Skip to content

[llvm][sroa] Disable support for invariant.group #151743

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 4 commits into from
Aug 5, 2025
Merged

[llvm][sroa] Disable support for invariant.group #151743

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
5129ea5
[llvm][sroa] Disabled support for `invariant.group`
tommymcm Aug 1, 2025
02c381f
[llvm][sroa] Added `invariant.group` tests from #107557 and #151574
tommymcm Aug 1, 2025
ee5d72d
[llvm][sroa] Removed unecessary loop from aggregate store with invari…
tommymcm Aug 4, 2025
a0147cb
Merge branch 'main' into disable-sroa-invariant-group
tommymcm Aug 4, 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
15 changes: 2 additions & 13 deletions llvm/lib/Transforms/Scalar/SROA.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1247,8 +1247,7 @@ class AllocaSlices::SliceBuilder : public PtrUseVisitor<SliceBuilder> {
"Map index doesn't point back to a slice with this user.");
}

// Disable SRoA for any intrinsics except for lifetime invariants and
// invariant group.
// Disable SRoA for any intrinsics except for lifetime invariants.
// FIXME: What about debug intrinsics? This matches old behavior, but
// doesn't make sense.
void visitIntrinsicInst(IntrinsicInst &II) {
Expand All @@ -1268,12 +1267,6 @@ class AllocaSlices::SliceBuilder : public PtrUseVisitor<SliceBuilder> {
return;
}

if (II.isLaunderOrStripInvariantGroup()) {
insertUse(II, Offset, AllocSize, true);
enqueueUsers(II);
return;
}

Base::visitIntrinsicInst(II);
}

Expand Down Expand Up @@ -3607,8 +3600,7 @@ class AllocaSliceRewriter : public InstVisitor<AllocaSliceRewriter, bool> {
}

bool visitIntrinsicInst(IntrinsicInst &II) {
assert((II.isLifetimeStartOrEnd() || II.isLaunderOrStripInvariantGroup() ||
II.isDroppable()) &&
assert((II.isLifetimeStartOrEnd() || II.isDroppable()) &&
"Unexpected intrinsic!");
LLVM_DEBUG(dbgs() << " original: " << II << "\n");

Expand All @@ -3622,9 +3614,6 @@ class AllocaSliceRewriter : public InstVisitor<AllocaSliceRewriter, bool> {
return true;
}

if (II.isLaunderOrStripInvariantGroup())
return true;

assert(II.getArgOperand(1) == OldPtr);
// Lifetime intrinsics are only promotable if they cover the whole alloca.
// Therefore, we drop lifetime intrinsics which don't cover the whole
Expand Down
104 changes: 97 additions & 7 deletions llvm/test/Transforms/SROA/invariant-group.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -11,10 +11,17 @@ declare i32 @somevalue()

define void @f() {
; CHECK-LABEL: @f(
; CHECK-NEXT: [[A:%.*]] = alloca [[T:%.*]], align 8
; CHECK-NEXT: [[A1_I8_INV:%.*]] = call ptr @llvm.launder.invariant.group.p0(ptr [[A]])
; CHECK-NEXT: [[A2:%.*]] = getelementptr inbounds [[T]], ptr [[A]], i32 0, i32 1
; CHECK-NEXT: [[SV1:%.*]] = call i32 @somevalue()
; CHECK-NEXT: [[SV2:%.*]] = call i32 @somevalue()
; CHECK-NEXT: call void @h(i32 [[SV1]])
; CHECK-NEXT: call void @h(i32 [[SV2]])
; CHECK-NEXT: store i32 [[SV1]], ptr [[A1_I8_INV]], align 4, !invariant.group [[META0:![0-9]+]]
; CHECK-NEXT: store i32 [[SV2]], ptr [[A2]], align 4
; CHECK-NEXT: [[V1:%.*]] = load i32, ptr [[A1_I8_INV]], align 4, !invariant.group [[META0]]
; CHECK-NEXT: [[V2:%.*]] = load i32, ptr [[A2]], align 4
; CHECK-NEXT: call void @h(i32 [[V1]])
; CHECK-NEXT: call void @h(i32 [[V2]])
; CHECK-NEXT: ret void
;
%a = alloca %t
Expand Down Expand Up @@ -44,7 +51,7 @@ define void @g() {
; CHECK-NEXT: [[A2:%.*]] = getelementptr inbounds [[T]], ptr [[A]], i32 0, i32 1
; CHECK-NEXT: [[SV1:%.*]] = call i32 @somevalue()
; CHECK-NEXT: [[SV2:%.*]] = call i32 @somevalue()
; CHECK-NEXT: store i32 [[SV1]], ptr [[A1_I8_INV]], align 4, !invariant.group [[META0:![0-9]+]]
; CHECK-NEXT: store i32 [[SV1]], ptr [[A1_I8_INV]], align 4, !invariant.group [[META0]]
; CHECK-NEXT: store i32 [[SV2]], ptr [[A2]], align 4
; CHECK-NEXT: [[V1:%.*]] = load i32, ptr [[A1_I8_INV]], align 4, !invariant.group [[META0]]
; CHECK-NEXT: [[V2:%.*]] = load i32, ptr [[A2]], align 4
Expand Down Expand Up @@ -81,6 +88,9 @@ define void @g() {

