Landing: 39eac69cd3af

Project / Subsystem

gcc / gcc

Date

2026-03-10

Author

Richard Biener

Commit

39eac69cd3afabaeaf70fed19722bf049eac9819

Source

github

Perf win

Yes

Breaking

No

All attributes

project
gcc
subsystem
gcc
patch_id
commit_hash
39eac69cd3afabaeaf70fed19722bf049eac9819
source_type
github
headline
Use scalar costs for peeling cost estimation in vectorizer.
tldr
GCC's vectorizer now uses pre-calculated scalar costs when estimating loop peeling costs, improving accuracy and compile time.
author
Richard Biener
outcome
committed
performance_win
true
breaking_change
false
series_id
series_parts
[]
tags
  • vectorization
  • optimization
  • performance
discussion_id_link
bugzilla_pr
date
2026-03-10T00:00:00.000Z

GCC’s vectorizer now uses the scalar_costs summary when computing the peeling cost, avoiding redundant computations. This change replaces repeated walks of LOOP_VINFO_SCALAR_ITERATION_COST and fallbacks to builtin_vectorization_cost with a direct usage of the scalar costs, which should also reduce compile time.