Skip to content

[VPlan][LV] Fix invalid truncation in VPScalarIVStepsRecipe #137832

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 3 commits into from
May 6, 2025
Merged

[VPlan][LV] Fix invalid truncation in VPScalarIVStepsRecipe #137832

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
25c647a
[VPlan][LV] Fix invalid truncation in VPScalarIVStepsRecipe
maryammo Apr 29, 2025
c478c6f
Use -disable-output instead of redirecting to /dev/null in the test
maryammo Apr 29, 2025
e0851d8
Use a single loop and validate test output
maryammo Apr 29, 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/Transforms/Vectorize/VPlanRecipes.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2134,7 +2134,7 @@ void VPScalarIVStepsRecipe::execute(VPTransformState &State) {
Builder.CreateMul(StartIdx0, ConstantInt::get(StartIdx0->getType(),
getUnrollPart(*this)));
}
StartIdx0 = Builder.CreateTrunc(StartIdx0, IntStepTy);
StartIdx0 = Builder.CreateSExtOrTrunc(StartIdx0, IntStepTy);
}

if (!FirstLaneOnly && State.VF.isScalable()) {
Expand Down
31 changes: 31 additions & 0 deletions llvm/test/Transforms/LoopVectorize/PowerPC/vplan-scalarivsext-crash.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,31 @@
; RUN: opt -passes=loop-vectorize -S < %s > /dev/null
; REQUIRES: asserts
Copy link
Contributor

@fhahn fhahn Apr 29, 2025

Choose a reason for hiding this comment

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

Please update the test to check the output as @lukel97 suggested, we should check we get the expected result. You then can also remove REQUIRES: asserts

Copy link
Contributor Author

@maryammo maryammo Apr 29, 2025

Choose a reason for hiding this comment

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

done


target datalayout = "E-m:a-p:32:32-Fi32-i64:64-n32"
target triple = "powerpc-ibm-aix7.2.0.0"

define void @__power_mod_NMOD_power_init(ptr %a, ptr %b, i32 %n) {
entry:
br label %loop_entry

loop_exit: ; preds = %loop_header
br label %loop_entry

loop_entry: ; preds = %loop_exit, %entry
%sum.0 = phi double [ 0.000000e+00, %entry ], [ %sum.1, %loop_exit ]
%x = load double, ptr %a, align 8
br label %loop_header
Copy link
Contributor

@fhahn fhahn Apr 29, 2025

Choose a reason for hiding this comment

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

Do we need the loop nest or can this simply be a single loop?

Copy link
Contributor Author

@maryammo maryammo Apr 29, 2025

Choose a reason for hiding this comment

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

I updated the test to use a single loop.


loop_header: ; preds = %loop_body, %loop_entry
%sum.1 = phi double [ %sum.0, %loop_entry ], [ %sum.next, %loop_body ]
%i = phi i32 [ 0, %loop_entry ], [ %i.next, %loop_body ]
%cond = icmp sgt i32 %i, %n
br i1 %cond, label %loop_exit, label %loop_body

loop_body: ; preds = %loop_header
store double %sum.1, ptr %b, align 8
%sum.next = fadd reassoc double %sum.1, %x
%i.next = add i32 %i, 1
br label %loop_header
}