Landing: bb0cbdac1969

Project / Subsystem

gcc / xtensa

Date

2026-05-08

Author

Takayuki 'January June' Suwa

Commit

bb0cbdac196986de933f4f93097de021c3686d7c

Source

github

Perf win

Yes

Breaking

No

All attributes

project
gcc
subsystem
xtensa
patch_id
commit_hash
bb0cbdac196986de933f4f93097de021c3686d7c
source_type
github
headline
Xtensa: Define HONOR_REG_ALLOC_ORDER as 1
tldr
This commit disables incorrect register save cost estimation in function prologues/epilogues for Xtensa, potentially reducing stack frame usage.
author
Takayuki 'January June' Suwa
outcome
committed
performance_win
true
breaking_change
false
series_id
series_parts
[]
tags
  • xtensa
  • register allocation
  • optimization
  • stack frame
discussion_id_link
bugzilla_pr
date
2026-05-08T00:00:00.000Z

The Xtensa ISA was allocating slightly more function stack frames after a previous patch related to IRA (Interprocedural Register Allocation). This commit disables the incorrect register save cost estimation in function prologues/epilogues by defining the HONOR_REG_ALLOC_ORDER macro as 1. This can reduce stack frame usage, especially when using the CALL0 ABI.