Author: Juneyoung Lee Date: 2021-01-05T11:07:49+09:00 New Revision: f665a8c5b8b42d88f89e1a3594b7d410ef206c32
URL: https://github.com/llvm/llvm-project/commit/f665a8c5b8b42d88f89e1a3594b7d410ef206c32 DIFF: https://github.com/llvm/llvm-project/commit/f665a8c5b8b42d88f89e1a3594b7d410ef206c32.diff LOG: [InstSimplify] gep with poison operand is poison This is a tiny update to fold gep poison into poison. :) Alive2 proofs: https://alive2.llvm.org/ce/z/7Nwdri https://alive2.llvm.org/ce/z/sDP4sC Added: Modified: llvm/lib/Analysis/InstructionSimplify.cpp llvm/test/Transforms/InstSimplify/gep.ll Removed: ################################################################################ diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index dfaf36a96953..659b71fae6a0 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -4242,6 +4242,11 @@ static Value *SimplifyGEPInst(Type *SrcTy, ArrayRef<Value *> Ops, else if (VectorType *VT = dyn_cast<VectorType>(Ops[1]->getType())) GEPTy = VectorType::get(GEPTy, VT->getElementCount()); + // getelementptr poison, idx -> poison + // getelementptr baseptr, poison -> poison + if (any_of(Ops, [](const auto *V) { return isa<PoisonValue>(V); })) + return PoisonValue::get(GEPTy); + if (Q.isUndefValue(Ops[0])) return UndefValue::get(GEPTy); diff --git a/llvm/test/Transforms/InstSimplify/gep.ll b/llvm/test/Transforms/InstSimplify/gep.ll index 804ce7f10a8c..e6670e4a9345 100644 --- a/llvm/test/Transforms/InstSimplify/gep.ll +++ b/llvm/test/Transforms/InstSimplify/gep.ll @@ -222,7 +222,7 @@ define <vscale x 2 x i64*> @ptr_idx_mix_scalar_scalable_vector() { define i8* @poison() { ; CHECK-LABEL: @poison( -; CHECK-NEXT: ret i8* undef +; CHECK-NEXT: ret i8* poison ; %v = getelementptr i8, i8* poison, i64 1 ret i8* %v @@ -230,8 +230,7 @@ define i8* @poison() { define i8* @poison2(i8* %baseptr) { ; CHECK-LABEL: @poison2( -; CHECK-NEXT: [[V:%.*]] = getelementptr i8, i8* [[BASEPTR:%.*]], i64 poison -; CHECK-NEXT: ret i8* [[V]] +; CHECK-NEXT: ret i8* poison ; %v = getelementptr i8, i8* %baseptr, i64 poison ret i8* %v _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
