LSV: Fix incorrectly increasing alignment

If the unaligned access has a dynamic offset, it may be odd which
would make the adjusted alignment incorrect to use.

llvm-svn: 281110

1 files changed, 129 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoadStoreVectorizer/AMDGPU/adjust-alloca-alignment.ll b/llvm/test/Transforms/LoadStoreVectorizer/AMDGPU/adjust-alloca-alignment.ll
new file mode 100644
index 00000000000..fbd9440d757
--- /dev/null
+++ b/llvm/test/Transforms/LoadStoreVectorizer/AMDGPU/adjust-alloca-alignment.ll
@@ -0,0 +1,129 @@
+; RUN: opt -S -load-store-vectorizer -mattr=-unaligned-buffer-access,+max-private-element-size-16 < %s | FileCheck -check-prefix=ALIGNED -check-prefix=ALL %s
+; RUN: opt -S -load-store-vectorizer -mattr=+unaligned-buffer-access,+max-private-element-size-16 < %s | FileCheck -check-prefix=UNALIGNED -check-prefix=ALL %s
+
+target datalayout = "e-p:32:32-p1:64:64-p2:64:64-p3:32:32-p4:64:64-p5:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-v2048:2048-n32:64"
+target triple = "amdgcn--"
+
+; ALL-LABEL: @load_unknown_offset_align1_i8(
+; ALL: alloca [128 x i8], align 1
+; UNALIGNED: load <2 x i8>, <2 x i8>* %{{[0-9]+}}, align 1{{$}}
+
+; ALIGNED: load i8, i8* %ptr0, align 1{{$}}
+; ALIGNED: load i8, i8* %ptr1, align 1{{$}}
+define void @load_unknown_offset_align1_i8(i8 addrspace(1)* noalias %out, i32 %offset) #0 {
+  %alloca = alloca [128 x i8], align 1
+  %ptr0 = getelementptr inbounds [128 x i8], [128 x i8]* %alloca, i32 0, i32 %offset
+  %val0 = load i8, i8* %ptr0, align 1
+  %ptr1 = getelementptr inbounds i8, i8* %ptr0, i32 1
+  %val1 = load i8, i8* %ptr1, align 1
+  %add = add i8 %val0, %val1
+  store i8 %add, i8 addrspace(1)* %out
+  ret void
+}
+
+; ALL-LABEL: @load_unknown_offset_align1_i16(
+; ALL: alloca [128 x i16], align 1{{$}}
+; UNALIGNED: load <2 x i16>, <2 x i16>* %{{[0-9]+}}, align 1{{$}}
+
+; ALIGNED: load i16, i16* %ptr0, align 1{{$}}
+; ALIGNED: load i16, i16* %ptr1, align 1{{$}}
+define void @load_unknown_offset_align1_i16(i16 addrspace(1)* noalias %out, i32 %offset) #0 {
+  %alloca = alloca [128 x i16], align 1
+  %ptr0 = getelementptr inbounds [128 x i16], [128 x i16]* %alloca, i32 0, i32 %offset
+  %val0 = load i16, i16* %ptr0, align 1
+  %ptr1 = getelementptr inbounds i16, i16* %ptr0, i32 1
+  %val1 = load i16, i16* %ptr1, align 1
+  %add = add i16 %val0, %val1
+  store i16 %add, i16 addrspace(1)* %out
+  ret void
+}
+
+; FIXME: Although the offset is unknown here, we know it is a multiple
+; of the element size, so should still be align 4
+
+; ALL-LABEL: @load_unknown_offset_align1_i32(
+; ALL: alloca [128 x i32], align 1
+; UNALIGNED: load <2 x i32>, <2 x i32>* %{{[0-9]+}}, align 1{{$}}
+
+; ALIGNED: load i32, i32* %ptr0, align 1
+; ALIGNED: load i32, i32* %ptr1, align 1
+define void @load_unknown_offset_align1_i32(i32 addrspace(1)* noalias %out, i32 %offset) #0 {
+  %alloca = alloca [128 x i32], align 1
+  %ptr0 = getelementptr inbounds [128 x i32], [128 x i32]* %alloca, i32 0, i32 %offset
+  %val0 = load i32, i32* %ptr0, align 1
