When extending a memset range past the front, set the alignment of the

memset region to the alignment of the new start address.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81810 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2009-09-14 23:39:10 +00:00
parent 4626268428
commit 264d245851
2 changed files with 19 additions and 0 deletions

View File

@ -273,6 +273,7 @@ void MemsetRanges::addStore(int64_t Start, StoreInst *SI) {
if (Start < I->Start) {
I->Start = Start;
I->StartPtr = SI->getPointerOperand();
I->Alignment = SI->getAlignment();
}
// Now we know that Start <= I->End and Start >= I->Start (so the startpoint

View File

@ -0,0 +1,18 @@
; RUN: opt < %s -S -memcpyopt | FileCheck %s
; The resulting memset is only 4-byte aligned, despite containing
; a 16-byte alignmed store in the middle.
; CHECK: call void @llvm.memset.i64(i8* %a01, i8 0, i64 16, i32 4)
define void @foo(i32* %p) {
%a0 = getelementptr i32* %p, i64 0
store i32 0, i32* %a0, align 4
%a1 = getelementptr i32* %p, i64 1
store i32 0, i32* %a1, align 16
%a2 = getelementptr i32* %p, i64 2
store i32 0, i32* %a2, align 4
%a3 = getelementptr i32* %p, i64 3
store i32 0, i32* %a3, align 4
ret void
}