1/* Multiply double values, narrowing the result to float, using soft-fp.
2 Copyright (C) 2018-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#define f32mulf64 __hide_f32mulf64
20#define f32mulf32x __hide_f32mulf32x
21#define fmull __hide_fmull
22#include <math.h>
23#undef f32mulf64
24#undef f32mulf32x
25#undef fmull
26
27#include <math-narrow.h>
28#include <soft-fp.h>
29#include <single.h>
30#include <double.h>
31
32float
33__fmul (double x, double y)
34{
35 FP_DECL_EX;
36 FP_DECL_D (X);
37 FP_DECL_D (Y);
38 FP_DECL_D (R);
39 FP_DECL_S (RN);
40 float ret;
41
42 FP_INIT_ROUNDMODE;
43 FP_UNPACK_D (X, x);
44 FP_UNPACK_D (Y, y);
45 FP_MUL_D (R, X, Y);
46#if _FP_W_TYPE_SIZE < _FP_FRACBITS_D
47 FP_TRUNC_COOKED (S, D, 1, 2, RN, R);
48#else
49 FP_TRUNC_COOKED (S, D, 1, 1, RN, R);
50#endif
51 FP_PACK_S (ret, RN);
52 FP_HANDLE_EXCEPTIONS;
53 CHECK_NARROW_MUL (ret, x, y);
54 return ret;
55}
56libm_alias_float_double (mul)
57

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