Skip to content

[InstCombine] Propagate invariant.load metadata across unpacked loads #152186

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 7 commits into from
Aug 14, 2025
Merged

[InstCombine] Propagate invariant.load metadata across unpacked loads #152186

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
a3d0e64
[InstCombine] Propagate invariant.load metadata across unpacked loads
VedantParanjape Aug 5, 2025
af85146
Merge branch 'main' into invariant-change
VedantParanjape Aug 5, 2025
71d9921
use enums in mdnode
VedantParanjape Aug 6, 2025
9899e69
adjust AAMetadata
VedantParanjape Aug 6, 2025
9955d70
Revert "adjust AAMetadata"
VedantParanjape Aug 13, 2025
2d4e276
addressed review
VedantParanjape Aug 13, 2025
efe732a
Merge branch 'main' into invariant-change
VedantParanjape Aug 14, 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
4 changes: 4 additions & 0 deletions llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -737,6 +737,8 @@ static Instruction *unpackLoadToAggregate(InstCombinerImpl &IC, LoadInst &LI) {
LoadInst *NewLoad = IC.combineLoadToNewType(LI, ST->getTypeAtIndex(0U),
".unpack");
NewLoad->setAAMetadata(LI.getAAMetadata());
// Copy invariant metadata from parent load.
NewLoad->copyMetadata(LI, LLVMContext::MD_invariant_load);
return IC.replaceInstUsesWith(LI, IC.Builder.CreateInsertValue(
PoisonValue::get(T), NewLoad, 0, Name));
}
Expand Down Expand Up @@ -764,6 +766,8 @@ static Instruction *unpackLoadToAggregate(InstCombinerImpl &IC, LoadInst &LI) {
Name + ".unpack");
// Propagate AA metadata. It'll still be valid on the narrowed load.
L->setAAMetadata(LI.getAAMetadata());
// Copy invariant metadata from parent load.
L->copyMetadata(LI, LLVMContext::MD_invariant_load);
V = IC.Builder.CreateInsertValue(V, L, i);
}

Expand Down
46 changes: 46 additions & 0 deletions llvm/test/Transforms/InstCombine/invariant-metadata-propagation.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,46 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt -S < %s -passes=instcombine | FileCheck %s

%struct.double2 = type { double, double }
%struct.double1 = type { double }

define %struct.double2 @func1(ptr addrspace(1) %a) {
; CHECK-LABEL: define %struct.double2 @func1(
; CHECK-SAME: ptr addrspace(1) [[A:%.*]]) {
; CHECK-NEXT: [[DOTUNPACK:%.*]] = load double, ptr addrspace(1) [[A]], align 16, !invariant.load [[META0:![0-9]+]]
; CHECK-NEXT: [[TMP1:%.*]] = insertvalue [[STRUCT_DOUBLE2:%.*]] poison, double [[DOTUNPACK]], 0
; CHECK-NEXT: [[DOTELT1:%.*]] = getelementptr inbounds nuw i8, ptr addrspace(1) [[A]], i64 8
; CHECK-NEXT: [[DOTUNPACK2:%.*]] = load double, ptr addrspace(1) [[DOTELT1]], align 8, !invariant.load [[META0]]
; CHECK-NEXT: [[TMP2:%.*]] = insertvalue [[STRUCT_DOUBLE2]] [[TMP1]], double [[DOTUNPACK2]], 1
; CHECK-NEXT: ret [[STRUCT_DOUBLE2]] [[TMP2]]
;
%1 = load %struct.double2, ptr addrspace(1) %a, align 16, !invariant.load !1
ret %struct.double2 %1
}

define %struct.double2 @func2(ptr %a) {
; CHECK-LABEL: define %struct.double2 @func2(
; CHECK-SAME: ptr [[A:%.*]]) {
; CHECK-NEXT: [[DOTUNPACK:%.*]] = load double, ptr [[A]], align 16, !invariant.load [[META0]]
; CHECK-NEXT: [[TMP1:%.*]] = insertvalue [[STRUCT_DOUBLE2:%.*]] poison, double [[DOTUNPACK]], 0
; CHECK-NEXT: [[DOTELT1:%.*]] = getelementptr inbounds nuw i8, ptr [[A]], i64 8
; CHECK-NEXT: [[DOTUNPACK2:%.*]] = load double, ptr [[DOTELT1]], align 8, !invariant.load [[META0]]
; CHECK-NEXT: [[TMP2:%.*]] = insertvalue [[STRUCT_DOUBLE2]] [[TMP1]], double [[DOTUNPACK2]], 1
; CHECK-NEXT: ret [[STRUCT_DOUBLE2]] [[TMP2]]
;
%1 = load %struct.double2, ptr %a, align 16, !invariant.load !1
ret %struct.double2 %1
}

define %struct.double1 @func3(ptr %a) {
; CHECK-LABEL: define %struct.double1 @func3(
; CHECK-SAME: ptr [[A:%.*]]) {
; CHECK-NEXT: [[DOTUNPACK:%.*]] = load double, ptr [[A]], align 16, !invariant.load [[META0]]
; CHECK-NEXT: [[TMP1:%.*]] = insertvalue [[STRUCT_DOUBLE1:%.*]] poison, double [[DOTUNPACK]], 0
; CHECK-NEXT: ret [[STRUCT_DOUBLE1]] [[TMP1]]
;
%1 = load %struct.double1, ptr %a, align 16, !invariant.load !1
ret %struct.double1 %1
}

!1 = !{}
Loading