool((R & CC0) | (R & CC1))
- // = bool(R & (CC0 | CC1)) <= by reversed distribution (contribution? ;)
- if (LHS0 == RHS0 && LHS1 == RHS1) {
- unsigned FCmpCodeL = getFCmpCode(PredL);
- unsigned FCmpCodeR = getFCmpCode(PredR);
- unsigned NewPred = IsAnd ? FCmpCodeL & FCmpCodeR : FCmpCodeL | FCmpCodeR;
-
- // Intersect the fast math flags.
- // TODO: We can union the fast math flags unless this is a logical select.
- return getFCmpValue(NewPred, LHS0, LHS1, Builder,
- FMFSource::intersect(LHS, RHS));
- }
-
- // This transform is not valid for a logical select.
- if (!IsLogicalSelect &&
- ((PredL == FCmpInst::FCMP_ORD && PredR == FCmpInst::FCMP_ORD && IsAnd) ||
- (PredL == FCmpInst::FCMP_UNO && PredR == FCmpInst::FCMP_UNO &&
- !IsAnd))) {
- if (LHS0->getType() != RHS0->getType())
- return nullptr;
-
- // FCmp canonicalization ensures that (fcmp ord/uno X, X) and
- // (fcmp ord/uno X, C) will be transformed to (fcmp X, +0.0).
- if (match(LHS1, m_PosZeroFP()) && match(RHS1, m_PosZeroFP())) {
- // Ignore the constants because they are obviously not NANs:
- // (fcmp ord x, 0.0) & (fcmp ord y, 0.0) -> (fcmp ord x, y)
- // (fcmp uno x, 0.0) | (fcmp uno y, 0.0) -> (fcmp uno x, y)
- return Builder.CreateFCmpFMF(PredL, LHS0, RHS0,
- FMFSource::intersect(LHS, RHS));
- }
- }
-
- if (IsAnd && stripSignOnlyFPOps(LHS0) == stripSignOnlyFPOps(RHS0)) {
- // and (fcmp ord x, 0), (fcmp u* x, inf) -> fcmp o* x, inf
- // and (fcmp ord x, 0), (fcmp u* fabs(x), inf) -> fcmp o* x, inf
- if (Value *Left = matchIsFiniteTest(Builder, LHS, RHS))
- return Left;
- if (Value *Right = matchIsFiniteTest(Builder, RHS, LHS))
- return Right;
- }
-
- // Turn at least two fcmps with constants into llvm.is.fpclass.
- //
- // If we can represent a combined value test with one class call, we can
- // potentially eliminate 4-6 instructions. If we can represent a test with a
- // single fcmp with fneg and fabs, that's likely a better canonical form.
- if (LHS->hasOneUse() && RHS->hasOneUse()) {
- auto [ClassValRHS, ClassMaskRHS] =
- fcmpToClassTest(PredR, *RHS->getFunction(), RHS0, RHS1);
- if (ClassValRHS) {
- auto [ClassValLHS, ClassMaskLHS] =
- fcmpToClassTest(PredL, *LHS->getFunction(), LHS0, LHS1);
- if (ClassValLHS == ClassValRHS) {
- unsigned CombinedMask = IsAnd ? (ClassMaskLHS & ClassMaskRHS)
- : (ClassMaskLHS | ClassMaskRHS);
- return Builder.CreateIntrinsic(
- Intrinsic::is_fpclass, {ClassValLHS->getType()},
- {ClassValLHS, Builder.getInt32(CombinedMask)});
- }
- }
- }
-
- // Canonicalize the range check idiom:
- // and (fcmp olt/ole/ult/ule x, C), (fcmp ogt/oge/ugt/uge x, -C)
- // --> fabs(x) olt/ole/ult/ule C
- // or (fcmp ogt/oge/ugt/uge x, C), (fcmp olt/ole/ult/ule x, -C)
- // --> fabs(x) ogt/oge/ugt/uge C
- // TODO: Generalize to handle a negated variable operand?
- const APFloat *LHSC, *RHSC;
- if (LHS0 == RHS0 && LHS->hasOneUse() && RHS->hasOneUse() &&
- FCmpInst::getSwappedPredicate(PredL) == PredR &&
- match(LHS1, m_APFloatAllowPoison(LHSC)) &&
- match(RHS1, m_APFloatAllowPoison(RHSC)) &&
- LHSC->bitwiseIsEqual(neg(*RHSC))) {
- auto IsLessThanOrLessEqual = [](FCmpInst::Predicate Pred) {
- switch (Pred) {
- case FCmpInst::FCMP_OLT:
- case FCmpInst::FCMP_OLE:
- case FCmpInst::FCMP_ULT:
- case FCmpInst::FCMP_ULE:
- return true;
- default:
- return false;
- }
- };
- if (IsLessThanOrLessEqual(IsAnd ? PredR : PredL)) {
- std::swap(LHSC, RHSC);
- std::swap(PredL, PredR);
- }
- if (IsLessThanOrLessEqual(IsAnd ? PredL : PredR)) {
- FastMathFlags NewFlag = LHS->getFastMathFlags();
- if (!IsLogicalSelect)
- NewFlag |= RHS->getFastMathFlags();
-
- Value *FAbs =
- Builder.CreateUnaryIntrinsic(Intrinsic::fabs, LHS0, NewFlag);
- return Builder.CreateFCmpFMF(
- PredL, FAbs, ConstantFP::get(LHS0->getType(), *LHSC), NewFlag);
- }
- }
-
- return nullptr;
-}
-
-/// Match an fcmp against a special value that performs a test possible by
-/// llvm.is.fpclass.
-static bool matchIsFPClassLikeFCmp(Value *Op, Value *&ClassVal,
- uint64_t &ClassMask) {
- auto *FCmp = dyn_cast<FCmpInst>(Op);
- if (!FCmp || !FCmp->hasOneUse())
- return false;
-
- std::tie(ClassVal, ClassMask) =
- fcmpToClassTest(FCmp->getPredicate(), *FCmp->getParent()->getParent(),
- FCmp->getOperand(0), FCmp->getOperand(1));
- return ClassVal != nullptr;
-}
-
-/// or (is_fpclass x, mask0), (is_fpclass x, mask1)
-/// -> is_fpclass x, (mask0 | mask1)
-/// and (is_fpclass x, mask0), (is_fpclass x, mask1)
-/// -> is_fpclass x, (mask0 & mask1)
-/// xor (is_fpclass x, mask0), (is_fpclass x, mask1)
-/// -> is_fpclass x, (mask0 ^ mask1)
-Instruction *InstCombinerImpl::foldLogicOfIsFPClass(BinaryOperator &BO,
- Value *Op0, Value *Op1) {
- Value *ClassVal0 = nullptr;
- Value *ClassVal1 = nullptr;
- uint64_t ClassMask0, ClassMask1;
-
- // Restrict to folding one fcmp into one is.fpclass for now, don't introduce a
- // new class.
- //
- // TODO: Support forming is.fpclass out of 2 separate fcmps when codegen is
- // better.
-
- bool IsLHSClass =
- match(Op0, m_OneUse(m_Intrinsic<Intrinsic::is_fpclass>(
- m_Value(ClassVal0), m_ConstantInt(ClassMask0))));
- bool IsRHSClass =
- match(Op1, m_OneUse(m_Intrinsic<Intrinsic::is_fpclass>(
- m_Value(ClassVal1), m_ConstantInt(ClassMask1))));
- if ((((IsLHSClass || matchIsFPClassLikeFCmp(Op0, ClassVal0, ClassMask0)) &&
- (IsRHSClass || matchIsFPClassLikeFCmp(Op1, ClassVal1, ClassMask1)))) &&
- ClassVal0 == ClassVal1) {
- unsigned NewClassMask;
- switch (BO.getOpcode()) {
- case Instruction::And:
- NewClassMask = ClassMask0 & ClassMask1;
- break;
- case Instruction::Or:
- NewClassMask = ClassMask0 | ClassMask1;
- break;
- case Instruction::Xor:
- NewClassMask = ClassMask0 ^ ClassMask1;
- break;
- default:
- llvm_unreachable("not a binary logic operator");
- }
-
- if (IsLHSClass) {
- auto *II = cast<IntrinsicInst>(Op0);
- II->setArgOperand(
- 1, ConstantInt::get(II->getArgOperand(1)->getType(), NewClassMask));
- return replaceInstUsesWith(BO, II);
- }
-
- if (IsRHSClass) {
- auto *II = cast<IntrinsicInst>(Op1);
- II->setArgOperand(
- 1, ConstantInt::get(II->getArgOperand(1)->getType(), NewClassMask));
- return replaceInstUsesWith(BO, II);
- }
-
- CallInst *NewClass =
- Builder.CreateIntrinsic(Intrinsic::is_fpclass, {ClassVal0->getType()},
- {ClassVal0, Builder.getInt32(NewClassMask)});
- return replaceInstUsesWith(BO, NewClass);
- }
-
- return nullptr;
-}
-
-/// Look for the pattern that conditionally negates a value via math operations:
-/// cond.splat = sext i1 cond
-/// sub = add cond.splat, x
-/// xor = xor sub, cond.splat
-/// and rewrite it to do the same, but via logical operations:
-/// value.neg = sub 0, value
-/// cond = select i1 neg, value.neg, value
-Instruction *InstCombinerImpl::canonicalizeConditionalNegationViaMathToSelect(
- BinaryOperator &I) {
- assert(I.getOpcode() == BinaryOperator::Xor && "Only for xor!");
- Value *Cond, *X;
- // As per complexity ordering, `xor` is not commutative here.
- if (!match(&I, m_c_BinOp(m_OneUse(m_Value()), m_Value())) ||
- !match(I.getOperand(1), m_SExt(m_Value(Cond))) ||
- !Cond->getType()->isIntOrIntVectorTy(1) ||
- !match(I.getOperand(0), m_c_Add(m_SExt(m_Specific(Cond)), m_Value(X))))
- return nullptr;
- return SelectInst::Create(Cond, Builder.CreateNeg(X, X->getName() + ".neg"),
- X);
-}
-
-/// This a limited reassociation for a special case (see above) where we are
-/// checking if two values are either both NAN (unordered) or not-NAN (ordered).
-/// This could be handled more generally in '-reassociation', but it seems like
-/// an unlikely pattern for a large number of logic ops and fcmps.
-static Instruction *reassociateFCmps(BinaryOperator &BO,
- InstCombiner::BuilderTy &Builder) {
- Instruction::BinaryOps Opcode = BO.getOpcode();
- assert((Opcode == Instruction::And || Opcode == Instruction::Or) &&
- "Expecting and/or op for fcmp transform");
-
- // There are 4 commuted variants of the pattern. Canonicalize operands of this
- // logic op so an fcmp is operand 0 and a matching logic op is operand 1.
- Value *Op0 = BO.getOperand(0), *Op1 = BO.getOperand(1), *X;
- if (match(Op1, m_FCmp(m_Value(), m_AnyZeroFP())))
- std::swap(Op0, Op1);
-
- // Match inner binop and the predicate for combining 2 NAN checks into 1.
- Value *BO10, *BO11;
- FCmpInst::Predicate NanPred = Opcode == Instruction::And ? FCmpInst::FCMP_ORD
- : FCmpInst::FCMP_UNO;
- if (!match(Op0, m_SpecificFCmp(NanPred, m_Value(X), m_AnyZeroFP())) ||
- !match(Op1, m_BinOp(Opcode, m_Value(BO10), m_Value(BO11))))
- return nullptr;
-
- // The inner logic op must have a matching fcmp operand.
- Value *Y;
- if (!match(BO10, m_SpecificFCmp(NanPred, m_Value(Y), m_AnyZeroFP())) ||
- X->getType() != Y->getType())
- std::swap(BO10, BO11);
-
- if (!match(BO10, m_SpecificFCmp(NanPred, m_Value(Y), m_AnyZeroFP())) ||
- X->getType() != Y->getType())
- return nullptr;
-
- // and (fcmp ord X, 0), (and (fcmp ord Y, 0), Z) --> and (fcmp ord X, Y), Z
- // or (fcmp uno X, 0), (or (fcmp uno Y, 0), Z) --> or (fcmp uno X, Y), Z
- // Intersect FMF from the 2 source fcmps.
- Value *NewFCmp =
- Builder.CreateFCmpFMF(NanPred, X, Y, FMFSource::intersect(Op0, BO10));
- return BinaryOperator::Create(Opcode, NewFCmp, BO11);
-}
-
-/// Match variations of De Morgan's Laws:
-/// (~A & ~B) == (~(A | B))
-/// (~A | ~B) == (~(A & B))
-static Instruction *matchDeMorgansLaws(BinaryOperator &I,
- InstCombiner &IC) {
- const Instruction::BinaryOps Opcode = I.getOpcode();
- assert((Opcode == Instruction::And || Opcode == Instruction::Or) &&
- "Trying to match De Morgan's Laws with something other than and/or");
-
- // Flip the logic operation.
- const Instruction::BinaryOps FlippedOpcode =
- (Opcode == Instruction::And) ? Instruction::Or : Instruction::And;
-
- Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
- Value *A, *B;
- if (match(Op0, m_OneUse(m_Not(m_Value(A)))) &&
- match(Op1, m_OneUse(m_Not(m_Value(B)))) &&
- !IC.isFreeToInvert(A, A->hasOneUse()) &&
- !IC.isFreeToInvert(B, B->hasOneUse())) {
- Value *AndOr =
- IC.Builder.CreateBinOp(FlippedOpcode, A, B, I.getName() + ".demorgan");
- return BinaryOperator::CreateNot(AndOr);
- }
-
- // The 'not' ops may require reassociation.
- // (A & ~B) & ~C --> A & ~(B | C)
- // (~B & A) & ~C --> A & ~(B | C)
- // (A | ~B) | ~C --> A | ~(B & C)
- // (~B | A) | ~C --> A | ~(B & C)
- Value *C;
- if (match(Op0, m_OneUse(m_c_BinOp(Opcode, m_Value(A), m_Not(m_Value(B))))) &&
- match(Op1, m_Not(m_Value(C)))) {
- Value *FlippedBO = IC.Builder.CreateBinOp(FlippedOpcode, B, C);
- return BinaryOperator::Create(Opcode, A, IC.Builder.CreateNot(FlippedBO));
- }
-
- return nullptr;
-}
-
-bool InstCombinerImpl::shouldOptimizeCast(CastInst *CI) {
- Value *CastSrc = CI->getOperand(0);
-
- // Noop casts and casts of constants should be eliminated trivially.
- if (CI->getSrcTy() == CI->getDestTy() || isa<Constant>(CastSrc))
- return false;
-
- // If this cast is paired with another cast that can be eliminated, we prefer
- // to have it eliminated.
- if (const auto *PrecedingCI = dyn_cast<CastInst>(CastSrc))
- if (isEliminableCastPair(PrecedingCI, CI))
- return false;
-
- return true;
-}
-
-/// Fold {and,or,xor} (cast X), C.
-static Instruction *foldLogicCastConstant(BinaryOperator &Logic, CastInst *Cast,
- InstCombinerImpl &IC) {
- Constant *C = dyn_cast<Constant>(Logic.getOperand(1));
- if (!C)
- return nullptr;
-
- auto LogicOpc = Logic.getOpcode();
- Type *DestTy = Logic.getType();
- Type *SrcTy = Cast->getSrcTy();
-
- // Move the logic operation ahead of a zext or sext if the constant is
- // unchanged in the smaller source type. Performing the logic in a smaller
- // type may provide more information to later folds, and the smaller logic
- // instruction may be cheaper (particularly in the case of vectors).
- Value *X;
- if (match(Cast, m_OneUse(m_ZExt(m_Value(X))))) {
- if (Constant *TruncC = IC.getLosslessUnsignedTrunc(C, SrcTy)) {
- // LogicOpc (zext X), C --> zext (LogicOpc X, C)
- Value *NewOp = IC.Builder.CreateBinOp(LogicOpc, X, TruncC);
- return new ZExtInst(NewOp, DestTy);
- }
- }
-
- if (match(Cast, m_OneUse(m_SExtLike(m_Value(X))))) {
- if (Constant *TruncC = IC.getLosslessSignedTrunc(C, SrcTy)) {
- // LogicOpc (sext X), C --> sext (LogicOpc X, C)
- Value *NewOp = IC.Builder.CreateBinOp(LogicOpc, X, TruncC);
- return new SExtInst(NewOp, DestTy);
- }
- }
-
- return nullptr;
-}
-
-/// Fold {and,or,xor} (cast X), Y.
-Instruction *InstCombinerImpl::foldCastedBitwiseLogic(BinaryOperator &I) {
- auto LogicOpc = I.getOpcode();
- assert(I.isBitwiseLogicOp() && "Unexpected opcode for bitwise logic folding");
-
- Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-
- // fold bitwise(A >> BW - 1, zext(icmp)) (BW is the scalar bits of the
- // type of A)
- // -> bitwise(zext(A < 0), zext(icmp))
- // -> zext(bitwise(A < 0, icmp))
- auto FoldBitwiseICmpZeroWithICmp = [&](Value *Op0,
- Value *Op1) -> Instruction * {
- Value *A;
- bool IsMatched =
- match(Op0,
- m_OneUse(m_LShr(
- m_Value(A),
- m_SpecificInt(Op0->getType()->getScalarSizeInBits() - 1)))) &&
- match(Op1, m_OneUse(m_ZExt(m_ICmp(m_Value(), m_Value()))));
-
- if (!IsMatched)
- return nullptr;
-
- auto *ICmpL =
- Builder.CreateICmpSLT(A, Constant::getNullValue(A->getType()));
- auto *ICmpR = cast<ZExtInst>(Op1)->getOperand(0);
- auto *BitwiseOp = Builder.CreateBinOp(LogicOpc, ICmpL, ICmpR);
-
- return new ZExtInst(BitwiseOp, Op0->getType());
- };
-
- if (auto *Ret = FoldBitwiseICmpZeroWithICmp(Op0, Op1))
- return Ret;
-
- if (auto *Ret = FoldBitwiseICmpZeroWithICmp(Op1, Op0))
- return Ret;
-
- CastInst *Cast0 = dyn_cast<CastInst>(Op0);
- if (!Cast0)
- return nullptr;
-
- // This must be a cast from an integer or integer vector source type to allow
- // transformation of the logic operation to the source type.
- Type *DestTy = I.getType();
- Type *SrcTy = Cast0->getSrcTy();
- if (!SrcTy->isIntOrIntVectorTy())
- return nullptr;
-
- if (Instruction *Ret = foldLogicCastConstant(I, Cast0, *this))
- return Ret;
-
- CastInst *Cast1 = dyn_cast<CastInst>(Op1);
- if (!Cast1)
- return nullptr;
-
- // Both operands of the logic operation are casts. The casts must be the
- // same kind for reduction.
- Instruction::CastOps CastOpcode = Cast0->getOpcode();
- if (CastOpcode != Cast1->getOpcode())
- return nullptr;
-
- // If the source types do not match, but the casts are matching extends, we
- // can still narrow the logic op.
- if (SrcTy != Cast1->getSrcTy()) {
- Value *X, *Y;
- if (match(Cast0, m_OneUse(m_ZExtOrSExt(m_Value(X)))) &&
- match(Cast1, m_OneUse(m_ZExtOrSExt(m_Value(Y))))) {
- // Cast the narrower source to the wider source type.
- unsigned XNumBits = X->getType()->getScalarSizeInBits();
- unsigned YNumBits = Y->getType()->getScalarSizeInBits();
- if (XNumBits < YNumBits)
- X = Builder.CreateCast(CastOpcode, X, Y->getType());
- else
- Y = Builder.CreateCast(CastOpcode, Y, X->getType());
- // Do the logic op in the intermediate width, then widen more.
- Value *NarrowLogic = Builder.CreateBinOp(LogicOpc, X, Y);
- return CastInst::Create(CastOpcode, NarrowLogic, DestTy);
- }
-
- // Give up for other cast opcodes.
- return nullptr;
- }
-
- Value *Cast0Src = Cast0->getOperand(0);
- Value *Cast1Src = Cast1->getOperand(0);
-
- // fold logic(cast(A), cast(B)) -> cast(logic(A, B))
- if ((Cast0->hasOneUse() || Cast1->hasOneUse()) &&
- shouldOptimizeCast(Cast0) && shouldOptimizeCast(Cast1)) {
- Value *NewOp = Builder.CreateBinOp(LogicOpc, Cast0Src, Cast1Src,
- I.getName());
- return CastInst::Create(CastOpcode, NewOp, DestTy);
- }
-
- return nullptr;
-}
-
-static Instruction *foldAndToXor(BinaryOperator &I,
- InstCombiner::BuilderTy &Builder) {
- assert(I.getOpcode() == Instruction::And);
- Value *Op0 = I.getOperand(0);
- Value *Op1 = I.getOperand(1);
- Value *A, *B;
-
- // Operand complexity canonicalization guarantees that the 'or' is Op0.
- // (A | B) & ~(A & B) --> A ^ B
- // (A | B) & ~(B & A) --> A ^ B
- if (match(&I, m_BinOp(m_Or(m_Value(A), m_Value(B)),
- m_Not(m_c_And(m_Deferred(A), m_Deferred(B))))))
- return BinaryOperator::CreateXor(A, B);
-
- // (A | ~B) & (~A | B) --> ~(A ^ B)
- // (A | ~B) & (B | ~A) --> ~(A ^ B)
- // (~B | A) & (~A | B) --> ~(A ^ B)
- // (~B | A) & (B | ~A) --> ~(A ^ B)
- if (Op0->hasOneUse() || Op1->hasOneUse())
- if (match(&I, m_BinOp(m_c_Or(m_Value(A), m_Not(m_Value(B))),
- m_c_Or(m_Not(m_Deferred(A)), m_Deferred(B)))))
- return BinaryOperator::CreateNot(Builder.CreateXor(A, B));
-
- return nullptr;
-}
-
-static Instruction *foldOrToXor(BinaryOperator &I,
- InstCombiner::BuilderTy &Builder) {
- assert(I.getOpcode() == Instruction::Or);
- Value *Op0 = I.getOperand(0);
- Value *Op1 = I.getOperand(1);
- Value *A, *B;
-
- // Operand complexity canonicalization guarantees that the 'and' is Op0.
