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-rw-r--r--llvm/lib/IR/DiagnosticInfo.cpp11
-rw-r--r--llvm/lib/IR/MDBuilder.cpp12
-rw-r--r--llvm/lib/Transforms/IPO/SampleProfile.cpp3
-rw-r--r--llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp4
-rw-r--r--llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp31
-rw-r--r--llvm/lib/Transforms/Utils/CMakeLists.txt1
-rw-r--r--llvm/lib/Transforms/Utils/MisExpect.cpp177
7 files changed, 8 insertions, 231 deletions
diff --git a/llvm/lib/IR/DiagnosticInfo.cpp b/llvm/lib/IR/DiagnosticInfo.cpp
index 99d5aec3f04..4a8e3cca349 100644
--- a/llvm/lib/IR/DiagnosticInfo.cpp
+++ b/llvm/lib/IR/DiagnosticInfo.cpp
@@ -370,16 +370,5 @@ std::string DiagnosticInfoOptimizationBase::getMsg() const {
return OS.str();
}
-DiagnosticInfoMisExpect::DiagnosticInfoMisExpect(const Instruction *Inst,
- Twine &Msg)
- : DiagnosticInfoWithLocationBase(DK_MisExpect, DS_Warning,
- *Inst->getParent()->getParent(),
- Inst->getDebugLoc()),
- Msg(Msg) {}
-
-void DiagnosticInfoMisExpect::print(DiagnosticPrinter &DP) const {
- DP << getLocationStr() << ": " << getMsg();
-}
-
void OptimizationRemarkAnalysisFPCommute::anchor() {}
void OptimizationRemarkAnalysisAliasing::anchor() {}
diff --git a/llvm/lib/IR/MDBuilder.cpp b/llvm/lib/IR/MDBuilder.cpp
index 7bdb85ace52..14bcb3a29b0 100644
--- a/llvm/lib/IR/MDBuilder.cpp
+++ b/llvm/lib/IR/MDBuilder.cpp
@@ -309,15 +309,3 @@ MDNode *MDBuilder::createIrrLoopHeaderWeight(uint64_t Weight) {
};
return MDNode::get(Context, Vals);
}
-
-MDNode *MDBuilder::createMisExpect(uint64_t Index, uint64_t LikleyWeight,
- uint64_t UnlikleyWeight) {
- auto *IntType = Type::getInt64Ty(Context);
- Metadata *Vals[] = {
- createString("misexpect"),
- createConstant(ConstantInt::get(IntType, Index)),
- createConstant(ConstantInt::get(IntType, LikleyWeight)),
- createConstant(ConstantInt::get(IntType, UnlikleyWeight)),
- };
- return MDNode::get(Context, Vals);
-}
diff --git a/llvm/lib/Transforms/IPO/SampleProfile.cpp b/llvm/lib/Transforms/IPO/SampleProfile.cpp
index d0cf63b35f4..eb4ddfd179b 100644
--- a/llvm/lib/Transforms/IPO/SampleProfile.cpp
+++ b/llvm/lib/Transforms/IPO/SampleProfile.cpp
@@ -72,7 +72,6 @@
#include "llvm/Transforms/Instrumentation.h"
#include "llvm/Transforms/Utils/CallPromotionUtils.h"
#include "llvm/Transforms/Utils/Cloning.h"
-#include "llvm/Transforms/Utils/MisExpect.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
@@ -1447,8 +1446,6 @@ void SampleProfileLoader::propagateWeights(Function &F) {
}
}
- misexpect::verifyMisExpect(TI, Weights, TI->getContext());
-
uint64_t TempWeight;
// Only set weights if there is at least one non-zero weight.
