[PATCH v2] math: Remove ldbl-128/s_fma.c

[Adhemerval Zanella Netto]

On 11/11/25 18:12, Wilco Dijkstra wrote:
> 
> v2: Remove more redundant files
> 
> Remove ldbl-128/s_fma.c - it makes no sense to use emulated float128
> operations to emulate FMA.  Benchmarking shows dbl-64/s_fma.c is about
> twice as fast.  Remove redundant dbl-64/s_fma.c includes in targets
> that were trying to work around this issue.
> 
> Passes buildmanyglibc on alpha/sparc/mips. OK for commit?

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> 
> ---
> 
> diff --git a/sysdeps/alpha/fpu/s_fma.c b/sysdeps/alpha/fpu/s_fma.c
> deleted file mode 100644
> index 8f62605870439f2a821b9ee95bc868a8794aa363..0000000000000000000000000000000000000000
> --- a/sysdeps/alpha/fpu/s_fma.c
> +++ /dev/null
> @@ -1,2 +0,0 @@
> -/* Always use dbl-64 version because long double is emulated in software.  */
> -#include <sysdeps/ieee754/dbl-64/s_fma.c>
> diff --git a/sysdeps/ieee754/ldbl-128/s_fma.c b/sysdeps/ieee754/ldbl-128/s_fma.c
> deleted file mode 100644
> index 01ca556260884553e2406581e94214730ce1f6eb..0000000000000000000000000000000000000000
> --- a/sysdeps/ieee754/ldbl-128/s_fma.c
> +++ /dev/null
> @@ -1,67 +0,0 @@
> -/* Compute x * y + z as ternary operation.
> -   Copyright (C) 2010-2025 Free Software Foundation, Inc.
> -   This file is part of the GNU C Library.
> -
> -   The GNU C Library is free software; you can redistribute it and/or
> -   modify it under the terms of the GNU Lesser General Public
> -   License as published by the Free Software Foundation; either
> -   version 2.1 of the License, or (at your option) any later version.
> -
> -   The GNU C Library is distributed in the hope that it will be useful,
> -   but WITHOUT ANY WARRANTY; without even the implied warranty of
> -   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> -   Lesser General Public License for more details.
> -
> -   You should have received a copy of the GNU Lesser General Public
> -   License along with the GNU C Library; if not, see
> -   <https://www.gnu.org/licenses/>.  */
> -
> -#define NO_MATH_REDIRECT
> -#define dfmal __hide_dfmal
> -#define f32xfmaf64 __hide_f32xfmaf64
> -#include <math.h>
> -#undef dfmal
> -#undef f32xfmaf64
> -#include <fenv.h>
> -#include <ieee754.h>
> -#include <libm-alias-double.h>
> -#include <math-narrow-alias.h>
> -#include <math-use-builtins.h>
> -
> -/* This implementation relies on long double being more than twice as
> -   precise as double and uses rounding to odd in order to avoid problems
> -   with double rounding.
> -   See a paper by Boldo and Melquiond:
> -   http://www.lri.fr/~melquion/doc/08-tc.pdf  */
> -
> -double
> -__fma (double x, double y, double z)
> -{
> -#if USE_FMA_BUILTIN
> -  return __builtin_fma (x, y, z);
> -#else
> -  fenv_t env;
> -  /* Multiplication is always exact.  */
> -  long double temp = (long double) x * (long double) y;
> -
> -  /* Ensure correct sign of an exact zero result by performing the
> -     addition in the original rounding mode in that case.  */
> -  if (temp == -z)
> -    return (double) temp + z;
> -
> -  union ieee854_long_double u;
> -  __feholdexcept (&env);
> -  __fesetround (FE_TOWARDZERO);
> -  /* Perform addition with round to odd.  */
> -  u.d = temp + (long double) z;
> -  if ((u.ieee.mantissa3 & 1) == 0 && u.ieee.exponent != 0x7fff)
> -    u.ieee.mantissa3 |= __fetestexcept (FE_INEXACT) != 0;
> -  __feupdateenv (&env);
> -  /* And finally truncation with round to nearest.  */
> -  return (double) u.d;
> -#endif /* ! USE_FMA_BUILTIN  */
> -}
> -#ifndef __fma
> -libm_alias_double (__fma, fma)
> -libm_alias_double_narrow (__fma, fma)
> -#endif
> diff --git a/sysdeps/mips/mips64/n32/fpu/s_fma.c b/sysdeps/mips/mips64/n32/fpu/s_fma.c
> deleted file mode 100644
> index b61fa643de9ccc00d9d4da48cd90a446a1ef78d9..0000000000000000000000000000000000000000
> --- a/sysdeps/mips/mips64/n32/fpu/s_fma.c
> +++ /dev/null
> @@ -1 +0,0 @@
> -#include <sysdeps/ieee754/dbl-64/s_fma.c>
> diff --git a/sysdeps/mips/mips64/n64/fpu/s_fma.c b/sysdeps/mips/mips64/n64/fpu/s_fma.c
> deleted file mode 100644
> index b61fa643de9ccc00d9d4da48cd90a446a1ef78d9..0000000000000000000000000000000000000000
> --- a/sysdeps/mips/mips64/n64/fpu/s_fma.c
> +++ /dev/null
> @@ -1 +0,0 @@
> -#include <sysdeps/ieee754/dbl-64/s_fma.c>
> diff --git a/sysdeps/sparc/sparc32/fpu/s_fma.c b/sysdeps/sparc/sparc32/fpu/s_fma.c
> deleted file mode 100644
> index 8f62605870439f2a821b9ee95bc868a8794aa363..0000000000000000000000000000000000000000
> --- a/sysdeps/sparc/sparc32/fpu/s_fma.c
> +++ /dev/null
> @@ -1,2 +0,0 @@
> -/* Always use dbl-64 version because long double is emulated in software.  */
> -#include <sysdeps/ieee754/dbl-64/s_fma.c>
> diff --git a/sysdeps/sparc/sparc64/fpu/s_fma.c b/sysdeps/sparc/sparc64/fpu/s_fma.c
> deleted file mode 100644
> index 8f62605870439f2a821b9ee95bc868a8794aa363..0000000000000000000000000000000000000000
> --- a/sysdeps/sparc/sparc64/fpu/s_fma.c
> +++ /dev/null
> @@ -1,2 +0,0 @@
> -/* Always use dbl-64 version because long double is emulated in software.  */
> -#include <sysdeps/ieee754/dbl-64/s_fma.c>
>