[llvm] r247088 - Revert r247080, "LowerBitSets: Extend pass to support functions as bitset
Peter Collingbourne via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 8 15:33:24 PDT 2015
Author: pcc
Date: Tue Sep 8 17:33:23 2015
New Revision: 247088
URL: http://llvm.org/viewvc/llvm-project?rev=247088&view=rev
Log:
Revert r247080, "LowerBitSets: Extend pass to support functions as bitset
members." as it causes test failures on a number of bots.
Removed:
llvm/trunk/test/Transforms/LowerBitSets/function-ext.ll
llvm/trunk/test/Transforms/LowerBitSets/function.ll
llvm/trunk/test/Transforms/LowerBitSets/nonstring.ll
Modified:
llvm/trunk/docs/BitSets.rst
llvm/trunk/docs/LangRef.rst
llvm/trunk/include/llvm/Transforms/IPO/LowerBitSets.h
llvm/trunk/lib/Transforms/IPO/LowerBitSets.cpp
llvm/trunk/test/Transforms/LowerBitSets/simple.ll
Modified: llvm/trunk/docs/BitSets.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/BitSets.rst?rev=247088&r1=247087&r2=247088&view=diff
==============================================================================
--- llvm/trunk/docs/BitSets.rst (original)
+++ llvm/trunk/docs/BitSets.rst Tue Sep 8 17:33:23 2015
@@ -10,41 +10,17 @@ for the type of the class or its derived
To use the mechanism, a client creates a global metadata node named
``llvm.bitsets``. Each element is a metadata node with three elements:
-
-1. a metadata object representing an identifier for the bitset
-2. either a global variable or a function
-3. a byte offset into the global (generally zero for functions)
-
-Each bitset must exclusively contain either global variables or functions.
-
-.. admonition:: Limitation
-
- The current implementation only supports functions as members of bitsets on
- the x86-32 and x86-64 architectures.
+the first is a metadata string containing an identifier for the bitset,
+the second is a global variable and the third is a byte offset into the
+global variable.
This will cause a link-time optimization pass to generate bitsets from the
-memory addresses referenced from the elements of the bitset metadata. The
-pass will lay out referenced global variables consecutively, so their
-definitions must be available at LTO time.
-
-A bit set containing functions is transformed into a jump table, which
-is a block of code consisting of one branch instruction for each of the
-functions in the bit set that branches to the target function, and redirect
-any taken function addresses to the corresponding jump table entry. In the
-object file's symbol table, the jump table entries take the identities of
-the original functions, so that addresses taken outside the module will pass
-any verification done inside the module.
-
-Jump tables may call external functions, so their definitions need not
-be available at LTO time. Note that if an externally defined function is a
-member of a bitset, there is no guarantee that its identity within the module
-will be the same as its identity outside of the module, as the former will
-be the jump table entry if a jump table is necessary.
-
-The `GlobalLayoutBuilder`_ class is responsible for laying out the globals
-efficiently to minimize the sizes of the underlying bitsets. An intrinsic,
-:ref:`llvm.bitset.test <bitset.test>`, generates code to test whether a
-given pointer is a member of a bitset.
+memory addresses referenced from the elements of the bitset metadata. The pass
+will lay out the referenced globals consecutively, so their definitions must
+be available at LTO time. The `GlobalLayoutBuilder`_ class is responsible for
+laying out the globals efficiently to minimize the sizes of the underlying
+bitsets. An intrinsic, :ref:`llvm.bitset.test <bitset.test>`, generates code
+to test whether a given pointer is a member of a bitset.
:Example:
@@ -57,25 +33,13 @@ given pointer is a member of a bitset.
@c = internal global i32 0
@d = internal global [2 x i32] [i32 0, i32 0]
- define void @e() {
- ret void
- }
-
- define void @f() {
- ret void
- }
-
- declare void @g()
-
- !llvm.bitsets = !{!0, !1, !2, !3, !4, !5, !6}
+ !llvm.bitsets = !{!0, !1, !2, !3, !4}
!0 = !{!"bitset1", i32* @a, i32 0}
!1 = !{!"bitset1", i32* @b, i32 0}
!2 = !{!"bitset2", i32* @b, i32 0}
!3 = !{!"bitset2", i32* @c, i32 0}
!4 = !{!"bitset2", i32* @d, i32 4}
- !5 = !{!"bitset3", void ()* @e, i32 0}
- !6 = !{!"bitset3", void ()* @g, i32 0}
declare i1 @llvm.bitset.test(i8* %ptr, metadata %bitset) nounwind readnone
@@ -91,12 +55,6 @@ given pointer is a member of a bitset.
ret i1 %x
}
- define i1 @baz(void ()* %p) {
- %pi8 = bitcast void ()* %p to i8*
- %x = call i1 @llvm.bitset.test(i8* %pi8, metadata !"bitset3")
- ret i1 %x
- }
-
define void @main() {
%a1 = call i1 @foo(i32* @a) ; returns 1
%b1 = call i1 @foo(i32* @b) ; returns 1
@@ -106,9 +64,6 @@ given pointer is a member of a bitset.
%c2 = call i1 @bar(i32* @c) ; returns 1
%d02 = call i1 @bar(i32* getelementptr ([2 x i32]* @d, i32 0, i32 0)) ; returns 0
%d12 = call i1 @bar(i32* getelementptr ([2 x i32]* @d, i32 0, i32 1)) ; returns 1
- %e = call i1 @baz(void ()* @e) ; returns 1
- %f = call i1 @baz(void ()* @f) ; returns 0
- %g = call i1 @baz(void ()* @g) ; returns 1
ret void
}
Modified: llvm/trunk/docs/LangRef.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/LangRef.rst?rev=247088&r1=247087&r2=247088&view=diff
==============================================================================
--- llvm/trunk/docs/LangRef.rst (original)
+++ llvm/trunk/docs/LangRef.rst Tue Sep 8 17:33:23 2015
@@ -11837,7 +11837,7 @@ Arguments:
""""""""""
The first argument is a pointer to be tested. The second argument is a
-metadata object representing an identifier for a :doc:`bitset <BitSets>`.
