From 5ed6229019de43df0ff4b3e73097781e0f1a6651 Mon Sep 17 00:00:00 2001 From: Simon Pilgrim Date: Thu, 2 Jan 2025 12:46:54 +0000 Subject: [PATCH] [VectorCombine] Add scalarizeLoadExtract infinite loop test from #120984 regression scalarizeLoadExtract replaces instructions up the use list, which can result in the vectorcombine worklist adding users back to the worklist when they should really be erased first. --- .../X86/load-extractelement-scalarization.ll | 26 +++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 llvm/test/Transforms/VectorCombine/X86/load-extractelement-scalarization.ll diff --git a/llvm/test/Transforms/VectorCombine/X86/load-extractelement-scalarization.ll b/llvm/test/Transforms/VectorCombine/X86/load-extractelement-scalarization.ll new file mode 100644 index 00000000000000..0acfeccb92ef72 --- /dev/null +++ b/llvm/test/Transforms/VectorCombine/X86/load-extractelement-scalarization.ll @@ -0,0 +1,26 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -passes=vector-combine -S -mtriple=x86_64-- -mattr=sse2 | FileCheck %s +; RUN: opt < %s -passes=vector-combine -S -mtriple=x86_64-- -mattr=avx2 | FileCheck %s + +; infinite loop if we add the erased instructions to the work list in the wrong order. +define void @multiple_extract(ptr %p) { +; CHECK-LABEL: @multiple_extract( +; CHECK-NEXT: [[VP:%.*]] = load ptr, ptr [[P:%.*]], align 8 +; CHECK-NEXT: [[TMP1:%.*]] = getelementptr inbounds <2 x i32>, ptr [[VP]], i32 0, i64 0 +; CHECK-NEXT: [[E0:%.*]] = load i32, ptr [[TMP1]], align 16 +; CHECK-NEXT: [[TMP2:%.*]] = getelementptr inbounds <2 x i32>, ptr [[VP]], i32 0, i64 1 +; CHECK-NEXT: [[E1:%.*]] = load i32, ptr [[TMP2]], align 4 +; CHECK-NEXT: store i32 [[E0]], ptr [[P]], align 4 +; CHECK-NEXT: [[P1:%.*]] = getelementptr inbounds nuw i8, ptr [[P]], i64 4 +; CHECK-NEXT: store i32 [[E1]], ptr [[P1]], align 4 +; CHECK-NEXT: ret void +; + %vp = load ptr, ptr %p, align 8 + %v = load <2 x i32>, ptr %vp, align 16 + %e0 = extractelement <2 x i32> %v, i64 0 + %e1 = extractelement <2 x i32> %v, i64 1 + store i32 %e0, ptr %p, align 4 + %p1 = getelementptr inbounds nuw i8, ptr %p, i64 4 + store i32 %e1, ptr %p1, align 4 + ret void +}