1/* Fused multiply-add of double values, narrowing the result to float,
2 using soft-fp.
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#include <libc-diag.h>
30
31/* R_e is not set in cases where it is not used in packing, but the
32 compiler does not see that it is set in all cases where it is
33 used, resulting in warnings that it may be used uninitialized.
34 The location of the warning differs in different versions of GCC,
35 it may be where R is defined using a macro or it may be where the
36 macro is defined. */
37DIAG_PUSH_NEEDS_COMMENT;
38DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wmaybe-uninitialized");
39
40#include <soft-fp.h>
41#include <single.h>
42#include <double.h>
43
44float
45__ffma (double x, double y, double z)
46{
47 FP_DECL_EX;
48 FP_DECL_D (X);
49 FP_DECL_D (Y);
50 FP_DECL_D (Z);
51 FP_DECL_D (R);
52 FP_DECL_S (RN);
53 float ret;
54
55 FP_INIT_ROUNDMODE;
56 FP_UNPACK_D (X, x);
57 FP_UNPACK_D (Y, y);
58 FP_UNPACK_D (Z, z);
59 FP_FMA_D (R, X, Y, Z);
60#if _FP_W_TYPE_SIZE < _FP_FRACBITS_D
61 FP_TRUNC_COOKED (S, D, 1, 2, RN, R);
62#else
63 FP_TRUNC_COOKED (S, D, 1, 1, RN, R);
64#endif
65 FP_PACK_S (ret, RN);
66 FP_HANDLE_EXCEPTIONS;
67 CHECK_NARROW_FMA (ret, x, y, z);
68 return ret;
69}
70DIAG_POP_NEEDS_COMMENT;
71
72libm_alias_float_double (fma)
73

source code of glibc/sysdeps/ieee754/soft-fp/s_ffma.c