+metadata string containing the name of a :doc:`bitset <BitSets>`.
Overview:
"""""""""
Modified: llvm/trunk/include/llvm/Transforms/IPO/LowerBitSets.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/IPO/LowerBitSets.h?rev=247088&r1=247087&r2=247088&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/IPO/LowerBitSets.h (original)
+++ llvm/trunk/include/llvm/Transforms/IPO/LowerBitSets.h Tue Sep 8 17:33:23 2015
@@ -26,7 +26,7 @@
namespace llvm {
class DataLayout;
-class GlobalObject;
+class GlobalVariable;
class Value;
class raw_ostream;
@@ -56,7 +56,7 @@ struct BitSetInfo {
bool containsGlobalOffset(uint64_t Offset) const;
bool containsValue(const DataLayout &DL,
- const DenseMap<GlobalObject *, uint64_t> &GlobalLayout,
+ const DenseMap<GlobalVariable *, uint64_t> &GlobalLayout,
Value *V, uint64_t COffset = 0) const;
void print(raw_ostream &OS) const;
Modified: llvm/trunk/lib/Transforms/IPO/LowerBitSets.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/LowerBitSets.cpp?rev=247088&r1=247087&r2=247088&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/LowerBitSets.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/LowerBitSets.cpp Tue Sep 8 17:33:23 2015
@@ -19,8 +19,6 @@
#include "llvm/ADT/Triple.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/GlobalObject.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instructions.h"
@@ -63,9 +61,9 @@ bool BitSetInfo::containsGlobalOffset(ui
bool BitSetInfo::containsValue(
const DataLayout &DL,
- const DenseMap<GlobalObject *, uint64_t> &GlobalLayout, Value *V,
+ const DenseMap<GlobalVariable *, uint64_t> &GlobalLayout, Value *V,
uint64_t COffset) const {
- if (auto GV = dyn_cast<GlobalObject>(V)) {
+ if (auto GV = dyn_cast<GlobalVariable>(V)) {
auto I = GlobalLayout.find(GV);
if (I == GlobalLayout.end())
return false;
@@ -213,48 +211,34 @@ struct LowerBitSets : public ModulePass
Module *M;
bool LinkerSubsectionsViaSymbols;
- Triple::ArchType Arch;
- Triple::ObjectFormatType ObjectFormat;
IntegerType *Int1Ty;
IntegerType *Int8Ty;
IntegerType *Int32Ty;
Type *Int32PtrTy;
IntegerType *Int64Ty;
- IntegerType *IntPtrTy;
+ Type *IntPtrTy;
// The llvm.bitsets named metadata.
NamedMDNode *BitSetNM;
- // Mapping from bitset identifiers to the call sites that test them.
- DenseMap<Metadata *, std::vector<CallInst *>> BitSetTestCallSites;
+ // Mapping from bitset mdstrings to the call sites that test them.
+ DenseMap<MDString *, std::vector<CallInst *>> BitSetTestCallSites;
std::vector<ByteArrayInfo> ByteArrayInfos;
BitSetInfo
- buildBitSet(Metadata *BitSet,
- const DenseMap<GlobalObject *, uint64_t> &GlobalLayout);
+ buildBitSet(MDString *BitSet,
+ const DenseMap<GlobalVariable *, uint64_t> &GlobalLayout);
ByteArrayInfo *createByteArray(BitSetInfo &BSI);
void allocateByteArrays();
Value *createBitSetTest(IRBuilder<> &B, BitSetInfo &BSI, ByteArrayInfo *&BAI,
Value *BitOffset);
- void lowerBitSetCalls(ArrayRef<Metadata *> BitSets,
- Constant *CombinedGlobalAddr,
- const DenseMap<GlobalObject *, uint64_t> &GlobalLayout);
Value *
lowerBitSetCall(CallInst *CI, BitSetInfo &BSI, ByteArrayInfo *&BAI,
- Constant *CombinedGlobal,
- const DenseMap<GlobalObject *, uint64_t> &GlobalLayout);
- void buildBitSetsFromGlobalVariables(ArrayRef<Metadata *> BitSets,
- ArrayRef<GlobalVariable *> Globals);
- unsigned getJumpTableEntrySize();
- Type *getJumpTableEntryType();
- Constant *createJumpTableEntry(GlobalObject *Src, Function *Dest,
- unsigned Distance);
- void verifyBitSetMDNode(MDNode *Op);
- void buildBitSetsFromFunctions(ArrayRef<Metadata *> BitSets,
- ArrayRef<Function *> Functions);
- void buildBitSetsFromDisjointSet(ArrayRef<Metadata *> BitSets,
- ArrayRef<GlobalObject *> Globals);
+ GlobalVariable *CombinedGlobal,
+ const DenseMap<GlobalVariable *, uint64_t> &GlobalLayout);
+ void buildBitSetsFromGlobals(const std::vector<MDString *> &BitSets,
+ const std::vector<GlobalVariable *> &Globals);
bool buildBitSets();
bool eraseBitSetMetadata();
@@ -278,8 +262,6 @@ bool LowerBitSets::doInitialization(Modu
Triple TargetTriple(M->getTargetTriple());
LinkerSubsectionsViaSymbols = TargetTriple.isMacOSX();
- Arch = TargetTriple.getArch();
- ObjectFormat = TargetTriple.getObjectFormat();
Int1Ty = Type::getInt1Ty(M->getContext());
Int8Ty = Type::getInt8Ty(M->getContext());
@@ -298,8 +280,8 @@ bool LowerBitSets::doInitialization(Modu
/// Build a bit set for BitSet using the object layouts in
/// GlobalLayout.
