From 2f817d1c9e7341d634931e3deb3f849ce67035da Mon Sep 17 00:00:00 2001 From: Farzon Lotfi Date: Wed, 25 Jun 2025 14:07:49 -0400 Subject: [PATCH] [DirectX] Limit GEP transformations to Arrays fixes #145408 Before we see the GEP we already have transformed Allocas that get passed the `isArrayOfVectors`. The problem with our `visitGetElementPtrInst` is that it was doing transformations for all allocas when it should be limiting it to the array cases. Technically we would have liked to make sure it was an array of vectors cases but by the time we see the GEP the type has been changed by replace all uses. There should not be a problem with looking at all Arrays since DXILDataScalarization does not change any indicies. --- .../Target/DirectX/DXILDataScalarization.cpp | 5 ++--- .../DirectX/issue-145408-gep-struct-fix.ll | 17 +++++++++++++++++ 2 files changed, 19 insertions(+), 3 deletions(-) create mode 100644 llvm/test/CodeGen/DirectX/issue-145408-gep-struct-fix.ll diff --git a/llvm/lib/Target/DirectX/DXILDataScalarization.cpp b/llvm/lib/Target/DirectX/DXILDataScalarization.cpp index 0a9b2bb99f7eb..71eb1349314ea 100644 --- a/llvm/lib/Target/DirectX/DXILDataScalarization.cpp +++ b/llvm/lib/Target/DirectX/DXILDataScalarization.cpp @@ -308,9 +308,8 @@ bool DataScalarizerVisitor::visitGetElementPtrInst(GetElementPtrInst &GEPI) { NeedsTransform = true; } else if (AllocaInst *Alloca = dyn_cast(PtrOperand)) { Type *AllocatedType = Alloca->getAllocatedType(); - // OrigGEPType might just be a pointer lets make sure - // to add the allocated type so we have a size - if (AllocatedType != OrigGEPType) { + // Only transform if the allocated type is an array + if (AllocatedType != OrigGEPType && isa(AllocatedType)) { NewGEPType = AllocatedType; NeedsTransform = true; } diff --git a/llvm/test/CodeGen/DirectX/issue-145408-gep-struct-fix.ll b/llvm/test/CodeGen/DirectX/issue-145408-gep-struct-fix.ll new file mode 100644 index 0000000000000..40d222cdf2f8f --- /dev/null +++ b/llvm/test/CodeGen/DirectX/issue-145408-gep-struct-fix.ll @@ -0,0 +1,17 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5 +; RUN: opt -S -dxil-data-scalarization -mtriple=dxil-pc-shadermodel6.3-library %s | FileCheck %s + +%struct.RawStruct8D = type { [8 x i32] } + +define void @test_no_transform_of_struct() { +; CHECK-LABEL: define void @test_no_transform_of_struct() { +; CHECK-NEXT: [[ENTRY:.*:]] +; CHECK-NEXT: [[OUTPUTSIZESLOCAL_I:%.*]] = alloca [[STRUCT_RAWSTRUCT8D:%.*]], align 4 +; CHECK-NEXT: [[ARRAYINIT_ELEMENT13_I76:%.*]] = getelementptr inbounds nuw [1 x %struct.RawStruct8D], ptr [[OUTPUTSIZESLOCAL_I]], i32 0, i32 0 +; CHECK-NEXT: ret void +; +entry: + %outputSizesLocal.i = alloca %struct.RawStruct8D, align 4 + %arrayinit.element13.i76 = getelementptr inbounds nuw [1 x %struct.RawStruct8D], ptr %outputSizesLocal.i, i32 0, i32 0 + ret void +}