- // (A & B) | ~(A | B) --> ~(A ^ B)
- // (A & B) | ~(B | A) --> ~(A ^ B)
- if (Op0->hasOneUse() || Op1->hasOneUse())
- if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
- match(Op1, m_Not(m_c_Or(m_Specific(A), m_Specific(B)))))
- return BinaryOperator::CreateNot(Builder.CreateXor(A, B));
-
- // Operand complexity canonicalization guarantees that the 'xor' is Op0.
- // (A ^ B) | ~(A | B) --> ~(A & B)
- // (A ^ B) | ~(B | A) --> ~(A & B)
- if (Op0->hasOneUse() || Op1->hasOneUse())
- if (match(Op0, m_Xor(m_Value(A), m_Value(B))) &&
- match(Op1, m_Not(m_c_Or(m_Specific(A), m_Specific(B)))))
- return BinaryOperator::CreateNot(Builder.CreateAnd(A, B));
-
- // (A & ~B) | (~A & B) --> A ^ B
- // (A & ~B) | (B & ~A) --> A ^ B
- // (~B & A) | (~A & B) --> A ^ B
- // (~B & A) | (B & ~A) --> A ^ B
- if (match(Op0, m_c_And(m_Value(A), m_Not(m_Value(B)))) &&
- match(Op1, m_c_And(m_Not(m_Specific(A)), m_Specific(B))))
- return BinaryOperator::CreateXor(A, B);
-
- return nullptr;
-}
-
-/// Return true if a constant shift amount is always less than the specified
-/// bit-width. If not, the shift could create poison in the narrower type.
-static bool canNarrowShiftAmt(Constant *C, unsigned BitWidth) {
- APInt Threshold(C->getType()->getScalarSizeInBits(), BitWidth);
- return match(C, m_SpecificInt_ICMP(ICmpInst::ICMP_ULT, Threshold));
-}
-
-/// Try to use narrower ops (sink zext ops) for an 'and' with binop operand and
-/// a common zext operand: and (binop (zext X), C), (zext X).
-Instruction *InstCombinerImpl::narrowMaskedBinOp(BinaryOperator &And) {
- // This transform could also apply to {or, and, xor}, but there are better
- // folds for those cases, so we don't expect those patterns here. AShr is not
- // handled because it should always be transformed to LShr in this sequence.
- // The subtract transform is different because it has a constant on the left.
- // Add/mul commute the constant to RHS; sub with constant RHS becomes add.
- Value *Op0 = And.getOperand(0), *Op1 = And.getOperand(1);
- Constant *C;
- if (!match(Op0, m_OneUse(m_Add(m_Specific(Op1), m_Constant(C)))) &&
- !match(Op0, m_OneUse(m_Mul(m_Specific(Op1), m_Constant(C)))) &&
- !match(Op0, m_OneUse(m_LShr(m_Specific(Op1), m_Constant(C)))) &&
- !match(Op0, m_OneUse(m_Shl(m_Specific(Op1), m_Constant(C)))) &&
- !match(Op0, m_OneUse(m_Sub(m_Constant(C), m_Specific(Op1)))))
- return nullptr;
-
- Value *X;
- if (!match(Op1, m_ZExt(m_Value(X))) || Op1->hasNUsesOrMore(3))
- return nullptr;
-
- Type *Ty = And.getType();
- if (!isa<VectorType>(Ty) && !shouldChangeType(Ty, X->getType()))
- return nullptr;
-
- // If we're narrowing a shift, the shift amount must be safe (less than the
- // width) in the narrower type. If the shift amount is greater, instsimplify
- // usually handles that case, but we can't guarantee/assert it.
- Instruction::BinaryOps Opc = cast<BinaryOperator>(Op0)->getOpcode();
- if (Opc == Instruction::LShr || Opc == Instruction::Shl)
- if (!canNarrowShiftAmt(C, X->getType()->getScalarSizeInBits()))
- return nullptr;
-
- // and (sub C, (zext X)), (zext X) --> zext (and (sub C', X), X)
- // and (binop (zext X), C), (zext X) --> zext (and (binop X, C'), X)
- Value *NewC = ConstantExpr::getTrunc(C, X->getType());
- Value *NewBO = Opc == Instruction::Sub ? Builder.CreateBinOp(Opc, NewC, X)
- : Builder.CreateBinOp(Opc, X, NewC);
- return new ZExtInst(Builder.CreateAnd(NewBO, X), Ty);
-}
-
-/// Try folding relatively complex patterns for both And and Or operations
-/// with all And and Or swapped.
-static Instruction *foldComplexAndOrPatterns(BinaryOperator &I,
- InstCombiner::BuilderTy &Builder) {
- const Instruction::BinaryOps Opcode = I.getOpcode();
- assert(Opcode == Instruction::And || Opcode == Instruction::Or);
-
- // Flip the logic operation.
- const Instruction::BinaryOps FlippedOpcode =
- (Opcode == Instruction::And) ? Instruction::Or : Instruction::And;
-
- Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
- Value *A, *B, *C, *X, *Y, *Dummy;
-
- // Match following expressions:
- // (~(A | B) & C)
- // (~(A & B) | C)
- // Captures X = ~(A | B) or ~(A & B)
- const auto matchNotOrAnd =
- [Opcode, FlippedOpcode](Value *Op, auto m_A, auto m_B, auto m_C,
- Value *&X, bool CountUses = false) -> bool {
- if (CountUses && !Op->hasOneUse())
- return false;
-
- if (match(Op, m_c_BinOp(FlippedOpcode,
- m_CombineAnd(m_Value(X),
- m_Not(m_c_BinOp(Opcode, m_A, m_B))),
- m_C)))
- return !CountUses || X->hasOneUse();
-
- return false;
- };
-
- // (~(A | B) & C) | ... --> ...
- // (~(A & B) | C) & ... --> ...
- // TODO: One use checks are conservative. We just need to check that a total
- // number of multiple used values does not exceed reduction
- // in operations.
- if (matchNotOrAnd(Op0, m_Value(A), m_Value(B), m_Value(C), X)) {
- // (~(A | B) & C) | (~(A | C) & B) --> (B ^ C) & ~A
- // (~(A & B) | C) & (~(A & C) | B) --> ~((B ^ C) & A)
- if (matchNotOrAnd(Op1, m_Specific(A), m_Specific(C), m_Specific(B), Dummy,
- true)) {
- Value *Xor = Builder.CreateXor(B, C);
- return (Opcode == Instruction::Or)
- ? BinaryOperator::CreateAnd(Xor, Builder.CreateNot(A))
- : BinaryOperator::CreateNot(Builder.CreateAnd(Xor, A));
- }
-
- // (~(A | B) & C) | (~(B | C) & A) --> (A ^ C) & ~B
- // (~(A & B) | C) & (~(B & C) | A) --> ~((A ^ C) & B)
- if (matchNotOrAnd(Op1, m_Specific(B), m_Specific(C), m_Specific(A), Dummy,
- true)) {
- Value *Xor = Builder.CreateXor(A, C);
- return (Opcode == Instruction::Or)
- ? BinaryOperator::CreateAnd(Xor, Builder.CreateNot(B))
- : BinaryOperator::CreateNot(Builder.CreateAnd(Xor, B));
- }
-
- // (~(A | B) & C) | ~(A | C) --> ~((B & C) | A)
- // (~(A & B) | C) & ~(A & C) --> ~((B | C) & A)
- if (match(Op1, m_OneUse(m_Not(m_OneUse(
- m_c_BinOp(Opcode, m_Specific(A), m_Specific(C)))))))
- return BinaryOperator::CreateNot(Builder.CreateBinOp(
- Opcode, Builder.CreateBinOp(FlippedOpcode, B, C), A));
-
- // (~(A | B) & C) | ~(B | C) --> ~((A & C) | B)
- // (~(A & B) | C) & ~(B & C) --> ~((A | C) & B)
- if (match(Op1, m_OneUse(m_Not(m_OneUse(
- m_c_BinOp(Opcode, m_Specific(B), m_Specific(C)))))))
- return BinaryOperator::CreateNot(Builder.CreateBinOp(
- Opcode, Builder.CreateBinOp(FlippedOpcode, A, C), B));
-
- // (~(A | B) & C) | ~(C | (A ^ B)) --> ~((A | B) & (C | (A ^ B)))
- // Note, the pattern with swapped and/or is not handled because the
- // result is more undefined than a source:
- // (~(A & B) | C) & ~(C & (A ^ B)) --> (A ^ B ^ C) | ~(A | C) is invalid.
- if (Opcode == Instruction::Or && Op0->hasOneUse() &&
- match(Op1, m_OneUse(m_Not(m_CombineAnd(
- m_Value(Y),
- m_c_BinOp(Opcode, m_Specific(C),
- m_c_Xor(m_Specific(A), m_Specific(B)))))))) {
- // X = ~(A | B)
- // Y = (C | (A ^ B)
- Value *Or = cast<BinaryOperator>(X)->getOperand(0);
- return BinaryOperator::CreateNot(Builder.CreateAnd(Or, Y));
- }
- }
-
- // (~A & B & C) | ... --> ...
- // (~A | B | C) | ... --> ...
- // TODO: One use checks are conservative. We just need to check that a total
- // number of multiple used values does not exceed reduction
- // in operations.
- if (match(Op0,
- m_OneUse(m_c_BinOp(FlippedOpcode,
- m_BinOp(FlippedOpcode, m_Value(B), m_Value(C)),
- m_CombineAnd(m_Value(X), m_Not(m_Value(A)))))) ||
- match(Op0, m_OneUse(m_c_BinOp(
- FlippedOpcode,
- m_c_BinOp(FlippedOpcode, m_Value(C),
- m_CombineAnd(m_Value(X), m_Not(m_Value(A)))),
- m_Value(B))))) {
- // X = ~A
- // (~A & B & C) | ~(A | B | C) --> ~(A | (B ^ C))
- // (~A | B | C) & ~(A & B & C) --> (~A | (B ^ C))
- if (match(Op1, m_OneUse(m_Not(m_c_BinOp(
- Opcode, m_c_BinOp(Opcode, m_Specific(A), m_Specific(B)),
- m_Specific(C))))) ||
- match(Op1, m_OneUse(m_Not(m_c_BinOp(
- Opcode, m_c_BinOp(Opcode, m_Specific(B), m_Specific(C)),
- m_Specific(A))))) ||
- match(Op1, m_OneUse(m_Not(m_c_BinOp(
- Opcode, m_c_BinOp(Opcode, m_Specific(A), m_Specific(C)),
- m_Specific(B)))))) {
- Value *Xor = Builder.CreateXor(B, C);
- return (Opcode == Instruction::Or)
- ? BinaryOperator::CreateNot(Builder.CreateOr(Xor, A))
- : BinaryOperator::CreateOr(Xor, X);
- }
-
- // (~A & B & C) | ~(A | B) --> (C | ~B) & ~A
- // (~A | B | C) & ~(A & B) --> (C & ~B) | ~A
- if (match(Op1, m_OneUse(m_Not(m_OneUse(
- m_c_BinOp(Opcode, m_Specific(A), m_Specific(B)))))))
- return BinaryOperator::Create(
- FlippedOpcode, Builder.CreateBinOp(Opcode, C, Builder.CreateNot(B)),
- X);
-
- // (~A & B & C) | ~(A | C) --> (B | ~C) & ~A
- // (~A | B | C) & ~(A & C) --> (B & ~C) | ~A
- if (match(Op1, m_OneUse(m_Not(m_OneUse(
- m_c_BinOp(Opcode, m_Specific(A), m_Specific(C)))))))
- return BinaryOperator::Create(
- FlippedOpcode, Builder.CreateBinOp(Opcode, B, Builder.CreateNot(C)),
- X);
- }
-
- return nullptr;
-}
-
-/// Try to reassociate a pair of binops so that values with one use only are
-/// part of the same instruction. This may enable folds that are limited with
-/// multi-use restrictions and makes it more likely to match other patterns that
-/// are looking for a common operand.
-static Instruction *reassociateForUses(BinaryOperator &BO,
- InstCombinerImpl::BuilderTy &Builder) {
- Instruction::BinaryOps Opcode = BO.getOpcode();
- Value *X, *Y, *Z;
- if (match(&BO,
- m_c_BinOp(Opcode, m_OneUse(m_BinOp(Opcode, m_Value(X), m_Value(Y))),
- m_OneUse(m_Value(Z))))) {
- if (!isa<Constant>(X) && !isa<Constant>(Y) && !isa<Constant>(Z)) {
- // (X op Y) op Z --> (Y op Z) op X
- if (!X->hasOneUse()) {
- Value *YZ = Builder.CreateBinOp(Opcode, Y, Z);
- return BinaryOperator::Create(Opcode, YZ, X);
- }
- // (X op Y) op Z --> (X op Z) op Y
- if (!Y->hasOneUse()) {
- Value *XZ = Builder.CreateBinOp(Opcode, X, Z);
- return BinaryOperator::Create(Opcode, XZ, Y);
- }
- }
- }
-
- return nullptr;
-}
-
-// Match
-// (X + C2) | C
-// (X + C2) ^ C
-// (X + C2) & C
-// and convert to do the bitwise logic first:
-// (X | C) + C2
-// (X ^ C) + C2
-// (X & C) + C2
-// iff bits affected by logic op are lower than last bit affected by math op
-static Instruction *canonicalizeLogicFirst(BinaryOperator &I,
- InstCombiner::BuilderTy &Builder) {
- Type *Ty = I.getType();
- Instruction::BinaryOps OpC = I.getOpcode();
- Value *Op0 = I.getOperand(0);
- Value *Op1 = I.getOperand(1);
- Value *X;
- const APInt *C, *C2;
-
- if (!(match(Op0, m_OneUse(m_Add(m_Value(X), m_APInt(C2)))) &&
- match(Op1, m_APInt(C))))
- return nullptr;
-
- unsigned Width = Ty->getScalarSizeInBits();
- unsigned LastOneMath = Width - C2->countr_zero();
-
- switch (OpC) {
- case Instruction::And:
- if (C->countl_one() < LastOneMath)
- return nullptr;
- break;
- case Instruction::Xor:
- case Instruction::Or:
- if (C->countl_zero() < LastOneMath)
- return nullptr;
- break;
- default:
- llvm_unreachable("Unexpected BinaryOp!");
- }
-
- Value *NewBinOp = Builder.CreateBinOp(OpC, X, ConstantInt::get(Ty, *C));
- return BinaryOperator::CreateWithCopiedFlags(Instruction::Add, NewBinOp,
- ConstantInt::get(Ty, *C2), Op0);
-}
-
-// binop(shift(ShiftedC1, ShAmt), shift(ShiftedC2, add(ShAmt, AddC))) ->
-// shift(binop(ShiftedC1, shift(ShiftedC2, AddC)), ShAmt)
-// where both shifts are the same and AddC is a valid shift amount.
-Instruction *InstCombinerImpl::foldBinOpOfDisplacedShifts(BinaryOperator &I) {
- assert((I.isBitwiseLogicOp() || I.getOpcode() == Instruction::Add) &&
- "Unexpected opcode");
-
- Value *ShAmt;
- Constant *ShiftedC1, *ShiftedC2, *AddC;
- Type *Ty = I.getType();
- unsigned BitWidth = Ty->getScalarSizeInBits();
- if (!match(&I, m_c_BinOp(m_Shift(m_ImmConstant(ShiftedC1), m_Value(ShAmt)),
- m_Shift(m_ImmConstant(ShiftedC2),
- m_AddLike(m_Deferred(ShAmt),
- m_ImmConstant(AddC))))))
- return nullptr;
-
- // Make sure the add constant is a valid shift amount.
- if (!match(AddC,
- m_SpecificInt_ICMP(ICmpInst::ICMP_ULT, APInt(BitWidth, BitWidth))))
- return nullptr;
-
- // Avoid constant expressions.
- auto *Op0Inst = dyn_cast<Instruction>(I.getOperand(0));
- auto *Op1Inst = dyn_cast<Instruction>(I.getOperand(1));
- if (!Op0Inst || !Op1Inst)
- return nullptr;
-
- // Both shifts must be the same.
- Instruction::BinaryOps ShiftOp =
- static_cast<Instruction::BinaryOps>(Op0Inst->getOpcode());
- if (ShiftOp != Op1Inst->getOpcode())
- return nullptr;
-
- // For adds, only left shifts are supported.
- if (I.getOpcode() == Instruction::Add && ShiftOp != Instruction::Shl)
- return nullptr;
-
- Value *NewC = Builder.CreateBinOp(
- I.getOpcode(), ShiftedC1, Builder.CreateBinOp(ShiftOp, ShiftedC2, AddC));
- return BinaryOperator::Create(ShiftOp, NewC, ShAmt);
-}
-
-// Fold and/or/xor with two equal intrinsic IDs:
-// bitwise(fshl (A, B, ShAmt), fshl(C, D, ShAmt))
-// -> fshl(bitwise(A, C), bitwise(B, D), ShAmt)
-// bitwise(fshr (A, B, ShAmt), fshr(C, D, ShAmt))
-// -> fshr(bitwise(A, C), bitwise(B, D), ShAmt)
-// bitwise(bswap(A), bswap(B)) -> bswap(bitwise(A, B))
-// bitwise(bswap(A), C) -> bswap(bitwise(A, bswap(C)))
-// bitwise(bitreverse(A), bitreverse(B)) -> bitreverse(bitwise(A, B))
-// bitwise(bitreverse(A), C) -> bitreverse(bitwise(A, bitreverse(C)))
-static Instruction *
-foldBitwiseLogicWithIntrinsics(BinaryOperator &I,
- InstCombiner::BuilderTy &Builder) {
- assert(I.isBitwiseLogicOp() && "Should and/or/xor");
- if (!I.getOperand(0)->hasOneUse())
- return nullptr;
- IntrinsicInst *X = dyn_cast<IntrinsicInst>(I.getOperand(0));
- if (!X)
- return nullptr;
-
- IntrinsicInst *Y = dyn_cast<IntrinsicInst>(I.getOperand(1));
- if (Y && (!Y->hasOneUse() || X->getIntrinsicID() != Y->getIntrinsicID()))
- return nullptr;
-
- Intrinsic::ID IID = X->getIntrinsicID();
- const APInt *RHSC;
- // Try to match constant RHS.
- if (!Y && (!(IID == Intrinsic::bswap || IID == Intrinsic::bitreverse) ||
- !match(I.getOperand(1), m_APInt(RHSC))))
- return nullptr;
-
- switch (IID) {
- case Intrinsic::fshl:
- case Intrinsic::fshr: {
- if (X->getOperand(2) != Y->getOperand(2))
- return nullptr;
- Value *NewOp0 =
- Builder.CreateBinOp(I.getOpcode(), X->getOperand(0), Y->getOperand(0));
- Value *NewOp1 =
- Builder.CreateBinOp(I.getOpcode(), X->getOperand(1), Y->getOperand(1));
- Function *F =
- Intrinsic::getOrInsertDeclaration(I.getModule(), IID, I.getType());
- return CallInst::Create(F, {NewOp0, NewOp1, X->getOperand(2)});
- }
- case Intrinsic::bswap:
- case Intrinsic::bitreverse: {
- Value *NewOp0 = Builder.CreateBinOp(
- I.getOpcode(), X->getOperand(0),
- Y ? Y->getOperand(0)
- : ConstantInt::get(I.getType(), IID == Intrinsic::bswap
- ? RHSC->byteSwap()
- : RHSC->reverseBits()));
- Function *F =
- Intrinsic::getOrInsertDeclaration(I.getModule(), IID, I.getType());
- return CallInst::Create(F, {NewOp0});
- }
- default:
- return nullptr;
- }
-}
-
-// Try to simplify V by replacing occurrences of Op with RepOp, but only look
-// through bitwise operations. In particular, for X | Y we try to replace Y with
-// 0 inside X and for X & Y we try to replace Y with -1 inside X.
-// Return the simplified result of X if successful, and nullptr otherwise.
-// If SimplifyOnly is true, no new instructions will be created.
-static Value *simplifyAndOrWithOpReplaced(Value *V, Value *Op, Value *RepOp,
- bool SimplifyOnly,
- InstCombinerImpl &IC,
- unsigned Depth = 0) {
- if (Op == RepOp)
- return nullptr;
-
- if (V == Op)
- return RepOp;
-
- auto *I = dyn_cast<BinaryOperator>(V);
- if (!I || !I->isBitwiseLogicOp() || Depth >= 3)
- return nullptr;
-
- if (!I->hasOneUse())
- SimplifyOnly = true;
-
- Value *NewOp0 = simplifyAndOrWithOpReplaced(I->getOperand(0), Op, RepOp,
- SimplifyOnly, IC, Depth + 1);
- Value *NewOp1 = simplifyAndOrWithOpReplaced(I->getOperand(1), Op, RepOp,
- SimplifyOnly, IC, Depth + 1);
- if (!NewOp0 && !NewOp1)
- return nullptr;
-
- if (!NewOp0)
- NewOp0 = I->getOperand(0);
- if (!NewOp1)
- NewOp1 = I->getOperand(1);
-
- if (Value *Res = simplifyBinOp(I->getOpcode(), NewOp0, NewOp1,
- IC.getSimplifyQuery().getWithInstruction(I)))
- return Res;
-
- if (SimplifyOnly)
- return nullptr;
- return IC.Builder.CreateBinOp(I->getOpcode(), NewOp0, NewOp1);
-}
-
-/// Reassociate and/or expressions to see if we can fold the inner and/or ops.
-/// TODO: Make this recursive; it's a little tricky because an arbitrary
-/// number of and/or instructions might have to be created.
-Value *InstCombinerImpl::reassociateBooleanAndOr(Value *LHS, Value *X, Value *Y,
- Instruction &I, bool IsAnd,
- bool RHSIsLogical) {
- Instruction::BinaryOps Opcode = IsAnd ? Instruction::And : Instruction::Or;
- // LHS bop (X lop Y) --> (LHS bop X) lop Y
- // LHS bop (X bop Y) --> (LHS bop X) bop Y
- if (Value *Res = foldBooleanAndOr(LHS, X, I, IsAnd, /*IsLogical=*/false))
- return RHSIsLogical ? Builder.CreateLogicalOp(Opcode, Res, Y)
- : Builder.CreateBinOp(Opcode, Res, Y);
- // LHS bop (X bop Y) --> X bop (LHS bop Y)
- // LHS bop (X lop Y) --> X lop (LHS bop Y)
- if (Value *Res = foldBooleanAndOr(LHS, Y, I, IsAnd, /*IsLogical=*/false))
- return RHSIsLogical ? Builder.CreateLogicalOp(Opcode, X, Res)
- : Builder.CreateBinOp(Opcode, X, Res);
- return nullptr;
-}
-
-// FIXME: We use commutative matchers (m_c_*) for some, but not all, matches
-// here. We should standardize that construct where it is needed or choose some
-// other way to ensure that commutated variants of patterns are not missed.