BitSetInfo LowerBitSets::buildBitSet(
- Metadata *BitSet,
- const DenseMap<GlobalObject *, uint64_t> &GlobalLayout) {
+ MDString *BitSet,
+ const DenseMap<GlobalVariable *, uint64_t> &GlobalLayout) {
BitSetBuilder BSB;
// Compute the byte offset of each element of this bitset.
@@ -307,11 +289,8 @@ BitSetInfo LowerBitSets::buildBitSet(
for (MDNode *Op : BitSetNM->operands()) {
if (Op->getOperand(0) != BitSet || !Op->getOperand(1))
continue;
- Constant *OpConst =
- cast<ConstantAsMetadata>(Op->getOperand(1))->getValue();
- if (auto GA = dyn_cast<GlobalAlias>(OpConst))
- OpConst = GA->getAliasee();
- auto OpGlobal = dyn_cast<GlobalObject>(OpConst);
+ auto OpGlobal = dyn_cast<GlobalVariable>(
+ cast<ConstantAsMetadata>(Op->getOperand(1))->getValue());
if (!OpGlobal)
continue;
uint64_t Offset =
@@ -460,16 +439,17 @@ Value *LowerBitSets::createBitSetTest(IR
/// replace the call with.
Value *LowerBitSets::lowerBitSetCall(
CallInst *CI, BitSetInfo &BSI, ByteArrayInfo *&BAI,
- Constant *CombinedGlobalIntAddr,
- const DenseMap<GlobalObject *, uint64_t> &GlobalLayout) {
+ GlobalVariable *CombinedGlobal,
+ const DenseMap<GlobalVariable *, uint64_t> &GlobalLayout) {
Value *Ptr = CI->getArgOperand(0);
const DataLayout &DL = M->getDataLayout();
if (BSI.containsValue(DL, GlobalLayout, Ptr))
- return ConstantInt::getTrue(M->getContext());
+ return ConstantInt::getTrue(CombinedGlobal->getParent()->getContext());
+ Constant *GlobalAsInt = ConstantExpr::getPtrToInt(CombinedGlobal, IntPtrTy);
Constant *OffsetedGlobalAsInt = ConstantExpr::getAdd(
- CombinedGlobalIntAddr, ConstantInt::get(IntPtrTy, BSI.ByteOffset));
+ GlobalAsInt, ConstantInt::get(IntPtrTy, BSI.ByteOffset));
BasicBlock *InitialBB = CI->getParent();
@@ -528,19 +508,18 @@ Value *LowerBitSets::lowerBitSetCall(
/// Given a disjoint set of bitsets and globals, layout the globals, build the
/// bit sets and lower the llvm.bitset.test calls.
-void LowerBitSets::buildBitSetsFromGlobalVariables(
- ArrayRef<Metadata *> BitSets, ArrayRef<GlobalVariable *> Globals) {
+void LowerBitSets::buildBitSetsFromGlobals(
+ const std::vector<MDString *> &BitSets,
+ const std::vector<GlobalVariable *> &Globals) {
// Build a new global with the combined contents of the referenced globals.
- // This global is a struct whose even-indexed elements contain the original
- // contents of the referenced globals and whose odd-indexed elements contain
- // any padding required to align the next element to the next power of 2.
std::vector<Constant *> GlobalInits;
const DataLayout &DL = M->getDataLayout();
for (GlobalVariable *G : Globals) {
GlobalInits.push_back(G->getInitializer());
uint64_t InitSize = DL.getTypeAllocSize(G->getInitializer()->getType());
- // Compute the amount of padding required.
+ // Compute the amount of padding required to align the next element to the
+ // next power of 2.
uint64_t Padding = NextPowerOf2(InitSize - 1) - InitSize;
// Cap at 128 was found experimentally to have a good data/instruction
@@ -562,12 +541,30 @@ void LowerBitSets::buildBitSetsFromGloba
DL.getStructLayout(cast<StructType>(NewInit->getType()));
// Compute the offsets of the original globals within the new global.
- DenseMap<GlobalObject *, uint64_t> GlobalLayout;
+ DenseMap<GlobalVariable *, uint64_t> GlobalLayout;
for (unsigned I = 0; I != Globals.size(); ++I)
// Multiply by 2 to account for padding elements.
GlobalLayout[Globals[I]] = CombinedGlobalLayout->getElementOffset(I * 2);
- lowerBitSetCalls(BitSets, CombinedGlobal, GlobalLayout);
+ // For each bitset in this disjoint set...
+ for (MDString *BS : BitSets) {
+ // Build the bitset.
+ BitSetInfo BSI = buildBitSet(BS, GlobalLayout);
+ DEBUG({
+ dbgs() << BS->getString() << ": ";
+ BSI.print(dbgs());
+ });
+
+ ByteArrayInfo *BAI = 0;
+
+ // Lower each call to llvm.bitset.test for this bitset.
+ for (CallInst *CI : BitSetTestCallSites[BS]) {
+ ++NumBitSetCallsLowered;
+ Value *Lowered = lowerBitSetCall(CI, BSI, BAI, CombinedGlobal, GlobalLayout);
+ CI->replaceAllUsesWith(Lowered);
+ CI->eraseFromParent();
+ }
+ }
// Build aliases pointing to offsets into the combined global for each
// global from which we built the combined global, and replace references
@@ -584,7 +581,6 @@ void LowerBitSets::buildBitSetsFromGloba
GlobalAlias *GAlias =
GlobalAlias::create(Globals[I]->getType(), Globals[I]->getLinkage(),
"", CombinedGlobalElemPtr, M);
- GAlias->setVisibility(Globals[I]->getVisibility());
GAlias->takeName(Globals[I]);
Globals[I]->replaceAllUsesWith(GAlias);
}
@@ -592,330 +588,6 @@ void LowerBitSets::buildBitSetsFromGloba
}
}
-void LowerBitSets::lowerBitSetCalls(
- ArrayRef<Metadata *> BitSets, Constant *CombinedGlobalAddr,
- const DenseMap<GlobalObject *, uint64_t> &GlobalLayout) {
- Constant *CombinedGlobalIntAddr =
- ConstantExpr::getPtrToInt(CombinedGlobalAddr, IntPtrTy);
-
- // For each bitset in this disjoint set...
