Do not spill operand debuginfo to stack for AArch64 SVE predicates `<vscale x N x i1>` where `N != 16` #150420

h3fang · 2025-12-27T02:42:10Z

This pull request tries to fix #150419.

The debuginfo for AArch64 SVE predicates <vscale x N x i1> where N != 16 should be ignored by this commit.

rust/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs

Lines 438 to 452 in 89eea57

    
           if operand.layout.ty.is_scalable_vector() 
        
               && bx.sess().target.arch == rustc_target::spec::Arch::AArch64 
        
               && let ty::Adt(adt, args) = &operand.layout.ty.kind() 
        
               && let Some(marker_type_field) = 
        
                   adt.non_enum_variant().fields.get(FieldIdx::from_u32(0)) 
        
           { 
        
               let marker_type = marker_type_field.ty(bx.tcx(), args); 
        
               // i.e. `<vscale x N x i1>` when `N != 16` 
        
               if let ty::Slice(element_ty) = marker_type.kind() 
        
                   && element_ty.is_bool() 
        
                   && adt.repr().scalable != Some(ScalableElt::ElementCount(16)) 
        
               { 
        
                   return; 
        
               } 
        
           }

But in line 446, the marker_type.kind() is ty::Bool instead of ty::Slice, so the code doesn't work as intended.

This pull request uses the Ty::scalable_vector_element_count_and_type method to fix the condition checks for <vscale x N x i1> where N != 16 and add a compiletest for this case.

rustbot · 2025-12-27T02:42:15Z

r? @dianqk

rustbot has assigned @dianqk.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

h3fang · 2025-12-27T02:55:54Z

r? @davidtwco

workingjubilee

I have a few comments about comments and a minor quibble about where to put the test.

View changes since this review

compiler/rustc_codegen_ssa/src/mir/debuginfo.rs

tests/codegen-llvm/scalable-vectors/debuginfo.rs

tests/ui/scalable-vectors/debuginfo-does-not-spill.rs

rustbot · 2025-12-27T06:17:03Z

Reminder, once the PR becomes ready for a review, use @rustbot ready.

… N x i1> where N != 16

rustbot · 2025-12-28T07:04:52Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

h3fang · 2025-12-28T07:06:20Z

@rustbot ready

workingjubilee · 2025-12-30T21:42:18Z

Excellent, excellent, happy to have it.

@bors r+ rollup

bors · 2025-12-30T21:42:21Z

📌 Commit 4c485a4 has been approved by workingjubilee

It is now in the queue for this repository.

…uwer Rollup of 3 pull requests Successful merges: - #150058 (Enable file locking support for Hurd) - #150420 (Do not spill operand debuginfo to stack for AArch64 SVE predicates `<vscale x N x i1>` where `N != 16`) - #150501 (Fix Typos in Platform Support Tables) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of #150420 - h3fang:sve-debuginfo-fix, r=workingjubilee Do not spill operand debuginfo to stack for AArch64 SVE predicates `<vscale x N x i1>` where `N != 16` This pull request tries to fix #150419. The debuginfo for AArch64 SVE predicates `<vscale x N x i1>` where `N != 16` should be ignored by this [commit](89eea57). https://github.com/rust-lang/rust/blob/89eea57594e3e1d8e618dd530ea1c8e7c9b4c7a4/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs#L438-L452 But in line 446, the `marker_type.kind()` is `ty::Bool` instead of `ty::Slice`, so the code doesn't work as intended. This pull request uses the [`Ty::scalable_vector_element_count_and_type`](https://github.com/rust-lang/rust/blob/main/compiler/rustc_middle/src/ty/sty.rs#L1272) method to fix the condition checks for `<vscale x N x i1>` where `N != 16` and add a compiletest for this case.

davidtwco · 2026-01-04T13:54:06Z

Thanks for this fix @h3fang and for handling the review @workingjubilee!

rustbot assigned dianqk Dec 27, 2025

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Dec 27, 2025

rustbot assigned davidtwco and unassigned dianqk Dec 27, 2025

h3fang force-pushed the sve-debuginfo-fix branch from b05e0a6 to ed1a5e7 Compare December 27, 2025 03:03

This comment has been minimized.

Sign in to view

h3fang force-pushed the sve-debuginfo-fix branch from ed1a5e7 to 0479d98 Compare December 27, 2025 03:59

workingjubilee requested changes Dec 27, 2025

View reviewed changes

rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Dec 27, 2025

h3fang added 3 commits December 28, 2025 14:59

fix typo and rephrase

435a027

fix condition checks for SVE <vscale x N x i1> when N != 16

f9007bc

add compiletest for debuginfo generation for SVE predicates <vscale x…

4c485a4

… N x i1> where N != 16

h3fang force-pushed the sve-debuginfo-fix branch from 0479d98 to 4c485a4 Compare December 28, 2025 07:04

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Dec 28, 2025

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Dec 30, 2025

JonathanBrouwer mentioned this pull request Dec 30, 2025

Rollup of 3 pull requests #150526

Merged

bors merged commit 4b49c9f into rust-lang:main Dec 31, 2025
11 checks passed

rustbot added this to the 1.94.0 milestone Dec 31, 2025

	if operand.layout.ty.is_scalable_vector()
	&& bx.sess().target.arch == rustc_target::spec::Arch::AArch64
	&& let ty::Adt(adt, args) = &operand.layout.ty.kind()
	&& let Some(marker_type_field) =
	adt.non_enum_variant().fields.get(FieldIdx::from_u32(0))
	{
	let marker_type = marker_type_field.ty(bx.tcx(), args);
	// i.e. `<vscale x N x i1>` when `N != 16`
	if let ty::Slice(element_ty) = marker_type.kind()
	&& element_ty.is_bool()
	&& adt.repr().scalable != Some(ScalableElt::ElementCount(16))
	{
	return;
	}
	}

Uh oh!

Do not spill operand debuginfo to stack for AArch64 SVE predicates <vscale x N x i1> where N != 16 #150420

Do not spill operand debuginfo to stack for AArch64 SVE predicates <vscale x N x i1> where N != 16 #150420

Conversation

h3fang commented Dec 27, 2025 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

rustbot commented Dec 27, 2025

Uh oh!

h3fang commented Dec 27, 2025

Uh oh!

This comment has been minimized.

workingjubilee left a comment • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

rustbot commented Dec 27, 2025

Uh oh!

rustbot commented Dec 28, 2025

Uh oh!

h3fang commented Dec 28, 2025

Uh oh!

workingjubilee commented Dec 30, 2025

Uh oh!

bors commented Dec 30, 2025

Uh oh!

Uh oh!

davidtwco commented Jan 4, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

7 participants

Do not spill operand debuginfo to stack for AArch64 SVE predicates `<vscale x N x i1>` where `N != 16` #150420

Do not spill operand debuginfo to stack for AArch64 SVE predicates `<vscale x N x i1>` where `N != 16` #150420

h3fang commented Dec 27, 2025 •

edited by rustbot

Loading

workingjubilee left a comment •

edited by rustbot

Loading