+  %ptr1 = getelementptr inbounds i32, i32* %ptr0, i32 1
+  %val1 = load i32, i32* %ptr1, align 1
+  %add = add i32 %val0, %val1
+  store i32 %add, i32 addrspace(1)* %out
+  ret void
+}
+
+; FIXME: Should always increase alignment of the load
+; Make sure alloca alignment isn't decreased
+; ALL-LABEL: @load_alloca16_unknown_offset_align1_i32(
+; ALL: alloca [128 x i32], align 16
+
+; UNALIGNED: load <2 x i32>, <2 x i32>* %{{[0-9]+}}, align 1{{$}}
+; ALIGNED: load <2 x i32>, <2 x i32>* %{{[0-9]+}}, align 4{{$}}
+define void @load_alloca16_unknown_offset_align1_i32(i32 addrspace(1)* noalias %out, i32 %offset) #0 {
+  %alloca = alloca [128 x i32], align 16
+  %ptr0 = getelementptr inbounds [128 x i32], [128 x i32]* %alloca, i32 0, i32 %offset
+  %val0 = load i32, i32* %ptr0, align 1
+  %ptr1 = getelementptr inbounds i32, i32* %ptr0, i32 1
+  %val1 = load i32, i32* %ptr1, align 1
+  %add = add i32 %val0, %val1
+  store i32 %add, i32 addrspace(1)* %out
+  ret void
+}
+
+; ALL-LABEL: @store_unknown_offset_align1_i8(
+; ALL: alloca [128 x i8], align 1
+; UNALIGNED: store <2 x i8> <i8 9, i8 10>, <2 x i8>* %{{[0-9]+}}, align 1{{$}}
+
+; ALIGNED: store i8 9, i8* %ptr0, align 1{{$}}
+; ALIGNED: store i8 10, i8* %ptr1, align 1{{$}}
+define void @store_unknown_offset_align1_i8(i8 addrspace(1)* noalias %out, i32 %offset) #0 {
+  %alloca = alloca [128 x i8], align 1
+  %ptr0 = getelementptr inbounds [128 x i8], [128 x i8]* %alloca, i32 0, i32 %offset
+  store i8 9, i8* %ptr0, align 1
+  %ptr1 = getelementptr inbounds i8, i8* %ptr0, i32 1
+  store i8 10, i8* %ptr1, align 1
+  ret void
+}
+
+; ALL-LABEL: @store_unknown_offset_align1_i16(
+; ALL: alloca [128 x i16], align 1
+; UNALIGNED: store <2 x i16> <i16 9, i16 10>, <2 x i16>* %{{[0-9]+}}, align 1{{$}}
+
+; ALIGNED: store i16 9, i16* %ptr0, align 1{{$}}
+; ALIGNED: store i16 10, i16* %ptr1, align 1{{$}}
+define void @store_unknown_offset_align1_i16(i16 addrspace(1)* noalias %out, i32 %offset) #0 {
+  %alloca = alloca [128 x i16], align 1
+  %ptr0 = getelementptr inbounds [128 x i16], [128 x i16]* %alloca, i32 0, i32 %offset
+  store i16 9, i16* %ptr0, align 1
+  %ptr1 = getelementptr inbounds i16, i16* %ptr0, i32 1
+  store i16 10, i16* %ptr1, align 1
+  ret void
+}
+
+; FIXME: Although the offset is unknown here, we know it is a multiple
+; of the element size, so it still should be align 4.
+
+; ALL-LABEL: @store_unknown_offset_align1_i32(
+; ALL: alloca [128 x i32], align 1
+
+; UNALIGNED: store <2 x i32> <i32 9, i32 10>, <2 x i32>* %{{[0-9]+}}, align 1{{$}}
+
+; ALIGNED: store i32 9, i32* %ptr0, align 1
+; ALIGNED: store i32 10, i32* %ptr1, align 1
+define void @store_unknown_offset_align1_i32(i32 addrspace(1)* noalias %out, i32 %offset) #0 {
+  %alloca = alloca [128 x i32], align 1
+  %ptr0 = getelementptr inbounds [128 x i32], [128 x i32]* %alloca, i32 0, i32 %offset
+  store i32 9, i32* %ptr0, align 1
+  %ptr1 = getelementptr inbounds i32, i32* %ptr0, i32 1
+  store i32 10, i32* %ptr1, align 1
+  ret void
+}
+
+attributes #0 = { nounwind }
+