- for (Metadata *BS : BitSets) {
- // Build the bitset.
- BitSetInfo BSI = buildBitSet(BS, GlobalLayout);
- DEBUG({
- if (auto BSS = dyn_cast<MDString>(BS))
- dbgs() << BSS->getString() << ": ";
- else
- dbgs() << "<unnamed>: ";
- BSI.print(dbgs());
- });
-
- ByteArrayInfo *BAI = 0;
-
- // Lower each call to llvm.bitset.test for this bitset.
- for (CallInst *CI : BitSetTestCallSites[BS]) {
- ++NumBitSetCallsLowered;
- Value *Lowered =
- lowerBitSetCall(CI, BSI, BAI, CombinedGlobalIntAddr, GlobalLayout);
- CI->replaceAllUsesWith(Lowered);
- CI->eraseFromParent();
- }
- }
-}
-
-void LowerBitSets::verifyBitSetMDNode(MDNode *Op) {
- if (Op->getNumOperands() != 3)
- report_fatal_error(
- "All operands of llvm.bitsets metadata must have 3 elements");
- if (!Op->getOperand(1))
- return;
-
- auto OpConstMD = dyn_cast<ConstantAsMetadata>(Op->getOperand(1));
- if (!OpConstMD)
- report_fatal_error("Bit set element must be a constant");
- auto OpGlobal = dyn_cast<GlobalObject>(OpConstMD->getValue());
- if (!OpGlobal)
- return;
-
- if (OpGlobal->isThreadLocal())
- report_fatal_error("Bit set element may not be thread-local");
- if (OpGlobal->hasSection())
- report_fatal_error("Bit set element may not have an explicit section");
-
- if (isa<GlobalVariable>(OpGlobal) && OpGlobal->isDeclarationForLinker())
- report_fatal_error("Bit set global var element must be a definition");
-
- auto OffsetConstMD = dyn_cast<ConstantAsMetadata>(Op->getOperand(2));
- if (!OffsetConstMD)
- report_fatal_error("Bit set element offset must be a constant");
- auto OffsetInt = dyn_cast<ConstantInt>(OffsetConstMD->getValue());
- if (!OffsetInt)
- report_fatal_error("Bit set element offset must be an integer constant");
-}
-
-static const unsigned kX86JumpTableEntrySize = 8;
-
-unsigned LowerBitSets::getJumpTableEntrySize() {
- if (Arch != Triple::x86 && Arch != Triple::x86_64)
- report_fatal_error("Unsupported architecture for jump tables");
-
- return kX86JumpTableEntrySize;
-}
-
-// Create a constant representing a jump table entry for the target. This
-// consists of an instruction sequence containing a relative branch to Dest. The
-// constant will be laid out at address Src+(Len*Distance) where Len is the
-// target-specific jump table entry size.
-Constant *LowerBitSets::createJumpTableEntry(GlobalObject *Src, Function *Dest,
- unsigned Distance) {
- if (Arch != Triple::x86 && Arch != Triple::x86_64)
- report_fatal_error("Unsupported architecture for jump tables");
-
- const unsigned kJmpPCRel32Code = 0xe9;
- const unsigned kInt3Code = 0xcc;
-
- ConstantInt *Jmp = ConstantInt::get(Int8Ty, kJmpPCRel32Code);
-
- // Build a constant representing the displacement between the constant's
- // address and Dest. This will resolve to a PC32 relocation referring to Dest.
- Constant *DestInt = ConstantExpr::getPtrToInt(Dest, IntPtrTy);
- Constant *SrcInt = ConstantExpr::getPtrToInt(Src, IntPtrTy);
- Constant *Disp = ConstantExpr::getSub(DestInt, SrcInt);
- ConstantInt *DispOffset =
- ConstantInt::get(IntPtrTy, Distance * kX86JumpTableEntrySize + 5);
- Constant *OffsetedDisp = ConstantExpr::getSub(Disp, DispOffset);
- OffsetedDisp = ConstantExpr::getTrunc(OffsetedDisp, Int32Ty);
-
- ConstantInt *Int3 = ConstantInt::get(Int8Ty, kInt3Code);
-
- Constant *Fields[] = {
- Jmp, OffsetedDisp, Int3, Int3, Int3,
- };
- return ConstantStruct::getAnon(Fields, /*Packed=*/true);
-}
-
-Type *LowerBitSets::getJumpTableEntryType() {
- if (Arch != Triple::x86 && Arch != Triple::x86_64)
- report_fatal_error("Unsupported architecture for jump tables");
-
- return StructType::get(M->getContext(),
- {Int8Ty, Int32Ty, Int8Ty, Int8Ty, Int8Ty},
- /*Packed=*/true);
-}
-
-/// Given a disjoint set of bitsets and functions, build a jump table for the
-/// functions, build the bit sets and lower the llvm.bitset.test calls.
