diff options
| -rw-r--r-- | lib/Transforms/Utils/SimplifyCFG.cpp | 5 | ||||
| -rw-r--r-- | test/Transforms/SimplifyCFG/select-gep.ll | 20 |
2 files changed, 25 insertions, 0 deletions
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index fb660dbfac..c6708857cb 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -247,6 +247,11 @@ static bool DominatesMergePoint(Value *V, BasicBlock *BB, if (PBB->getFirstNonPHIOrDbg() != I) return false; break; + case Instruction::GetElementPtr: + // GEPs are cheap if all indices are constant. + if (!cast<GetElementPtrInst>(I)->hasAllConstantIndices()) + return false; + break; case Instruction::Add: case Instruction::Sub: case Instruction::And: diff --git a/test/Transforms/SimplifyCFG/select-gep.ll b/test/Transforms/SimplifyCFG/select-gep.ll new file mode 100644 index 0000000000..6330ccdb29 --- /dev/null +++ b/test/Transforms/SimplifyCFG/select-gep.ll @@ -0,0 +1,20 @@ +; RUN: opt -S -simplifycfg %s | FileCheck %s + +define i8* @test1(i8* %x) nounwind { +entry: + %tmp1 = load i8* %x, align 1 + %cmp = icmp eq i8 %tmp1, 47 + br i1 %cmp, label %if.then, label %if.end + +if.then: + %incdec.ptr = getelementptr inbounds i8* %x, i64 1 + br label %if.end + +if.end: + %x.addr = phi i8* [ %incdec.ptr, %if.then ], [ %x, %entry ] + ret i8* %x.addr + +; CHECK: @test1 +; CHECK: %x.addr = select i1 %cmp, i8* %incdec.ptr, i8* %x +; CHECK: ret i8* %x.addr +} |