diff --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp --- a/llvm/lib/Transforms/Scalar/GVN.cpp +++ b/llvm/lib/Transforms/Scalar/GVN.cpp @@ -2460,10 +2460,14 @@ if (isa(CurInst)) return false; - // We don't currently value number ANY inline asm calls. - if (auto *CallB = dyn_cast(CurInst)) + if (auto *CallB = dyn_cast(CurInst)) { + // We don't currently value number ANY inline asm calls. if (CallB->isInlineAsm()) return false; + // Don't do PRE on convergent calls. + if (CallB->isConvergent()) + return false; + } uint32_t ValNo = VN.lookup(CurInst); diff --git a/llvm/test/Transforms/GVN/pre-skip-convergent.ll b/llvm/test/Transforms/GVN/pre-skip-convergent.ll --- a/llvm/test/Transforms/GVN/pre-skip-convergent.ll +++ b/llvm/test/Transforms/GVN/pre-skip-convergent.ll @@ -1,5 +1,6 @@ ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt -S -gvn -o - %s | FileCheck %s +; RUN: opt -S -passes=gvn -o - %s | FileCheck %s define i32 @foo(i1 %cond, i32* %q, i32* %p) { ; CHECK-LABEL: @foo( @@ -9,12 +10,11 @@ ; CHECK-NEXT: br i1 [[COND:%.*]], label [[PRE:%.*]], label [[MERGE:%.*]] ; CHECK: pre: ; CHECK-NEXT: [[T0:%.*]] = load i32, i32* [[P:%.*]], align 4 -; CHECK-NEXT: [[DOTPRE:%.*]] = call i32 @llvm.convergent(i32 [[T0]]) ; CHECK-NEXT: br label [[MERGE]] ; CHECK: merge: -; CHECK-NEXT: [[R0_PRE_PHI:%.*]] = phi i32 [ [[DOTPRE]], [[PRE]] ], [ [[V0]], [[ENTRY:%.*]] ] -; CHECK-NEXT: [[M0:%.*]] = phi i32 [ [[T0]], [[PRE]] ], [ 0, [[ENTRY]] ] -; CHECK-NEXT: ret i32 [[R0_PRE_PHI]] +; CHECK-NEXT: [[M0:%.*]] = phi i32 [ [[T0]], [[PRE]] ], [ 0, [[ENTRY:%.*]] ] +; CHECK-NEXT: [[R0:%.*]] = call i32 @llvm.convergent(i32 [[M0]]) +; CHECK-NEXT: ret i32 [[R0]] ; entry: %v0 = call i32 @llvm.convergent(i32 0)