[llvm] r335306 - [Instrumentation] Add Call Graph Profile pass
Michael J. Spencer via llvm-commits
llvm-commits at lists.llvm.org
Thu Jun 21 16:31:10 PDT 2018
Author: mspencer
Date: Thu Jun 21 16:31:10 2018
New Revision: 335306
URL: http://llvm.org/viewvc/llvm-project?rev=335306&view=rev
Log:
[Instrumentation] Add Call Graph Profile pass
This patch adds support for generating a call graph profile from Branch Frequency Info.
The CGProfile module pass simply gets the block profile count for each BB and scans for call instructions. For each call instruction it adds an edge from the current function to the called function with the current BB block profile count as the weight.
After scanning all the functions, it generates an appending module flag containing the data. The format looks like:
!llvm.module.flags = !{!0}
!0 = !{i32 5, !"CG Profile", !1}
!1 = !{!2, !3, !4} ; List of edges
!2 = !{void ()* @a, void ()* @b, i64 32} ; Edge from a to b with a weight of 32
!3 = !{void (i1)* @freq, void ()* @a, i64 11}
!4 = !{void (i1)* @freq, void ()* @b, i64 20}
Differential Revision: https://reviews.llvm.org/D48105
Added:
llvm/trunk/lib/Transforms/Instrumentation/CGProfile.cpp
llvm/trunk/test/Instrumentation/cgprofile.ll
llvm/trunk/test/MC/ELF/cgprofile.ll
llvm/trunk/test/Verifier/module-flags-cgprofile.ll
Modified:
llvm/trunk/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
llvm/trunk/include/llvm/InitializePasses.h
llvm/trunk/include/llvm/LinkAllPasses.h
llvm/trunk/include/llvm/Transforms/Instrumentation.h
llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
llvm/trunk/lib/IR/Verifier.cpp
llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp
llvm/trunk/lib/Transforms/Instrumentation/CMakeLists.txt
llvm/trunk/lib/Transforms/Instrumentation/Instrumentation.cpp
Modified: llvm/trunk/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h?rev=335306&r1=335305&r2=335306&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h (original)
+++ llvm/trunk/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h Thu Jun 21 16:31:10 2018
@@ -36,11 +36,14 @@ class TargetLoweringObjectFileELF : publ
protected:
MCSymbolRefExpr::VariantKind PLTRelativeVariantKind =
MCSymbolRefExpr::VK_None;
+ const TargetMachine *TM;
public:
TargetLoweringObjectFileELF() = default;
~TargetLoweringObjectFileELF() override = default;
+ void Initialize(MCContext &Ctx, const TargetMachine &TM) override;
+
/// Emit Obj-C garbage collection and linker options.
void emitModuleMetadata(MCStreamer &Streamer, Module &M) const override;
Modified: llvm/trunk/include/llvm/InitializePasses.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/InitializePasses.h?rev=335306&r1=335305&r2=335306&view=diff
==============================================================================
--- llvm/trunk/include/llvm/InitializePasses.h (original)
+++ llvm/trunk/include/llvm/InitializePasses.h Thu Jun 21 16:31:10 2018
@@ -94,6 +94,7 @@ void initializeCFGViewerLegacyPassPass(P
void initializeCFIInstrInserterPass(PassRegistry&);
void initializeCFLAndersAAWrapperPassPass(PassRegistry&);
void initializeCFLSteensAAWrapperPassPass(PassRegistry&);
+void initializeCGProfilePassPass(PassRegistry&);
void initializeCallGraphDOTPrinterPass(PassRegistry&);
void initializeCallGraphPrinterLegacyPassPass(PassRegistry&);
void initializeCallGraphViewerPass(PassRegistry&);
Modified: llvm/trunk/include/llvm/LinkAllPasses.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/LinkAllPasses.h?rev=335306&r1=335305&r2=335306&view=diff
==============================================================================
--- llvm/trunk/include/llvm/LinkAllPasses.h (original)
+++ llvm/trunk/include/llvm/LinkAllPasses.h Thu Jun 21 16:31:10 2018
@@ -80,6 +80,7 @@ namespace {
(void) llvm::createCallGraphDOTPrinterPass();
(void) llvm::createCallGraphViewerPass();
(void) llvm::createCFGSimplificationPass();
+ (void) llvm::createCGProfilePass();
(void) llvm::createCFLAndersAAWrapperPass();
(void) llvm::createCFLSteensAAWrapperPass();
(void) llvm::createStructurizeCFGPass();
Modified: llvm/trunk/include/llvm/Transforms/Instrumentation.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Instrumentation.h?rev=335306&r1=335305&r2=335306&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Instrumentation.h (original)
+++ llvm/trunk/include/llvm/Transforms/Instrumentation.h Thu Jun 21 16:31:10 2018
@@ -187,6 +187,8 @@ struct SanitizerCoverageOptions {
ModulePass *createSanitizerCoverageModulePass(
const SanitizerCoverageOptions &Options = SanitizerCoverageOptions());
+ModulePass *createCGProfilePass();
+
/// Calculate what to divide by to scale counts.