// In any other case, let the analyzer set weights.
diff --git a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
index c8cf1805c66..73a91d909a9 100644
--- a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
+++ b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
@@ -108,7 +108,6 @@
#include "llvm/Transforms/Instrumentation.h"
#include "llvm/Transforms/Instrumentation/PGOInstrumentation.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/MisExpect.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
@@ -1777,9 +1776,6 @@ void llvm::setProfMetadata(Module *M, Instruction *TI,
: Weights) {
dbgs() << W << " ";
} dbgs() << "\n";);
-
- misexpect::verifyMisExpect(TI, Weights, TI->getContext());
-
TI->setMetadata(LLVMContext::MD_prof, MDB.createBranchWeights(Weights));
if (EmitBranchProbability) {
std::string BrCondStr = getBranchCondString(TI);
diff --git a/llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp b/llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
index cdb1d790667..0d67c0d740e 100644
--- a/llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
+++ b/llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
@@ -26,7 +26,6 @@
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Transforms/Scalar.h"
-#include "llvm/Transforms/Utils/MisExpect.h"
using namespace llvm;
@@ -72,20 +71,15 @@ static bool handleSwitchExpect(SwitchInst &SI) {
unsigned n = SI.getNumCases(); // +1 for default case.
SmallVector<uint32_t, 16> Weights(n + 1, UnlikelyBranchWeight);
- uint64_t Index = (Case == *SI.case_default()) ? 0 : Case.getCaseIndex() + 1;
- Weights[Index] = LikelyBranchWeight;
-
- SI.setMetadata(
- LLVMContext::MD_misexpect,
- MDBuilder(CI->getContext())
- .createMisExpect(Index, LikelyBranchWeight, UnlikelyBranchWeight));
-
- SI.setCondition(ArgValue);
- misexpect::checkFrontendInstrumentation(SI);
+ if (Case == *SI.case_default())
+ Weights[0] = LikelyBranchWeight;
+ else
+ Weights[Case.getCaseIndex() + 1] = LikelyBranchWeight;
SI.setMetadata(LLVMContext::MD_prof,
MDBuilder(CI->getContext()).createBranchWeights(Weights));
+ SI.setCondition(ArgValue);
return true;
}
@@ -286,28 +280,19 @@ template <class BrSelInst> static bool handleBrSelExpect(BrSelInst &BSI) {
MDBuilder MDB(CI->getContext());
MDNode *Node;
- MDNode *ExpNode;
if ((ExpectedValue->getZExtValue() == ValueComparedTo) ==
- (Predicate == CmpInst::ICMP_EQ)) {
+ (Predicate == CmpInst::ICMP_EQ))
Node = MDB.createBranchWeights(LikelyBranchWeight, UnlikelyBranchWeight);
- ExpNode = MDB.createMisExpect(0, LikelyBranchWeight, UnlikelyBranchWeight);
- } else {
+ else
Node = MDB.createBranchWeights(UnlikelyBranchWeight, LikelyBranchWeight);
- ExpNode = MDB.createMisExpect(1, LikelyBranchWeight, UnlikelyBranchWeight);
- }
- BSI.setMetadata(LLVMContext::MD_misexpect, ExpNode);
+ BSI.setMetadata(LLVMContext::MD_prof, Node);
if (CmpI)
CmpI->setOperand(0, ArgValue);
else
BSI.setCondition(ArgValue);
-
- misexpect::checkFrontendInstrumentation(BSI);
-
- BSI.setMetadata(LLVMContext::MD_prof, Node);
-
return true;
}
diff --git a/llvm/lib/Transforms/Utils/CMakeLists.txt b/llvm/lib/Transforms/Utils/CMakeLists.txt
index 115f543a8ec..c232aa6223c 100644
--- a/llvm/lib/Transforms/Utils/CMakeLists.txt
+++ b/llvm/lib/Transforms/Utils/CMakeLists.txt
@@ -40,7 +40,6 @@ add_llvm_library(LLVMTransformUtils
LowerSwitch.cpp
Mem2Reg.cpp
MetaRenamer.cpp
- MisExpect.cpp
ModuleUtils.cpp
NameAnonGlobals.cpp
PredicateInfo.cpp
diff --git a/llvm/lib/Transforms/Utils/MisExpect.cpp b/llvm/lib/Transforms/Utils/MisExpect.cpp
deleted file mode 100644
index 26d3402bd27..00000000000
--- a/llvm/lib/Transforms/Utils/MisExpect.cpp
+++ /dev/null
@@ -1,177 +0,0 @@
-//===--- MisExpect.cpp - Check the use of llvm.expect with PGO data -------===//
-//
-// 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 contains code to emit warnings for potentially incorrect usage of the
-// llvm.expect intrinsic. This utility extracts the threshold values from
-// metadata associated with the instrumented Branch or Switch instruction. The
-// threshold values are then used to determine if a warning should be emmited.
