Landing: 87039d23cb9a

Project / Subsystem

gcc / tree-optimization

Date

2026-06-08

Author

Richard Biener

Commit

87039d23cb9ab43f74da905226e1fac9b4de10bc

Source

github

Perf win

No

Breaking

No

All attributes

project
gcc
subsystem
tree-optimization
patch_id
commit_hash
87039d23cb9ab43f74da905226e1fac9b4de10bc
source_type
github
headline
Vectorization pattern for constant multiplication now correctly sets vector types.
tldr
A bug preventing correct vector type assignment for constant multiplication patterns in vectorization has been resolved.
author
Richard Biener
outcome
committed
performance_win
false
breaking_change
false
series_id
series_parts
[]
tags
  • optimization
  • bugfix
  • vectorization
  • types
discussion_id_link
bugzilla_pr
date
2026-06-08T00:00:00.000Z

This commit addresses a bug in GCC’s vectorization pass where, during the pattern recognition of integer multiplication by a constant, the appropriate unsigned vector type was not being assigned to the resulting pattern statement. This omission could lead to incorrect vector types, particularly affecting code dealing with undefined behavior checks for vector reduction and potentially causing wrong code in non-reduction cases. The fix ensures that the correct vector type is explicitly assigned, improving the accuracy of vectorized code.