///
/// Given the maximum count, calculate a divisor that will scale all the
Modified: llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp?rev=335306&r1=335305&r2=335306&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp (original)
+++ llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp Thu Jun 21 16:31:10 2018
@@ -91,6 +91,12 @@ static void GetObjCImageInfo(Module &M,
// ELF
//===----------------------------------------------------------------------===//
+void TargetLoweringObjectFileELF::Initialize(MCContext &Ctx,
+ const TargetMachine &TgtM) {
+ TargetLoweringObjectFile::Initialize(Ctx, TgtM);
+ TM = &TgtM;
+}
+
void TargetLoweringObjectFileELF::emitModuleMetadata(MCStreamer &Streamer,
Module &M) const {
auto &C = getContext();
@@ -116,15 +122,49 @@ void TargetLoweringObjectFileELF::emitMo
StringRef Section;
GetObjCImageInfo(M, Version, Flags, Section);
- if (Section.empty())
+ if (!Section.empty()) {
+ auto *S = C.getELFSection(Section, ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
+ Streamer.SwitchSection(S);
+ Streamer.EmitLabel(C.getOrCreateSymbol(StringRef("OBJC_IMAGE_INFO")));
+ Streamer.EmitIntValue(Version, 4);
+ Streamer.EmitIntValue(Flags, 4);
+ Streamer.AddBlankLine();
+ }
+
+ SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
+ M.getModuleFlagsMetadata(ModuleFlags);
+
+ MDNode *CFGProfile = nullptr;
+
+ for (const auto &MFE : ModuleFlags) {
+ StringRef Key = MFE.Key->getString();
+ if (Key == "CG Profile") {
+ CFGProfile = cast<MDNode>(MFE.Val);
+ break;
+ }
+ }
+
+ if (!CFGProfile)
return;
- auto *S = C.getELFSection(Section, ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
- Streamer.SwitchSection(S);
- Streamer.EmitLabel(C.getOrCreateSymbol(StringRef("OBJC_IMAGE_INFO")));
- Streamer.EmitIntValue(Version, 4);
- Streamer.EmitIntValue(Flags, 4);
- Streamer.AddBlankLine();
+ auto GetSym = [this](const MDOperand &MDO) {
+ auto V = cast<ValueAsMetadata>(MDO);
+ const Function *F = cast<Function>(V->getValue());
+ return TM->getSymbol(F);
+ };
+
+ for (const auto &Edge : CFGProfile->operands()) {
+ MDNode *E = cast<MDNode>(Edge);
+ const MCSymbol *From = GetSym(E->getOperand(0));
+ const MCSymbol *To = GetSym(E->getOperand(1));
+ uint64_t Count = cast<ConstantAsMetadata>(E->getOperand(2))
+ ->getValue()
+ ->getUniqueInteger()
+ .getZExtValue();
+ Streamer.emitCGProfileEntry(
+ MCSymbolRefExpr::create(From, MCSymbolRefExpr::VK_None, C),
+ MCSymbolRefExpr::create(To, MCSymbolRefExpr::VK_None, C), Count);
+ }
}
MCSymbol *TargetLoweringObjectFileELF::getCFIPersonalitySymbol(
Modified: llvm/trunk/lib/IR/Verifier.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Verifier.cpp?rev=335306&r1=335305&r2=335306&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Verifier.cpp (original)
+++ llvm/trunk/lib/IR/Verifier.cpp Thu Jun 21 16:31:10 2018
@@ -409,6 +409,7 @@ private:
void visitModuleFlag(const MDNode *Op,
DenseMap<const MDString *, const MDNode *> &SeenIDs,
SmallVectorImpl<const MDNode *> &Requirements);
+ void visitModuleFlagCGProfileEntry(const MDOperand &MDO);
void visitFunction(const Function &F);
void visitBasicBlock(BasicBlock &BB);
void visitRangeMetadata(Instruction &I, MDNode *Range, Type *Ty);
@@ -1411,6 +1412,25 @@ Verifier::visitModuleFlag(const MDNode *
