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f10eff58 | 1 | /* Raise given exceptions. |
b168057a | 2 | Copyright (C) 2004-2015 Free Software Foundation, Inc. |
f10eff58 DJ |
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 | ||
22423683 | 15 | You should have received a copy of the GNU Lesser General Public |
ab84e3ff PE |
16 | License along with the GNU C Library. If not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
f10eff58 DJ |
18 | |
19 | #include <fpu_control.h> | |
20 | #include <fenv.h> | |
21 | #include <float.h> | |
a4ca5195 | 22 | #include <arm-features.h> |
f10eff58 | 23 | |
f10eff58 DJ |
24 | |
25 | int | |
0747f818 | 26 | __feraiseexcept (int excepts) |
f10eff58 | 27 | { |
1a2f40e5 W |
28 | /* Fail if a VFP unit isn't present unless nothing needs to be done. */ |
29 | if (!ARM_HAVE_VFP) | |
30 | return (excepts != 0); | |
31 | else | |
f10eff58 | 32 | { |
1a2f40e5 | 33 | fpu_control_t fpscr; |
f10eff58 DJ |
34 | const float fp_zero = 0.0, fp_one = 1.0, fp_max = FLT_MAX, |
35 | fp_min = FLT_MIN, fp_1e32 = 1.0e32f, fp_two = 2.0, | |
36 | fp_three = 3.0; | |
37 | ||
38 | /* Raise exceptions represented by EXPECTS. But we must raise only | |
39 | one signal at a time. It is important that if the overflow/underflow | |
40 | exception and the inexact exception are given at the same time, | |
41 | the overflow/underflow exception follows the inexact exception. After | |
42 | each exception we read from the fpscr, to force the exception to be | |
43 | raised immediately. */ | |
44 | ||
45 | /* There are additional complications because this file may be compiled | |
46 | without VFP support enabled, and we also can't assume that the | |
47 | assembler has VFP instructions enabled. To get around this we use the | |
48 | generic coprocessor mnemonics and avoid asking GCC to put float values | |
49 | in VFP registers. */ | |
50 | ||
51 | /* First: invalid exception. */ | |
52 | if (FE_INVALID & excepts) | |
53 | __asm__ __volatile__ ( | |
54 | "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ | |
55 | "cdp p10, 8, cr0, cr0, cr0, 0\n\t" /* fdivs s0, s0, s0 */ | |
56 | "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ | |
57 | : "m" (fp_zero) | |
58 | : "s0"); | |
59 | ||
60 | /* Next: division by zero. */ | |
61 | if (FE_DIVBYZERO & excepts) | |
62 | __asm__ __volatile__ ( | |
63 | "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ | |
64 | "ldcl p10, cr0, %2\n\t" /* flds s1, %2 */ | |
65 | "cdp p10, 8, cr0, cr0, cr0, 1\n\t" /* fdivs s0, s0, s1 */ | |
66 | "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ | |
67 | : "m" (fp_one), "m" (fp_zero) | |
68 | : "s0", "s1"); | |
69 | ||
70 | /* Next: overflow. */ | |
71 | if (FE_OVERFLOW & excepts) | |
72 | /* There's no way to raise overflow without also raising inexact. */ | |
73 | __asm__ __volatile__ ( | |
74 | "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ | |
75 | "ldcl p10, cr0, %2\n\t" /* flds s1, %2 */ | |
76 | "cdp p10, 3, cr0, cr0, cr0, 1\n\t" /* fadds s0, s0, s1 */ | |
77 | "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ | |
78 | : "m" (fp_max), "m" (fp_1e32) | |
79 | : "s0", "s1"); | |
80 | ||
81 | /* Next: underflow. */ | |
82 | if (FE_UNDERFLOW & excepts) | |
83 | __asm__ __volatile__ ( | |
84 | "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ | |
85 | "ldcl p10, cr0, %2\n\t" /* flds s1, %2 */ | |
86 | "cdp p10, 8, cr0, cr0, cr0, 1\n\t" /* fdivs s0, s0, s1 */ | |
87 | "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ | |
88 | : "m" (fp_min), "m" (fp_three) | |
89 | : "s0", "s1"); | |
90 | ||
91 | /* Last: inexact. */ | |
92 | if (FE_INEXACT & excepts) | |
93 | __asm__ __volatile__ ( | |
94 | "ldc p10, cr0, %1\n\t" /* flds s0, %1 */ | |
95 | "ldcl p10, cr0, %2\n\t" /* flds s1, %2 */ | |
96 | "cdp p10, 8, cr0, cr0, cr0, 1\n\t" /* fdivs s0, s0, s1 */ | |
97 | "mrc p10, 7, %0, cr1, cr0, 0" : "=r" (fpscr) /* fmrx %0, fpscr */ | |
98 | : "m" (fp_two), "m" (fp_three) | |
99 | : "s0", "s1"); | |
100 | ||
101 | /* Success. */ | |
102 | return 0; | |
103 | } | |
f10eff58 | 104 | } |
0747f818 JM |
105 | libm_hidden_def (__feraiseexcept) |
106 | weak_alias (__feraiseexcept, feraiseexcept) | |
107 | libm_hidden_weak (feraiseexcept) |