-//
-// MisExpect metadata is generated when llvm.expect intrinsics are lowered see
-// LowerExpectIntrinsic.cpp
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Transforms/Utils/MisExpect.h"
-#include "llvm/ADT/Twine.h"
-#include "llvm/Analysis/OptimizationRemarkEmitter.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DiagnosticInfo.h"
-#include "llvm/IR/Instruction.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/LLVMContext.h"
-#include "llvm/Support/BranchProbability.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/FormatVariadic.h"
-#include <cstdint>
-#include <functional>
-#include <numeric>
-
-#define DEBUG_TYPE "misexpect"
-
-using namespace llvm;
-using namespace misexpect;
-
-namespace llvm {
-
-// Command line option to enable/disable the warning when profile data suggests
-// a mismatch with the use of the llvm.expect intrinsic
-static cl::opt<bool> PGOWarnMisExpect(
- "pgo-warn-misexpect", cl::init(false), cl::Hidden,
- cl::desc("Use this option to turn on/off "
- "warnings about incorrect usage of llvm.expect intrinsics."));
-
-} // namespace llvm
-
-namespace {
-
-Instruction *getOprndOrInst(Instruction *I) {
- assert(I != nullptr && "MisExpect target Instruction cannot be nullptr");
- Instruction *Ret = nullptr;
- if (auto *B = dyn_cast<BranchInst>(I)) {
- Ret = dyn_cast<Instruction>(B->getCondition());
- }
- // TODO: Find a way to resolve condition location for switches
- // Using the condition of the switch seems to often resolve to an earlier
- // point in the program, i.e. the calculation of the switch condition, rather
- // than the switches location in the source code. Thus, we should use the
- // instruction to get source code locations rather than the condition to
- // improve diagnostic output, such as the caret. If the same problem exists
- // for branch instructions, then we should remove this function and directly
- // use the instruction
- //
- // else if (auto S = dyn_cast<SwitchInst>(I)) {
- // Ret = I;
- //}
- return Ret ? Ret : I;
-}
-
-void emitMisexpectDiagnostic(Instruction *I, LLVMContext &Ctx,
- uint64_t ProfCount, uint64_t TotalCount) {
- double PercentageCorrect = (double)ProfCount / TotalCount;
- auto PerString =
- formatv("{0:P} ({1} / {2})", PercentageCorrect, ProfCount, TotalCount);
- auto RemStr = formatv(
- "Potential performance regression from use of the llvm.expect intrinsic: "
- "Annotation was correct on {0} of profiled executions.",
- PerString);
- Twine Msg(PerString);
- Instruction *Cond = getOprndOrInst(I);
- if (PGOWarnMisExpect)
- Ctx.diagnose(DiagnosticInfoMisExpect(Cond, Msg));
- OptimizationRemarkEmitter ORE(I->getParent()->getParent());
- ORE.emit(OptimizationRemark(DEBUG_TYPE, "misexpect", Cond) << RemStr.str());
-}
-
-} // namespace
-
-namespace llvm {
-namespace misexpect {
-
-void verifyMisExpect(Instruction *I, const SmallVector<uint32_t, 4> &Weights,
- LLVMContext &Ctx) {
- if (auto *MisExpectData = I->getMetadata(LLVMContext::MD_misexpect)) {