define void @store_and_launder() {
; CHECK-LABEL: @store_and_launder(
; CHECK-NEXT: [[VALPTR:%.*]] = alloca i32, align 4
; CHECK-NEXT: store i32 0, ptr [[VALPTR]], align 4
; CHECK-NEXT: [[BARR:%.*]] = call ptr @llvm.launder.invariant.group.p0(ptr [[VALPTR]])
; CHECK-NEXT: ret void
;
%valptr = alloca i32, align 4
Expand All @@ -91,7 +101,10 @@ define void @store_and_launder() {

define i32 @launder_and_load() {
; CHECK-LABEL: @launder_and_load(
; CHECK-NEXT: ret i32 undef
; CHECK-NEXT: [[VALPTR:%.*]] = alloca i32, align 4
; CHECK-NEXT: [[BARR:%.*]] = call ptr @llvm.launder.invariant.group.p0(ptr [[VALPTR]])
; CHECK-NEXT: [[V2:%.*]] = load i32, ptr [[VALPTR]], align 4
; CHECK-NEXT: ret i32 [[V2]]
;
%valptr = alloca i32, align 4
%barr = call ptr @llvm.launder.invariant.group.p0(ptr %valptr)
Expand All @@ -101,6 +114,9 @@ define i32 @launder_and_load() {

define void @launder_and_ptr_arith() {
; CHECK-LABEL: @launder_and_ptr_arith(
; CHECK-NEXT: [[VALPTR:%.*]] = alloca i32, align 4
; CHECK-NEXT: [[BARR:%.*]] = call ptr @llvm.launder.invariant.group.p0(ptr [[VALPTR]])
; CHECK-NEXT: [[A2:%.*]] = getelementptr inbounds i32, ptr [[VALPTR]], i32 0
; CHECK-NEXT: ret void
;
%valptr = alloca i32, align 4
Expand Down Expand Up @@ -140,9 +156,13 @@ end:

define void @partial_promotion_of_alloca() {
; CHECK-LABEL: @partial_promotion_of_alloca(
; CHECK-NEXT: [[STRUCT_PTR_SROA_2:%.*]] = alloca i32, align 4
; CHECK-NEXT: store volatile i32 0, ptr [[STRUCT_PTR_SROA_2]], align 4
; CHECK-NEXT: [[STRUCT_PTR_SROA_2_0_STRUCT_PTR_SROA_2_4_LOAD_VAL:%.*]] = load volatile i32, ptr [[STRUCT_PTR_SROA_2]], align 4
; CHECK-NEXT: [[STRUCT_PTR:%.*]] = alloca [[T:%.*]], align 4
; CHECK-NEXT: [[FIELD_PTR:%.*]] = getelementptr inbounds [[T]], ptr [[STRUCT_PTR]], i32 0, i32 0
; CHECK-NEXT: store i32 0, ptr [[FIELD_PTR]], align 4
; CHECK-NEXT: [[VOLATILE_FIELD_PTR:%.*]] = getelementptr inbounds [[T]], ptr [[STRUCT_PTR]], i32 0, i32 1
; CHECK-NEXT: store volatile i32 0, ptr [[VOLATILE_FIELD_PTR]], align 4, !invariant.group [[META0]]
; CHECK-NEXT: [[BARR:%.*]] = call ptr @llvm.launder.invariant.group.p0(ptr [[STRUCT_PTR]])
; CHECK-NEXT: [[LOAD_VAL:%.*]] = load volatile i32, ptr [[VOLATILE_FIELD_PTR]], align 4, !invariant.group [[META0]]
; CHECK-NEXT: ret void
;
%struct_ptr = alloca %t, align 4
Expand All @@ -155,6 +175,76 @@ define void @partial_promotion_of_alloca() {
ret void
}

define void @memcpy_after_laundering_alloca(ptr %ptr) {
; CHECK-LABEL: @memcpy_after_laundering_alloca(
; CHECK-NEXT: [[ALLOCA:%.*]] = alloca { i64, i64 }, align 8
; CHECK-NEXT: [[LAUNDER:%.*]] = call ptr @llvm.launder.invariant.group.p0(ptr [[ALLOCA]])
; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr [[LAUNDER]], ptr [[PTR:%.*]], i64 16, i1 false)
; CHECK-NEXT: ret void
;
%alloca = alloca { i64, i64 }, align 8
%launder = call ptr @llvm.launder.invariant.group.p0(ptr %alloca)
call void @llvm.memcpy.p0.p0.i64(ptr %launder, ptr %ptr, i64 16, i1 false)
ret void
}

