Re: [PATCH 1/6] MIPSr6/math: Use builtin fma and fmaf

[YunQiang Su <syq@gcc.gnu.org>]

Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> 于2024年5月22日周三 21:42写道：
>
>
>
> On 13/05/24 05:14, YunQiang Su wrote:
> > MIPSr6 has MADDF.s/MADDF.d instructions, which are fused.
> >
> > In MIPS ISA, double support can be subsetted.  Only FMAF is enabled
> > for this case.
> >
> >       * sysdeps/mips/fpu/math-use-builtins-fma.h
> >
> > Signed-off-by: YunQiang Su <syq@gcc.gnu.org>
> > ---
> >  sysdeps/mips/fpu/math-use-builtins-fma.h | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
> >  create mode 100644 sysdeps/mips/fpu/math-use-builtins-fma.h
> >
> > diff --git a/sysdeps/mips/fpu/math-use-builtins-fma.h b/sysdeps/mips/fpu/math-use-builtins-fma.h
> > new file mode 100644
> > index 0000000000..6e296fd4c0
> > --- /dev/null
> > +++ b/sysdeps/mips/fpu/math-use-builtins-fma.h
> > @@ -0,0 +1,13 @@
> > +#if __mips_isa_rev >= 6
> > +#  if defined(__mips_single_float)
>
> Usually for a single case we write as '#ifdef __mips_single_float,
> also the identation is a single space.
>

In fact I sent V2, can you have a look at it?
https://sourceware.org/pipermail/libc-alpha/2024-May/156668.html

> The rest look ok, gcc seems to emit the the MADDF.X even with
> pretty old versions (gcc 5.5.0).
>
> > +#    define USE_FMA_BUILTIN 0
> > +#  else
> > +#    define USE_FMA_BUILTIN 1
> > +#  endif
> > +#  define USE_FMAF_BUILTIN 1
> > +#else
> > +#  define USE_FMA_BUILTIN 0
> > +#  define USE_FMAF_BUILTIN 0
> > +#endif
> > +#define USE_FMAL_BUILTIN 0
> > +#define USE_FMAF128_BUILTIN 0