[llvm] r286297 - [ThinLTO] Prevent exporting of locals used/defined in module level asm
Teresa Johnson via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 8 13:53:36 PST 2016
Author: tejohnson
Date: Tue Nov 8 15:53:35 2016
New Revision: 286297
URL: http://llvm.org/viewvc/llvm-project?rev=286297&view=rev
Log:
[ThinLTO] Prevent exporting of locals used/defined in module level asm
Summary:
This patch uses the same approach added for inline asm in r285513 to
similarly prevent promotion/renaming of locals used or defined in module
level asm.
All static global values defined in normal IR and used in module level asm
should be included on either the llvm.used or llvm.compiler.used global.
The former were already being flagged as NoRename in the summary, and
I've simply added llvm.compiler.used values to this handling.
Module level asm may also contain defs of values. We need to prevent
export of any refs to local values defined in module level asm (e.g. a
ref in normal IR), since that also requires renaming/promotion of the
local. To do that, the summary index builder looks at all values in the
module level asm string that are not marked Weak or Global, which is
exactly the set of locals that are defined. A summary is created for
each of these local defs and flagged as NoRename.
This required adding handling to the BitcodeWriter to look at GV
declarations to see if they have a summary (rather than skipping them
all).
Finally, added an assert to IRObjectFile::CollectAsmUndefinedRefs to
ensure that an MCAsmParser is available, otherwise the module asm parse
would silently fail. Initialized the asm parser in the opt tool for use
in testing this fix.
Fixes PR30610.
Reviewers: mehdi_amini
Subscribers: johanengelen, krasin, llvm-commits
Differential Revision: https://reviews.llvm.org/D26146
Added:
llvm/trunk/test/ThinLTO/X86/Inputs/module_asm2.ll
llvm/trunk/test/ThinLTO/X86/module_asm2.ll
Modified:
llvm/trunk/include/llvm/Support/TargetRegistry.h
llvm/trunk/lib/Analysis/LLVMBuild.txt
llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp
llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp
llvm/trunk/lib/Object/IRObjectFile.cpp
llvm/trunk/test/LTO/X86/current-section.ll
llvm/trunk/tools/opt/opt.cpp
Modified: llvm/trunk/include/llvm/Support/TargetRegistry.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/TargetRegistry.h?rev=286297&r1=286296&r2=286297&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/TargetRegistry.h (original)
+++ llvm/trunk/include/llvm/Support/TargetRegistry.h Tue Nov 8 15:53:35 2016
@@ -280,6 +280,9 @@ public:
/// hasMCAsmBackend - Check if this target supports .o generation.
bool hasMCAsmBackend() const { return MCAsmBackendCtorFn != nullptr; }
+ /// hasMCAsmParser - Check if this target supports assembly parsing.
+ bool hasMCAsmParser() const { return MCAsmParserCtorFn != nullptr; }
+
/// @}
/// @name Feature Constructors
/// @{
Modified: llvm/trunk/lib/Analysis/LLVMBuild.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/LLVMBuild.txt?rev=286297&r1=286296&r2=286297&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/LLVMBuild.txt (original)
+++ llvm/trunk/lib/Analysis/LLVMBuild.txt Tue Nov 8 15:53:35 2016
@@ -19,4 +19,4 @@
type = Library
name = Analysis
parent = Libraries
-required_libraries = Core Support ProfileData
+required_libraries = Core Support ProfileData Object
Modified: llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp?rev=286297&r1=286296&r2=286297&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp Tue Nov 8 15:53:35 2016
@@ -13,6 +13,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/ModuleSummaryAnalysis.h"
+#include "llvm/ADT/Triple.h"
#include "llvm/Analysis/BlockFrequencyInfo.h"
#include "llvm/Analysis/BlockFrequencyInfoImpl.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
@@ -24,6 +25,7 @@
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/ValueSymbolTable.h"
+#include "llvm/Object/IRObjectFile.h"
#include "llvm/Pass.h"
using namespace llvm;
@@ -194,12 +196,22 @@ ModuleSummaryIndex llvm::buildModuleSumm
ProfileSummaryInfo *PSI) {
ModuleSummaryIndex Index;
- // Identify the local values in the llvm.used set, which should not be
- // exported as they would then require renaming and promotion, but we
- // may have opaque uses e.g. in inline asm.