Assert(M.getNamedMetadata("llvm.linker.options"),
"'Linker Options' named metadata no longer supported");
}
+
+ if (ID->getString() == "CG Profile") {
+ for (const MDOperand &MDO : cast<MDNode>(Op->getOperand(2))->operands())
+ visitModuleFlagCGProfileEntry(MDO);
+ }
+}
+
+void Verifier::visitModuleFlagCGProfileEntry(const MDOperand &MDO) {
+ auto Node = dyn_cast_or_null<MDNode>(MDO);
+ Assert(Node && Node->getNumOperands() == 3, "expected a MDNode triple", MDO);
+ auto From = dyn_cast_or_null<ValueAsMetadata>(Node->getOperand(0));
+ Assert(From && isa<Function>(From->getValue()), "expected a Function",
+ Node->getOperand(0));
+ auto To = dyn_cast_or_null<ValueAsMetadata>(Node->getOperand(1));
+ Assert(To && isa<Function>(To->getValue()), "expected a Function",
+ Node->getOperand(1));
+ auto Count = dyn_cast_or_null<ConstantAsMetadata>(Node->getOperand(2));
+ Assert(Count && Count->getType()->isIntegerTy(),
+ "expected an integer constant", Node->getOperand(2));
}
/// Return true if this attribute kind only applies to functions.
Modified: llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp?rev=335306&r1=335305&r2=335306&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp Thu Jun 21 16:31:10 2018
@@ -694,6 +694,8 @@ void PassManagerBuilder::populateModuleP
MPM.add(createConstantMergePass()); // Merge dup global constants
}
+ MPM.add(createCGProfilePass());
+
if (MergeFunctions)
MPM.add(createMergeFunctionsPass());
Added: llvm/trunk/lib/Transforms/Instrumentation/CGProfile.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/CGProfile.cpp?rev=335306&view=auto
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/CGProfile.cpp (added)
+++ llvm/trunk/lib/Transforms/Instrumentation/CGProfile.cpp Thu Jun 21 16:31:10 2018
@@ -0,0 +1,110 @@
+//===-- CGProfile.cpp -----------------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/MapVector.h"
+#include "llvm/Analysis/BlockFrequencyInfo.h"
+#include "llvm/Analysis/BranchProbabilityInfo.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/MDBuilder.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/Transforms/Instrumentation.h"
+
+#include <array>
+
+using namespace llvm;
+
+class CGProfilePass : public ModulePass {
+public:
+ static char ID;
+
+ CGProfilePass() : ModulePass(ID) {
+ initializeCGProfilePassPass(*PassRegistry::getPassRegistry());
+ }
+
+ StringRef getPassName() const override { return "CGProfilePass"; }
+
+private:
+ bool runOnModule(Module &M) override;
+ bool addModuleFlags(
+ Module &M,
+ MapVector<std::pair<Function *, Function *>, uint64_t> &Counts) const;
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.addRequired<BlockFrequencyInfoWrapperPass>();
+ AU.addRequired<BranchProbabilityInfoWrapperPass>();
+ }
+};
+
+bool CGProfilePass::runOnModule(Module &M) {
+ if (skipModule(M))
+ return false;
+
+ MapVector<std::pair<Function *, Function *>, uint64_t> Counts;
+
+ for (auto &F : M) {
+ if (F.isDeclaration())
+ continue;
+ getAnalysis<BranchProbabilityInfoWrapperPass>(F).getBPI();
+ auto &BFI = getAnalysis<BlockFrequencyInfoWrapperPass>(F).getBFI();
+ for (const auto &BB : F) {
+ Optional<uint64_t> BBCount = BFI.getBlockProfileCount(&BB);
+ if (!BBCount)
+ continue;
+ for (const auto &I : BB) {
+ auto *CI = dyn_cast<CallInst>(&I);
