Landing: 1bc2fdc4f4cb
Project / Subsystem
gcc / i386
Date
2026-07-29
Author
Jakub Jelinek
Commit
1bc2fdc4f4cbe1b68237f49f211473c56d8a44a3
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- i386
- patch_id
- —
- commit_hash
- 1bc2fdc4f4cbe1b68237f49f211473c56d8a44a3
- source_type
- github
- headline
- i386: Fix ICE on out of bounds vector elt access [PR126446]
- tldr
- Fixes compiler ICE when accessing vector elements with out-of-bounds or negative indices.
- author
- Jakub Jelinek
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • x86
- • vectorization
- • compiler bug
- • optimization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-07-29T00:00:00.000Z
This commit resolves a compiler Internal Compiler Error (ICE) on x86_64 when accessing vector elements with out-of-bounds or negative indices. The issue occurred because the index check, which uses poly_uint64, failed for negative long long values, leading to incorrect optimization. The fix ensures that out-of-bounds accesses to vector elements are handled gracefully by emitting a no-op move, preventing the ICE and avoiding undefined behavior.