+ // Identify the local values in the llvm.used and llvm.compiler.used sets,
+ // which should not be exported as they would then require renaming and
+ // promotion, but we may have opaque uses e.g. in inline asm. We collect them
+ // here because we use this information to mark functions containing inline
+ // assembly calls as not importable.
+ SmallPtrSet<GlobalValue *, 8> LocalsUsed;
SmallPtrSet<GlobalValue *, 8> Used;
+ // First collect those in the llvm.used set.
collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
- SmallPtrSet<GlobalValue *, 8> LocalsUsed;
+ for (auto *V : Used) {
+ if (V->hasLocalLinkage())
+ LocalsUsed.insert(V);
+ }
+ Used.clear();
+ // Next collect those in the llvm.compiler.used set.
+ collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ true);
for (auto *V : Used) {
if (V->hasLocalLinkage())
LocalsUsed.insert(V);
@@ -244,6 +256,47 @@ ModuleSummaryIndex llvm::buildModuleSumm
Summary->setNoRename();
}
+ if (!M.getModuleInlineAsm().empty()) {
+ // Collect the local values defined by module level asm, and set up
+ // summaries for these symbols so that they can be marked as NoRename,
+ // to prevent export of any use of them in regular IR that would require
+ // renaming within the module level asm. Note we don't need to create a
+ // summary for weak or global defs, as they don't need to be flagged as
+ // NoRename, and defs in module level asm can't be imported anyway.
+ // Also, any values used but not defined within module level asm should
+ // be listed on the llvm.used or llvm.compiler.used global and marked as
+ // referenced from there.
+ // FIXME: Rename CollectAsmUndefinedRefs to something more general, as we
+ // are also using it to find the file-scope locals defined in module asm.
+ object::IRObjectFile::CollectAsmUndefinedRefs(
+ Triple(M.getTargetTriple()), M.getModuleInlineAsm(),
+ [&M, &Index](StringRef Name, object::BasicSymbolRef::Flags Flags) {
+ // Symbols not marked as Weak or Global are local definitions.
+ if (Flags & (object::BasicSymbolRef::SF_Weak ||
+ object::BasicSymbolRef::SF_Global))
+ return;
+ GlobalValue *GV = M.getNamedValue(Name);
+ if (!GV)
+ return;
+ assert(GV->isDeclaration() && "Def in module asm already has definition");
+ GlobalValueSummary::GVFlags GVFlags(GlobalValue::InternalLinkage,
+ /* NoRename */ true,
+ /*IsNotViableToInline */ true);
+ // Create the appropriate summary type.
+ if (isa<Function>(GV)) {
+ std::unique_ptr<FunctionSummary> Summary =
+ llvm::make_unique<FunctionSummary>(GVFlags, 0);
+ Summary->setNoRename();
+ Index.addGlobalValueSummary(Name, std::move(Summary));
+ } else {
+ std::unique_ptr<GlobalVarSummary> Summary =
+ llvm::make_unique<GlobalVarSummary>(GVFlags);
+ Summary->setNoRename();
+ Index.addGlobalValueSummary(Name, std::move(Summary));
+ }
+ });
+ }
+
return Index;
}
Modified: llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp?rev=286297&r1=286296&r2=286297&view=diff
==============================================================================
--- llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp (original)
+++ llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp Tue Nov 8 15:53:35 2016
@@ -3327,11 +3327,16 @@ void ModuleBitcodeWriter::writePerModule
void ModuleBitcodeWriter::writeModuleLevelReferences(
const GlobalVariable &V, SmallVector<uint64_t, 64> &NameVals,
unsigned FSModRefsAbbrev) {
- // Only interested in recording variable defs in the summary.
- if (V.isDeclaration())
+ auto Summaries =
+ Index->findGlobalValueSummaryList(GlobalValue::getGUID(V.getName()));
+ if (Summaries == Index->end()) {
+ // Only declarations should not have a summary (a declaration might however
+ // have a summary if the def was in module level asm).