-Instruction *InstCombinerImpl::visitAnd(BinaryOperator &I) {
- Type *Ty = I.getType();
-
- if (Value *V = simplifyAndInst(I.getOperand(0), I.getOperand(1),
- SQ.getWithInstruction(&I)))
- return replaceInstUsesWith(I, V);
-
- if (SimplifyAssociativeOrCommutative(I))
- return &I;
-
- if (Instruction *X = foldVectorBinop(I))
- return X;
-
- if (Instruction *Phi = foldBinopWithPhiOperands(I))
- return Phi;
-
- // See if we can simplify any instructions used by the instruction whose sole
- // purpose is to compute bits we don't care about.
- if (SimplifyDemandedInstructionBits(I))
- return &I;
-
- // Do this before using distributive laws to catch simple and/or/not patterns.
- if (Instruction *Xor = foldAndToXor(I, Builder))
- return Xor;
-
- if (Instruction *X = foldComplexAndOrPatterns(I, Builder))
- return X;
-
- // (A|B)&(A|C) -> A|(B&C) etc
- if (Value *V = foldUsingDistributiveLaws(I))
- return replaceInstUsesWith(I, V);
-
- if (Instruction *R = foldBinOpShiftWithShift(I))
- return R;
-
- Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-
- Value *X, *Y;
- const APInt *C;
- if ((match(Op0, m_OneUse(m_LogicalShift(m_One(), m_Value(X)))) ||
- (match(Op0, m_OneUse(m_Shl(m_APInt(C), m_Value(X)))) && (*C)[0])) &&
- match(Op1, m_One())) {
- // (1 >> X) & 1 --> zext(X == 0)
- // (C << X) & 1 --> zext(X == 0), when C is odd
- Value *IsZero = Builder.CreateICmpEQ(X, ConstantInt::get(Ty, 0));
- return new ZExtInst(IsZero, Ty);
- }
-
- // (-(X & 1)) & Y --> (X & 1) == 0 ? 0 : Y
- Value *Neg;
- if (match(&I,
- m_c_And(m_CombineAnd(m_Value(Neg),
- m_OneUse(m_Neg(m_And(m_Value(), m_One())))),
- m_Value(Y)))) {
- Value *Cmp = Builder.CreateIsNull(Neg);
- return SelectInst::Create(Cmp, ConstantInt::getNullValue(Ty), Y);
- }
-
- // Canonicalize:
- // (X +/- Y) & Y --> ~X & Y when Y is a power of 2.
- if (match(&I, m_c_And(m_Value(Y), m_OneUse(m_CombineOr(
- m_c_Add(m_Value(X), m_Deferred(Y)),
- m_Sub(m_Value(X), m_Deferred(Y)))))) &&
- isKnownToBeAPowerOfTwo(Y, /*OrZero*/ true, /*Depth*/ 0, &I))
- return BinaryOperator::CreateAnd(Builder.CreateNot(X), Y);
-
- if (match(Op1, m_APInt(C))) {
- const APInt *XorC;
- if (match(Op0, m_OneUse(m_Xor(m_Value(X), m_APInt(XorC))))) {
- // (X ^ C1) & C2 --> (X & C2) ^ (C1&C2)
- Constant *NewC = ConstantInt::get(Ty, *C & *XorC);
- Value *And = Builder.CreateAnd(X, Op1);
- And->takeName(Op0);
- return BinaryOperator::CreateXor(And, NewC);
- }
-
- const APInt *OrC;
- if (match(Op0, m_OneUse(m_Or(m_Value(X), m_APInt(OrC))))) {
- // (X | C1) & C2 --> (X & C2^(C1&C2)) | (C1&C2)
- // NOTE: This reduces the number of bits set in the & mask, which
- // can expose opportunities for store narrowing for scalars.
- // NOTE: SimplifyDemandedBits should have already removed bits from C1
- // that aren't set in C2. Meaning we can replace (C1&C2) with C1 in
- // above, but this feels safer.
- APInt Together = *C & *OrC;
- Value *And = Builder.CreateAnd(X, ConstantInt::get(Ty, Together ^ *C));
- And->takeName(Op0);
- return BinaryOperator::CreateOr(And, ConstantInt::get(Ty, Together));
- }
-
- unsigned Width = Ty->getScalarSizeInBits();
- const APInt *ShiftC;
- if (match(Op0, m_OneUse(m_SExt(m_AShr(m_Value(X), m_APInt(ShiftC))))) &&
- ShiftC->ult(Width)) {
- if (*C == APInt::getLowBitsSet(Width, Width - ShiftC->getZExtValue())) {
- // We are clearing high bits that were potentially set by sext+ashr:
- // and (sext (ashr X, ShiftC)), C --> lshr (sext X), ShiftC
- Value *Sext = Builder.CreateSExt(X, Ty);
- Constant *ShAmtC = ConstantInt::get(Ty, ShiftC->zext(Width));
- return BinaryOperator::CreateLShr(Sext, ShAmtC);
- }
- }
-
- // If this 'and' clears the sign-bits added by ashr, replace with lshr:
- // and (ashr X, ShiftC), C --> lshr X, ShiftC
- if (match(Op0, m_AShr(m_Value(X), m_APInt(ShiftC))) && ShiftC->ult(Width) &&
- C->isMask(Width - ShiftC->getZExtValue()))
- return BinaryOperator::CreateLShr(X, ConstantInt::get(Ty, *ShiftC));
-
- const APInt *AddC;
- if (match(Op0, m_Add(m_Value(X), m_APInt(AddC)))) {
- // If we are masking the result of the add down to exactly one bit and
- // the constant we are adding has no bits set below that bit, then the
- // add is flipping a single bit. Example:
- // (X + 4) & 4 --> (X & 4) ^ 4
- if (Op0->hasOneUse() && C->isPowerOf2() && (*AddC & (*C - 1)) == 0) {
- assert((*C & *AddC) != 0 && "Expected common bit");
- Value *NewAnd = Builder.CreateAnd(X, Op1);
- return BinaryOperator::CreateXor(NewAnd, Op1);
- }
- }
-
- // ((C1 OP zext(X)) & C2) -> zext((C1 OP X) & C2) if C2 fits in the
- // bitwidth of X and OP behaves well when given trunc(C1) and X.
- auto isNarrowableBinOpcode = [](BinaryOperator *B) {
- switch (B->getOpcode()) {
- case Instruction::Xor:
- case Instruction::Or:
- case Instruction::Mul:
- case Instruction::Add:
- case Instruction::Sub:
- return true;
- default:
- return false;
- }
- };
- BinaryOperator *BO;
- if (match(Op0, m_OneUse(m_BinOp(BO))) && isNarrowableBinOpcode(BO)) {
- Instruction::BinaryOps BOpcode = BO->getOpcode();
- Value *X;
- const APInt *C1;
- // TODO: The one-use restrictions could be relaxed a little if the AND
- // is going to be removed.
- // Try to narrow the 'and' and a binop with constant operand:
- // and (bo (zext X), C1), C --> zext (and (bo X, TruncC1), TruncC)
- if (match(BO, m_c_BinOp(m_OneUse(m_ZExt(m_Value(X))), m_APInt(C1))) &&
- C->isIntN(X->getType()->getScalarSizeInBits())) {
- unsigned XWidth = X->getType()->getScalarSizeInBits();
- Constant *TruncC1 = ConstantInt::get(X->getType(), C1->trunc(XWidth));
- Value *BinOp = isa<ZExtInst>(BO->getOperand(0))
- ? Builder.CreateBinOp(BOpcode, X, TruncC1)
- : Builder.CreateBinOp(BOpcode, TruncC1, X);
- Constant *TruncC = ConstantInt::get(X->getType(), C->trunc(XWidth));
- Value *And = Builder.CreateAnd(BinOp, TruncC);
- return new ZExtInst(And, Ty);
- }
-
- // Similar to above: if the mask matches the zext input width, then the
- // 'and' can be eliminated, so we can truncate the other variable op:
- // and (bo (zext X), Y), C --> zext (bo X, (trunc Y))
- if (isa<Instruction>(BO->getOperand(0)) &&
- match(BO->getOperand(0), m_OneUse(m_ZExt(m_Value(X)))) &&
- C->isMask(X->getType()->getScalarSizeInBits())) {
- Y = BO->getOperand(1);
- Value *TrY = Builder.CreateTrunc(Y, X->getType(), Y->getName() + ".tr");
- Value *NewBO =
- Builder.CreateBinOp(BOpcode, X, TrY, BO->getName() + ".narrow");
- return new ZExtInst(NewBO, Ty);
- }
- // and (bo Y, (zext X)), C --> zext (bo (trunc Y), X)
- if (isa<Instruction>(BO->getOperand(1)) &&
- match(BO->getOperand(1), m_OneUse(m_ZExt(m_Value(X)))) &&
- C->isMask(X->getType()->getScalarSizeInBits())) {
- Y = BO->getOperand(0);
- Value *TrY = Builder.CreateTrunc(Y, X->getType(), Y->getName() + ".tr");
- Value *NewBO =
- Builder.CreateBinOp(BOpcode, TrY, X, BO->getName() + ".narrow");
- return new ZExtInst(NewBO, Ty);
- }
- }
-
- // This is intentionally placed after the narrowing transforms for
- // efficiency (transform directly to the narrow logic op if possible).
- // If the mask is only needed on one incoming arm, push the 'and' op up.
- if (match(Op0, m_OneUse(m_Xor(m_Value(X), m_Value(Y)))) ||
- match(Op0, m_OneUse(m_Or(m_Value(X), m_Value(Y))))) {
- APInt NotAndMask(~(*C));
- BinaryOperator::BinaryOps BinOp = cast<BinaryOperator>(Op0)->getOpcode();
- if (MaskedValueIsZero(X, NotAndMask, 0, &I)) {
- // Not masking anything out for the LHS, move mask to RHS.
- // and ({x}or X, Y), C --> {x}or X, (and Y, C)
- Value *NewRHS = Builder.CreateAnd(Y, Op1, Y->getName() + ".masked");
- return BinaryOperator::Create(BinOp, X, NewRHS);
- }
- if (!isa<Constant>(Y) && MaskedValueIsZero(Y, NotAndMask, 0, &I)) {
- // Not masking anything out for the RHS, move mask to LHS.
- // and ({x}or X, Y), C --> {x}or (and X, C), Y
- Value *NewLHS = Builder.CreateAnd(X, Op1, X->getName() + ".masked");
- return BinaryOperator::Create(BinOp, NewLHS, Y);
- }
- }
-
- // When the mask is a power-of-2 constant and op0 is a shifted-power-of-2
- // constant, test if the shift amount equals the offset bit index:
- // (ShiftC << X) & C --> X == (log2(C) - log2(ShiftC)) ? C : 0
- // (ShiftC >> X) & C --> X == (log2(ShiftC) - log2(C)) ? C : 0
- if (C->isPowerOf2() &&
- match(Op0, m_OneUse(m_LogicalShift(m_Power2(ShiftC), m_Value(X))))) {
- int Log2ShiftC = ShiftC->exactLogBase2();
- int Log2C = C->exactLogBase2();
- bool IsShiftLeft =
- cast<BinaryOperator>(Op0)->getOpcode() == Instruction::Shl;
- int BitNum = IsShiftLeft ? Log2C - Log2ShiftC : Log2ShiftC - Log2C;
- assert(BitNum >= 0 && "Expected demanded bits to handle impossible mask");
- Value *Cmp = Builder.CreateICmpEQ(X, ConstantInt::get(Ty, BitNum));
- return SelectInst::Create(Cmp, ConstantInt::get(Ty, *C),
- ConstantInt::getNullValue(Ty));
- }
-
- Constant *C1, *C2;
- const APInt *C3 = C;
- Value *X;
- if (C3->isPowerOf2()) {
- Constant *Log2C3 = ConstantInt::get(Ty, C3->countr_zero());
- if (match(Op0, m_OneUse(m_LShr(m_Shl(m_ImmConstant(C1), m_Value(X)),
- m_ImmConstant(C2)))) &&
- match(C1, m_Power2())) {
- Constant *Log2C1 = ConstantExpr::getExactLogBase2(C1);
- Constant *LshrC = ConstantExpr::getAdd(C2, Log2C3);
- KnownBits KnownLShrc = computeKnownBits(LshrC, 0, nullptr);
- if (KnownLShrc.getMaxValue().ult(Width)) {
- // iff C1,C3 is pow2 and C2 + cttz(C3) < BitWidth:
- // ((C1 << X) >> C2) & C3 -> X == (cttz(C3)+C2-cttz(C1)) ? C3 : 0
- Constant *CmpC = ConstantExpr::getSub(LshrC, Log2C1);
- Value *Cmp = Builder.CreateICmpEQ(X, CmpC);
- return SelectInst::Create(Cmp, ConstantInt::get(Ty, *C3),
- ConstantInt::getNullValue(Ty));
- }
- }
-
- if (match(Op0, m_OneUse(m_Shl(m_LShr(m_ImmConstant(C1), m_Value(X)),
- m_ImmConstant(C2)))) &&
- match(C1, m_Power2())) {
- Constant *Log2C1 = ConstantExpr::getExactLogBase2(C1);
- Constant *Cmp =
- ConstantFoldCompareInstOperands(ICmpInst::ICMP_ULT, Log2C3, C2, DL);
- if (Cmp && Cmp->isZeroValue()) {
- // iff C1,C3 is pow2 and Log2(C3) >= C2:
- // ((C1 >> X) << C2) & C3 -> X == (cttz(C1)+C2-cttz(C3)) ? C3 : 0
- Constant *ShlC = ConstantExpr::getAdd(C2, Log2C1);
- Constant *CmpC = ConstantExpr::getSub(ShlC, Log2C3);
- Value *Cmp = Builder.CreateICmpEQ(X, CmpC);
- return SelectInst::Create(Cmp, ConstantInt::get(Ty, *C3),
- ConstantInt::getNullValue(Ty));
- }
- }
- }
- }
-
- // If we are clearing the sign bit of a floating-point value, convert this to
- // fabs, then cast back to integer.
- //
- // This is a generous interpretation for noimplicitfloat, this is not a true
- // floating-point operation.
- //
- // Assumes any IEEE-represented type has the sign bit in the high bit.
- // TODO: Unify with APInt matcher. This version allows undef unlike m_APInt
- Value *CastOp;
- if (match(Op0, m_ElementWiseBitCast(m_Value(CastOp))) &&
- match(Op1, m_MaxSignedValue()) &&
- !Builder.GetInsertBlock()->getParent()->hasFnAttribute(
- Attribute::NoImplicitFloat)) {
- Type *EltTy = CastOp->getType()->getScalarType();
- if (EltTy->isFloatingPointTy() && EltTy->isIEEE()) {
- Value *FAbs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, CastOp);
- return new BitCastInst(FAbs, I.getType());
- }
- }
-
- // and(shl(zext(X), Y), SignMask) -> and(sext(X), SignMask)
- // where Y is a valid shift amount.
- if (match(&I, m_And(m_OneUse(m_Shl(m_ZExt(m_Value(X)), m_Value(Y))),
- m_SignMask())) &&
- match(Y, m_SpecificInt_ICMP(
- ICmpInst::Predicate::ICMP_EQ,
- APInt(Ty->getScalarSizeInBits(),
- Ty->getScalarSizeInBits() -
- X->getType()->getScalarSizeInBits())))) {
- auto *SExt = Builder.CreateSExt(X, Ty, X->getName() + ".signext");
- return BinaryOperator::CreateAnd(SExt, Op1);
- }
-
- if (Instruction *Z = narrowMaskedBinOp(I))
- return Z;
-
- if (I.getType()->isIntOrIntVectorTy(1)) {
- if (auto *SI0 = dyn_cast<SelectInst>(Op0)) {
- if (auto *R =
- foldAndOrOfSelectUsingImpliedCond(Op1, *SI0, /* IsAnd */ true))
- return R;
- }
- if (auto *SI1 = dyn_cast<SelectInst>(Op1)) {
- if (auto *R =
- foldAndOrOfSelectUsingImpliedCond(Op0, *SI1, /* IsAnd */ true))
- return R;
- }
- }
-
- if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
- return FoldedLogic;
-
- if (Instruction *DeMorgan = matchDeMorgansLaws(I, *this))
- return DeMorgan;
-
- {
- Value *A, *B, *C;
- // A & ~(A ^ B) --> A & B
- if (match(Op1, m_Not(m_c_Xor(m_Specific(Op0), m_Value(B)))))
- return BinaryOperator::CreateAnd(Op0, B);
- // ~(A ^ B) & A --> A & B
- if (match(Op0, m_Not(m_c_Xor(m_Specific(Op1), m_Value(B)))))
- return BinaryOperator::CreateAnd(Op1, B);
-
- // (A ^ B) & ((B ^ C) ^ A) -> (A ^ B) & ~C
- if (match(Op0, m_Xor(m_Value(A), m_Value(B))) &&
- match(Op1, m_Xor(m_Xor(m_Specific(B), m_Value(C)), m_Specific(A)))) {
- Value *NotC = Op1->hasOneUse()
- ? Builder.CreateNot(C)
- : getFreelyInverted(C, C->hasOneUse(), &Builder);
- if (NotC != nullptr)
- return BinaryOperator::CreateAnd(Op0, NotC);
- }
-
- // ((A ^ C) ^ B) & (B ^ A) -> (B ^ A) & ~C
- if (match(Op0, m_Xor(m_Xor(m_Value(A), m_Value(C)), m_Value(B))) &&
- match(Op1, m_Xor(m_Specific(B), m_Specific(A)))) {
- Value *NotC = Op0->hasOneUse()
- ? Builder.CreateNot(C)
- : getFreelyInverted(C, C->hasOneUse(), &Builder);
- if (NotC != nullptr)
- return BinaryOperator::CreateAnd(Op1, Builder.CreateNot(C));
- }
-
- // (A | B) & (~A ^ B) -> A & B
- // (A | B) & (B ^ ~A) -> A & B
- // (B | A) & (~A ^ B) -> A & B
- // (B | A) & (B ^ ~A) -> A & B
- if (match(Op1, m_c_Xor(m_Not(m_Value(A)), m_Value(B))) &&
- match(Op0, m_c_Or(m_Specific(A), m_Specific(B))))
- return BinaryOperator::CreateAnd(A, B);
-
- // (~A ^ B) & (A | B) -> A & B
- // (~A ^ B) & (B | A) -> A & B
- // (B ^ ~A) & (A | B) -> A & B
- // (B ^ ~A) & (B | A) -> A & B
- if (match(Op0, m_c_Xor(m_Not(m_Value(A)), m_Value(B))) &&
- match(Op1, m_c_Or(m_Specific(A), m_Specific(B))))
- return BinaryOperator::CreateAnd(A, B);
-
- // (~A | B) & (A ^ B) -> ~A & B
- // (~A | B) & (B ^ A) -> ~A & B
- // (B | ~A) & (A ^ B) -> ~A & B
- // (B | ~A) & (B ^ A) -> ~A & B
- if (match(Op0, m_c_Or(m_Not(m_Value(A)), m_Value(B))) &&
- match(Op1, m_c_Xor(m_Specific(A), m_Specific(B))))
- return BinaryOperator::CreateAnd(Builder.CreateNot(A), B);
-
- // (A ^ B) & (~A | B) -> ~A & B
- // (B ^ A) & (~A | B) -> ~A & B
- // (A ^ B) & (B | ~A) -> ~A & B
- // (B ^ A) & (B | ~A) -> ~A & B
- if (match(Op1, m_c_Or(m_Not(m_Value(A)), m_Value(B))) &&
- match(Op0, m_c_Xor(m_Specific(A), m_Specific(B))))
- return BinaryOperator::CreateAnd(Builder.CreateNot(A), B);
- }
-
- if (Value *Res =
- foldBooleanAndOr(Op0, Op1, I, /*IsAnd=*/true, /*IsLogical=*/false))
- return replaceInstUsesWith(I, Res);
-
- if (match(Op1, m_OneUse(m_LogicalAnd(m_Value(X), m_Value(Y))))) {
- bool IsLogical = isa<SelectInst>(Op1);
- if (auto *V = reassociateBooleanAndOr(Op0, X, Y, I, /*IsAnd=*/true,
- /*RHSIsLogical=*/IsLogical))
- return replaceInstUsesWith(I, V);
- }
- if (match(Op0, m_OneUse(m_LogicalAnd(m_Value(X), m_Value(Y))))) {
- bool IsLogical = isa<SelectInst>(Op0);
- if (auto *V = reassociateBooleanAndOr(Op1, X, Y, I, /*IsAnd=*/true,
- /*RHSIsLogical=*/IsLogical))
- return replaceInstUsesWith(I, V);
- }
-
- if (Instruction *FoldedFCmps = reassociateFCmps(I, Builder))
- return FoldedFCmps;
-
- if (Instruction *CastedAnd = foldCastedBitwiseLogic(I))
- return CastedAnd;
-
- if (Instruction *Sel = foldBinopOfSextBoolToSelect(I))
- return Sel;
-
- // and(sext(A), B) / and(B, sext(A)) --> A ? B : 0, where A is i1 or <N x i1>.
- // TODO: Move this into foldBinopOfSextBoolToSelect as a more generalized fold
- // with binop identity constant. But creating a select with non-constant
- // arm may not be reversible due to poison semantics. Is that a good
- // canonicalization?
- Value *A, *B;
- if (match(&I, m_c_And(m_SExt(m_Value(A)), m_Value(B))) &&
- A->getType()->isIntOrIntVectorTy(1))
- return SelectInst::Create(A, B, Constant::getNullValue(Ty));
-
- // Similarly, a 'not' of the bool translates to a swap of the select arms:
- // ~sext(A) & B / B & ~sext(A) --> A ? 0 : B
- if (match(&I, m_c_And(m_Not(m_SExt(m_Value(A))), m_Value(B))) &&
- A->getType()->isIntOrIntVectorTy(1))
- return SelectInst::Create(A, Constant::getNullValue(Ty), B);
-
- // and(zext(A), B) -> A ? (B & 1) : 0
- if (match(&I, m_c_And(m_OneUse(m_ZExt(m_Value(A))), m_Value(B))) &&
- A->getType()->isIntOrIntVectorTy(1))
- return SelectInst::Create(A, Builder.CreateAnd(B, ConstantInt::get(Ty, 1)),
- Constant::getNullValue(Ty));
-
- // (-1 + A) & B --> A ? 0 : B where A is 0/1.