-void LowerBitSets::buildBitSetsFromFunctions(ArrayRef<Metadata *> BitSets,
- ArrayRef<Function *> Functions) {
- // Unlike the global bitset builder, the function bitset builder cannot
- // re-arrange functions in a particular order and base its calculations on the
- // layout of the functions' entry points, as we have no idea how large a
- // particular function will end up being (the size could even depend on what
- // this pass does!) Instead, we build a jump table, which is a block of code
- // consisting of one branch instruction for each of the functions in the bit
- // set that branches to the target function, and redirect any taken function
- // addresses to the corresponding jump table entry. In the object file's
- // symbol table, the symbols for the target functions also refer to the jump
- // table entries, so that addresses taken outside the module will pass any
- // verification done inside the module.
- //
- // In more concrete terms, suppose we have three functions f, g, h which are
- // members of a single bitset, and a function foo that returns their
- // addresses:
- //
- // f:
- // mov 0, %eax
- // ret
- //
- // g:
- // mov 1, %eax
- // ret
- //
- // h:
- // mov 2, %eax
- // ret
- //
- // foo:
- // mov f, %eax
- // mov g, %edx
- // mov h, %ecx
- // ret
- //
- // To create a jump table for these functions, we instruct the LLVM code
- // generator to output a jump table in the .text section. This is done by
- // representing the instructions in the jump table as an LLVM constant and
- // placing them in a global variable in the .text section. The end result will
- // (conceptually) look like this:
- //
- // f:
- // jmp .Ltmp0 ; 5 bytes
- // int3 ; 1 byte
- // int3 ; 1 byte
- // int3 ; 1 byte
- //
- // g:
- // jmp .Ltmp1 ; 5 bytes
- // int3 ; 1 byte
- // int3 ; 1 byte
- // int3 ; 1 byte
- //
- // h:
- // jmp .Ltmp2 ; 5 bytes
- // int3 ; 1 byte
- // int3 ; 1 byte
- // int3 ; 1 byte
- //
- // .Ltmp0:
- // mov 0, %eax
- // ret
- //
- // .Ltmp1:
- // mov 1, %eax
- // ret
- //
- // .Ltmp2:
- // mov 2, %eax
- // ret
- //
- // foo:
- // mov f, %eax
- // mov g, %edx
- // mov h, %ecx
- // ret
- //
- // Because the addresses of f, g, h are evenly spaced at a power of 2, in the
- // normal case the check can be carried out using the same kind of simple
- // arithmetic that we normally use for globals.
-
- assert(!Functions.empty());
-
- // Build a simple layout based on the regular layout of jump tables.
- DenseMap<GlobalObject *, uint64_t> GlobalLayout;
- unsigned EntrySize = getJumpTableEntrySize();
- for (unsigned I = 0; I != Functions.size(); ++I)
- GlobalLayout[Functions[I]] = I * EntrySize;
-
- // Create a constant to hold the jump table.
- ArrayType *JumpTableType =
- ArrayType::get(getJumpTableEntryType(), Functions.size());
- auto JumpTable = new GlobalVariable(*M, JumpTableType,
- /*isConstant=*/true,
- GlobalValue::PrivateLinkage, nullptr);
- JumpTable->setSection(ObjectFormat == Triple::MachO
- ? "__TEXT,__text,regular,pure_instructions"
- : ".text");
- lowerBitSetCalls(BitSets, JumpTable, GlobalLayout);
-
- // Build aliases pointing to offsets into the jump table, and replace
- // references to the original functions with references to the aliases.
- for (unsigned I = 0; I != Functions.size(); ++I) {
- Constant *CombinedGlobalElemPtr = ConstantExpr::getBitCast(
- ConstantExpr::getGetElementPtr(
- JumpTableType, JumpTable,
- ArrayRef<Constant *>{ConstantInt::get(IntPtrTy, 0),
- ConstantInt::get(IntPtrTy, I)}),
- Functions[I]->getType());
- if (LinkerSubsectionsViaSymbols || Functions[I]->isDeclarationForLinker()) {
- Functions[I]->replaceAllUsesWith(CombinedGlobalElemPtr);
- } else {
- GlobalAlias *GAlias = GlobalAlias::create(Functions[I]->getType(),
- Functions[I]->getLinkage(), "",
- CombinedGlobalElemPtr, M);
- GAlias->setVisibility(Functions[I]->getVisibility());
- GAlias->takeName(Functions[I]);
- Functions[I]->replaceAllUsesWith(GAlias);
- }
- if (!Functions[I]->isDeclarationForLinker())
- Functions[I]->setLinkage(GlobalValue::PrivateLinkage);
- }
-
- // Build and set the jump table's initializer.
- std::vector<Constant *> JumpTableEntries;
- for (unsigned I = 0; I != Functions.size(); ++I)
- JumpTableEntries.push_back(
- createJumpTableEntry(JumpTable, Functions[I], I));
- JumpTable->setInitializer(
- ConstantArray::get(JumpTableType, JumpTableEntries));
-}
-
-void LowerBitSets::buildBitSetsFromDisjointSet(
- ArrayRef<Metadata *> BitSets, ArrayRef<GlobalObject *> Globals) {
- llvm::DenseMap<Metadata *, uint64_t> BitSetIndices;
- llvm::DenseMap<GlobalObject *, uint64_t> GlobalIndices;
- for (auto B : BitSets)
- BitSetIndices[B] = BitSetIndices.size();
- for (auto G : Globals)
- GlobalIndices[G] = GlobalIndices.size();
-
- // For each bitset, build a set of indices that refer to globals referenced by
- // the bitset.
- std::vector<std::set<uint64_t>> BitSetMembers(BitSets.size());
- if (BitSetNM) {
- for (MDNode *Op : BitSetNM->operands()) {
- // Op = { bitset name, global, offset }
- if (!Op->getOperand(1))
- continue;
- auto I = BitSetIndices.find(Op->getOperand(0));
- if (I == BitSetIndices.end())
- continue;
-
- auto OpGlobal = dyn_cast<GlobalObject>(
- cast<ConstantAsMetadata>(Op->getOperand(1))->getValue());
- if (!OpGlobal)
- continue;
- BitSetMembers[I->second].insert(GlobalIndices[OpGlobal]);
- }
- }
-
- // Order the sets of indices by size. The GlobalLayoutBuilder works best
- // when given small index sets first.