+ assert(V.isDeclaration());
return;
+ }
+ auto *Summary = Summaries->second.front().get();
NameVals.push_back(VE.getValueID(&V));
- auto *Summary = Index->getGlobalValueSummary(V);
GlobalVarSummary *VS = cast<GlobalVarSummary>(Summary);
NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
@@ -3409,14 +3414,20 @@ void ModuleBitcodeWriter::writePerModule
// Iterate over the list of functions instead of the Index to
// ensure the ordering is stable.
for (const Function &F : M) {
- if (F.isDeclaration())
- continue;
// Summary emission does not support anonymous functions, they have to
// renamed using the anonymous function renaming pass.
if (!F.hasName())
report_fatal_error("Unexpected anonymous function when writing summary");
- auto *Summary = Index->getGlobalValueSummary(F);
+ auto Summaries =
+ Index->findGlobalValueSummaryList(GlobalValue::getGUID(F.getName()));
+ if (Summaries == Index->end()) {
+ // Only declarations should not have a summary (a declaration might
+ // however have a summary if the def was in module level asm).
+ assert(F.isDeclaration());
+ continue;
+ }
+ auto *Summary = Summaries->second.front().get();
writePerModuleFunctionSummaryRecord(NameVals, Summary, VE.getValueID(&F),
FSCallsAbbrev, FSCallsProfileAbbrev, F);
}
Modified: llvm/trunk/lib/Object/IRObjectFile.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Object/IRObjectFile.cpp?rev=286297&r1=286296&r2=286297&view=diff
==============================================================================
--- llvm/trunk/lib/Object/IRObjectFile.cpp (original)
+++ llvm/trunk/lib/Object/IRObjectFile.cpp Tue Nov 8 15:53:35 2016
@@ -54,8 +54,7 @@ void IRObjectFile::CollectAsmUndefinedRe
std::string Err;
const Target *T = TargetRegistry::lookupTarget(TT.str(), Err);
- if (!T)
- return;
+ assert(T && T->hasMCAsmParser());
std::unique_ptr<MCRegisterInfo> MRI(T->createMCRegInfo(TT.str()));
if (!MRI)
Modified: llvm/trunk/test/LTO/X86/current-section.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/LTO/X86/current-section.ll?rev=286297&r1=286296&r2=286297&view=diff
==============================================================================
--- llvm/trunk/test/LTO/X86/current-section.ll (original)
+++ llvm/trunk/test/LTO/X86/current-section.ll Tue Nov 8 15:53:35 2016
@@ -2,4 +2,7 @@
; RUN: llvm-lto -o %t2 %t1
; REQUIRES: default_triple
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
module asm ".align 4"
Added: llvm/trunk/test/ThinLTO/X86/Inputs/module_asm2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/ThinLTO/X86/Inputs/module_asm2.ll?rev=286297&view=auto
==============================================================================
--- llvm/trunk/test/ThinLTO/X86/Inputs/module_asm2.ll (added)
+++ llvm/trunk/test/ThinLTO/X86/Inputs/module_asm2.ll Tue Nov 8 15:53:35 2016
@@ -0,0 +1,12 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define i32 @main({ i64, { i64, i8* }* } %unnamed) #0 {
+ %1 = call i32 @func1() #1
+ %2 = call i32 @func2() #1
+ %3 = call i32 @func3() #1
+ ret i32 %1
+}
+declare i32 @func1() #1
+declare i32 @func2() #1
+declare i32 @func3() #1
Added: llvm/trunk/test/ThinLTO/X86/module_asm2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/ThinLTO/X86/module_asm2.ll?rev=286297&view=auto
==============================================================================
--- llvm/trunk/test/ThinLTO/X86/module_asm2.ll (added)
+++ llvm/trunk/test/ThinLTO/X86/module_asm2.ll Tue Nov 8 15:53:35 2016
@@ -0,0 +1,84 @@
+; Test to ensure that uses and defs in module level asm are handled
+; appropriately. Specifically, we should conservatively block importing
+; of any references to these values, as they can't be renamed.
