diff --git a/llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp b/llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp --- a/llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp +++ b/llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp @@ -746,47 +746,15 @@ if (!isStructPathTBAA(MD)) return MD; - TBAAStructTagNode Tag(MD); - SmallVector Sub; - Sub.push_back(MD->getOperand(0)); - Sub.push_back(MD->getOperand(1)); - ConstantInt *InnerOffset = mdconst::extract(MD->getOperand(2)); - - if (Tag.isNewFormat()) { - ConstantInt *InnerSize = mdconst::extract(MD->getOperand(3)); - - if (InnerOffset->getZExtValue() + InnerSize->getZExtValue() <= Offset) { - return nullptr; - } - - uint64_t NewSize = InnerSize->getZExtValue(); - uint64_t NewOffset = InnerOffset->getZExtValue() - Offset; - if (InnerOffset->getZExtValue() < Offset) { - NewOffset = 0; - NewSize -= Offset - InnerOffset->getZExtValue(); - } - - Sub.push_back(ConstantAsMetadata::get( - ConstantInt::get(InnerOffset->getType(), NewOffset))); - - Sub.push_back(ConstantAsMetadata::get( - ConstantInt::get(InnerSize->getType(), NewSize))); - - // immutable type - if (MD->getNumOperands() >= 5) - Sub.push_back(MD->getOperand(4)); - } else { - if (InnerOffset->getZExtValue() < Offset) - return nullptr; - - Sub.push_back(ConstantAsMetadata::get(ConstantInt::get( - InnerOffset->getType(), InnerOffset->getZExtValue() - Offset))); - - // immutable type - if (MD->getNumOperands() >= 4) - Sub.push_back(MD->getOperand(3)); - } - return MDNode::get(MD->getContext(), Sub); + // The correct behavior here is to add the offset into the TBAA + // struct node offset. The base type, however may not have defined + // a type at this additional offset, resulting in errors. Since + // this method is only used within a given load/store access + // the offset provided is only used to subdivide the previous load + // maintaining the validity of the previous TBAA. + // + // This, however, should be revisited in the future. + return MD; } MDNode *AAMDNodes::ShiftTBAAStruct(MDNode *MD, size_t Offset) { diff --git a/llvm/test/Transforms/SROA/tbaa-subload.ll b/llvm/test/Transforms/SROA/tbaa-subload.ll new file mode 100644 --- /dev/null +++ b/llvm/test/Transforms/SROA/tbaa-subload.ll @@ -0,0 +1,36 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt -S -sroa %s | FileCheck %s + +; This should not crash + +%class.ar = type { i8 } +%class.anon = type <{ %class.ar, [7 x i8], { i64, i64 } }> + +define void @caller() { +; CHECK-LABEL: @caller( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[AGG:%.*]] = alloca [[CLASS_ANON:%.*]], align 8 +; CHECK-NEXT: [[OFF:%.*]] = getelementptr inbounds [[CLASS_ANON]], %class.anon* [[AGG]], i32 0, i32 2 +; CHECK-NEXT: [[DOTFCA_0_GEP:%.*]] = getelementptr inbounds { i64, i64 }, { i64, i64 }* [[OFF]], i32 0, i32 0 +; CHECK-NEXT: store i64 1, i64* [[DOTFCA_0_GEP]], align 8, !tbaa [[TBAA0:![0-9]+]] +; CHECK-NEXT: [[DOTFCA_1_GEP:%.*]] = getelementptr inbounds { i64, i64 }, { i64, i64 }* [[OFF]], i32 0, i32 1 +; CHECK-NEXT: store i64 2, i64* [[DOTFCA_1_GEP]], align 8, !tbaa [[TBAA0]] +; CHECK-NEXT: call void @use(%class.anon* [[AGG]]) +; CHECK-NEXT: ret void +; +entry: + %agg = alloca %class.anon, align 8 + %off = getelementptr inbounds %class.anon, %class.anon* %agg, i32 0, i32 2 + store { i64, i64 } { i64 1, i64 2 }, { i64, i64 }* %off, align 8, !tbaa !7 + call void @use(%class.anon* %agg) + ret void +} + +declare void @use(%class.anon* %this) + +!3 = !{!"omnipotent char", !4, i64 0} +!4 = !{!"Simple C++ TBAA"} + +!7 = !{!8, !3, i64 8} +!8 = !{!"_ZTSZN2ax2baEMS_FvvE2an2arE3$_0", !9, i64 0, !3, i64 8} +!9 = !{!"_ZTS2ar"}