- std::stable_sort(
- BitSetMembers.begin(), BitSetMembers.end(),
- [](const std::set<uint64_t> &O1, const std::set<uint64_t> &O2) {
- return O1.size() < O2.size();
- });
-
- // Create a GlobalLayoutBuilder and provide it with index sets as layout
- // fragments. The GlobalLayoutBuilder tries to lay out members of fragments as
- // close together as possible.
- GlobalLayoutBuilder GLB(Globals.size());
- for (auto &&MemSet : BitSetMembers)
- GLB.addFragment(MemSet);
-
- // Build the bitsets from this disjoint set.
- if (Globals.empty() || isa<GlobalVariable>(Globals[0])) {
- // Build a vector of global variables with the computed layout.
- std::vector<GlobalVariable *> OrderedGVs(Globals.size());
- auto OGI = OrderedGVs.begin();
- for (auto &&F : GLB.Fragments) {
- for (auto &&Offset : F) {
- auto GV = dyn_cast<GlobalVariable>(Globals[Offset]);
- if (!GV)
- report_fatal_error(
- "Bit set may not contain both global variables and functions");
- *OGI++ = GV;
- }
- }
-
- buildBitSetsFromGlobalVariables(BitSets, OrderedGVs);
- } else {
- // Build a vector of functions with the computed layout.
- std::vector<Function *> OrderedFns(Globals.size());
- auto OFI = OrderedFns.begin();
- for (auto &&F : GLB.Fragments) {
- for (auto &&Offset : F) {
- auto Fn = dyn_cast<Function>(Globals[Offset]);
- if (!Fn)
- report_fatal_error(
- "Bit set may not contain both global variables and functions");
- *OFI++ = Fn;
- }
- }
-
- buildBitSetsFromFunctions(BitSets, OrderedFns);
- }
-}
-
/// Lower all bit sets in this module.
bool LowerBitSets::buildBitSets() {
Function *BitSetTestFunc =
@@ -926,36 +598,24 @@ bool LowerBitSets::buildBitSets() {
// Equivalence class set containing bitsets and the globals they reference.
// This is used to partition the set of bitsets in the module into disjoint
// sets.
- typedef EquivalenceClasses<PointerUnion<GlobalObject *, Metadata *>>
+ typedef EquivalenceClasses<PointerUnion<GlobalVariable *, MDString *>>
GlobalClassesTy;
GlobalClassesTy GlobalClasses;
- // Verify the bitset metadata and build a mapping from bitset identifiers to
- // their last observed index in BitSetNM. This will used later to
- // deterministically order the list of bitset identifiers.
- llvm::DenseMap<Metadata *, unsigned> BitSetIdIndices;
- if (BitSetNM) {
- for (unsigned I = 0, E = BitSetNM->getNumOperands(); I != E; ++I) {
- MDNode *Op = BitSetNM->getOperand(I);
- verifyBitSetMDNode(Op);
- BitSetIdIndices[Op] = I;
- }
- }
-
for (const Use &U : BitSetTestFunc->uses()) {
auto CI = cast<CallInst>(U.getUser());
auto BitSetMDVal = dyn_cast<MetadataAsValue>(CI->getArgOperand(1));
- if (!BitSetMDVal)
+ if (!BitSetMDVal || !isa<MDString>(BitSetMDVal->getMetadata()))
report_fatal_error(
- "Second argument of llvm.bitset.test must be metadata");
- auto BitSet = BitSetMDVal->getMetadata();
+ "Second argument of llvm.bitset.test must be metadata string");
+ auto BitSet = cast<MDString>(BitSetMDVal->getMetadata());
// Add the call site to the list of call sites for this bit set. We also use
// BitSetTestCallSites to keep track of whether we have seen this bit set
// before. If we have, we don't need to re-add the referenced globals to the
// equivalence class.
- std::pair<DenseMap<Metadata *, std::vector<CallInst *>>::iterator,
+ std::pair<DenseMap<MDString *, std::vector<CallInst *>>::iterator,
bool> Ins =
BitSetTestCallSites.insert(
std::make_pair(BitSet, std::vector<CallInst *>()));
@@ -970,16 +630,31 @@ bool LowerBitSets::buildBitSets() {
if (!BitSetNM)
continue;
- // Add the referenced globals to the bitset's equivalence class.
+ // Verify the bitset metadata and add the referenced globals to the bitset's
+ // equivalence class.
for (MDNode *Op : BitSetNM->operands()) {
+ if (Op->getNumOperands() != 3)
+ report_fatal_error(
+ "All operands of llvm.bitsets metadata must have 3 elements");
+
if (Op->getOperand(0) != BitSet || !Op->getOperand(1))
continue;
- auto OpGlobal = dyn_cast<GlobalObject>(
- cast<ConstantAsMetadata>(Op->getOperand(1))->getValue());
+ auto OpConstMD = dyn_cast<ConstantAsMetadata>(Op->getOperand(1));
+ if (!OpConstMD)
+ report_fatal_error("Bit set element must be a constant");
+ auto OpGlobal = dyn_cast<GlobalVariable>(OpConstMD->getValue());
if (!OpGlobal)
continue;
+ auto OffsetConstMD = dyn_cast<ConstantAsMetadata>(Op->getOperand(2));
+ if (!OffsetConstMD)
+ report_fatal_error("Bit set element offset must be a constant");
+ auto OffsetInt = dyn_cast<ConstantInt>(OffsetConstMD->getValue());
+ if (!OffsetInt)
+ report_fatal_error(
+ "Bit set element offset must be an integer constant");
+
CurSet = GlobalClasses.unionSets(
CurSet, GlobalClasses.findLeader(GlobalClasses.insert(OpGlobal)));
}
@@ -996,25 +671,71 @@ bool LowerBitSets::buildBitSets() {
++NumBitSetDisjointSets;
- // Build the list of bitsets in this disjoint set.
