1 /* Software floating-point emulation.
2 Helper routine for _Q_* routines.
3 Simulate exceptions using double arithmetics.
4 Copyright (C) 1999-2022 Free Software Foundation, Inc.
5 This file is part of the GNU C Library.
6
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Lesser General Public
9 License as published by the Free Software Foundation; either
10 version 2.1 of the License, or (at your option) any later version.
11
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
16
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, see
19 <https://www.gnu.org/licenses/>. */
20
21 #include <float.h>
22 #include <math.h>
23 #include <assert.h>
24 #include "soft-fp.h"
25
26 unsigned long long ___Q_zero = 0x0000000000000000ULL;
27
___Q_simulate_exceptions(int exceptions)28 void ___Q_simulate_exceptions(int exceptions)
29 {
30 if (exceptions & FP_EX_INVALID)
31 {
32 float f = 0.0;
33 __asm__ __volatile__ ("fdivs %0, %0, %0" : "+f" (f));
34 }
35 if (exceptions & FP_EX_DIVZERO)
36 {
37 float f = 1.0, g = 0.0;
38 __asm__ __volatile__ ("fdivs %0, %1, %0"
39 : "+f" (f)
40 : "f" (g));
41 }
42 if (exceptions & FP_EX_OVERFLOW)
43 {
44 float f = FLT_MAX;
45 __asm__ __volatile__("fmuls %0, %0, %0" : "+f" (f));
46 exceptions &= ~FP_EX_INEXACT;
47 }
48 if (exceptions & FP_EX_UNDERFLOW)
49 {
50 float f = FLT_MIN;
51 __asm__ __volatile__("fmuls %0, %0, %0" : "+f" (f));
52 exceptions &= ~FP_EX_INEXACT;
53 }
54 if (exceptions & FP_EX_INEXACT)
55 {
56 double d = 1.0, e = M_PI;
57 __asm__ __volatile__ ("fdivd %0, %1, %0"
58 : "+f" (d)
59 : "f" (e));
60 }
61 }
62