Landing: d15703b27aa4

Project / Subsystem

gcc / risc-v

Date

2026-07-07

Author

wangjue

Commit

d15703b27aa4924ca3438066ae0759e7379b3e0b

Source

github

Perf win

Yes

Breaking

No

All attributes

project
gcc
subsystem
risc-v
patch_id
commit_hash
d15703b27aa4924ca3438066ae0759e7379b3e0b
source_type
github
headline
RISC-V adds small loop unrolling support
tldr
New -munroll-only-small-loops option provides conservative loop unrolling for RISC-V, balancing performance gains with code size.
author
wangjue
outcome
committed
performance_win
true
breaking_change
false
series_id
series_parts
[]
tags
  • risc-v
  • optimization
  • loops
discussion_id_link
bugzilla_pr
date
2026-07-07T00:00:00.000Z

A new option, -munroll-only-small-loops, has been introduced for the RISC-V backend to enable conservative loop unrolling. This feature selectively unrolls small loops based on instruction thresholds to improve performance without significantly increasing code size or cache misses. It is enabled by default at -O2 and above, mirroring behavior on i386, and can be overridden by explicit unrolling flags. Existing tests not focused on unrolling are adjusted to maintain their original behavior.