+ if (!CI)
+ continue;
+ Function *CalledF = CI->getCalledFunction();
+ if (!CalledF || CalledF->isIntrinsic())
+ continue;
+
+ uint64_t &Count = Counts[std::make_pair(&F, CalledF)];
+ Count = SaturatingAdd(Count, *BBCount);
+ }
+ }
+ }
+
+ return addModuleFlags(M, Counts);
+}
+
+bool CGProfilePass::addModuleFlags(
+ Module &M,
+ MapVector<std::pair<Function *, Function *>, uint64_t> &Counts) const {
+ if (Counts.empty())
+ return false;
+
+ LLVMContext &Context = M.getContext();
+ MDBuilder MDB(Context);
+ std::vector<Metadata *> Nodes;
+
+ for (auto E : Counts) {
+ SmallVector<Metadata *, 3> Vals;
+ Vals.push_back(ValueAsMetadata::get(E.first.first));
+ Vals.push_back(ValueAsMetadata::get(E.first.second));
+ Vals.push_back(MDB.createConstant(
+ ConstantInt::get(Type::getInt64Ty(Context), E.second)));
+ Nodes.push_back(MDNode::get(Context, Vals));
+ }
+
+ M.addModuleFlag(Module::Append, "CG Profile", MDNode::get(Context, Nodes));
+ return true;
+}
+
+char CGProfilePass::ID = 0;
+INITIALIZE_PASS_BEGIN(CGProfilePass, "cg-profile",
+ "Generate profile information from the call graph.",
+ false, false)
+INITIALIZE_PASS_DEPENDENCY(BlockFrequencyInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(BranchProbabilityInfoWrapperPass)
+INITIALIZE_PASS_END(CGProfilePass, "cg-profile",
+ "Generate profile information from the call graph.", false,
+ false)
+
+ModulePass *llvm::createCGProfilePass() { return new CGProfilePass(); }
Modified: llvm/trunk/lib/Transforms/Instrumentation/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/CMakeLists.txt?rev=335306&r1=335305&r2=335306&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/CMakeLists.txt (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/CMakeLists.txt Thu Jun 21 16:31:10 2018
@@ -1,6 +1,7 @@
add_llvm_library(LLVMInstrumentation
AddressSanitizer.cpp
BoundsChecking.cpp
+ CGProfile.cpp
DataFlowSanitizer.cpp
GCOVProfiling.cpp
MemorySanitizer.cpp
Modified: llvm/trunk/lib/Transforms/Instrumentation/Instrumentation.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/Instrumentation.cpp?rev=335306&r1=335305&r2=335306&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/Instrumentation.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/Instrumentation.cpp Thu Jun 21 16:31:10 2018
@@ -60,6 +60,7 @@ void llvm::initializeInstrumentation(Pas
initializeAddressSanitizerModulePass(Registry);
initializeBoundsCheckingLegacyPassPass(Registry);
initializeGCOVProfilerLegacyPassPass(Registry);
+ initializeCGProfilePassPass(Registry);
initializePGOInstrumentationGenLegacyPassPass(Registry);
initializePGOInstrumentationUseLegacyPassPass(Registry);
initializePGOIndirectCallPromotionLegacyPassPass(Registry);
Added: llvm/trunk/test/Instrumentation/cgprofile.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/cgprofile.ll?rev=335306&view=auto
==============================================================================
--- llvm/trunk/test/Instrumentation/cgprofile.ll (added)
+++ llvm/trunk/test/Instrumentation/cgprofile.ll Thu Jun 21 16:31:10 2018
@@ -0,0 +1,28 @@
+; RUN: opt < %s -cg-profile -S | FileCheck %s
+
+declare void @b()
+
+define void @a() !prof !1 {
+ call void @b()
+ ret void
+}
+
+define void @freq(i1 %cond) !prof !1 {
+ br i1 %cond, label %A, label %B, !prof !2
