Skip to content

[ARM] Do not assume memory intrinsics specify alignment. #138356

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
May 7, 2025
Merged

[ARM] Do not assume memory intrinsics specify alignment. #138356

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 3 additions & 3 deletions llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1169,8 +1169,8 @@ int ARMTTIImpl::getNumMemOps(const IntrinsicInst *I) const {
return -1;

const unsigned Size = C->getValue().getZExtValue();
const Align DstAlign = *MC->getDestAlign();
const Align SrcAlign = *MC->getSourceAlign();
const Align DstAlign = MC->getDestAlign().valueOrOne();
const Align SrcAlign = MC->getSourceAlign().valueOrOne();

MOp = MemOp::Copy(Size, /*DstAlignCanChange*/ false, DstAlign, SrcAlign,
/*IsVolatile*/ false);
Expand All @@ -1184,7 +1184,7 @@ int ARMTTIImpl::getNumMemOps(const IntrinsicInst *I) const {
return -1;

const unsigned Size = C->getValue().getZExtValue();
const Align DstAlign = *MS->getDestAlign();
const Align DstAlign = MS->getDestAlign().valueOrOne();

MOp = MemOp::Set(Size, /*DstAlignCanChange*/ false, DstAlign,
/*IsZeroMemset*/ false, /*IsVolatile*/ false);
Expand Down
16 changes: 16 additions & 0 deletions llvm/test/Analysis/CostModel/ARM/memcpy.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,22 @@ target triple = "thumbv7m-arm-unknown-eabi"
; Align 1, 1
;;;;;;;;;;;;

define void @memcpy_0(ptr %d, ptr %s) {
;
; with/without strict-align:
;
; ldrb r1, [r1]
; strb r1, [r0]
;
; COMMON-LABEL: 'memcpy_0'
; COMMON-NEXT: Cost Model: Found an estimated cost of 2 for instruction: call void @llvm.memcpy.p0.p0.i32(ptr %d, ptr %s, i32 1, i1 false)
; COMMON-NEXT: Cost Model: Found an estimated cost of 1 for instruction: ret void
;
entry:
call void @llvm.memcpy.p0.p0.i32(ptr %d, ptr %s, i32 1, i1 false)
ret void
}

define void @memcpy_1(ptr %d, ptr %s) {
;
; with/without strict-align:
Expand Down