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Re: [committed] Add FMA support for MIPS
"Joseph S. Myers" <joseph@codesourcery.com> writes:
> Are you sure these are fused operations? The MIPS32 manual I have to hand
> right now (MD00086 Revision 2.62) says explicitly for MADD.fmt, for
> example: "The intermediate product is rounded according to the current
> rounding mode in FCSR. ... The results and flags are as if separate
> floating-point multiply and add instructions were executed.".
Ouch. Serves me right for not checking. They were fused in the
original R8000 implementation, but now I look at the MIPS IV spec,
it too explicitly says that only revisions of the R8000 used the
fused model, and that all subsequent MIPS IV implementations used
the unfused one.
R8000 isn't important enough now to support a whole different model,
so... patch reverted and brown paper bag duly adopted. Thanks a lot
for catching my carelessness before it found its way into a release.
Richard