sysdeps/x86/fpu/s_ffma.c

   1 /* Fused multiply-add of double value, narrowing the result to float.
   2    x86 version.
   3    Copyright (C) 2021-2024 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #define f32fmaf64 __hide_f32fmaf64
  21 #define f32fmaf32x __hide_f32fmaf32x
  22 #define ffmal __hide_ffmal
  23 #include <math.h>
  24 #undef f32fmaf64
  25 #undef f32fmaf32x
  26 #undef ffmal
  27
  28 #include <math-narrow.h>
  29
  30 #ifndef __FP_FAST_FMA
  31 /* Depending on the details of the glibc configuration, fma might use
  32    either SSE or 387 arithmetic; ensure that both parts of the
  33    floating-point state are handled in the round-to-odd code.  If
  34    __FP_FAST_FMA is defined, that implies that the compiler is using
  35    SSE floating point and that the fma call will be inlined, so the
  36    x86 macros will work with only the SSE state and that is
  37    sufficient.  */
  38 # undef libc_feholdexcept_setround
  39 # define libc_feholdexcept_setround     default_libc_feholdexcept_setround
  40 # undef libc_feupdateenv_test
  41 # define libc_feupdateenv_test          default_libc_feupdateenv_test
  42 #endif
  43
  44 float
  45 __ffma (double x, double y, double z)
  46 {
  47   NARROW_FMA_ROUND_TO_ODD (x, y, z, float, union ieee754_double, , mantissa1,
  48                            false);
  49 }
  50 libm_alias_float_double (fma)