https://github.com/fhahn created https://github.com/llvm/llvm-project/pull/81285
Retain TBAAStruct if we fail to match the access to a single field. All users at the moment use this when using the full size of the original access. SROA also retains the original TBAAStruct when accessing parts at offset 0. Motivation for this and follow-on patches is to improve codegen for libc++, where using memcpy limits optimizations, like vectorization for code iteration over std::vector<std::complex<float>>: https://godbolt.org/z/f3vqYos3c Depends on https://github.com/llvm/llvm-project/pull/81284 >From 99cf032dfabb21b820559bae61d2354e56336fdd Mon Sep 17 00:00:00 2001 From: Florian Hahn <f...@fhahn.com> Date: Fri, 9 Feb 2024 16:25:32 +0000 Subject: [PATCH] [TBAA] Only clear TBAAStruct if field can be extracted. Retain TBAAStruct if we fail to match the access to a single field. All users at the moment use this when using the full size of the original access. SROA also retains the original TBAAStruct when accessing parts at offset 0. Motivation for this and follow-on patches is to improve codegen for libc++, where using memcpy limits optimizations, like vectorization for code iteration over std::vector<std::complex<float>>: https://godbolt.org/z/f3vqYos3c Depends on https://github.com/llvm/llvm-project/pull/81284 --- llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp | 8 +++++--- llvm/test/Transforms/InstCombine/struct-assign-tbaa.ll | 5 +++-- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp b/llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp index edc08cde686f1f..bfd70414c0340c 100644 --- a/llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp +++ b/llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp @@ -821,13 +821,15 @@ MDNode *AAMDNodes::extendToTBAA(MDNode *MD, ssize_t Len) { AAMDNodes AAMDNodes::adjustForAccess(unsigned AccessSize) { AAMDNodes New = *this; MDNode *M = New.TBAAStruct; - New.TBAAStruct = nullptr; if (M && M->getNumOperands() == 3 && M->getOperand(0) && mdconst::hasa<ConstantInt>(M->getOperand(0)) && mdconst::extract<ConstantInt>(M->getOperand(0))->isZero() && M->getOperand(1) && mdconst::hasa<ConstantInt>(M->getOperand(1)) && - mdconst::extract<ConstantInt>(M->getOperand(1))->getValue() == AccessSize && - M->getOperand(2) && isa<MDNode>(M->getOperand(2))) + mdconst::extract<ConstantInt>(M->getOperand(1))->getValue() == + AccessSize && + M->getOperand(2) && isa<MDNode>(M->getOperand(2))) { + New.TBAAStruct = nullptr; New.TBAA = cast<MDNode>(M->getOperand(2)); + } return New; } diff --git a/llvm/test/Transforms/InstCombine/struct-assign-tbaa.ll b/llvm/test/Transforms/InstCombine/struct-assign-tbaa.ll index 1042c413fbb7bb..996d2c0e67e165 100644 --- a/llvm/test/Transforms/InstCombine/struct-assign-tbaa.ll +++ b/llvm/test/Transforms/InstCombine/struct-assign-tbaa.ll @@ -38,8 +38,8 @@ define ptr @test2() { define void @test3_multiple_fields(ptr nocapture %a, ptr nocapture %b) { ; CHECK-LABEL: @test3_multiple_fields( ; CHECK-NEXT: entry: -; CHECK-NEXT: [[TMP0:%.*]] = load i64, ptr [[B:%.*]], align 4 -; CHECK-NEXT: store i64 [[TMP0]], ptr [[A:%.*]], align 4 +; CHECK-NEXT: [[TMP0:%.*]] = load i64, ptr [[B:%.*]], align 4, !tbaa.struct [[TBAA_STRUCT3:![0-9]+]] +; CHECK-NEXT: store i64 [[TMP0]], ptr [[A:%.*]], align 4, !tbaa.struct [[TBAA_STRUCT3]] ; CHECK-NEXT: ret void ; entry: @@ -86,4 +86,5 @@ entry: ; CHECK: [[TBAA0]] = !{[[META1:![0-9]+]], [[META1]], i64 0} ; CHECK: [[META1]] = !{!"float", [[META2:![0-9]+]]} ; CHECK: [[META2]] = !{!"Simple C/C++ TBAA"} +; CHECK: [[TBAA_STRUCT3]] = !{i64 0, i64 4, [[TBAA0]], i64 4, i64 4, [[TBAA0]]} ;. _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
