Intel FMA (Fused Multiply-Add)
AssessTechniques
A CPU instruction set extension for fused multiply-add floating-point operations.
Why it's here
Placed in Assess: 1 article(s) of evidence from 1 source(s), led by research-stage coverage, with 1 in the last 30 days. Confidence 24%. Low accumulated evidence, so it defaults conservatively pending more signal.
Evidence (1)
- 5Hacker News·10/12/2026researchMystery of Intel’s undocumented FMA rounding instruction
A Hacker News post investigates vfmaddrnd231pd, an Intel FMA-related instruction described in older Software Development Manual versions but absent from the 2026 edition. The author reports it is unrecognized by assemblers and triggers a #UD on tested hardware, suggesting the documentation may reference a removed or incomplete feature.