- std::vector<Metadata *> BitSets;
- std::vector<GlobalObject *> Globals;
+ // Build the list of bitsets and referenced globals in this disjoint set.
+ std::vector<MDString *> BitSets;
+ std::vector<GlobalVariable *> Globals;
+ llvm::DenseMap<MDString *, uint64_t> BitSetIndices;
+ llvm::DenseMap<GlobalVariable *, uint64_t> GlobalIndices;
for (GlobalClassesTy::member_iterator MI = GlobalClasses.member_begin(I);
MI != GlobalClasses.member_end(); ++MI) {
- if ((*MI).is<Metadata *>())
- BitSets.push_back(MI->get<Metadata *>());
- else
- Globals.push_back(MI->get<GlobalObject *>());
+ if ((*MI).is<MDString *>()) {
+ BitSetIndices[MI->get<MDString *>()] = BitSets.size();
+ BitSets.push_back(MI->get<MDString *>());
+ } else {
+ GlobalIndices[MI->get<GlobalVariable *>()] = Globals.size();
+ Globals.push_back(MI->get<GlobalVariable *>());
+ }
+ }
+
+ // For each bitset, build a set of indices that refer to globals referenced
+ // by the bitset.
+ std::vector<std::set<uint64_t>> BitSetMembers(BitSets.size());
+ if (BitSetNM) {
+ for (MDNode *Op : BitSetNM->operands()) {
+ // Op = { bitset name, global, offset }
+ if (!Op->getOperand(1))
+ continue;
+ auto I = BitSetIndices.find(cast<MDString>(Op->getOperand(0)));
+ if (I == BitSetIndices.end())
+ continue;
+
+ auto OpGlobal = dyn_cast<GlobalVariable>(
+ cast<ConstantAsMetadata>(Op->getOperand(1))->getValue());
+ if (!OpGlobal)
+ continue;
+ BitSetMembers[I->second].insert(GlobalIndices[OpGlobal]);
+ }
}
- // Order bitsets by BitSetNM index for determinism. This ordering is stable
- // as there is a one-to-one mapping between metadata and indices.
- std::sort(BitSets.begin(), BitSets.end(), [&](Metadata *M1, Metadata *M2) {
- return BitSetIdIndices[M1] < BitSetIdIndices[M2];
+ // Order the sets of indices by size. The GlobalLayoutBuilder works best
+ // when given small index sets first.
+ std::stable_sort(
+ BitSetMembers.begin(), BitSetMembers.end(),
+ [](const std::set<uint64_t> &O1, const std::set<uint64_t> &O2) {
+ return O1.size() < O2.size();
+ });
+
+ // Create a GlobalLayoutBuilder and provide it with index sets as layout
+ // fragments. The GlobalLayoutBuilder tries to lay out members of fragments
+ // as close together as possible.
+ GlobalLayoutBuilder GLB(Globals.size());
+ for (auto &&MemSet : BitSetMembers)
+ GLB.addFragment(MemSet);
+
+ // Build a vector of globals with the computed layout.
+ std::vector<GlobalVariable *> OrderedGlobals(Globals.size());
+ auto OGI = OrderedGlobals.begin();
+ for (auto &&F : GLB.Fragments)
+ for (auto &&Offset : F)
+ *OGI++ = Globals[Offset];
+
+ // Order bitsets by name for determinism.
+ std::sort(BitSets.begin(), BitSets.end(), [](MDString *S1, MDString *S2) {
+ return S1->getString() < S2->getString();
});
- // Lower the bitsets in this disjoint set.
- buildBitSetsFromDisjointSet(BitSets, Globals);
+ // Build the bitsets from this disjoint set.
+ buildBitSetsFromGlobals(BitSets, OrderedGlobals);
}
allocateByteArrays();
Removed: llvm/trunk/test/Transforms/LowerBitSets/function-ext.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LowerBitSets/function-ext.ll?rev=247087&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LowerBitSets/function-ext.ll (original)
+++ llvm/trunk/test/Transforms/LowerBitSets/function-ext.ll (removed)
@@ -1,22 +0,0 @@
-; RUN: opt -S -lowerbitsets < %s | FileCheck %s
-
-; Tests that we correctly handle external references, including the case where
-; all functions in a bitset are external references.
-
-target triple = "x86_64-unknown-linux-gnu"
-
-declare void @foo()
-
-; CHECK: @[[JT:.*]] = private constant [1 x <{ i8, i32, i8, i8, i8 }>] [<{ i8, i32, i8, i8, i8 }> <{ i8 -23, i32 trunc (i64 sub (i64 sub (i64 ptrtoint (void ()* @foo to i64), i64 ptrtoint ([1 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to i64)), i64 5) to i32), i8 -52, i8 -52, i8 -52 }>], section ".text"
-
-define i1 @bar(i8* %ptr) {
- ; CHECK: icmp eq i64 {{.*}}, ptrtoint ([1 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to i64)
- %p = call i1 @llvm.bitset.test(i8* %ptr, metadata !"void")
- ret i1 %p
-}
-
-declare i1 @llvm.bitset.test(i8* %ptr, metadata %bitset) nounwind readnone
-
-!0 = !{!"void", void ()* @foo, i64 0}
-
-!llvm.bitsets = !{!0}
Removed: llvm/trunk/test/Transforms/LowerBitSets/function.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LowerBitSets/function.ll?rev=247087&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LowerBitSets/function.ll (original)
+++ llvm/trunk/test/Transforms/LowerBitSets/function.ll (removed)
@@ -1,35 +0,0 @@
-; RUN: opt -S -lowerbitsets < %s | FileCheck %s
-
-; Tests that we correctly create a jump table for bitsets containing 2 or more
-; functions.
