From fac554a1317bf32daf5698740670025ae14e6bcc Mon Sep 17 00:00:00 2001 From: Nick Lewycky Date: Sun, 29 Nov 2009 21:40:55 +0000 Subject: [PATCH] Teach ConstantFolding to do a better job when folding gep(bitcast). This permits the devirtualization of llvm.org/PR3100#c9 when compiled by clang. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90099 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/ConstantFolding.cpp | 1 + test/Transforms/InstCombine/getelementptr.ll | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp index 8d60907f8cb..96f738edad4 100644 --- a/lib/Analysis/ConstantFolding.cpp +++ b/lib/Analysis/ConstantFolding.cpp @@ -564,6 +564,7 @@ static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, // we eliminate over-indexing of the notional static type array bounds. // This makes it easy to determine if the getelementptr is "inbounds". // Also, this helps GlobalOpt do SROA on GlobalVariables. + Ptr = cast(Ptr->stripPointerCasts()); const Type *Ty = Ptr->getType(); SmallVector NewIdxs; do { diff --git a/test/Transforms/InstCombine/getelementptr.ll b/test/Transforms/InstCombine/getelementptr.ll index 285e0ba602f..de325f64021 100644 --- a/test/Transforms/InstCombine/getelementptr.ll +++ b/test/Transforms/InstCombine/getelementptr.ll @@ -445,7 +445,7 @@ define i32 @test35() nounwind { i8* getelementptr (%t1* bitcast (%t0* @s to %t1*), i32 0, i32 1, i32 0)) nounwind ret i32 0 ; CHECK: @test35 -; CHECK: call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([17 x i8]* @"\01LC8", i64 0, i64 0), i8* bitcast (i8** getelementptr (%t1* bitcast (%t0* @s to %t1*), i64 1, i32 0) to i8*)) nounwind +; CHECK: call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([17 x i8]* @"\01LC8", i64 0, i64 0), i8* getelementptr inbounds (%t0* @s, i64 0, i32 1, i64 0)) nounwind } ; Instcombine should constant-fold the GEP so that indices that have