From 1ff08e389f82561659945bab8a55bdba5fc8e9dc Mon Sep 17 00:00:00 2001 From: "Duncan P. N. Exon Smith" Date: Sun, 2 Feb 2014 22:43:55 +0000 Subject: Lower llvm.expect intrinsic correctly for i1 LowerExpectIntrinsic previously only understood the idiom of an expect intrinsic followed by a comparison with zero. For llvm.expect.i1, the comparison would be stripped by the early-cse pass. Patch by Daniel Micay. llvm-svn: 200664 --- llvm/lib/Transforms/Utils/LowerExpectIntrinsic.cpp | 23 +++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) (limited to 'llvm/lib/Transforms') diff --git a/llvm/lib/Transforms/Utils/LowerExpectIntrinsic.cpp b/llvm/lib/Transforms/Utils/LowerExpectIntrinsic.cpp index e017f501209..596fd371151 100644 --- a/llvm/lib/Transforms/Utils/LowerExpectIntrinsic.cpp +++ b/llvm/lib/Transforms/Utils/LowerExpectIntrinsic.cpp @@ -94,15 +94,25 @@ bool LowerExpectIntrinsic::HandleIfExpect(BranchInst *BI) { return false; // Handle non-optimized IR code like: - // %expval = call i64 @llvm.expect.i64.i64(i64 %conv1, i64 1) + // %expval = call i64 @llvm.expect.i64(i64 %conv1, i64 1) // %tobool = icmp ne i64 %expval, 0 // br i1 %tobool, label %if.then, label %if.end + // + // Or the following simpler case: + // %expval = call i1 @llvm.expect.i1(i1 %cmp, i1 1) + // br i1 %expval, label %if.then, label %if.end + + CallInst *CI; ICmpInst *CmpI = dyn_cast(BI->getCondition()); - if (!CmpI || CmpI->getPredicate() != CmpInst::ICMP_NE) - return false; + if (!CmpI) { + CI = dyn_cast(BI->getCondition()); + } else { + if (CmpI->getPredicate() != CmpInst::ICMP_NE) + return false; + CI = dyn_cast(CmpI->getOperand(0)); + } - CallInst *CI = dyn_cast(CmpI->getOperand(0)); if (!CI) return false; @@ -127,7 +137,10 @@ bool LowerExpectIntrinsic::HandleIfExpect(BranchInst *BI) { BI->setMetadata(LLVMContext::MD_prof, Node); - CmpI->setOperand(0, ArgValue); + if (CmpI) + CmpI->setOperand(0, ArgValue); + else + BI->setCondition(ArgValue); return true; } -- cgit v1.2.3