3 ms·
Nope. RISCV gives slightly different FP64 answers than X86 which gives slightly different answers than Arm (NEON). Optimizations in FMACs can lead to LSB diffe
by SavantIdiot 5y ago
Nope. RISCV gives slightly different FP64 answers than X86 which gives slightly different answers than Arm (NEON).
Optimizations in FMACs can lead to LSB differences. IEEE doesn't specify how an FMAC is to be implemented, only the format of the number.
(Also: I'm 99% sure I'm right... still 1% could be wrong as I understand it.)
- zokier 5y ago> Optimizations in FMACs can lead to LSB differences. IEEE doesn't specify how an FMAC is to be implemented, only the format of the number. Quoth the spec: > Each of the computational operations that return a numeric result specified by this standard shall be performed as if it first produced an intermediate result correct to infinite precision and with unbounded range, and then rounded that intermediate result, if necessary, to fit in the destination’s format (see 4 and 7).