-
-target triple = "x86_64-unknown-linux-gnu"
-target datalayout = "e-p:64:64"
-
-; CHECK: @[[JT:.*]] = private constant [2 x <{ i8, i32, i8, i8, i8 }>] [<{ i8, i32, i8, i8, i8 }> <{ i8 -23, i32 trunc (i64 sub (i64 sub (i64 ptrtoint (void ()* @[[FNAME:.*]] to i64), i64 ptrtoint ([2 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to i64)), i64 5) to i32), i8 -52, i8 -52, i8 -52 }>, <{ i8, i32, i8, i8, i8 }> <{ i8 -23, i32 trunc (i64 sub (i64 sub (i64 ptrtoint (void ()* @[[GNAME:.*]] to i64), i64 ptrtoint ([2 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to i64)), i64 13) to i32), i8 -52, i8 -52, i8 -52 }>], section ".text"
-
-; CHECK: @f = alias bitcast ([2 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to void ()*)
-; CHECK: @g = alias bitcast (<{ i8, i32, i8, i8, i8 }>* getelementptr inbounds ([2 x <{ i8, i32, i8, i8, i8 }>], [2 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]], i64 0, i64 1) to void ()*)
-
-; CHECK: define private void @[[FNAME]]() {
-define void @f() {
- ret void
-}
-
-; CHECK: define private void @[[GNAME]]() {
-define void @g() {
- ret void
-}
-
-!0 = !{!"bitset1", void ()* @f, i32 0}
-!1 = !{!"bitset1", void ()* @g, i32 0}
-
-!llvm.bitsets = !{ !0, !1 }
-
-declare i1 @llvm.bitset.test(i8* %ptr, metadata %bitset) nounwind readnone
-
-define i1 @foo(i8* %p) {
- ; CHECK: sub i64 {{.*}}, ptrtoint ([2 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to i64)
- %x = call i1 @llvm.bitset.test(i8* %p, metadata !"bitset1")
- ret i1 %x
-}
Removed: llvm/trunk/test/Transforms/LowerBitSets/nonstring.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LowerBitSets/nonstring.ll?rev=247087&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LowerBitSets/nonstring.ll (original)
+++ llvm/trunk/test/Transforms/LowerBitSets/nonstring.ll (removed)
@@ -1,34 +0,0 @@
-; RUN: opt -S -lowerbitsets < %s | FileCheck %s
-
-; Tests that non-string metadata nodes may be used as bitset identifiers.
-
-target datalayout = "e-p:32:32"
-
-; CHECK: @[[BNAME:.*]] = private constant { [2 x i32] }
-; CHECK: @[[ANAME:.*]] = private constant { i32 }
-
- at a = constant i32 1
- at b = constant [2 x i32] [i32 2, i32 3]
-
-!0 = !{!2, i32* @a, i32 0}
-!1 = !{!3, [2 x i32]* @b, i32 0}
-!2 = distinct !{}
-!3 = distinct !{}
-
-!llvm.bitsets = !{ !0, !1 }
-
-declare i1 @llvm.bitset.test(i8* %ptr, metadata %bitset) nounwind readnone
-
-; CHECK-LABEL: @foo
-define i1 @foo(i8* %p) {
- ; CHECK: icmp eq i32 {{.*}}, ptrtoint ({ i32 }* @[[ANAME]] to i32)
- %x = call i1 @llvm.bitset.test(i8* %p, metadata !2)
- ret i1 %x
-}
-
-; CHECK-LABEL: @bar
-define i1 @bar(i8* %p) {
- ; CHECK: icmp eq i32 {{.*}}, ptrtoint ({ [2 x i32] }* @[[BNAME]] to i32)
- %x = call i1 @llvm.bitset.test(i8* %p, metadata !3)
- ret i1 %x
-}
Modified: llvm/trunk/test/Transforms/LowerBitSets/simple.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LowerBitSets/simple.ll?rev=247088&r1=247087&r2=247088&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LowerBitSets/simple.ll (original)
+++ llvm/trunk/test/Transforms/LowerBitSets/simple.ll Tue Sep 8 17:33:23 2015
@@ -6,8 +6,8 @@ target datalayout = "e-p:32:32"
; CHECK: [[G:@[^ ]*]] = private constant { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] } { i32 1, [0 x i8] zeroinitializer, [63 x i32] zeroinitializer, [4 x i8] zeroinitializer, i32 3, [0 x i8] zeroinitializer, [2 x i32] [i32 4, i32 5] }
@a = constant i32 1
- at b = hidden constant [63 x i32] zeroinitializer
- at c = protected constant i32 3
+ at b = constant [63 x i32] zeroinitializer
+ at c = constant i32 3
@d = constant [2 x i32] [i32 4, i32 5]
; CHECK: [[BA:@[^ ]*]] = private constant [68 x i8] c"\03\01\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\02\00\01"
@@ -43,8 +43,8 @@ target datalayout = "e-p:32:32"
; CHECK: @bits_use.{{[0-9]*}} = private alias i8* @bits{{[0-9]*}}
; CHECK: @a = alias getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 0)
-; CHECK: @b = hidden alias getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 2)
-; CHECK: @c = protected alias getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 4)
+; CHECK: @b = alias getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 2)
+; CHECK: @c = alias getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 4)
; CHECK: @d = alias getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 6)
; CHECK-DARWIN: @aptr = constant i32* getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }, { i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G:@[^ ]*]], i32 0, i32 0)
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