- auto *MisExpectDataName = dyn_cast<MDString>(MisExpectData->getOperand(0));
- if (MisExpectDataName &&
- MisExpectDataName->getString().equals("misexpect")) {
- LLVM_DEBUG(llvm::dbgs() << "------------------\n");
- LLVM_DEBUG(llvm::dbgs()
- << "Function: " << I->getFunction()->getName() << "\n");
- LLVM_DEBUG(llvm::dbgs() << "Instruction: " << *I << ":\n");
- LLVM_DEBUG(for (int Idx = 0, Size = Weights.size(); Idx < Size; ++Idx) {
- llvm::dbgs() << "Weights[" << Idx << "] = " << Weights[Idx] << "\n";
- });
-
- // extract values from misexpect metadata
- const auto *IndexCint =
- mdconst::dyn_extract<ConstantInt>(MisExpectData->getOperand(1));
- const auto *LikelyCInt =
- mdconst::dyn_extract<ConstantInt>(MisExpectData->getOperand(2));
- const auto *UnlikelyCInt =
- mdconst::dyn_extract<ConstantInt>(MisExpectData->getOperand(3));
-
- if (!IndexCint || !LikelyCInt || !UnlikelyCInt)
- return;
-
- const uint64_t Index = IndexCint->getZExtValue();
- const uint64_t LikelyBranchWeight = LikelyCInt->getZExtValue();
- const uint64_t UnlikelyBranchWeight = UnlikelyCInt->getZExtValue();
- const uint64_t ProfileCount = Weights[Index];
- const uint64_t CaseTotal = std::accumulate(
- Weights.begin(), Weights.end(), (uint64_t)0, std::plus<uint64_t>());
- const uint64_t NumUnlikelyTargets = Weights.size() - 1;
-
- const uint64_t TotalBranchWeight =
- LikelyBranchWeight + (UnlikelyBranchWeight * NumUnlikelyTargets);
-
- const llvm::BranchProbability LikelyThreshold(LikelyBranchWeight,
- TotalBranchWeight);
- uint64_t ScaledThreshold = LikelyThreshold.scale(CaseTotal);
-
- LLVM_DEBUG(llvm::dbgs()
- << "Unlikely Targets: " << NumUnlikelyTargets << ":\n");
- LLVM_DEBUG(llvm::dbgs() << "Profile Count: " << ProfileCount << ":\n");
- LLVM_DEBUG(llvm::dbgs()
- << "Scaled Threshold: " << ScaledThreshold << ":\n");
- LLVM_DEBUG(llvm::dbgs() << "------------------\n");
- if (ProfileCount < ScaledThreshold)
- emitMisexpectDiagnostic(I, Ctx, ProfileCount, CaseTotal);
- }
- }
-}
-
-void checkFrontendInstrumentation(Instruction &I) {
- if (auto *MD = I.getMetadata(LLVMContext::MD_prof)) {
- unsigned NOps = MD->getNumOperands();
-
- // Only emit misexpect diagnostics if at least 2 branch weights are present.
- // Less than 2 branch weights means that the profiling metadata is:
- // 1) incorrect/corrupted
- // 2) not branch weight metadata
- // 3) completely deterministic
- // In these cases we should not emit any diagnostic related to misexpect.
- if (NOps < 3)
- return;
-
- // Operand 0 is a string tag "branch_weights"
- if (MDString *Tag = cast<MDString>(MD->getOperand(0))) {
- if (Tag->getString().equals("branch_weights")) {
- SmallVector<uint32_t, 4> RealWeights(NOps - 1);
- for (unsigned i = 1; i < NOps; i++) {
- ConstantInt *Value =
- mdconst::dyn_extract<ConstantInt>(MD->getOperand(i));
- RealWeights[i - 1] = Value->getZExtValue();
- }
- verifyMisExpect(&I, RealWeights, I.getContext());
- }
- }
- }
-}
-
-} // namespace misexpect
-} // namespace llvm
-#undef DEBUG_TYPE
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