Skip to content

Global string alignment #142346

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

Open
wants to merge 2 commits into
base: main
Choose a base branch
from
Open

Global string alignment #142346

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
318f053
Align global strings according to data layout
dominik-steenken May 26, 2025
ae1cafc
[SystemZ] Add codegen test for global string alignment
dominik-steenken May 30, 2025
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
2 changes: 1 addition & 1 deletion llvm/lib/IR/IRBuilder.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -52,7 +52,7 @@ GlobalVariable *IRBuilderBase::CreateGlobalString(StringRef Str,
*M, StrConstant->getType(), true, GlobalValue::PrivateLinkage,
StrConstant, Name, nullptr, GlobalVariable::NotThreadLocal, AddressSpace);
GV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
GV->setAlignment(Align(1));
GV->setAlignment(M->getDataLayout().getPrefTypeAlign(getInt8Ty()));
return GV;
}

Expand Down
15 changes: 15 additions & 0 deletions llvm/test/Transforms/InstCombine/SystemZ/printf-opt-alignment.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,15 @@
; RUN: opt < %s --passes=instcombine -S -mtriple=systemz-unknown | FileCheck %s
;
; Check that string replacements inserted by the instcombiner are properly aligned.
; The specific case checked replaces `printf("foo\n")` with `puts("foo")`

@msg1 = constant [17 x i8] c"Alignment Check\0A\00", align 2
; CHECK: c"Alignment Check\00", align 2

; Function Attrs: noinline nounwind
define dso_local void @foo() #0 {
%call = call signext i32 (ptr, ...) @printf(ptr noundef @msg1)
ret void
}

declare signext i32 @printf(ptr noundef, ...) #1