+A:
+ call void @a();
+ ret void
+B:
+ call void @b();
+ ret void
+}
+
+!1 = !{!"function_entry_count", i64 32}
+!2 = !{!"branch_weights", i32 5, i32 10}
+
+; CHECK: !llvm.module.flags = !{![[cgprof:[0-9]+]]}
+; CHECK: ![[cgprof]] = !{i32 5, !"CG Profile", ![[prof:[0-9]+]]}
+; CHECK: ![[prof]] = !{![[e0:[0-9]+]], ![[e1:[0-9]+]], ![[e2:[0-9]+]]}
+; CHECK: ![[e0]] = !{void ()* @a, void ()* @b, i64 32}
+; CHECK: ![[e1]] = !{void (i1)* @freq, void ()* @a, i64 11}
+; CHECK: ![[e2]] = !{void (i1)* @freq, void ()* @b, i64 20}
Added: llvm/trunk/test/MC/ELF/cgprofile.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ELF/cgprofile.ll?rev=335306&view=auto
==============================================================================
--- llvm/trunk/test/MC/ELF/cgprofile.ll (added)
+++ llvm/trunk/test/MC/ELF/cgprofile.ll Thu Jun 21 16:31:10 2018
@@ -0,0 +1,50 @@
+; RUN: llc -filetype=asm %s -o - -mtriple x86_64-pc-linux-gnu | FileCheck %s
+; RUN: llc -filetype=obj %s -o %t -mtriple x86_64-pc-linux-gnu
+; RUN: llvm-readobj -elf-cg-profile %t | FileCheck %s --check-prefix=OBJ
+
+declare void @b()
+
+define void @a() {
+ call void @b()
+ ret void
+}
+
+define void @freq(i1 %cond) {
+ br i1 %cond, label %A, label %B
+A:
+ call void @a();
+ ret void
+B:
+ call void @b();
+ ret void
+}
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 5, !"CG Profile", !1}
+!1 = !{!2, !3, !4}
+!2 = !{void ()* @a, void ()* @b, i64 32}
+!3 = !{void (i1)* @freq, void ()* @a, i64 11}
+!4 = !{void (i1)* @freq, void ()* @b, i64 20}
+
+; CHECK: .cg_profile a, b, 32
+; CHECK: .cg_profile freq, a, 11
+; CHECK: .cg_profile freq, b, 20
+
+; OBJ: CGProfile [
+; OBJ: CGProfileEntry {
+; OBJ: From: a
+; OBJ: To: b
+; OBJ: Weight: 32
+; OBJ: }
+; OBJ: CGProfileEntry {
+; OBJ: From: freq
+; OBJ: To: a
+; OBJ: Weight: 11
+; OBJ: }
+; OBJ: CGProfileEntry {
+; OBJ: From: freq
+; OBJ: To: b
+; OBJ: Weight: 20
+; OBJ: }
+; OBJ:]
Added: llvm/trunk/test/Verifier/module-flags-cgprofile.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Verifier/module-flags-cgprofile.ll?rev=335306&view=auto
==============================================================================
--- llvm/trunk/test/Verifier/module-flags-cgprofile.ll (added)
+++ llvm/trunk/test/Verifier/module-flags-cgprofile.ll Thu Jun 21 16:31:10 2018
@@ -0,0 +1,30 @@
+; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
+
+declare void @b()
+declare void @a()
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 5, !"CG Profile", !1}
+!1 = !{!2, !"", !3, !4, !5, !6, !7, !8}
+!2 = !{void ()* @a, void ()* @b, i64 32}
+!3 = !{void ()* @a, void ()* @b}
+!4 = !{void ()* @a, void ()* @b, i64 32, i64 32}
+!5 = !{!"a", void ()* @b, i64 32}
+!6 = !{void ()* @a, !"b", i64 32}
+!7 = !{void ()* @a, void ()* @b, !""}
+!8 = !{void ()* @a, void ()* @b, null}
+
+; CHECK: expected a MDNode triple
+; CHECK: !""
+; CHECK: expected a MDNode triple
+; CHECK: !3 = !{void ()* @a, void ()* @b}
+; CHECK: expected a MDNode triple
+; CHECK: !4 = !{void ()* @a, void ()* @b, i64 32, i64 32}
+; CHECK: expected a Function
+; CHECK: !"a"
+; CHECK: expected a Function
+; CHECK: !"b"
+; CHECK: expected an integer constant
+; CHECK: !""
+; CHECK: expected an integer constant
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