+; RUN: opt -module-summary %s -o %t1.bc
+; RUN: opt -module-summary %p/Inputs/module_asm2.ll -o %t2.bc
+
+; RUN: llvm-lto -thinlto-action=run -exported-symbol=main -exported-symbol=func1 -exported-symbol=func2 -exported-symbol=func3 %t1.bc %t2.bc
+; RUN: llvm-nm %t1.bc.thinlto.o | FileCheck %s --check-prefix=NM0
+; RUN: llvm-nm %t2.bc.thinlto.o | FileCheck %s --check-prefix=NM1
+
+; RUN: llvm-lto2 %t1.bc %t2.bc -o %t.o -save-temps \
+; RUN: -r=%t1.bc,foo,plx \
+; RUN: -r=%t1.bc,b,pl \
+; RUN: -r=%t1.bc,x,pl \
+; RUN: -r=%t1.bc,func1,pl \
+; RUN: -r=%t1.bc,func2,pl \
+; RUN: -r=%t1.bc,func3,pl \
+; RUN: -r=%t2.bc,main,plx \
+; RUN: -r=%t2.bc,func1,l \
+; RUN: -r=%t2.bc,func2,l \
+; RUN: -r=%t2.bc,func3,l
+; RUN: llvm-nm %t.o.0 | FileCheck %s --check-prefix=NM0
+; RUN: llvm-nm %t.o.1 | FileCheck %s --check-prefix=NM1
+
+; Check that local values b and x, which are referenced on
+; llvm.used and llvm.compiler.used, respectively, are not promoted.
+; Similarly, foo which is defined in module level asm should not be
+; promoted.
+; NM0-DAG: d b
+; NM0-DAG: d x
+; NM0-DAG: t foo
+; NM0-DAG: T func1
+; NM0-DAG: T func2
+; NM0-DAG: T func3
+
+; Ensure that foo, b and x are likewise not exported (imported as refs
+; into the other module), since they can't be promoted. Additionally,
+; referencing functions func1, func2 and func3 should not have been
+; imported.
+; NM1-NOT: foo
+; NM1-NOT: b
+; NM1-NOT: x
+; NM1-DAG: U func1
+; NM1-DAG: U func2
+; NM1-DAG: U func3
+; NM1-DAG: T main
+; NM1-NOT: foo
+; NM1-NOT: b
+; NM1-NOT: x
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+ at b = internal global i32 1, align 4
+ at x = internal global i32 1, align 4
+
+ at llvm.compiler.used = appending global [1 x i8*] [i8* bitcast (i32* @b to i8*)], section "llvm.metadata"
+ at llvm.used = appending global [1 x i8*] [i8* bitcast (i32* @x to i8*)], section "llvm.metadata"
+
+module asm "\09.text"
+module asm "\09.type\09foo, at function"
+module asm "foo:"
+module asm "\09movl b, %eax"
+module asm "\09movl x, %edx"
+module asm "\09ret "
+module asm "\09.size\09foo, .-foo"
+module asm ""
+
+declare i16 @foo() #0
+
+define i32 @func1() #1 {
+ call i16 @foo()
+ ret i32 1
+}
+
+define i32 @func2() #1 {
+ %1 = load i32, i32* @b, align 4
+ ret i32 %1
+}
+
+define i32 @func3() #1 {
+ %1 = load i32, i32* @x, align 4
+ ret i32 %1
+}
Modified: llvm/trunk/tools/opt/opt.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/opt/opt.cpp?rev=286297&r1=286296&r2=286297&view=diff
==============================================================================
--- llvm/trunk/tools/opt/opt.cpp (original)
+++ llvm/trunk/tools/opt/opt.cpp Tue Nov 8 15:53:35 2016
@@ -364,6 +364,7 @@ int main(int argc, char **argv) {
InitializeAllTargets();
InitializeAllTargetMCs();
InitializeAllAsmPrinters();
+ InitializeAllAsmParsers();
// Initialize passes
PassRegistry &Registry = *PassRegistry::getPassRegistry();
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