- if (match(&I, m_c_And(m_OneUse(m_Add(m_ZExtOrSelf(m_Value(A)), m_AllOnes())),
- m_Value(B)))) {
- if (A->getType()->isIntOrIntVectorTy(1))
- return SelectInst::Create(A, Constant::getNullValue(Ty), B);
- if (computeKnownBits(A, /* Depth */ 0, &I).countMaxActiveBits() <= 1) {
- return SelectInst::Create(
- Builder.CreateICmpEQ(A, Constant::getNullValue(A->getType())), B,
- Constant::getNullValue(Ty));
- }
- }
-
- // (iN X s>> (N-1)) & Y --> (X s< 0) ? Y : 0 -- with optional sext
- if (match(&I, m_c_And(m_OneUse(m_SExtOrSelf(
- m_AShr(m_Value(X), m_APIntAllowPoison(C)))),
- m_Value(Y))) &&
- *C == X->getType()->getScalarSizeInBits() - 1) {
- Value *IsNeg = Builder.CreateIsNeg(X, "isneg");
- return SelectInst::Create(IsNeg, Y, ConstantInt::getNullValue(Ty));
- }
- // If there's a 'not' of the shifted value, swap the select operands:
- // ~(iN X s>> (N-1)) & Y --> (X s< 0) ? 0 : Y -- with optional sext
- if (match(&I, m_c_And(m_OneUse(m_SExtOrSelf(
- m_Not(m_AShr(m_Value(X), m_APIntAllowPoison(C))))),
- m_Value(Y))) &&
- *C == X->getType()->getScalarSizeInBits() - 1) {
- Value *IsNeg = Builder.CreateIsNeg(X, "isneg");
- return SelectInst::Create(IsNeg, ConstantInt::getNullValue(Ty), Y);
- }
-
- // (~x) & y --> ~(x | (~y)) iff that gets rid of inversions
- if (sinkNotIntoOtherHandOfLogicalOp(I))
- return &I;
-
- // An and recurrence w/loop invariant step is equivelent to (and start, step)
- PHINode *PN = nullptr;
- Value *Start = nullptr, *Step = nullptr;
- if (matchSimpleRecurrence(&I, PN, Start, Step) && DT.dominates(Step, PN))
- return replaceInstUsesWith(I, Builder.CreateAnd(Start, Step));
-
- if (Instruction *R = reassociateForUses(I, Builder))
- return R;
-
- if (Instruction *Canonicalized = canonicalizeLogicFirst(I, Builder))
- return Canonicalized;
-
- if (Instruction *Folded = foldLogicOfIsFPClass(I, Op0, Op1))
- return Folded;
-
- if (Instruction *Res = foldBinOpOfDisplacedShifts(I))
- return Res;
-
- if (Instruction *Res = foldBitwiseLogicWithIntrinsics(I, Builder))
- return Res;
-
- if (Value *V =
- simplifyAndOrWithOpReplaced(Op0, Op1, Constant::getAllOnesValue(Ty),
- /*SimplifyOnly*/ false, *this))
- return BinaryOperator::CreateAnd(V, Op1);
- if (Value *V =
- simplifyAndOrWithOpReplaced(Op1, Op0, Constant::getAllOnesValue(Ty),
- /*SimplifyOnly*/ false, *this))
- return BinaryOperator::CreateAnd(Op0, V);
- // I is the 'and' instruction
-if (auto *Add = dyn_cast<BinaryOperator>(I.getOperand(0))) {
- if (Add->getOpcode() == Instruction::Add) {
- Value *LHS = Add->getOperand(0); // should be shl
- ConstantInt *AddConst = dyn_cast<ConstantInt>(Add->getOperand(1));
- ConstantInt *AndConst = dyn_cast<ConstantInt>(I.getOperand(1));
- if (AddConst && AndConst) {
- // check if AddConst is 47 and AndConst is -32
- if (AddConst->equalsInt(47) && AndConst->getSExtValue() == -32) {
- // Check if LHS is shl i64 %a, 5
- if (auto *Shl = dyn_cast<BinaryOperator>(LHS)) {
- if (Shl->getOpcode() == Instruction::Shl) {
- ConstantInt *ShlConst = dyn_cast<ConstantInt>(Shl->getOperand(1));
- if (ShlConst && ShlConst->equalsInt(5)) {
- // You've matched the pattern!
- // Replace with: shl i64 (add i64 %a, 1), 5
- IRBuilder<> Builder(&I);
- Value *NewAdd = Builder.CreateAdd(Shl->getOperand(0), ConstantInt::get(I.getType(), 1));
- Value *NewShl = Builder.CreateShl(NewAdd, ShlConst);
- I.replaceAllUsesWith(NewShl);
- }
- }
- }
- }
- }
- }
-}
- return nullptr;
-}
-
-Instruction *InstCombinerImpl::matchBSwapOrBitReverse(Instruction &I,
- bool MatchBSwaps,
- bool MatchBitReversals) {
- SmallVector<Instruction *, 4> Insts;
- if (!recognizeBSwapOrBitReverseIdiom(&I, MatchBSwaps, MatchBitReversals,
- Insts))
- return nullptr;
- Instruction *LastInst = Insts.pop_back_val();
- LastInst->removeFromParent();
-
- for (auto *Inst : Insts) {
- Inst->setDebugLoc(I.getDebugLoc());
- Worklist.push(Inst);
- }
- return LastInst;
-}
-
-std::optional<std::pair<Intrinsic::ID, SmallVector<Value *, 3>>>
-InstCombinerImpl::convertOrOfShiftsToFunnelShift(Instruction &Or) {
- // TODO: Can we reduce the code duplication between this and the related
- // rotate matching code under visitSelect and visitTrunc?
- assert(Or.getOpcode() == BinaryOperator::Or && "Expecting or instruction");
-
- unsigned Width = Or.getType()->getScalarSizeInBits();
-
- Instruction *Or0, *Or1;
- if (!match(Or.getOperand(0), m_Instruction(Or0)) ||
- !match(Or.getOperand(1), m_Instruction(Or1)))
- return std::nullopt;
-
- bool IsFshl = true; // Sub on LSHR.
- SmallVector<Value *, 3> FShiftArgs;
-
- // First, find an or'd pair of opposite shifts:
- // or (lshr ShVal0, ShAmt0), (shl ShVal1, ShAmt1)
- if (isa<BinaryOperator>(Or0) && isa<BinaryOperator>(Or1)) {
- Value *ShVal0, *ShVal1, *ShAmt0, *ShAmt1;
- if (!match(Or0,
- m_OneUse(m_LogicalShift(m_Value(ShVal0), m_Value(ShAmt0)))) ||
- !match(Or1,
- m_OneUse(m_LogicalShift(m_Value(ShVal1), m_Value(ShAmt1)))) ||
- Or0->getOpcode() == Or1->getOpcode())
- return std::nullopt;
-
- // Canonicalize to or(shl(ShVal0, ShAmt0), lshr(ShVal1, ShAmt1)).
- if (Or0->getOpcode() == BinaryOperator::LShr) {
- std::swap(Or0, Or1);
- std::swap(ShVal0, ShVal1);
- std::swap(ShAmt0, ShAmt1);
- }
- assert(Or0->getOpcode() == BinaryOperator::Shl &&
- Or1->getOpcode() == BinaryOperator::LShr &&
- "Illegal or(shift,shift) pair");
-
- // Match the shift amount operands for a funnel shift pattern. This always
- // matches a subtraction on the R operand.
- auto matchShiftAmount = [&](Value *L, Value *R, unsigned Width) -> Value * {
- // Check for constant shift amounts that sum to the bitwidth.
- const APInt *LI, *RI;
- if (match(L, m_APIntAllowPoison(LI)) && match(R, m_APIntAllowPoison(RI)))
- if (LI->ult(Width) && RI->ult(Width) && (*LI + *RI) == Width)
- return ConstantInt::get(L->getType(), *LI);
-
- Constant *LC, *RC;
- if (match(L, m_Constant(LC)) && match(R, m_Constant(RC)) &&
- match(L,
- m_SpecificInt_ICMP(ICmpInst::ICMP_ULT, APInt(Width, Width))) &&
- match(R,
- m_SpecificInt_ICMP(ICmpInst::ICMP_ULT, APInt(Width, Width))) &&
- match(ConstantExpr::getAdd(LC, RC), m_SpecificIntAllowPoison(Width)))
- return ConstantExpr::mergeUndefsWith(LC, RC);
-
- // (shl ShVal, X) | (lshr ShVal, (Width - x)) iff X < Width.
- // We limit this to X < Width in case the backend re-expands the
- // intrinsic, and has to reintroduce a shift modulo operation (InstCombine
- // might remove it after this fold). This still doesn't guarantee that the
- // final codegen will match this original pattern.
- if (match(R, m_OneUse(m_Sub(m_SpecificInt(Width), m_Specific(L))))) {
- KnownBits KnownL = computeKnownBits(L, /*Depth*/ 0, &Or);
- return KnownL.getMaxValue().ult(Width) ? L : nullptr;
- }
-
- // For non-constant cases, the following patterns currently only work for
- // rotation patterns.
- // TODO: Add general funnel-shift compatible patterns.
- if (ShVal0 != ShVal1)
- return nullptr;
-
- // For non-constant cases we don't support non-pow2 shift masks.
- // TODO: Is it worth matching urem as well?
- if (!isPowerOf2_32(Width))
- return nullptr;
-
- // The shift amount may be masked with negation:
- // (shl ShVal, (X & (Width - 1))) | (lshr ShVal, ((-X) & (Width - 1)))
- Value *X;
- unsigned Mask = Width - 1;
- if (match(L, m_And(m_Value(X), m_SpecificInt(Mask))) &&
- match(R, m_And(m_Neg(m_Specific(X)), m_SpecificInt(Mask))))
- return X;
-
- // (shl ShVal, X) | (lshr ShVal, ((-X) & (Width - 1)))
- if (match(R, m_And(m_Neg(m_Specific(L)), m_SpecificInt(Mask))))
- return L;
-
- // Similar to above, but the shift amount may be extended after masking,
- // so return the extended value as the parameter for the intrinsic.
- if (match(L, m_ZExt(m_And(m_Value(X), m_SpecificInt(Mask)))) &&
- match(R,
- m_And(m_Neg(m_ZExt(m_And(m_Specific(X), m_SpecificInt(Mask)))),
- m_SpecificInt(Mask))))
- return L;
-
- if (match(L, m_ZExt(m_And(m_Value(X), m_SpecificInt(Mask)))) &&
- match(R, m_ZExt(m_And(m_Neg(m_Specific(X)), m_SpecificInt(Mask)))))
- return L;
-
- return nullptr;
- };
-
- Value *ShAmt = matchShiftAmount(ShAmt0, ShAmt1, Width);
- if (!ShAmt) {
- ShAmt = matchShiftAmount(ShAmt1, ShAmt0, Width);
- IsFshl = false; // Sub on SHL.
- }
- if (!ShAmt)
- return std::nullopt;
-
- FShiftArgs = {ShVal0, ShVal1, ShAmt};
- } else if (isa<ZExtInst>(Or0) || isa<ZExtInst>(Or1)) {
- // If there are two 'or' instructions concat variables in opposite order:
- //
- // Slot1 and Slot2 are all zero bits.
- // | Slot1 | Low | Slot2 | High |
- // LowHigh = or (shl (zext Low), ZextLowShlAmt), (zext High)
- // | Slot2 | High | Slot1 | Low |
- // HighLow = or (shl (zext High), ZextHighShlAmt), (zext Low)
- //
- // the latter 'or' can be safely convert to
- // -> HighLow = fshl LowHigh, LowHigh, ZextHighShlAmt
- // if ZextLowShlAmt + ZextHighShlAmt == Width.
- if (!isa<ZExtInst>(Or1))
- std::swap(Or0, Or1);
-
- Value *High, *ZextHigh, *Low;
- const APInt *ZextHighShlAmt;
- if (!match(Or0,
- m_OneUse(m_Shl(m_Value(ZextHigh), m_APInt(ZextHighShlAmt)))))
- return std::nullopt;
-
- if (!match(Or1, m_ZExt(m_Value(Low))) ||
- !match(ZextHigh, m_ZExt(m_Value(High))))
- return std::nullopt;
-
- unsigned HighSize = High->getType()->getScalarSizeInBits();
- unsigned LowSize = Low->getType()->getScalarSizeInBits();
- // Make sure High does not overlap with Low and most significant bits of
- // High aren't shifted out.
- if (ZextHighShlAmt->ult(LowSize) || ZextHighShlAmt->ugt(Width - HighSize))
- return std::nullopt;
-
- for (User *U : ZextHigh->users()) {
- Value *X, *Y;
- if (!match(U, m_Or(m_Value(X), m_Value(Y))))
- continue;
-
- if (!isa<ZExtInst>(Y))
- std::swap(X, Y);
-
- const APInt *ZextLowShlAmt;
- if (!match(X, m_Shl(m_Specific(Or1), m_APInt(ZextLowShlAmt))) ||
- !match(Y, m_Specific(ZextHigh)) || !DT.dominates(U, &Or))
- continue;
-
- // HighLow is good concat. If sum of two shifts amount equals to Width,
- // LowHigh must also be a good concat.
- if (*ZextLowShlAmt + *ZextHighShlAmt != Width)
- continue;
-
- // Low must not overlap with High and most significant bits of Low must
- // not be shifted out.
- assert(ZextLowShlAmt->uge(HighSize) &&
- ZextLowShlAmt->ule(Width - LowSize) && "Invalid concat");
-
- FShiftArgs = {U, U, ConstantInt::get(Or0->getType(), *ZextHighShlAmt)};
- break;
- }
- }
-
- if (FShiftArgs.empty())
- return std::nullopt;
-
- Intrinsic::ID IID = IsFshl ? Intrinsic::fshl : Intrinsic::fshr;
- return std::make_pair(IID, FShiftArgs);
-}
-
-/// Match UB-safe variants of the funnel shift intrinsic.
-static Instruction *matchFunnelShift(Instruction &Or, InstCombinerImpl &IC) {
- if (auto Opt = IC.convertOrOfShiftsToFunnelShift(Or)) {
- auto [IID, FShiftArgs] = *Opt;
- Function *F =
- Intrinsic::getOrInsertDeclaration(Or.getModule(), IID, Or.getType());
- return CallInst::Create(F, FShiftArgs);
- }
-
- return nullptr;
-}
-
-/// Attempt to combine or(zext(x),shl(zext(y),bw/2) concat packing patterns.
-static Instruction *matchOrConcat(Instruction &Or,
- InstCombiner::BuilderTy &Builder) {
- assert(Or.getOpcode() == Instruction::Or && "bswap requires an 'or'");
- Value *Op0 = Or.getOperand(0), *Op1 = Or.getOperand(1);
- Type *Ty = Or.getType();
-
- unsigned Width = Ty->getScalarSizeInBits();
- if ((Width & 1) != 0)
- return nullptr;
- unsigned HalfWidth = Width / 2;
-
- // Canonicalize zext (lower half) to LHS.
- if (!isa<ZExtInst>(Op0))
- std::swap(Op0, Op1);
-
- // Find lower/upper half.
- Value *LowerSrc, *ShlVal, *UpperSrc;
- const APInt *C;
- if (!match(Op0, m_OneUse(m_ZExt(m_Value(LowerSrc)))) ||
- !match(Op1, m_OneUse(m_Shl(m_Value(ShlVal), m_APInt(C)))) ||
- !match(ShlVal, m_OneUse(m_ZExt(m_Value(UpperSrc)))))
- return nullptr;
- if (*C != HalfWidth || LowerSrc->getType() != UpperSrc->getType() ||
- LowerSrc->getType()->getScalarSizeInBits() != HalfWidth)
- return nullptr;
-
- auto ConcatIntrinsicCalls = [&](Intrinsic::ID id, Value *Lo, Value *Hi) {
- Value *NewLower = Builder.CreateZExt(Lo, Ty);
- Value *NewUpper = Builder.CreateZExt(Hi, Ty);
- NewUpper = Builder.CreateShl(NewUpper, HalfWidth);
- Value *BinOp = Builder.CreateOr(NewLower, NewUpper);
- return Builder.CreateIntrinsic(id, Ty, BinOp);
- };
-
- // BSWAP: Push the concat down, swapping the lower/upper sources.
- // concat(bswap(x),bswap(y)) -> bswap(concat(x,y))
- Value *LowerBSwap, *UpperBSwap;
- if (match(LowerSrc, m_BSwap(m_Value(LowerBSwap))) &&
- match(UpperSrc, m_BSwap(m_Value(UpperBSwap))))
- return ConcatIntrinsicCalls(Intrinsic::bswap, UpperBSwap, LowerBSwap);
-
- // BITREVERSE: Push the concat down, swapping the lower/upper sources.
- // concat(bitreverse(x),bitreverse(y)) -> bitreverse(concat(x,y))
- Value *LowerBRev, *UpperBRev;
- if (match(LowerSrc, m_BitReverse(m_Value(LowerBRev))) &&
- match(UpperSrc, m_BitReverse(m_Value(UpperBRev))))
- return ConcatIntrinsicCalls(Intrinsic::bitreverse, UpperBRev, LowerBRev);
-
- return nullptr;
-}
-
-/// If all elements of two constant vectors are 0/-1 and inverses, return true.
-static bool areInverseVectorBitmasks(Constant *C1, Constant *C2) {
- unsigned NumElts = cast<FixedVectorType>(C1->getType())->getNumElements();
- for (unsigned i = 0; i != NumElts; ++i) {
- Constant *EltC1 = C1->getAggregateElement(i);
- Constant *EltC2 = C2->getAggregateElement(i);
- if (!EltC1 || !EltC2)
- return false;
-
- // One element must be all ones, and the other must be all zeros.
- if (!((match(EltC1, m_Zero()) && match(EltC2, m_AllOnes())) ||
- (match(EltC2, m_Zero()) && match(EltC1, m_AllOnes()))))
- return false;
- }
- return true;
-}
-
-/// We have an expression of the form (A & C) | (B & D). If A is a scalar or
-/// vector composed of all-zeros or all-ones values and is the bitwise 'not' of
-/// B, it can be used as the condition operand of a select instruction.
-/// We will detect (A & C) | ~(B | D) when the flag ABIsTheSame enabled.
-Value *InstCombinerImpl::getSelectCondition(Value *A, Value *B,
- bool ABIsTheSame) {
- // We may have peeked through bitcasts in the caller.
- // Exit immediately if we don't have (vector) integer types.
- Type *Ty = A->getType();
- if (!Ty->isIntOrIntVectorTy() || !B->getType()->isIntOrIntVectorTy())
- return nullptr;
-
- // If A is the 'not' operand of B and has enough signbits, we have our answer.
- if (ABIsTheSame ? (A == B) : match(B, m_Not(m_Specific(A)))) {
- // If these are scalars or vectors of i1, A can be used directly.
- if (Ty->isIntOrIntVectorTy(1))
- return A;
-
- // If we look through a vector bitcast, the caller will bitcast the operands
- // to match the condition's number of bits (N x i1).
- // To make this poison-safe, disallow bitcast from wide element to narrow
- // element. That could allow poison in lanes where it was not present in the
- // original code.
- A = peekThroughBitcast(A);
- if (A->getType()->isIntOrIntVectorTy()) {
- unsigned NumSignBits = ComputeNumSignBits(A);
- if (NumSignBits == A->getType()->getScalarSizeInBits() &&
- NumSignBits <= Ty->getScalarSizeInBits())
- return Builder.CreateTrunc(A, CmpInst::makeCmpResultType(A->getType()));
- }
- return nullptr;
- }
-
- // TODO: add support for sext and constant case
- if (ABIsTheSame)
- return nullptr;
-
- // If both operands are constants, see if the constants are inverse bitmasks.
- Constant *AConst, *BConst;
- if (match(A, m_Constant(AConst)) && match(B, m_Constant(BConst)))
- if (AConst == ConstantExpr::getNot(BConst) &&
- ComputeNumSignBits(A) == Ty->getScalarSizeInBits())
- return Builder.CreateZExtOrTrunc(A, CmpInst::makeCmpResultType(Ty));
-
- // Look for more complex patterns. The 'not' op may be hidden behind various
- // casts. Look through sexts and bitcasts to find the booleans.
- Value *Cond;
- Value *NotB;
- if (match(A, m_SExt(m_Value(Cond))) &&
- Cond->getType()->isIntOrIntVectorTy(1)) {
- // A = sext i1 Cond; B = sext (not (i1 Cond))
- if (match(B, m_SExt(m_Not(m_Specific(Cond)))))
- return Cond;
-
- // A = sext i1 Cond; B = not ({bitcast} (sext (i1 Cond)))
- // TODO: The one-use checks are unnecessary or misplaced. If the caller
- // checked for uses on logic ops/casts, that should be enough to
- // make this transform worthwhile.
- if (match(B, m_OneUse(m_Not(m_Value(NotB))))) {
- NotB = peekThroughBitcast(NotB, true);
- if (match(NotB, m_SExt(m_Specific(Cond))))
- return Cond;
- }
- }
-
- // All scalar (and most vector) possibilities should be handled now.
- // Try more matches that only apply to non-splat constant vectors.
- if (!Ty->isVectorTy())
- return nullptr;
-
- // If both operands are xor'd with constants using the same sexted boolean
- // operand, see if the constants are inverse bitmasks.
- // TODO: Use ConstantExpr::getNot()?
- if (match(A, (m_Xor(m_SExt(m_Value(Cond)), m_Constant(AConst)))) &&
- match(B, (m_Xor(m_SExt(m_Specific(Cond)), m_Constant(BConst)))) &&
- Cond->getType()->isIntOrIntVectorTy(1) &&
- areInverseVectorBitmasks(AConst, BConst)) {
- AConst = ConstantExpr::getTrunc(AConst, CmpInst::makeCmpResultType(Ty));
- return Builder.CreateXor(Cond, AConst);
- }
- return nullptr;
-}
-
-/// We have an expression of the form (A & B) | (C & D). Try to simplify this
-/// to "A' ? B : D", where A' is a boolean or vector of booleans.