define void @memcpy_after_laundering_alloca_slices(ptr %ptr) {
; CHECK-LABEL: @memcpy_after_laundering_alloca_slices(
; CHECK-NEXT: [[ALLOCA:%.*]] = alloca { [16 x i8], i64, [16 x i8] }, align 8
; CHECK-NEXT: [[LAUNDER:%.*]] = call ptr @llvm.launder.invariant.group.p0(ptr [[ALLOCA]])
; CHECK-NEXT: [[GEP:%.*]] = getelementptr i8, ptr [[LAUNDER]], i64 16
; CHECK-NEXT: store i64 0, ptr [[GEP]], align 4
; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr [[LAUNDER]], ptr [[PTR:%.*]], i64 40, i1 false)
; CHECK-NEXT: ret void
;
%alloca = alloca { [16 x i8], i64, [16 x i8] }, align 8
%launder = call ptr @llvm.launder.invariant.group.p0(ptr %alloca)
%gep = getelementptr i8, ptr %launder, i64 16
store i64 0, ptr %gep
call void @llvm.memcpy.p0.p0.i64(ptr %launder, ptr %ptr, i64 40, i1 false)
ret void
}

define void @launder_in_loop() {
Copy link
Contributor

@nikic nikic Aug 2, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I don't think the fact that it's in a loop is actually relevant?

%t = type { i32, i32 }

define void @test_agg_store() {
  %struct_ptr = alloca %t, align 4
  %struct_ptr_fresh = call ptr @llvm.launder.invariant.group.p0(ptr %struct_ptr)
  store %t zeroinitializer, ptr %struct_ptr_fresh, align 4, !invariant.group !{}
  ret void
}

is enough to reproduce the crash. To avoid everything being optimized away only keeping the loop body is sufficient:

%t = type { i32, i32 }

define void @test_agg_store() {
  %struct_ptr = alloca %t, align 4
  %struct_ptr_fresh = call ptr @llvm.launder.invariant.group.p0(ptr %struct_ptr)
  %struct = call %t @make_t()
  store %t %struct, ptr %struct_ptr_fresh, align 4, !invariant.group !{}
  %first_ptr = getelementptr %t, ptr %struct_ptr_fresh, i32 0, i32 0
  %first = load i32, ptr %first_ptr, align 4
  %second_ptr = getelementptr %t, ptr %struct_ptr_fresh, i32 0, i32 1
  %second = load i32, ptr %second_ptr, align 4
  ret void
}

declare %t @make_t()

Copy link
Contributor Author

@tommymcm tommymcm Aug 4, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Good catch, I've updated the test.

; CHECK-LABEL: @launder_in_loop(
; CHECK-NEXT: [[STRUCT_PTR:%.*]] = alloca [[T:%.*]], i64 1, align 4
; CHECK-NEXT: br label [[HEADER:%.*]]
; CHECK: header:
; CHECK-NEXT: br i1 true, label [[BODY:%.*]], label [[EXIT:%.*]]
; CHECK: body:
; CHECK-NEXT: [[STRUCT_PTR_FRESH:%.*]] = call ptr @llvm.launder.invariant.group.p0(ptr [[STRUCT_PTR]])
; CHECK-NEXT: [[STRUCT:%.*]] = call [[T]] @[[MAKE_T:[a-zA-Z0-9_$\"\\.-]*[a-zA-Z_$\"\\.-][a-zA-Z0-9_$\"\\.-]*]]()
; CHECK-NEXT: store [[T]] [[STRUCT]], ptr [[STRUCT_PTR_FRESH]], align 4, !invariant.group [[META0]]
; CHECK-NEXT: [[FIRST_PTR:%.*]] = getelementptr [[T]], ptr [[STRUCT_PTR_FRESH]], i32 0, i32 0
; CHECK-NEXT: [[FIRST:%.*]] = load i32, ptr [[FIRST_PTR]], align 4
; CHECK-NEXT: [[SECOND_PTR:%.*]] = getelementptr [[T]], ptr [[STRUCT_PTR_FRESH]], i32 0, i32 1
; CHECK-NEXT: [[SECOND:%.*]] = load i32, ptr [[SECOND_PTR]], align 4
; CHECK-NEXT: br label [[HEADER]]
; CHECK: exit:
; CHECK-NEXT: ret void
;
%struct_ptr = alloca %t, i64 1, align 4
br label %header

header:
br i1 true, label %body, label %exit

body: ; preds = %6
%struct_ptr_fresh = call ptr @llvm.launder.invariant.group.p0(ptr %struct_ptr)
%struct = call %t @make_t()
store %t %struct, ptr %struct_ptr_fresh, align 4, !invariant.group !0
%first_ptr = getelementptr %t, ptr %struct_ptr_fresh, i32 0, i32 0
%first = load i32, ptr %first_ptr, align 4
%second_ptr = getelementptr %t, ptr %struct_ptr_fresh, i32 0, i32 1
%second = load i32, ptr %second_ptr, align 4
br label %header

exit:
ret void
}

declare %t @make_t()

declare void @use(ptr)

!0 = !{}
Expand Down