Landing: 61fc8acde23b
Project / Subsystem
gcc / gcc
Date
2026-04-30
Author
Vladimir N. Makarov
Commit
61fc8acde23b047c669011fc5b390b6ebf68097d
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc
- patch_id
- —
- commit_hash
- 61fc8acde23b047c669011fc5b390b6ebf68097d
- source_type
- github
- headline
- Process operand NO_REGS class for register cost calculation
- tldr
- Fixes register cost calculation for operands with the NO_REGS class, potentially changing generated code.
- author
- Vladimir N. Makarov
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • gcc
- • IRA
- • register allocation
- • optimization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-04-30T00:00:00.000Z
This commit fixes an issue in GCC’s intermediate representation (IRA) where the cost of instructions was not being accurately calculated when operands had the NO_REGS class. The record_reg_classes function lacked special processing for this case, leading to potentially inflated instruction cost estimates. This correction can lead to changes in generated code as the register allocator now has a more accurate picture of instruction costs.