Landing: f9c50f4ac496
Project / Subsystem
gcc / x86
Date
2026-08-24
Author
H.J. Lu
Commit
f9c50f4ac496d96439ff8a5b7d10fe0e5b7aa1f5
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- x86
- patch_id
- —
- commit_hash
- f9c50f4ac496d96439ff8a5b7d10fe0e5b7aa1f5
- source_type
- github
- headline
- x86 FP emulation: Flush denormals to zero for vcvtneps2bf16
- tldr
- Floating-point emulation for vcvtneps2bf16 now flushes denormal inputs to zero, aligning behavior and improving predictability.
- author
- H.J. Lu
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • x86
- • floating point
- • emulation
- • optimization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-08-24T00:00:00.000Z
The emulation code for the vcvtneps2bf16 instruction, used in truncsfbf-5.c and truncsfbf-6.c, has been updated to flush denormal floating-point inputs to zero. This change ensures consistent behavior by treating small, subnormal numbers as zero before conversion, and includes new test cases to verify this behavior.