diff options
5 files changed, 17 insertions, 7 deletions
diff --git a/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp index 2fc93681e98..afe0c9d2fc4 100644 --- a/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp +++ b/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp @@ -68,6 +68,7 @@ #include "llvm/IR/PatternMatch.h" #include "llvm/Support/raw_ostream.h" #include "llvm/Transforms/Scalar.h" +#include "llvm/Transforms/Utils/Local.h" using namespace llvm; using namespace PatternMatch; @@ -599,9 +600,14 @@ void StraightLineStrengthReduce::rewriteCandidateWithBasis( switch (C.CandidateKind) { case Candidate::Add: case Candidate::Mul: + // C = Basis + Bump if (BinaryOperator::isNeg(Bump)) { + // If Bump is a neg instruction, emit C = Basis - (-Bump). Reduced = Builder.CreateSub(Basis.Ins, BinaryOperator::getNegArgument(Bump)); + // We only use the negative argument of Bump, and Bump itself may be + // trivially dead. + RecursivelyDeleteTriviallyDeadInstructions(Bump); } else { Reduced = Builder.CreateAdd(Basis.Ins, Bump); } @@ -637,7 +643,6 @@ void StraightLineStrengthReduce::rewriteCandidateWithBasis( }; Reduced->takeName(C.Ins); C.Ins->replaceAllUsesWith(Reduced); - C.Ins->dropAllReferences(); // Unlink C.Ins so that we can skip other candidates also corresponding to // C.Ins. The actual deletion is postponed to the end of runOnFunction. C.Ins->removeFromParent(); @@ -670,8 +675,13 @@ bool StraightLineStrengthReduce::runOnFunction(Function &F) { } // Delete all unlink instructions. - for (auto I : UnlinkedInstructions) { - delete I; + for (auto *UnlinkedInst : UnlinkedInstructions) { + for (unsigned I = 0, E = UnlinkedInst->getNumOperands(); I != E; ++I) { + Value *Op = UnlinkedInst->getOperand(I); + UnlinkedInst->setOperand(I, nullptr); + RecursivelyDeleteTriviallyDeadInstructions(Op); + } + delete UnlinkedInst; } bool Ret = !UnlinkedInstructions.empty(); UnlinkedInstructions.clear(); diff --git a/llvm/test/Transforms/StraightLineStrengthReduce/X86/no-slsr.ll b/llvm/test/Transforms/StraightLineStrengthReduce/X86/no-slsr.ll index e2201ce23f6..f11cbc5897a 100644 --- a/llvm/test/Transforms/StraightLineStrengthReduce/X86/no-slsr.ll +++ b/llvm/test/Transforms/StraightLineStrengthReduce/X86/no-slsr.ll @@ -1,4 +1,4 @@ -; RUN: opt < %s -slsr -gvn -dce -S | FileCheck %s +; RUN: opt < %s -slsr -gvn -S | FileCheck %s target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" target triple = "x86_64-unknown-linux-gnu" diff --git a/llvm/test/Transforms/StraightLineStrengthReduce/slsr-add.ll b/llvm/test/Transforms/StraightLineStrengthReduce/slsr-add.ll index 4c79be0577e..e25ddc2888a 100644 --- a/llvm/test/Transforms/StraightLineStrengthReduce/slsr-add.ll +++ b/llvm/test/Transforms/StraightLineStrengthReduce/slsr-add.ll @@ -1,4 +1,4 @@ -; RUN: opt < %s -slsr -gvn -dce -S | FileCheck %s +; RUN: opt < %s -slsr -gvn -S | FileCheck %s target datalayout = "e-i64:64-v16:16-v32:32-n16:32:64" diff --git a/llvm/test/Transforms/StraightLineStrengthReduce/slsr-gep.ll b/llvm/test/Transforms/StraightLineStrengthReduce/slsr-gep.ll index 3944739aeaa..bd92780a036 100644 --- a/llvm/test/Transforms/StraightLineStrengthReduce/slsr-gep.ll +++ b/llvm/test/Transforms/StraightLineStrengthReduce/slsr-gep.ll @@ -1,4 +1,4 @@ -; RUN: opt < %s -slsr -gvn -dce -S | FileCheck %s +; RUN: opt < %s -slsr -gvn -S | FileCheck %s target datalayout = "e-i64:64-v16:16-v32:32-n16:32:64" diff --git a/llvm/test/Transforms/StraightLineStrengthReduce/slsr-mul.ll b/llvm/test/Transforms/StraightLineStrengthReduce/slsr-mul.ll index 1c7333dab9f..97e68d5bf51 100644 --- a/llvm/test/Transforms/StraightLineStrengthReduce/slsr-mul.ll +++ b/llvm/test/Transforms/StraightLineStrengthReduce/slsr-mul.ll @@ -1,4 +1,4 @@ -; RUN: opt < %s -slsr -gvn -dce -S | FileCheck %s +; RUN: opt < %s -slsr -gvn -S | FileCheck %s target datalayout = "e-i64:64-v16:16-v32:32-n16:32:64" |