-/// When InvertFalseVal is set to true, we try to match the pattern
-/// where we have peeked through a 'not' op and A and C are the same:
-/// (A & B) | ~(A | D) --> (A & B) | (~A & ~D) --> A' ? B : ~D
-Value *InstCombinerImpl::matchSelectFromAndOr(Value *A, Value *B, Value *C,
- Value *D, bool InvertFalseVal) {
- // The potential condition of the select may be bitcasted. In that case, look
- // through its bitcast and the corresponding bitcast of the 'not' condition.
- Type *OrigType = A->getType();
- A = peekThroughBitcast(A, true);
- C = peekThroughBitcast(C, true);
- if (Value *Cond = getSelectCondition(A, C, InvertFalseVal)) {
- // ((bc Cond) & B) | ((bc ~Cond) & D) --> bc (select Cond, (bc B), (bc D))
- // If this is a vector, we may need to cast to match the condition's length.
- // The bitcasts will either all exist or all not exist. The builder will
- // not create unnecessary casts if the types already match.
- Type *SelTy = A->getType();
- if (auto *VecTy = dyn_cast<VectorType>(Cond->getType())) {
- // For a fixed or scalable vector get N from <{vscale x} N x iM>
- unsigned Elts = VecTy->getElementCount().getKnownMinValue();
- // For a fixed or scalable vector, get the size in bits of N x iM; for a
- // scalar this is just M.
- unsigned SelEltSize = SelTy->getPrimitiveSizeInBits().getKnownMinValue();
- Type *EltTy = Builder.getIntNTy(SelEltSize / Elts);
- SelTy = VectorType::get(EltTy, VecTy->getElementCount());
- }
- Value *BitcastB = Builder.CreateBitCast(B, SelTy);
- if (InvertFalseVal)
- D = Builder.CreateNot(D);
- Value *BitcastD = Builder.CreateBitCast(D, SelTy);
- Value *Select = Builder.CreateSelect(Cond, BitcastB, BitcastD);
- return Builder.CreateBitCast(Select, OrigType);
- }
-
- return nullptr;
-}
-
-// (icmp eq X, C) | (icmp ult Other, (X - C)) -> (icmp ule Other, (X - (C + 1)))
-// (icmp ne X, C) & (icmp uge Other, (X - C)) -> (icmp ugt Other, (X - (C + 1)))
-static Value *foldAndOrOfICmpEqConstantAndICmp(ICmpInst *LHS, ICmpInst *RHS,
- bool IsAnd, bool IsLogical,
- IRBuilderBase &Builder) {
- Value *LHS0 = LHS->getOperand(0);
- Value *RHS0 = RHS->getOperand(0);
- Value *RHS1 = RHS->getOperand(1);
-
- ICmpInst::Predicate LPred =
- IsAnd ? LHS->getInversePredicate() : LHS->getPredicate();
- ICmpInst::Predicate RPred =
- IsAnd ? RHS->getInversePredicate() : RHS->getPredicate();
-
- const APInt *CInt;
- if (LPred != ICmpInst::ICMP_EQ ||
- !match(LHS->getOperand(1), m_APIntAllowPoison(CInt)) ||
- !LHS0->getType()->isIntOrIntVectorTy() ||
- !(LHS->hasOneUse() || RHS->hasOneUse()))
- return nullptr;
-
- auto MatchRHSOp = [LHS0, CInt](const Value *RHSOp) {
- return match(RHSOp,
- m_Add(m_Specific(LHS0), m_SpecificIntAllowPoison(-*CInt))) ||
- (CInt->isZero() && RHSOp == LHS0);
- };
-
- Value *Other;
- if (RPred == ICmpInst::ICMP_ULT && MatchRHSOp(RHS1))
- Other = RHS0;
- else if (RPred == ICmpInst::ICMP_UGT && MatchRHSOp(RHS0))
- Other = RHS1;
- else
- return nullptr;
-
- if (IsLogical)
- Other = Builder.CreateFreeze(Other);
-
- return Builder.CreateICmp(
- IsAnd ? ICmpInst::ICMP_ULT : ICmpInst::ICMP_UGE,
- Builder.CreateSub(LHS0, ConstantInt::get(LHS0->getType(), *CInt + 1)),
- Other);
-}
-
-/// Fold (icmp)&(icmp) or (icmp)|(icmp) if possible.
-/// If IsLogical is true, then the and/or is in select form and the transform
-/// must be poison-safe.
-Value *InstCombinerImpl::foldAndOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
- Instruction &I, bool IsAnd,
- bool IsLogical) {
- const SimplifyQuery Q = SQ.getWithInstruction(&I);
-
- ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
- Value *LHS0 = LHS->getOperand(0), *RHS0 = RHS->getOperand(0);
- Value *LHS1 = LHS->getOperand(1), *RHS1 = RHS->getOperand(1);
-
- const APInt *LHSC = nullptr, *RHSC = nullptr;
- match(LHS1, m_APInt(LHSC));
- match(RHS1, m_APInt(RHSC));
-
- // (icmp1 A, B) | (icmp2 A, B) --> (icmp3 A, B)
- // (icmp1 A, B) & (icmp2 A, B) --> (icmp3 A, B)
- if (predicatesFoldable(PredL, PredR)) {
- if (LHS0 == RHS1 && LHS1 == RHS0) {
- PredL = ICmpInst::getSwappedPredicate(PredL);
- std::swap(LHS0, LHS1);
- }
- if (LHS0 == RHS0 && LHS1 == RHS1) {
- unsigned Code = IsAnd ? getICmpCode(PredL) & getICmpCode(PredR)
- : getICmpCode(PredL) | getICmpCode(PredR);
- bool IsSigned = LHS->isSigned() || RHS->isSigned();
- return getNewICmpValue(Code, IsSigned, LHS0, LHS1, Builder);
- }
- }
-
- // handle (roughly):
- // (icmp ne (A & B), C) | (icmp ne (A & D), E)
- // (icmp eq (A & B), C) & (icmp eq (A & D), E)
- if (Value *V = foldLogOpOfMaskedICmps(LHS, RHS, IsAnd, IsLogical, Builder, Q))
- return V;
-
- if (Value *V =
- foldAndOrOfICmpEqConstantAndICmp(LHS, RHS, IsAnd, IsLogical, Builder))
- return V;
- // We can treat logical like bitwise here, because both operands are used on
- // the LHS, and as such poison from both will propagate.
- if (Value *V = foldAndOrOfICmpEqConstantAndICmp(RHS, LHS, IsAnd,
- /*IsLogical*/ false, Builder))
- return V;
-
- if (Value *V =
- foldAndOrOfICmpsWithConstEq(LHS, RHS, IsAnd, IsLogical, Builder, Q))
- return V;
- // We can convert this case to bitwise and, because both operands are used
- // on the LHS, and as such poison from both will propagate.
- if (Value *V = foldAndOrOfICmpsWithConstEq(RHS, LHS, IsAnd,
- /*IsLogical=*/false, Builder, Q)) {
- // If RHS is still used, we should drop samesign flag.
- if (IsLogical && RHS->hasSameSign() && !RHS->use_empty()) {
- RHS->setSameSign(false);
- addToWorklist(RHS);
- }
- return V;
- }
-
- if (Value *V = foldIsPowerOf2OrZero(LHS, RHS, IsAnd, Builder, *this))
- return V;
- if (Value *V = foldIsPowerOf2OrZero(RHS, LHS, IsAnd, Builder, *this))
- return V;
-
- // TODO: One of these directions is fine with logical and/or, the other could
- // be supported by inserting freeze.
- if (!IsLogical) {
- // E.g. (icmp slt x, 0) | (icmp sgt x, n) --> icmp ugt x, n
- // E.g. (icmp sge x, 0) & (icmp slt x, n) --> icmp ult x, n
- if (Value *V = simplifyRangeCheck(LHS, RHS, /*Inverted=*/!IsAnd))
- return V;
-
- // E.g. (icmp sgt x, n) | (icmp slt x, 0) --> icmp ugt x, n
- // E.g. (icmp slt x, n) & (icmp sge x, 0) --> icmp ult x, n
- if (Value *V = simplifyRangeCheck(RHS, LHS, /*Inverted=*/!IsAnd))
- return V;
- }
-
- // TODO: Add conjugated or fold, check whether it is safe for logical and/or.
- if (IsAnd && !IsLogical)
- if (Value *V = foldSignedTruncationCheck(LHS, RHS, I, Builder))
- return V;
-
- if (Value *V = foldIsPowerOf2(LHS, RHS, IsAnd, Builder, *this))
- return V;
-
- if (Value *V = foldPowerOf2AndShiftedMask(LHS, RHS, IsAnd, Builder))
- return V;
-
- // TODO: Verify whether this is safe for logical and/or.
- if (!IsLogical) {
- if (Value *X = foldUnsignedUnderflowCheck(LHS, RHS, IsAnd, Q, Builder))
- return X;
- if (Value *X = foldUnsignedUnderflowCheck(RHS, LHS, IsAnd, Q, Builder))
- return X;
- }
-
- // (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0)
- // (icmp eq A, 0) & (icmp eq B, 0) --> (icmp eq (A|B), 0)
- // TODO: Remove this and below when foldLogOpOfMaskedICmps can handle undefs.
- if (PredL == (IsAnd ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE) &&
- PredL == PredR && match(LHS1, m_ZeroInt()) && match(RHS1, m_ZeroInt()) &&
- LHS0->getType() == RHS0->getType() &&
- (!IsLogical || isGuaranteedNotToBePoison(RHS0))) {
- Value *NewOr = Builder.CreateOr(LHS0, RHS0);
- return Builder.CreateICmp(PredL, NewOr,
- Constant::getNullValue(NewOr->getType()));
- }
-
- // (icmp ne A, -1) | (icmp ne B, -1) --> (icmp ne (A&B), -1)
- // (icmp eq A, -1) & (icmp eq B, -1) --> (icmp eq (A&B), -1)
- if (PredL == (IsAnd ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE) &&
- PredL == PredR && match(LHS1, m_AllOnes()) && match(RHS1, m_AllOnes()) &&
- LHS0->getType() == RHS0->getType() &&
- (!IsLogical || isGuaranteedNotToBePoison(RHS0))) {
- Value *NewAnd = Builder.CreateAnd(LHS0, RHS0);
- return Builder.CreateICmp(PredL, NewAnd,
- Constant::getAllOnesValue(LHS0->getType()));
- }
-
- if (!IsLogical)
- if (Value *V =
- foldAndOrOfICmpsWithPow2AndWithZero(Builder, LHS, RHS, IsAnd, Q))
- return V;
-
- // This only handles icmp of constants: (icmp1 A, C1) | (icmp2 B, C2).
- if (!LHSC || !RHSC)
- return nullptr;
-
- // (trunc x) == C1 & (and x, CA) == C2 -> (and x, CA|CMAX) == C1|C2
- // (trunc x) != C1 | (and x, CA) != C2 -> (and x, CA|CMAX) != C1|C2
- // where CMAX is the all ones value for the truncated type,
- // iff the lower bits of C2 and CA are zero.
- if (PredL == (IsAnd ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE) &&
- PredL == PredR && LHS->hasOneUse() && RHS->hasOneUse()) {
- Value *V;
- const APInt *AndC, *SmallC = nullptr, *BigC = nullptr;
-
- // (trunc x) == C1 & (and x, CA) == C2
- // (and x, CA) == C2 & (trunc x) == C1
- if (match(RHS0, m_Trunc(m_Value(V))) &&
- match(LHS0, m_And(m_Specific(V), m_APInt(AndC)))) {
- SmallC = RHSC;
- BigC = LHSC;
- } else if (match(LHS0, m_Trunc(m_Value(V))) &&
- match(RHS0, m_And(m_Specific(V), m_APInt(AndC)))) {
- SmallC = LHSC;
- BigC = RHSC;
- }
-
- if (SmallC && BigC) {
- unsigned BigBitSize = BigC->getBitWidth();
- unsigned SmallBitSize = SmallC->getBitWidth();
-
- // Check that the low bits are zero.
- APInt Low = APInt::getLowBitsSet(BigBitSize, SmallBitSize);
- if ((Low & *AndC).isZero() && (Low & *BigC).isZero()) {
- Value *NewAnd = Builder.CreateAnd(V, Low | *AndC);
- APInt N = SmallC->zext(BigBitSize) | *BigC;
- Value *NewVal = ConstantInt::get(NewAnd->getType(), N);
- return Builder.CreateICmp(PredL, NewAnd, NewVal);
- }
- }
- }
-
- // Match naive pattern (and its inverted form) for checking if two values
- // share same sign. An example of the pattern:
- // (icmp slt (X & Y), 0) | (icmp sgt (X | Y), -1) -> (icmp sgt (X ^ Y), -1)
- // Inverted form (example):
- // (icmp slt (X | Y), 0) & (icmp sgt (X & Y), -1) -> (icmp slt (X ^ Y), 0)
- bool TrueIfSignedL, TrueIfSignedR;
- if (isSignBitCheck(PredL, *LHSC, TrueIfSignedL) &&
- isSignBitCheck(PredR, *RHSC, TrueIfSignedR) &&
- (RHS->hasOneUse() || LHS->hasOneUse())) {
- Value *X, *Y;
- if (IsAnd) {
- if ((TrueIfSignedL && !TrueIfSignedR &&
- match(LHS0, m_Or(m_Value(X), m_Value(Y))) &&
- match(RHS0, m_c_And(m_Specific(X), m_Specific(Y)))) ||
- (!TrueIfSignedL && TrueIfSignedR &&
- match(LHS0, m_And(m_Value(X), m_Value(Y))) &&
- match(RHS0, m_c_Or(m_Specific(X), m_Specific(Y))))) {
- Value *NewXor = Builder.CreateXor(X, Y);
- return Builder.CreateIsNeg(NewXor);
- }
- } else {
- if ((TrueIfSignedL && !TrueIfSignedR &&
- match(LHS0, m_And(m_Value(X), m_Value(Y))) &&
- match(RHS0, m_c_Or(m_Specific(X), m_Specific(Y)))) ||
- (!TrueIfSignedL && TrueIfSignedR &&
- match(LHS0, m_Or(m_Value(X), m_Value(Y))) &&
- match(RHS0, m_c_And(m_Specific(X), m_Specific(Y))))) {
- Value *NewXor = Builder.CreateXor(X, Y);
- return Builder.CreateIsNotNeg(NewXor);
- }
- }
- }
-
- return foldAndOrOfICmpsUsingRanges(LHS, RHS, IsAnd);
-}
-
-/// If IsLogical is true, then the and/or is in select form and the transform
-/// must be poison-safe.
-Value *InstCombinerImpl::foldBooleanAndOr(Value *LHS, Value *RHS,
- Instruction &I, bool IsAnd,
- bool IsLogical) {
- if (!LHS->getType()->isIntOrIntVectorTy(1))
- return nullptr;
-
- if (auto *LHSCmp = dyn_cast<ICmpInst>(LHS))
- if (auto *RHSCmp = dyn_cast<ICmpInst>(RHS))
- if (Value *Res = foldAndOrOfICmps(LHSCmp, RHSCmp, I, IsAnd, IsLogical))
- return Res;
-
- if (auto *LHSCmp = dyn_cast<FCmpInst>(LHS))
- if (auto *RHSCmp = dyn_cast<FCmpInst>(RHS))
- if (Value *Res = foldLogicOfFCmps(LHSCmp, RHSCmp, IsAnd, IsLogical))
- return Res;
-
- if (Value *Res = foldEqOfParts(LHS, RHS, IsAnd))
- return Res;
-
- return nullptr;
-}
-
-static Value *foldOrOfInversions(BinaryOperator &I,
- InstCombiner::BuilderTy &Builder) {
- assert(I.getOpcode() == Instruction::Or &&
- "Simplification only supports or at the moment.");
-
- Value *Cmp1, *Cmp2, *Cmp3, *Cmp4;
- if (!match(I.getOperand(0), m_And(m_Value(Cmp1), m_Value(Cmp2))) ||
- !match(I.getOperand(1), m_And(m_Value(Cmp3), m_Value(Cmp4))))
- return nullptr;
-
- // Check if any two pairs of the and operations are inversions of each other.
- if (isKnownInversion(Cmp1, Cmp3) && isKnownInversion(Cmp2, Cmp4))
- return Builder.CreateXor(Cmp1, Cmp4);
- if (isKnownInversion(Cmp1, Cmp4) && isKnownInversion(Cmp2, Cmp3))
- return Builder.CreateXor(Cmp1, Cmp3);
-
- return nullptr;
-}
-
-// FIXME: We use commutative matchers (m_c_*) for some, but not all, matches
-// here. We should standardize that construct where it is needed or choose some
-// other way to ensure that commutated variants of patterns are not missed.
-Instruction *InstCombinerImpl::visitOr(BinaryOperator &I) {
- if (Value *V = simplifyOrInst(I.getOperand(0), I.getOperand(1),
- SQ.getWithInstruction(&I)))
- return replaceInstUsesWith(I, V);
-
- if (SimplifyAssociativeOrCommutative(I))
- return &I;
-
- if (Instruction *X = foldVectorBinop(I))
- return X;
-
- if (Instruction *Phi = foldBinopWithPhiOperands(I))
- return Phi;
-
- // See if we can simplify any instructions used by the instruction whose sole
- // purpose is to compute bits we don't care about.
- if (SimplifyDemandedInstructionBits(I))
- return &I;
-
- // Do this before using distributive laws to catch simple and/or/not patterns.
- if (Instruction *Xor = foldOrToXor(I, Builder))
- return Xor;
-
- if (Instruction *X = foldComplexAndOrPatterns(I, Builder))
- return X;
-
- // (A & B) | (C & D) -> A ^ D where A == ~C && B == ~D
- // (A & B) | (C & D) -> A ^ C where A == ~D && B == ~C
- if (Value *V = foldOrOfInversions(I, Builder))
- return replaceInstUsesWith(I, V);
-
- // (A&B)|(A&C) -> A&(B|C) etc
- if (Value *V = foldUsingDistributiveLaws(I))
- return replaceInstUsesWith(I, V);
-
- Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
- Type *Ty = I.getType();
- if (Ty->isIntOrIntVectorTy(1)) {
- if (auto *SI0 = dyn_cast<SelectInst>(Op0)) {
- if (auto *R =
- foldAndOrOfSelectUsingImpliedCond(Op1, *SI0, /* IsAnd */ false))
- return R;
- }
- if (auto *SI1 = dyn_cast<SelectInst>(Op1)) {
- if (auto *R =
- foldAndOrOfSelectUsingImpliedCond(Op0, *SI1, /* IsAnd */ false))
- return R;
- }
- }
-
- if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
- return FoldedLogic;
-
- if (Instruction *BitOp = matchBSwapOrBitReverse(I, /*MatchBSwaps*/ true,
- /*MatchBitReversals*/ true))
- return BitOp;
-
- if (Instruction *Funnel = matchFunnelShift(I, *this))
- return Funnel;
-
- if (Instruction *Concat = matchOrConcat(I, Builder))
- return replaceInstUsesWith(I, Concat);
-
- if (Instruction *R = foldBinOpShiftWithShift(I))
- return R;
-
- if (Instruction *R = tryFoldInstWithCtpopWithNot(&I))
- return R;
-
- if (cast<PossiblyDisjointInst>(I).isDisjoint()) {
- if (Instruction *R =
- foldAddLikeCommutative(I.getOperand(0), I.getOperand(1),
- /*NSW=*/true, /*NUW=*/true))
- return R;
- if (Instruction *R =
- foldAddLikeCommutative(I.getOperand(1), I.getOperand(0),
- /*NSW=*/true, /*NUW=*/true))
- return R;
- }
-
- Value *X, *Y;
- const APInt *CV;
- if (match(&I, m_c_Or(m_OneUse(m_Xor(m_Value(X), m_APInt(CV))), m_Value(Y))) &&
- !CV->isAllOnes() && MaskedValueIsZero(Y, *CV, 0, &I)) {
- // (X ^ C) | Y -> (X | Y) ^ C iff Y & C == 0
- // The check for a 'not' op is for efficiency (if Y is known zero --> ~X).
- Value *Or = Builder.CreateOr(X, Y);
- return BinaryOperator::CreateXor(Or, ConstantInt::get(Ty, *CV));
- }
-
- // If the operands have no common bits set:
- // or (mul X, Y), X --> add (mul X, Y), X --> mul X, (Y + 1)
- if (match(&I, m_c_DisjointOr(m_OneUse(m_Mul(m_Value(X), m_Value(Y))),
- m_Deferred(X)))) {
- Value *IncrementY = Builder.CreateAdd(Y, ConstantInt::get(Ty, 1));
- return BinaryOperator::CreateMul(X, IncrementY);
- }
-
- // (A & C) | (B & D)
- Value *A, *B, *C, *D;
- if (match(Op0, m_And(m_Value(A), m_Value(C))) &&
- match(Op1, m_And(m_Value(B), m_Value(D)))) {
-
- // (A & C0) | (B & C1)
- const APInt *C0, *C1;
- if (match(C, m_APInt(C0)) && match(D, m_APInt(C1))) {
- Value *X;
- if (*C0 == ~*C1) {
- // ((X | B) & MaskC) | (B & ~MaskC) -> (X & MaskC) | B
- if (match(A, m_c_Or(m_Value(X), m_Specific(B))))
- return BinaryOperator::CreateOr(Builder.CreateAnd(X, *C0), B);
- // (A & MaskC) | ((X | A) & ~MaskC) -> (X & ~MaskC) | A
- if (match(B, m_c_Or(m_Specific(A), m_Value(X))))
- return BinaryOperator::CreateOr(Builder.CreateAnd(X, *C1), A);
-
- // ((X ^ B) & MaskC) | (B & ~MaskC) -> (X & MaskC) ^ B
- if (match(A, m_c_Xor(m_Value(X), m_Specific(B))))
- return BinaryOperator::CreateXor(Builder.CreateAnd(X, *C0), B);
- // (A & MaskC) | ((X ^ A) & ~MaskC) -> (X & ~MaskC) ^ A
- if (match(B, m_c_Xor(m_Specific(A), m_Value(X))))
- return BinaryOperator::CreateXor(Builder.CreateAnd(X, *C1), A);
- }
-
- if ((*C0 & *C1).isZero()) {
- // ((X | B) & C0) | (B & C1) --> (X | B) & (C0 | C1)
- // iff (C0 & C1) == 0 and (X & ~C0) == 0
- if (match(A, m_c_Or(m_Value(X), m_Specific(B))) &&
- MaskedValueIsZero(X, ~*C0, 0, &I)) {
- Constant *C01 = ConstantInt::get(Ty, *C0 | *C1);
- return BinaryOperator::CreateAnd(A, C01);
- }
- // (A & C0) | ((X | A) & C1) --> (X | A) & (C0 | C1)
- // iff (C0 & C1) == 0 and (X & ~C1) == 0
- if (match(B, m_c_Or(m_Value(X), m_Specific(A))) &&
- MaskedValueIsZero(X, ~*C1, 0, &I)) {
- Constant *C01 = ConstantInt::get(Ty, *C0 | *C1);
- return BinaryOperator::CreateAnd(B, C01);
- }
- // ((X | C2) & C0) | ((X | C3) & C1) --> (X | C2 | C3) & (C0 | C1)
- // iff (C0 & C1) == 0 and (C2 & ~C0) == 0 and (C3 & ~C1) == 0.
- const APInt *C2, *C3;
- if (match(A, m_Or(m_Value(X), m_APInt(C2))) &&
- match(B, m_Or(m_Specific(X), m_APInt(C3))) &&
- (*C2 & ~*C0).isZero() && (*C3 & ~*C1).isZero()) {
- Value *Or = Builder.CreateOr(X, *C2 | *C3, "bitfield");
- Constant *C01 = ConstantInt::get(Ty, *C0 | *C1);
- return BinaryOperator::CreateAnd(Or, C01);
- }
- }
- }
-
- // Don't try to form a select if it's unlikely that we'll get rid of at
- // least one of the operands. A select is generally more expensive than the
- // 'or' that it is replacing.
- if (Op0->hasOneUse() || Op1->hasOneUse()) {
- // (Cond & C) | (~Cond & D) -> Cond ? C : D, and commuted variants.
- if (Value *V = matchSelectFromAndOr(A, C, B, D))
- return replaceInstUsesWith(I, V);
- if (Value *V = matchSelectFromAndOr(A, C, D, B))
- return replaceInstUsesWith(I, V);
- if (Value *V = matchSelectFromAndOr(C, A, B, D))
- return replaceInstUsesWith(I, V);
- if (Value *V = matchSelectFromAndOr(C, A, D, B))
- return replaceInstUsesWith(I, V);
- if (Value *V = matchSelectFromAndOr(B, D, A, C))
- return replaceInstUsesWith(I, V);
- if (Value *V = matchSelectFromAndOr(B, D, C, A))
- return replaceInstUsesWith(I, V);
- if (Value *V = matchSelectFromAndOr(D, B, A, C))
- return replaceInstUsesWith(I, V);
- if (Value *V = matchSelectFromAndOr(D, B, C, A))
- return replaceInstUsesWith(I, V);
- }
- }
-
- if (match(Op0, m_And(m_Value(A), m_Value(C))) &&
- match(Op1, m_Not(m_Or(m_Value(B), m_Value(D)))) &&
- (Op0->hasOneUse() || Op1->hasOneUse())) {
- // (Cond & C) | ~(Cond | D) -> Cond ? C : ~D
- if (Value *V = matchSelectFromAndOr(A, C, B, D, true))
- return replaceInstUsesWith(I, V);
- if (Value *V = matchSelectFromAndOr(A, C, D, B, true))
- return replaceInstUsesWith(I, V);
- if (Value *V = matchSelectFromAndOr(C, A, B, D, true))
- return replaceInstUsesWith(I, V);
- if (Value *V = matchSelectFromAndOr(C, A, D, B, true))
- return replaceInstUsesWith(I, V);
- }
-
- // (A ^ B) | ((B ^ C) ^ A) -> (A ^ B) | C
- if (match(Op0, m_Xor(m_Value(A), m_Value(B))))
- if (match(Op1,
- m_c_Xor(m_c_Xor(m_Specific(B), m_Value(C)), m_Specific(A))) ||
- match(Op1, m_c_Xor(m_c_Xor(m_Specific(A), m_Value(C)), m_Specific(B))))
- return BinaryOperator::CreateOr(Op0, C);
-
- // ((B ^ C) ^ A) | (A ^ B) -> (A ^ B) | C
- if (match(Op1, m_Xor(m_Value(A), m_Value(B))))
- if (match(Op0,
- m_c_Xor(m_c_Xor(m_Specific(B), m_Value(C)), m_Specific(A))) ||
- match(Op0, m_c_Xor(m_c_Xor(m_Specific(A), m_Value(C)), m_Specific(B))))
- return BinaryOperator::CreateOr(Op1, C);
-
- if (Instruction *DeMorgan = matchDeMorgansLaws(I, *this))
- return DeMorgan;
-
- // Canonicalize xor to the RHS.
- bool SwappedForXor = false;
- if (match(Op0, m_Xor(m_Value(), m_Value()))) {
- std::swap(Op0, Op1);
- SwappedForXor = true;
- }
-
- if (match(Op1, m_Xor(m_Value(A), m_Value(B)))) {
- // (A | ?) | (A ^ B) --> (A | ?) | B
- // (B | ?) | (A ^ B) --> (B | ?) | A
- if (match(Op0, m_c_Or(m_Specific(A), m_Value())))
- return BinaryOperator::CreateOr(Op0, B);
- if (match(Op0, m_c_Or(m_Specific(B), m_Value())))
- return BinaryOperator::CreateOr(Op0, A);
-
- // (A & B) | (A ^ B) --> A | B
- // (B & A) | (A ^ B) --> A | B
- if (match(Op0, m_c_And(m_Specific(A), m_Specific(B))))
- return BinaryOperator::CreateOr(A, B);
-
- // ~A | (A ^ B) --> ~(A & B)
- // ~B | (A ^ B) --> ~(A & B)
- // The swap above should always make Op0 the 'not'.
- if ((Op0->hasOneUse() || Op1->hasOneUse()) &&
- (match(Op0, m_Not(m_Specific(A))) || match(Op0, m_Not(m_Specific(B)))))
- return BinaryOperator::CreateNot(Builder.CreateAnd(A, B));
-
- // Same as above, but peek through an 'and' to the common operand:
- // ~(A & ?) | (A ^ B) --> ~((A & ?) & B)
- // ~(B & ?) | (A ^ B) --> ~((B & ?) & A)
- Instruction *And;
- if ((Op0->hasOneUse() || Op1->hasOneUse()) &&
- match(Op0, m_Not(m_CombineAnd(m_Instruction(And),
- m_c_And(m_Specific(A), m_Value())))))
- return BinaryOperator::CreateNot(Builder.CreateAnd(And, B));
- if ((Op0->hasOneUse() || Op1->hasOneUse()) &&
- match(Op0, m_Not(m_CombineAnd(m_Instruction(And),
- m_c_And(m_Specific(B), m_Value())))))
- return BinaryOperator::CreateNot(Builder.CreateAnd(And, A));
-
- // (~A | C) | (A ^ B) --> ~(A & B) | C
- // (~B | C) | (A ^ B) --> ~(A & B) | C
- if (Op0->hasOneUse() && Op1->hasOneUse() &&
- (match(Op0, m_c_Or(m_Not(m_Specific(A)), m_Value(C))) ||
- match(Op0, m_c_Or(m_Not(m_Specific(B)), m_Value(C))))) {
- Value *Nand = Builder.CreateNot(Builder.CreateAnd(A, B), "nand");
- return BinaryOperator::CreateOr(Nand, C);
- }
- }
-
- if (SwappedForXor)
- std::swap(Op0, Op1);
-
- if (Value *Res =
- foldBooleanAndOr(Op0, Op1, I, /*IsAnd=*/false, /*IsLogical=*/false))
- return replaceInstUsesWith(I, Res);
-
- if (match(Op1, m_OneUse(m_LogicalOr(m_Value(X), m_Value(Y))))) {
- bool IsLogical = isa<SelectInst>(Op1);
- if (auto *V = reassociateBooleanAndOr(Op0, X, Y, I, /*IsAnd=*/false,
- /*RHSIsLogical=*/IsLogical))
- return replaceInstUsesWith(I, V);
- }
- if (match(Op0, m_OneUse(m_LogicalOr(m_Value(X), m_Value(Y))))) {
- bool IsLogical = isa<SelectInst>(Op0);
- if (auto *V = reassociateBooleanAndOr(Op1, X, Y, I, /*IsAnd=*/false,
- /*RHSIsLogical=*/IsLogical))
- return replaceInstUsesWith(I, V);
- }
-
- if (Instruction *FoldedFCmps = reassociateFCmps(I, Builder))
- return FoldedFCmps;
-
- if (Instruction *CastedOr = foldCastedBitwiseLogic(I))
- return CastedOr;
-
- if (Instruction *Sel = foldBinopOfSextBoolToSelect(I))
- return Sel;
-
- // or(sext(A), B) / or(B, sext(A)) --> A ? -1 : B, where A is i1 or <N x i1>.
- // TODO: Move this into foldBinopOfSextBoolToSelect as a more generalized fold
- // with binop identity constant. But creating a select with non-constant
- // arm may not be reversible due to poison semantics. Is that a good
- // canonicalization?
- if (match(&I, m_c_Or(m_OneUse(m_SExt(m_Value(A))), m_Value(B))) &&
- A->getType()->isIntOrIntVectorTy(1))
- return SelectInst::Create(A, ConstantInt::getAllOnesValue(Ty), B);
-
- // Note: If we've gotten to the point of visiting the outer OR, then the
- // inner one couldn't be simplified. If it was a constant, then it won't
- // be simplified by a later pass either, so we try swapping the inner/outer
- // ORs in the hopes that we'll be able to simplify it this way.
- // (X|C) | V --> (X|V) | C
- ConstantInt *CI;
- if (Op0->hasOneUse() && !match(Op1, m_ConstantInt()) &&
- match(Op0, m_Or(m_Value(A), m_ConstantInt(CI)))) {
- Value *Inner = Builder.CreateOr(A, Op1);
- Inner->takeName(Op0);
- return BinaryOperator::CreateOr(Inner, CI);
- }
-
- // Change (or (bool?A:B),(bool?C:D)) --> (bool?(or A,C):(or B,D))
- // Since this OR statement hasn't been optimized further yet, we hope
- // that this transformation will allow the new ORs to be optimized.
- {
- Value *X = nullptr, *Y = nullptr;
- if (Op0->hasOneUse() && Op1->hasOneUse() &&
- match(Op0, m_Select(m_Value(X), m_Value(A), m_Value(B))) &&
- match(Op1, m_Select(m_Value(Y), m_Value(C), m_Value(D))) && X == Y) {
- Value *orTrue = Builder.CreateOr(A, C);
- Value *orFalse = Builder.CreateOr(B, D);
- return SelectInst::Create(X, orTrue, orFalse);
- }
- }
-
- // or(ashr(subNSW(Y, X), ScalarSizeInBits(Y) - 1), X) --> X s> Y ? -1 : X.
- {
- Value *X, *Y;
- if (match(&I, m_c_Or(m_OneUse(m_AShr(
- m_NSWSub(m_Value(Y), m_Value(X)),
- m_SpecificInt(Ty->getScalarSizeInBits() - 1))),
- m_Deferred(X)))) {
- Value *NewICmpInst = Builder.CreateICmpSGT(X, Y);
- Value *AllOnes = ConstantInt::getAllOnesValue(Ty);
- return SelectInst::Create(NewICmpInst, AllOnes, X);
- }
- }
-
- {
- // ((A & B) ^ A) | ((A & B) ^ B) -> A ^ B
- // (A ^ (A & B)) | (B ^ (A & B)) -> A ^ B
- // ((A & B) ^ B) | ((A & B) ^ A) -> A ^ B
- // (B ^ (A & B)) | (A ^ (A & B)) -> A ^ B
- const auto TryXorOpt = [&](Value *Lhs, Value *Rhs) -> Instruction * {
- if (match(Lhs, m_c_Xor(m_And(m_Value(A), m_Value(B)), m_Deferred(A))) &&
- match(Rhs,
- m_c_Xor(m_And(m_Specific(A), m_Specific(B)), m_Specific(B)))) {
- return BinaryOperator::CreateXor(A, B);
- }
- return nullptr;
- };
-
- if (Instruction *Result = TryXorOpt(Op0, Op1))
- return Result;
- if (Instruction *Result = TryXorOpt(Op1, Op0))
- return Result;
- }
-
- if (Instruction *V =
- canonicalizeCondSignextOfHighBitExtractToSignextHighBitExtract(I))
- return V;
-
- CmpPredicate Pred;
- Value *Mul, *Ov, *MulIsNotZero, *UMulWithOv;
- // Check if the OR weakens the overflow condition for umul.with.overflow by
- // treating any non-zero result as overflow. In that case, we overflow if both
- // umul.with.overflow operands are != 0, as in that case the result can only
- // be 0, iff the multiplication overflows.
- if (match(&I,
- m_c_Or(m_CombineAnd(m_ExtractValue<1>(m_Value(UMulWithOv)),
- m_Value(Ov)),
- m_CombineAnd(
- m_SpecificICmp(ICmpInst::ICMP_NE,
- m_CombineAnd(m_ExtractValue<0>(
- m_Deferred(UMulWithOv)),
- m_Value(Mul)),
- m_ZeroInt()),
- m_Value(MulIsNotZero)))) &&
- (Ov->hasOneUse() || (MulIsNotZero->hasOneUse() && Mul->hasOneUse()))) {
- Value *A, *B;
- if (match(UMulWithOv, m_Intrinsic<Intrinsic::umul_with_overflow>(
- m_Value(A), m_Value(B)))) {
- Value *NotNullA = Builder.CreateIsNotNull(A);
- Value *NotNullB = Builder.CreateIsNotNull(B);
- return BinaryOperator::CreateAnd(NotNullA, NotNullB);
- }
- }
-
- /// Res, Overflow = xxx_with_overflow X, C1
- /// Try to canonicalize the pattern "Overflow | icmp pred Res, C2" into
- /// "Overflow | icmp pred X, C2 +/- C1".
- const WithOverflowInst *WO;
- const Value *WOV;
- const APInt *C1, *C2;
- if (match(&I, m_c_Or(m_CombineAnd(m_ExtractValue<1>(m_CombineAnd(
- m_WithOverflowInst(WO), m_Value(WOV))),
- m_Value(Ov)),
- m_OneUse(m_ICmp(Pred, m_ExtractValue<0>(m_Deferred(WOV)),
- m_APInt(C2))))) &&
- (WO->getBinaryOp() == Instruction::Add ||
- WO->getBinaryOp() == Instruction::Sub) &&
- (ICmpInst::isEquality(Pred) ||
- WO->isSigned() == ICmpInst::isSigned(Pred)) &&
- match(WO->getRHS(), m_APInt(C1))) {
- bool Overflow;
- APInt NewC = WO->getBinaryOp() == Instruction::Add
- ? (ICmpInst::isSigned(Pred) ? C2->ssub_ov(*C1, Overflow)
- : C2->usub_ov(*C1, Overflow))
- : (ICmpInst::isSigned(Pred) ? C2->sadd_ov(*C1, Overflow)
- : C2->uadd_ov(*C1, Overflow));
- if (!Overflow || ICmpInst::isEquality(Pred)) {
- Value *NewCmp = Builder.CreateICmp(
- Pred, WO->getLHS(), ConstantInt::get(WO->getLHS()->getType(), NewC));
- return BinaryOperator::CreateOr(Ov, NewCmp);
- }
- }
-
- // (~x) | y --> ~(x & (~y)) iff that gets rid of inversions
- if (sinkNotIntoOtherHandOfLogicalOp(I))
- return &I;
-
- // Improve "get low bit mask up to and including bit X" pattern:
- // (1 << X) | ((1 << X) + -1) --> -1 l>> (bitwidth(x) - 1 - X)
- if (match(&I, m_c_Or(m_Add(m_Shl(m_One(), m_Value(X)), m_AllOnes()),
- m_Shl(m_One(), m_Deferred(X)))) &&
- match(&I, m_c_Or(m_OneUse(m_Value()), m_Value()))) {
- Value *Sub = Builder.CreateSub(
- ConstantInt::get(Ty, Ty->getScalarSizeInBits() - 1), X);
- return BinaryOperator::CreateLShr(Constant::getAllOnesValue(Ty), Sub);
- }
-
- // An or recurrence w/loop invariant step is equivelent to (or start, step)
- PHINode *PN = nullptr;
- Value *Start = nullptr, *Step = nullptr;
- if (matchSimpleRecurrence(&I, PN, Start, Step) && DT.dominates(Step, PN))
- return replaceInstUsesWith(I, Builder.CreateOr(Start, Step));
-
- // (A & B) | (C | D) or (C | D) | (A & B)
- // Can be combined if C or D is of type (A/B & X)
- if (match(&I, m_c_Or(m_OneUse(m_And(m_Value(A), m_Value(B))),
- m_OneUse(m_Or(m_Value(C), m_Value(D)))))) {
- // (A & B) | (C | ?) -> C | (? | (A & B))
- // (A & B) | (C | ?) -> C | (? | (A & B))
- // (A & B) | (C | ?) -> C | (? | (A & B))
- // (A & B) | (C | ?) -> C | (? | (A & B))
- // (C | ?) | (A & B) -> C | (? | (A & B))
- // (C | ?) | (A & B) -> C | (? | (A & B))
- // (C | ?) | (A & B) -> C | (? | (A & B))
- // (C | ?) | (A & B) -> C | (? | (A & B))
- if (match(D, m_OneUse(m_c_And(m_Specific(A), m_Value()))) ||
- match(D, m_OneUse(m_c_And(m_Specific(B), m_Value()))))
- return BinaryOperator::CreateOr(
- C, Builder.CreateOr(D, Builder.CreateAnd(A, B)));
- // (A & B) | (? | D) -> (? | (A & B)) | D
- // (A & B) | (? | D) -> (? | (A & B)) | D
- // (A & B) | (? | D) -> (? | (A & B)) | D
- // (A & B) | (? | D) -> (? | (A & B)) | D
- // (? | D) | (A & B) -> (? | (A & B)) | D
- // (? | D) | (A & B) -> (? | (A & B)) | D
- // (? | D) | (A & B) -> (? | (A & B)) | D
- // (? | D) | (A & B) -> (? | (A & B)) | D
- if (match(C, m_OneUse(m_c_And(m_Specific(A), m_Value()))) ||
- match(C, m_OneUse(m_c_And(m_Specific(B), m_Value()))))
- return BinaryOperator::CreateOr(
- Builder.CreateOr(C, Builder.CreateAnd(A, B)), D);
- }
-
- if (Instruction *R = reassociateForUses(I, Builder))
- return R;
-
- if (Instruction *Canonicalized = canonicalizeLogicFirst(I, Builder))
- return Canonicalized;
-
- if (Instruction *Folded = foldLogicOfIsFPClass(I, Op0, Op1))
- return Folded;
-
- if (Instruction *Res = foldBinOpOfDisplacedShifts(I))
- return Res;
-
- // If we are setting the sign bit of a floating-point value, convert
- // this to fneg(fabs), then cast back to integer.
- //
- // If the result isn't immediately cast back to a float, this will increase
- // the number of instructions. This is still probably a better canonical form
- // as it enables FP value tracking.
- //
- // Assumes any IEEE-represented type has the sign bit in the high bit.
- //
- // This is generous interpretation of noimplicitfloat, this is not a true
- // floating-point operation.
- Value *CastOp;
- if (match(Op0, m_ElementWiseBitCast(m_Value(CastOp))) &&
- match(Op1, m_SignMask()) &&
- !Builder.GetInsertBlock()->getParent()->hasFnAttribute(
- Attribute::NoImplicitFloat)) {
- Type *EltTy = CastOp->getType()->getScalarType();
- if (EltTy->isFloatingPointTy() && EltTy->isIEEE()) {
- Value *FAbs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, CastOp);
- Value *FNegFAbs = Builder.CreateFNeg(FAbs);
- return new BitCastInst(FNegFAbs, I.getType());
- }
- }
-
- // (X & C1) | C2 -> X & (C1 | C2) iff (X & C2) == C2
- if (match(Op0, m_OneUse(m_And(m_Value(X), m_APInt(C1)))) &&
- match(Op1, m_APInt(C2))) {
- KnownBits KnownX = computeKnownBits(X, /*Depth*/ 0, &I);
- if ((KnownX.One & *C2) == *C2)
- return BinaryOperator::CreateAnd(X, ConstantInt::get(Ty, *C1 | *C2));
- }
-
- if (Instruction *Res = foldBitwiseLogicWithIntrinsics(I, Builder))
- return Res;
-
- if (Value *V =
- simplifyAndOrWithOpReplaced(Op0, Op1, Constant::getNullValue(Ty),
- /*SimplifyOnly*/ false, *this))
- return BinaryOperator::CreateOr(V, Op1);
- if (Value *V =
- simplifyAndOrWithOpReplaced(Op1, Op0, Constant::getNullValue(Ty),
- /*SimplifyOnly*/ false, *this))
- return BinaryOperator::CreateOr(Op0, V);
-
- if (cast<PossiblyDisjointInst>(I).isDisjoint())
- if (Value *V = SimplifyAddWithRemainder(I))
- return replaceInstUsesWith(I, V);
-
- return nullptr;
-}
-
-/// A ^ B can be specified using other logic ops in a variety of patterns. We
-/// can fold these early and efficiently by morphing an existing instruction.
-static Instruction *foldXorToXor(BinaryOperator &I,
- InstCombiner::BuilderTy &Builder) {
- assert(I.getOpcode() == Instruction::Xor);
- Value *Op0 = I.getOperand(0);
- Value *Op1 = I.getOperand(1);
- Value *A, *B;
-
- // There are 4 commuted variants for each of the basic patterns.
-
- // (A & B) ^ (A | B) -> A ^ B
- // (A & B) ^ (B | A) -> A ^ B
- // (A | B) ^ (A & B) -> A ^ B
- // (A | B) ^ (B & A) -> A ^ B
- if (match(&I, m_c_Xor(m_And(m_Value(A), m_Value(B)),
- m_c_Or(m_Deferred(A), m_Deferred(B)))))
- return BinaryOperator::CreateXor(A, B);
-
- // (A | ~B) ^ (~A | B) -> A ^ B
- // (~B | A) ^ (~A | B) -> A ^ B
- // (~A | B) ^ (A | ~B) -> A ^ B
- // (B | ~A) ^ (A | ~B) -> A ^ B
- if (match(&I, m_Xor(m_c_Or(m_Value(A), m_Not(m_Value(B))),
- m_c_Or(m_Not(m_Deferred(A)), m_Deferred(B)))))
- return BinaryOperator::CreateXor(A, B);
-
- // (A & ~B) ^ (~A & B) -> A ^ B
- // (~B & A) ^ (~A & B) -> A ^ B
- // (~A & B) ^ (A & ~B) -> A ^ B
- // (B & ~A) ^ (A & ~B) -> A ^ B
- if (match(&I, m_Xor(m_c_And(m_Value(A), m_Not(m_Value(B))),
- m_c_And(m_Not(m_Deferred(A)), m_Deferred(B)))))
- return BinaryOperator::CreateXor(A, B);
-
- // For the remaining cases we need to get rid of one of the operands.
- if (!Op0->hasOneUse() && !Op1->hasOneUse())
- return nullptr;
-
- // (A | B) ^ ~(A & B) -> ~(A ^ B)
- // (A | B) ^ ~(B & A) -> ~(A ^ B)
- // (A & B) ^ ~(A | B) -> ~(A ^ B)
- // (A & B) ^ ~(B | A) -> ~(A ^ B)
- // Complexity sorting ensures the not will be on the right side.
- if ((match(Op0, m_Or(m_Value(A), m_Value(B))) &&
- match(Op1, m_Not(m_c_And(m_Specific(A), m_Specific(B))))) ||
- (match(Op0, m_And(m_Value(A), m_Value(B))) &&
- match(Op1, m_Not(m_c_Or(m_Specific(A), m_Specific(B))))))
- return BinaryOperator::CreateNot(Builder.CreateXor(A, B));
-
- return nullptr;
-}
-
-Value *InstCombinerImpl::foldXorOfICmps(ICmpInst *LHS, ICmpInst *RHS,
- BinaryOperator &I) {
- assert(I.getOpcode() == Instruction::Xor && I.getOperand(0) == LHS &&
- I.getOperand(1) == RHS && "Should be 'xor' with these operands");
-
- ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
- Value *LHS0 = LHS->getOperand(0), *LHS1 = LHS->getOperand(1);
- Value *RHS0 = RHS->getOperand(0), *RHS1 = RHS->getOperand(1);
-
- if (predicatesFoldable(PredL, PredR)) {
- if (LHS0 == RHS1 && LHS1 == RHS0) {
- std::swap(LHS0, LHS1);
- PredL = ICmpInst::getSwappedPredicate(PredL);
- }
- if (LHS0 == RHS0 && LHS1 == RHS1) {
- // (icmp1 A, B) ^ (icmp2 A, B) --> (icmp3 A, B)
- unsigned Code = getICmpCode(PredL) ^ getICmpCode(PredR);
- bool IsSigned = LHS->isSigned() || RHS->isSigned();
- return getNewICmpValue(Code, IsSigned, LHS0, LHS1, Builder);
- }
- }
-
- // TODO: This can be generalized to compares of non-signbits using
- // decomposeBitTestICmp(). It could be enhanced more by using (something like)
- // foldLogOpOfMaskedICmps().
- const APInt *LC, *RC;
- if (match(LHS1, m_APInt(LC)) && match(RHS1, m_APInt(RC)) &&
- LHS0->getType() == RHS0->getType() &&
- LHS0->getType()->isIntOrIntVectorTy()) {
- // Convert xor of signbit tests to signbit test of xor'd values:
- // (X > -1) ^ (Y > -1) --> (X ^ Y) < 0
- // (X < 0) ^ (Y < 0) --> (X ^ Y) < 0
- // (X > -1) ^ (Y < 0) --> (X ^ Y) > -1
- // (X < 0) ^ (Y > -1) --> (X ^ Y) > -1
- bool TrueIfSignedL, TrueIfSignedR;
- if ((LHS->hasOneUse() || RHS->hasOneUse()) &&
- isSignBitCheck(PredL, *LC, TrueIfSignedL) &&
- isSignBitCheck(PredR, *RC, TrueIfSignedR)) {
- Value *XorLR = Builder.CreateXor(LHS0, RHS0);
- return TrueIfSignedL == TrueIfSignedR ? Builder.CreateIsNeg(XorLR) :
- Builder.CreateIsNotNeg(XorLR);
- }
-
- // Fold (icmp pred1 X, C1) ^ (icmp pred2 X, C2)
- // into a single comparison using range-based reasoning.
- if (LHS0 == RHS0) {
- ConstantRange CR1 = ConstantRange::makeExactICmpRegion(PredL, *LC);
- ConstantRange CR2 = ConstantRange::makeExactICmpRegion(PredR, *RC);
- auto CRUnion = CR1.exactUnionWith(CR2);
- auto CRIntersect = CR1.exactIntersectWith(CR2);
- if (CRUnion && CRIntersect)
- if (auto CR = CRUnion->exactIntersectWith(CRIntersect->inverse())) {
- if (CR->isFullSet())
- return ConstantInt::getTrue(I.getType());
- if (CR->isEmptySet())
- return ConstantInt::getFalse(I.getType());
-
- CmpInst::Predicate NewPred;
- APInt NewC, Offset;
- CR->getEquivalentICmp(NewPred, NewC, Offset);
-
- if ((Offset.isZero() && (LHS->hasOneUse() || RHS->hasOneUse())) ||
- (LHS->hasOneUse() && RHS->hasOneUse())) {
- Value *NewV = LHS0;
- Type *Ty = LHS0->getType();
- if (!Offset.isZero())
- NewV = Builder.CreateAdd(NewV, ConstantInt::get(Ty, Offset));
- return Builder.CreateICmp(NewPred, NewV,
- ConstantInt::get(Ty, NewC));
- }
- }
- }
- }
-
- // Instead of trying to imitate the folds for and/or, decompose this 'xor'
- // into those logic ops. That is, try to turn this into an and-of-icmps
- // because we have many folds for that pattern.
- //
- // This is based on a truth table definition of xor:
- // X ^ Y --> (X | Y) & !(X & Y)
- if (Value *OrICmp = simplifyBinOp(Instruction::Or, LHS, RHS, SQ)) {
- // TODO: If OrICmp is true, then the definition of xor simplifies to !(X&Y).
- // TODO: If OrICmp is false, the whole thing is false (InstSimplify?).
- if (Value *AndICmp = simplifyBinOp(Instruction::And, LHS, RHS, SQ)) {
- // TODO: Independently handle cases where the 'and' side is a constant.
- ICmpInst *X = nullptr, *Y = nullptr;
- if (OrICmp == LHS && AndICmp == RHS) {
- // (LHS | RHS) & !(LHS & RHS) --> LHS & !RHS --> X & !Y
- X = LHS;
- Y = RHS;
- }
- if (OrICmp == RHS && AndICmp == LHS) {
- // !(LHS & RHS) & (LHS | RHS) --> !LHS & RHS --> !Y & X
- X = RHS;
- Y = LHS;
- }
- if (X && Y && (Y->hasOneUse() || canFreelyInvertAllUsersOf(Y, &I))) {
- // Invert the predicate of 'Y', thus inverting its output.
- Y->setPredicate(Y->getInversePredicate());
- // So, are there other uses of Y?
- if (!Y->hasOneUse()) {
- // We need to adapt other uses of Y though. Get a value that matches
- // the original value of Y before inversion. While this increases
- // immediate instruction count, we have just ensured that all the
- // users are freely-invertible, so that 'not' *will* get folded away.
- BuilderTy::InsertPointGuard Guard(Builder);
- // Set insertion point to right after the Y.
- Builder.SetInsertPoint(Y->getParent(), ++(Y->getIterator()));
- Value *NotY = Builder.CreateNot(Y, Y->getName() + ".not");
- // Replace all uses of Y (excluding the one in NotY!) with NotY.
- Worklist.pushUsersToWorkList(*Y);
- Y->replaceUsesWithIf(NotY,
- [NotY](Use &U) { return U.getUser() != NotY; });
- }
- // All done.
- return Builder.CreateAnd(LHS, RHS);
- }
- }
- }
-
- return nullptr;
-}
-
-/// If we have a masked merge, in the canonical form of:
-/// (assuming that A only has one use.)
-/// | A | |B|
-/// ((x ^ y) & M) ^ y
-/// | D |
-/// * If M is inverted:
-/// | D |
-/// ((x ^ y) & ~M) ^ y
-/// We can canonicalize by swapping the final xor operand
-/// to eliminate the 'not' of the mask.
-/// ((x ^ y) & M) ^ x
-/// * If M is a constant, and D has one use, we transform to 'and' / 'or' ops
-/// because that shortens the dependency chain and improves analysis:
-/// (x & M) | (y & ~M)
-static Instruction *visitMaskedMerge(BinaryOperator &I,
- InstCombiner::BuilderTy &Builder) {
- Value *B, *X, *D;
- Value *M;
- if (!match(&I, m_c_Xor(m_Value(B),
- m_OneUse(m_c_And(
- m_CombineAnd(m_c_Xor(m_Deferred(B), m_Value(X)),
- m_Value(D)),
- m_Value(M))))))
- return nullptr;
-
- Value *NotM;
- if (match(M, m_Not(m_Value(NotM)))) {
- // De-invert the mask and swap the value in B part.
- Value *NewA = Builder.CreateAnd(D, NotM);
- return BinaryOperator::CreateXor(NewA, X);
- }
-
- Constant *C;
- if (D->hasOneUse() && match(M, m_Constant(C))) {
- // Propagating undef is unsafe. Clamp undef elements to -1.
- Type *EltTy = C->getType()->getScalarType();
- C = Constant::replaceUndefsWith(C, ConstantInt::getAllOnesValue(EltTy));
- // Unfold.
- Value *LHS = Builder.CreateAnd(X, C);
- Value *NotC = Builder.CreateNot(C);
- Value *RHS = Builder.CreateAnd(B, NotC);
- return BinaryOperator::CreateOr(LHS, RHS);
- }
-
- return nullptr;
-}
-
-static Instruction *foldNotXor(BinaryOperator &I,
- InstCombiner::BuilderTy &Builder) {
- Value *X, *Y;
- // FIXME: one-use check is not needed in general, but currently we are unable
- // to fold 'not' into 'icmp', if that 'icmp' has multiple uses. (D35182)
- if (!match(&I, m_Not(m_OneUse(m_Xor(m_Value(X), m_Value(Y))))))
- return nullptr;
-
- auto hasCommonOperand = [](Value *A, Value *B, Value *C, Value *D) {
- return A == C || A == D || B == C || B == D;
- };
-
- Value *A, *B, *C, *D;
- // Canonicalize ~((A & B) ^ (A | ?)) -> (A & B) | ~(A | ?)
- // 4 commuted variants
- if (match(X, m_And(m_Value(A), m_Value(B))) &&
- match(Y, m_Or(m_Value(C), m_Value(D))) && hasCommonOperand(A, B, C, D)) {
- Value *NotY = Builder.CreateNot(Y);
- return BinaryOperator::CreateOr(X, NotY);
- };
-
- // Canonicalize ~((A | ?) ^ (A & B)) -> (A & B) | ~(A | ?)
- // 4 commuted variants
- if (match(Y, m_And(m_Value(A), m_Value(B))) &&
- match(X, m_Or(m_Value(C), m_Value(D))) && hasCommonOperand(A, B, C, D)) {
- Value *NotX = Builder.CreateNot(X);
- return BinaryOperator::CreateOr(Y, NotX);
- };
-
- return nullptr;
-}
-
-/// Canonicalize a shifty way to code absolute value to the more common pattern
-/// that uses negation and select.
-static Instruction *canonicalizeAbs(BinaryOperator &Xor,
- InstCombiner::BuilderTy &Builder) {
- assert(Xor.getOpcode() == Instruction::Xor && "Expected an xor instruction.");
-
- // There are 4 potential commuted variants. Move the 'ashr' candidate to Op1.
- // We're relying on the fact that we only do this transform when the shift has
- // exactly 2 uses and the add has exactly 1 use (otherwise, we might increase
- // instructions).
- Value *Op0 = Xor.getOperand(0), *Op1 = Xor.getOperand(1);
- if (Op0->hasNUses(2))
- std::swap(Op0, Op1);
-
- Type *Ty = Xor.getType();
- Value *A;
- const APInt *ShAmt;
- if (match(Op1, m_AShr(m_Value(A), m_APInt(ShAmt))) &&
- Op1->hasNUses(2) && *ShAmt == Ty->getScalarSizeInBits() - 1 &&
- match(Op0, m_OneUse(m_c_Add(m_Specific(A), m_Specific(Op1))))) {
- // Op1 = ashr i32 A, 31 ; smear the sign bit
- // xor (add A, Op1), Op1 ; add -1 and flip bits if negative
- // --> (A < 0) ? -A : A
- Value *IsNeg = Builder.CreateIsNeg(A);
- // Copy the nsw flags from the add to the negate.
- auto *Add = cast<BinaryOperator>(Op0);
- Value *NegA = Add->hasNoUnsignedWrap()
- ? Constant::getNullValue(A->getType())
- : Builder.CreateNeg(A, "", Add->hasNoSignedWrap());
- return SelectInst::Create(IsNeg, NegA, A);
- }
- return nullptr;
-}
-
-static bool canFreelyInvert(InstCombiner &IC, Value *Op,
- Instruction *IgnoredUser) {
- auto *I = dyn_cast<Instruction>(Op);
- return I && IC.isFreeToInvert(I, /*WillInvertAllUses=*/true) &&
- IC.canFreelyInvertAllUsersOf(I, IgnoredUser);
-}
-
-static Value *freelyInvert(InstCombinerImpl &IC, Value *Op,
- Instruction *IgnoredUser) {
- auto *I = cast<Instruction>(Op);
- IC.Builder.SetInsertPoint(*I->getInsertionPointAfterDef());
- Value *NotOp = IC.Builder.CreateNot(Op, Op->getName() + ".not");
- Op->replaceUsesWithIf(NotOp,
- [NotOp](Use &U) { return U.getUser() != NotOp; });
- IC.freelyInvertAllUsersOf(NotOp, IgnoredUser);
- return NotOp;
-}
-
-// Transform
-// z = ~(x &/| y)
-// into:
-// z = ((~x) |/& (~y))
-// iff both x and y are free to invert and all uses of z can be freely updated.
-bool InstCombinerImpl::sinkNotIntoLogicalOp(Instruction &I) {
- Value *Op0, *Op1;
- if (!match(&I, m_LogicalOp(m_Value(Op0), m_Value(Op1))))
- return false;
-
- // If this logic op has not been simplified yet, just bail out and let that
- // happen first. Otherwise, the code below may wrongly invert.
- if (Op0 == Op1)
- return false;
-
- Instruction::BinaryOps NewOpc =
- match(&I, m_LogicalAnd()) ? Instruction::Or : Instruction::And;
- bool IsBinaryOp = isa<BinaryOperator>(I);
-
- // Can our users be adapted?
- if (!InstCombiner::canFreelyInvertAllUsersOf(&I, /*IgnoredUser=*/nullptr))
- return false;
-
- // And can the operands be adapted?
- if (!canFreelyInvert(*this, Op0, &I) || !canFreelyInvert(*this, Op1, &I))
- return false;
-
- Op0 = freelyInvert(*this, Op0, &I);
- Op1 = freelyInvert(*this, Op1, &I);
-
- Builder.SetInsertPoint(*I.getInsertionPointAfterDef());
- Value *NewLogicOp;
- if (IsBinaryOp)
- NewLogicOp = Builder.CreateBinOp(NewOpc, Op0, Op1, I.getName() + ".not");
- else
- NewLogicOp =
- Builder.CreateLogicalOp(NewOpc, Op0, Op1, I.getName() + ".not");
-
- replaceInstUsesWith(I, NewLogicOp);
- // We can not just create an outer `not`, it will most likely be immediately
- // folded back, reconstructing our initial pattern, and causing an
- // infinite combine loop, so immediately manually fold it away.
- freelyInvertAllUsersOf(NewLogicOp);
- return true;
-}
-
-// Transform
-// z = (~x) &/| y
-// into:
-// z = ~(x |/& (~y))
-// iff y is free to invert and all uses of z can be freely updated.
-bool InstCombinerImpl::sinkNotIntoOtherHandOfLogicalOp(Instruction &I) {
- Value *Op0, *Op1;
- if (!match(&I, m_LogicalOp(m_Value(Op0), m_Value(Op1))))
- return false;
- Instruction::BinaryOps NewOpc =
- match(&I, m_LogicalAnd()) ? Instruction::Or : Instruction::And;
- bool IsBinaryOp = isa<BinaryOperator>(I);
-
- Value *NotOp0 = nullptr;
- Value *NotOp1 = nullptr;
- Value **OpToInvert = nullptr;
- if (match(Op0, m_Not(m_Value(NotOp0))) && canFreelyInvert(*this, Op1, &I)) {
- Op0 = NotOp0;
- OpToInvert = &Op1;
- } else if (match(Op1, m_Not(m_Value(NotOp1))) &&
- canFreelyInvert(*this, Op0, &I)) {
- Op1 = NotOp1;
- OpToInvert = &Op0;
- } else
- return false;
-
- // And can our users be adapted?
- if (!InstCombiner::canFreelyInvertAllUsersOf(&I, /*IgnoredUser=*/nullptr))
- return false;
-
- *OpToInvert = freelyInvert(*this, *OpToInvert, &I);
-
- Builder.SetInsertPoint(*I.getInsertionPointAfterDef());
- Value *NewBinOp;
- if (IsBinaryOp)
- NewBinOp = Builder.CreateBinOp(NewOpc, Op0, Op1, I.getName() + ".not");
- else
- NewBinOp = Builder.CreateLogicalOp(NewOpc, Op0, Op1, I.getName() + ".not");
- replaceInstUsesWith(I, NewBinOp);
- // We can not just create an outer `not`, it will most likely be immediately
- // folded back, reconstructing our initial pattern, and causing an
- // infinite combine loop, so immediately manually fold it away.
- freelyInvertAllUsersOf(NewBinOp);
- return true;
-}
-
-Instruction *InstCombinerImpl::foldNot(BinaryOperator &I) {
- Value *NotOp;
- if (!match(&I, m_Not(m_Value(NotOp))))
- return nullptr;
-
- // Apply DeMorgan's Law for 'nand' / 'nor' logic with an inverted operand.
- // We must eliminate the and/or (one-use) for these transforms to not increase
- // the instruction count.
- //
- // ~(~X & Y) --> (X | ~Y)
- // ~(Y & ~X) --> (X | ~Y)
- //
- // Note: The logical matches do not check for the commuted patterns because
- // those are handled via SimplifySelectsFeedingBinaryOp().
- Type *Ty = I.getType();
- Value *X, *Y;
- if (match(NotOp, m_OneUse(m_c_And(m_Not(m_Value(X)), m_Value(Y))))) {
- Value *NotY = Builder.CreateNot(Y, Y->getName() + ".not");
- return BinaryOperator::CreateOr(X, NotY);
- }
- if (match(NotOp, m_OneUse(m_LogicalAnd(m_Not(m_Value(X)), m_Value(Y))))) {
- Value *NotY = Builder.CreateNot(Y, Y->getName() + ".not");
- return SelectInst::Create(X, ConstantInt::getTrue(Ty), NotY);
- }
-
- // ~(~X | Y) --> (X & ~Y)
- // ~(Y | ~X) --> (X & ~Y)
- if (match(NotOp, m_OneUse(m_c_Or(m_Not(m_Value(X)), m_Value(Y))))) {
- Value *NotY = Builder.CreateNot(Y, Y->getName() + ".not");
- return BinaryOperator::CreateAnd(X, NotY);
- }
- if (match(NotOp, m_OneUse(m_LogicalOr(m_Not(m_Value(X)), m_Value(Y))))) {
- Value *NotY = Builder.CreateNot(Y, Y->getName() + ".not");
- return SelectInst::Create(X, NotY, ConstantInt::getFalse(Ty));
- }
-
- // Is this a 'not' (~) fed by a binary operator?
- BinaryOperator *NotVal;
- if (match(NotOp, m_BinOp(NotVal))) {
- // ~((-X) | Y) --> (X - 1) & (~Y)
- if (match(NotVal,
- m_OneUse(m_c_Or(m_OneUse(m_Neg(m_Value(X))), m_Value(Y))))) {
- Value *DecX = Builder.CreateAdd(X, ConstantInt::getAllOnesValue(Ty));
- Value *NotY = Builder.CreateNot(Y);
- return BinaryOperator::CreateAnd(DecX, NotY);
- }
-
- // ~(~X >>s Y) --> (X >>s Y)
- if (match(NotVal, m_AShr(m_Not(m_Value(X)), m_Value(Y))))
- return BinaryOperator::CreateAShr(X, Y);
-
- // Treat lshr with non-negative operand as ashr.
- // ~(~X >>u Y) --> (X >>s Y) iff X is known negative
- if (match(NotVal, m_LShr(m_Not(m_Value(X)), m_Value(Y))) &&
- isKnownNegative(X, SQ.getWithInstruction(NotVal)))
- return BinaryOperator::CreateAShr(X, Y);
-
- // Bit-hack form of a signbit test for iN type:
- // ~(X >>s (N - 1)) --> sext i1 (X > -1) to iN
- unsigned FullShift = Ty->getScalarSizeInBits() - 1;
- if (match(NotVal, m_OneUse(m_AShr(m_Value(X), m_SpecificInt(FullShift))))) {
- Value *IsNotNeg = Builder.CreateIsNotNeg(X, "isnotneg");
- return new SExtInst(IsNotNeg, Ty);
- }
-
- // If we are inverting a right-shifted constant, we may be able to eliminate
- // the 'not' by inverting the constant and using the opposite shift type.
- // Canonicalization rules ensure that only a negative constant uses 'ashr',
- // but we must check that in case that transform has not fired yet.
-
- // ~(C >>s Y) --> ~C >>u Y (when inverting the replicated sign bits)
- Constant *C;
- if (match(NotVal, m_AShr(m_Constant(C), m_Value(Y))) &&
- match(C, m_Negative()))
- return BinaryOperator::CreateLShr(ConstantExpr::getNot(C), Y);
-
- // ~(C >>u Y) --> ~C >>s Y (when inverting the replicated sign bits)
- if (match(NotVal, m_LShr(m_Constant(C), m_Value(Y))) &&
- match(C, m_NonNegative()))
- return BinaryOperator::CreateAShr(ConstantExpr::getNot(C), Y);
-
- // ~(X + C) --> ~C - X
- if (match(NotVal, m_Add(m_Value(X), m_ImmConstant(C))))
- return BinaryOperator::CreateSub(ConstantExpr::getNot(C), X);
-
- // ~(X - Y) --> ~X + Y
- // FIXME: is it really beneficial to sink the `not` here?
- if (match(NotVal, m_Sub(m_Value(X), m_Value(Y))))
- if (isa<Constant>(X) || NotVal->hasOneUse())
- return BinaryOperator::CreateAdd(Builder.CreateNot(X), Y);
-
- // ~(~X + Y) --> X - Y
- if (match(NotVal, m_c_Add(m_Not(m_Value(X)), m_Value(Y))))
- return BinaryOperator::CreateWithCopiedFlags(Instruction::Sub, X, Y,
- NotVal);
- }
-
- // not (cmp A, B) = !cmp A, B
- CmpPredicate Pred;
- if (match(NotOp, m_Cmp(Pred, m_Value(), m_Value())) &&
- (NotOp->hasOneUse() ||
- InstCombiner::canFreelyInvertAllUsersOf(cast<Instruction>(NotOp),
- /*IgnoredUser=*/nullptr))) {
- cast<CmpInst>(NotOp)->setPredicate(CmpInst::getInversePredicate(Pred));
- freelyInvertAllUsersOf(NotOp);
- return &I;
- }
-
- // Move a 'not' ahead of casts of a bool to enable logic reduction:
- // not (bitcast (sext i1 X)) --> bitcast (sext (not i1 X))
- if (match(NotOp, m_OneUse(m_BitCast(m_OneUse(m_SExt(m_Value(X)))))) && X->getType()->isIntOrIntVectorTy(1)) {
- Type *SextTy = cast<BitCastOperator>(NotOp)->getSrcTy();
- Value *NotX = Builder.CreateNot(X);
- Value *Sext = Builder.CreateSExt(NotX, SextTy);
- return new BitCastInst(Sext, Ty);
- }
-
- if (auto *NotOpI = dyn_cast<Instruction>(NotOp))
- if (sinkNotIntoLogicalOp(*NotOpI))
- return &I;
-
- // Eliminate a bitwise 'not' op of 'not' min/max by inverting the min/max:
- // ~min(~X, ~Y) --> max(X, Y)
- // ~max(~X, Y) --> min(X, ~Y)
- auto *II = dyn_cast<IntrinsicInst>(NotOp);
- if (II && II->hasOneUse()) {
- if (match(NotOp, m_c_MaxOrMin(m_Not(m_Value(X)), m_Value(Y)))) {
- Intrinsic::ID InvID = getInverseMinMaxIntrinsic(II->getIntrinsicID());
- Value *NotY = Builder.CreateNot(Y);
- Value *InvMaxMin = Builder.CreateBinaryIntrinsic(InvID, X, NotY);
- return replaceInstUsesWith(I, InvMaxMin);
- }
-
- if (II->getIntrinsicID() == Intrinsic::is_fpclass) {
- ConstantInt *ClassMask = cast<ConstantInt>(II->getArgOperand(1));
- II->setArgOperand(
- 1, ConstantInt::get(ClassMask->getType(),
- ~ClassMask->getZExtValue() & fcAllFlags));
- return replaceInstUsesWith(I, II);
- }
- }
-
- if (NotOp->hasOneUse()) {
- // Pull 'not' into operands of select if both operands are one-use compares
- // or one is one-use compare and the other one is a constant.
- // Inverting the predicates eliminates the 'not' operation.
- // Example:
- // not (select ?, (cmp TPred, ?, ?), (cmp FPred, ?, ?) -->
- // select ?, (cmp InvTPred, ?, ?), (cmp InvFPred, ?, ?)
- // not (select ?, (cmp TPred, ?, ?), true -->
- // select ?, (cmp InvTPred, ?, ?), false
- if (auto *Sel = dyn_cast<SelectInst>(NotOp)) {
- Value *TV = Sel->getTrueValue();
- Value *FV = Sel->getFalseValue();
- auto *CmpT = dyn_cast<CmpInst>(TV);
- auto *CmpF = dyn_cast<CmpInst>(FV);
- bool InvertibleT = (CmpT && CmpT->hasOneUse()) || isa<Constant>(TV);
- bool InvertibleF = (CmpF && CmpF->hasOneUse()) || isa<Constant>(FV);
- if (InvertibleT && InvertibleF) {
- if (CmpT)
- CmpT->setPredicate(CmpT->getInversePredicate());
- else
- Sel->setTrueValue(ConstantExpr::getNot(cast<Constant>(TV)));
- if (CmpF)
- CmpF->setPredicate(CmpF->getInversePredicate());
- else
- Sel->setFalseValue(ConstantExpr::getNot(cast<Constant>(FV)));
- return replaceInstUsesWith(I, Sel);
- }
- }
- }
-
- if (Instruction *NewXor = foldNotXor(I, Builder))
- return NewXor;
-
- // TODO: Could handle multi-use better by checking if all uses of NotOp (other
- // than I) can be inverted.
- if (Value *R = getFreelyInverted(NotOp, NotOp->hasOneUse(), &Builder))
- return replaceInstUsesWith(I, R);
-
- return nullptr;
-}
-
-// FIXME: We use commutative matchers (m_c_*) for some, but not all, matches
-// here. We should standardize that construct where it is needed or choose some
-// other way to ensure that commutated variants of patterns are not missed.
-Instruction *InstCombinerImpl::visitXor(BinaryOperator &I) {
- if (Value *V = simplifyXorInst(I.getOperand(0), I.getOperand(1),
- SQ.getWithInstruction(&I)))
- return replaceInstUsesWith(I, V);
-
- if (SimplifyAssociativeOrCommutative(I))
- return &I;
-
- if (Instruction *X = foldVectorBinop(I))
- return X;
-
- if (Instruction *Phi = foldBinopWithPhiOperands(I))
- return Phi;
-
- if (Instruction *NewXor = foldXorToXor(I, Builder))
- return NewXor;
-
- // (A&B)^(A&C) -> A&(B^C) etc
- if (Value *V = foldUsingDistributiveLaws(I))
- return replaceInstUsesWith(I, V);
-
- // See if we can simplify any instructions used by the instruction whose sole
- // purpose is to compute bits we don't care about.
- if (SimplifyDemandedInstructionBits(I))
- return &I;
-
- if (Instruction *R = foldNot(I))
- return R;
-
- if (Instruction *R = foldBinOpShiftWithShift(I))
- return R;
-
- Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
- Value *X, *Y, *M;
-
- // (X | Y) ^ M -> (X ^ M) ^ Y
- // (X | Y) ^ M -> (Y ^ M) ^ X
- if (match(&I, m_c_Xor(m_OneUse(m_DisjointOr(m_Value(X), m_Value(Y))),
- m_Value(M)))) {
- if (Value *XorAC = simplifyXorInst(X, M, SQ.getWithInstruction(&I)))
- return BinaryOperator::CreateXor(XorAC, Y);
-
- if (Value *XorBC = simplifyXorInst(Y, M, SQ.getWithInstruction(&I)))
- return BinaryOperator::CreateXor(XorBC, X);
- }
-
- // Fold (X & M) ^ (Y & ~M) -> (X & M) | (Y & ~M)
- // This it a special case in haveNoCommonBitsSet, but the computeKnownBits
- // calls in there are unnecessary as SimplifyDemandedInstructionBits should
- // have already taken care of those cases.
- if (match(&I, m_c_Xor(m_c_And(m_Not(m_Value(M)), m_Value()),
- m_c_And(m_Deferred(M), m_Value())))) {
- if (isGuaranteedNotToBeUndef(M))
- return BinaryOperator::CreateDisjointOr(Op0, Op1);
- else
- return BinaryOperator::CreateOr(Op0, Op1);
- }
-
- if (Instruction *Xor = visitMaskedMerge(I, Builder))
- return Xor;
-
- Constant *C1;
- if (match(Op1, m_Constant(C1))) {
- Constant *C2;
-
- if (match(Op0, m_OneUse(m_Or(m_Value(X), m_ImmConstant(C2)))) &&
- match(C1, m_ImmConstant())) {
- // (X | C2) ^ C1 --> (X & ~C2) ^ (C1^C2)
- C2 = Constant::replaceUndefsWith(
- C2, Constant::getAllOnesValue(C2->getType()->getScalarType()));
- Value *And = Builder.CreateAnd(
- X, Constant::mergeUndefsWith(ConstantExpr::getNot(C2), C1));
- return BinaryOperator::CreateXor(
- And, Constant::mergeUndefsWith(ConstantExpr::getXor(C1, C2), C1));
- }
-
- // Use DeMorgan and reassociation to eliminate a 'not' op.
- if (match(Op0, m_OneUse(m_Or(m_Not(m_Value(X)), m_Constant(C2))))) {
- // (~X | C2) ^ C1 --> ((X & ~C2) ^ -1) ^ C1 --> (X & ~C2) ^ ~C1
- Value *And = Builder.CreateAnd(X, ConstantExpr::getNot(C2));
- return BinaryOperator::CreateXor(And, ConstantExpr::getNot(C1));
- }
- if (match(Op0, m_OneUse(m_And(m_Not(m_Value(X)), m_Constant(C2))))) {
- // (~X & C2) ^ C1 --> ((X | ~C2) ^ -1) ^ C1 --> (X | ~C2) ^ ~C1
- Value *Or = Builder.CreateOr(X, ConstantExpr::getNot(C2));
- return BinaryOperator::CreateXor(Or, ConstantExpr::getNot(C1));
- }
-
- // Convert xor ([trunc] (ashr X, BW-1)), C =>
- // select(X >s -1, C, ~C)
- // The ashr creates "AllZeroOrAllOne's", which then optionally inverses the
- // constant depending on whether this input is less than 0.
- const APInt *CA;
- if (match(Op0, m_OneUse(m_TruncOrSelf(
- m_AShr(m_Value(X), m_APIntAllowPoison(CA))))) &&
- *CA == X->getType()->getScalarSizeInBits() - 1 &&
- !match(C1, m_AllOnes())) {
- assert(!C1->isZeroValue() && "Unexpected xor with 0");
- Value *IsNotNeg = Builder.CreateIsNotNeg(X);
- return SelectInst::Create(IsNotNeg, Op1, Builder.CreateNot(Op1));
- }
- }
-
- Type *Ty = I.getType();
- {
- const APInt *RHSC;
- if (match(Op1, m_APInt(RHSC))) {
- Value *X;
- const APInt *C;
- // (C - X) ^ signmaskC --> (C + signmaskC) - X
- if (RHSC->isSignMask() && match(Op0, m_Sub(m_APInt(C), m_Value(X))))
- return BinaryOperator::CreateSub(ConstantInt::get(Ty, *C + *RHSC), X);
-
- // (X + C) ^ signmaskC --> X + (C + signmaskC)
- if (RHSC->isSignMask() && match(Op0, m_Add(m_Value(X), m_APInt(C))))
- return BinaryOperator::CreateAdd(X, ConstantInt::get(Ty, *C + *RHSC));
-
- // (X | C) ^ RHSC --> X ^ (C ^ RHSC) iff X & C == 0
- if (match(Op0, m_Or(m_Value(X), m_APInt(C))) &&
- MaskedValueIsZero(X, *C, 0, &I))
- return BinaryOperator::CreateXor(X, ConstantInt::get(Ty, *C ^ *RHSC));
-
- // When X is a power-of-two or zero and zero input is poison:
- // ctlz(i32 X) ^ 31 --> cttz(X)
- // cttz(i32 X) ^ 31 --> ctlz(X)
- auto *II = dyn_cast<IntrinsicInst>(Op0);
- if (II && II->hasOneUse() && *RHSC == Ty->getScalarSizeInBits() - 1) {
- Intrinsic::ID IID = II->getIntrinsicID();
- if ((IID == Intrinsic::ctlz || IID == Intrinsic::cttz) &&
- match(II->getArgOperand(1), m_One()) &&
- isKnownToBeAPowerOfTwo(II->getArgOperand(0), /*OrZero */ true)) {
- IID = (IID == Intrinsic::ctlz) ? Intrinsic::cttz : Intrinsic::ctlz;
- Function *F =
- Intrinsic::getOrInsertDeclaration(II->getModule(), IID, Ty);
- return CallInst::Create(F, {II->getArgOperand(0), Builder.getTrue()});
- }
- }
-
- // If RHSC is inverting the remaining bits of shifted X,
- // canonicalize to a 'not' before the shift to help SCEV and codegen:
- // (X << C) ^ RHSC --> ~X << C
- if (match(Op0, m_OneUse(m_Shl(m_Value(X), m_APInt(C)))) &&
- *RHSC == APInt::getAllOnes(Ty->getScalarSizeInBits()).shl(*C)) {
- Value *NotX = Builder.CreateNot(X);
- return BinaryOperator::CreateShl(NotX, ConstantInt::get(Ty, *C));
- }
- // (X >>u C) ^ RHSC --> ~X >>u C
- if (match(Op0, m_OneUse(m_LShr(m_Value(X), m_APInt(C)))) &&
- *RHSC == APInt::getAllOnes(Ty->getScalarSizeInBits()).lshr(*C)) {
- Value *NotX = Builder.CreateNot(X);
- return BinaryOperator::CreateLShr(NotX, ConstantInt::get(Ty, *C));
- }
- // TODO: We could handle 'ashr' here as well. That would be matching
- // a 'not' op and moving it before the shift. Doing that requires
- // preventing the inverse fold in canShiftBinOpWithConstantRHS().
- }
-
- // If we are XORing the sign bit of a floating-point value, convert
- // this to fneg, then cast back to integer.
- //
- // This is generous interpretation of noimplicitfloat, this is not a true
- // floating-point operation.
- //
- // Assumes any IEEE-represented type has the sign bit in the high bit.
- // TODO: Unify with APInt matcher. This version allows undef unlike m_APInt
- Value *CastOp;
- if (match(Op0, m_ElementWiseBitCast(m_Value(CastOp))) &&
- match(Op1, m_SignMask()) &&
- !Builder.GetInsertBlock()->getParent()->hasFnAttribute(
- Attribute::NoImplicitFloat)) {
- Type *EltTy = CastOp->getType()->getScalarType();
- if (EltTy->isFloatingPointTy() && EltTy->isIEEE()) {
- Value *FNeg = Builder.CreateFNeg(CastOp);
- return new BitCastInst(FNeg, I.getType());
- }
- }
- }
-
- // FIXME: This should not be limited to scalar (pull into APInt match above).
- {
- Value *X;
- ConstantInt *C1, *C2, *C3;
- // ((X^C1) >> C2) ^ C3 -> (X>>C2) ^ ((C1>>C2)^C3)
- if (match(Op1, m_ConstantInt(C3)) &&
- match(Op0, m_LShr(m_Xor(m_Value(X), m_ConstantInt(C1)),
- m_ConstantInt(C2))) &&
- Op0->hasOneUse()) {
- // fold (C1 >> C2) ^ C3
- APInt FoldConst = C1->getValue().lshr(C2->getValue());
- FoldConst ^= C3->getValue();
- // Prepare the two operands.
- auto *Opnd0 = Builder.CreateLShr(X, C2);
- Opnd0->takeName(Op0);
- return BinaryOperator::CreateXor(Opnd0, ConstantInt::get(Ty, FoldConst));
- }
- }
-
- if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
- return FoldedLogic;
-
- // Y ^ (X | Y) --> X & ~Y
- // Y ^ (Y | X) --> X & ~Y
- if (match(Op1, m_OneUse(m_c_Or(m_Value(X), m_Specific(Op0)))))
- return BinaryOperator::CreateAnd(X, Builder.CreateNot(Op0));
- // (X | Y) ^ Y --> X & ~Y
- // (Y | X) ^ Y --> X & ~Y
- if (match(Op0, m_OneUse(m_c_Or(m_Value(X), m_Specific(Op1)))))
- return BinaryOperator::CreateAnd(X, Builder.CreateNot(Op1));
-
- // Y ^ (X & Y) --> ~X & Y
- // Y ^ (Y & X) --> ~X & Y
- if (match(Op1, m_OneUse(m_c_And(m_Value(X), m_Specific(Op0)))))
- return BinaryOperator::CreateAnd(Op0, Builder.CreateNot(X));
- // (X & Y) ^ Y --> ~X & Y
- // (Y & X) ^ Y --> ~X & Y
- // Canonical form is (X & C) ^ C; don't touch that.
- // TODO: A 'not' op is better for analysis and codegen, but demanded bits must
- // be fixed to prefer that (otherwise we get infinite looping).
- if (!match(Op1, m_Constant()) &&
- match(Op0, m_OneUse(m_c_And(m_Value(X), m_Specific(Op1)))))
- return BinaryOperator::CreateAnd(Op1, Builder.CreateNot(X));
-
- Value *A, *B, *C;
- // (A ^ B) ^ (A | C) --> (~A & C) ^ B -- There are 4 commuted variants.
- if (match(&I, m_c_Xor(m_OneUse(m_Xor(m_Value(A), m_Value(B))),
- m_OneUse(m_c_Or(m_Deferred(A), m_Value(C))))))
- return BinaryOperator::CreateXor(
- Builder.CreateAnd(Builder.CreateNot(A), C), B);
-
- // (A ^ B) ^ (B | C) --> (~B & C) ^ A -- There are 4 commuted variants.
- if (match(&I, m_c_Xor(m_OneUse(m_Xor(m_Value(A), m_Value(B))),
- m_OneUse(m_c_Or(m_Deferred(B), m_Value(C))))))
- return BinaryOperator::CreateXor(
- Builder.CreateAnd(Builder.CreateNot(B), C), A);
-
- // (A & B) ^ (A ^ B) -> (A | B)
- if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
- match(Op1, m_c_Xor(m_Specific(A), m_Specific(B))))
- return BinaryOperator::CreateOr(A, B);
- // (A ^ B) ^ (A & B) -> (A | B)
- if (match(Op0, m_Xor(m_Value(A), m_Value(B))) &&
- match(Op1, m_c_And(m_Specific(A), m_Specific(B))))
- return BinaryOperator::CreateOr(A, B);
-
- // (A & ~B) ^ ~A -> ~(A & B)
- // (~B & A) ^ ~A -> ~(A & B)
- if (match(Op0, m_c_And(m_Value(A), m_Not(m_Value(B)))) &&
- match(Op1, m_Not(m_Specific(A))))
- return BinaryOperator::CreateNot(Builder.CreateAnd(A, B));
-
- // (~A & B) ^ A --> A | B -- There are 4 commuted variants.
- if (match(&I, m_c_Xor(m_c_And(m_Not(m_Value(A)), m_Value(B)), m_Deferred(A))))
- return BinaryOperator::CreateOr(A, B);
-
- // (~A | B) ^ A --> ~(A & B)
- if (match(Op0, m_OneUse(m_c_Or(m_Not(m_Specific(Op1)), m_Value(B)))))
- return BinaryOperator::CreateNot(Builder.CreateAnd(Op1, B));
-
- // A ^ (~A | B) --> ~(A & B)
- if (match(Op1, m_OneUse(m_c_Or(m_Not(m_Specific(Op0)), m_Value(B)))))
- return BinaryOperator::CreateNot(Builder.CreateAnd(Op0, B));
-
- // (A | B) ^ (A | C) --> (B ^ C) & ~A -- There are 4 commuted variants.
- // TODO: Loosen one-use restriction if common operand is a constant.
- Value *D;
- if (match(Op0, m_OneUse(m_Or(m_Value(A), m_Value(B)))) &&
- match(Op1, m_OneUse(m_Or(m_Value(C), m_Value(D))))) {
- if (B == C || B == D)
- std::swap(A, B);
- if (A == C)
- std::swap(C, D);
- if (A == D) {
- Value *NotA = Builder.CreateNot(A);
- return BinaryOperator::CreateAnd(Builder.CreateXor(B, C), NotA);
- }
- }
-
- // (A & B) ^ (A | C) --> A ? ~B : C -- There are 4 commuted variants.
- if (I.getType()->isIntOrIntVectorTy(1) &&
- match(&I, m_c_Xor(m_OneUse(m_LogicalAnd(m_Value(A), m_Value(B))),
- m_OneUse(m_LogicalOr(m_Value(C), m_Value(D)))))) {
- bool NeedFreeze = isa<SelectInst>(Op0) && isa<SelectInst>(Op1) && B == D;
- if (B == C || B == D)
- std::swap(A, B);
- if (A == C)
- std::swap(C, D);
- if (A == D) {
- if (NeedFreeze)
- A = Builder.CreateFreeze(A);
- Value *NotB = Builder.CreateNot(B);
- return SelectInst::Create(A, NotB, C);
- }
- }
-
- if (auto *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
- if (auto *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
- if (Value *V = foldXorOfICmps(LHS, RHS, I))
- return replaceInstUsesWith(I, V);
-
- if (Instruction *CastedXor = foldCastedBitwiseLogic(I))
- return CastedXor;
-
- if (Instruction *Abs = canonicalizeAbs(I, Builder))
- return Abs;
-
- // Otherwise, if all else failed, try to hoist the xor-by-constant:
- // (X ^ C) ^ Y --> (X ^ Y) ^ C
- // Just like we do in other places, we completely avoid the fold
- // for constantexprs, at least to avoid endless combine loop.
- if (match(&I, m_c_Xor(m_OneUse(m_Xor(m_CombineAnd(m_Value(X),
- m_Unless(m_ConstantExpr())),
- m_ImmConstant(C1))),
- m_Value(Y))))
- return BinaryOperator::CreateXor(Builder.CreateXor(X, Y), C1);
-
- if (Instruction *R = reassociateForUses(I, Builder))
- return R;
-
- if (Instruction *Canonicalized = canonicalizeLogicFirst(I, Builder))
- return Canonicalized;
-
- if (Instruction *Folded = foldLogicOfIsFPClass(I, Op0, Op1))
- return Folded;
-
- if (Instruction *Folded = canonicalizeConditionalNegationViaMathToSelect(I))
- return Folded;
-
- if (Instruction *Res = foldBinOpOfDisplacedShifts(I))
- return Res;
-
- if (Instruction *Res = foldBitwiseLogicWithIntrinsics(I, Builder))
- return Res;
-
- return nullptr;
-}
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