1 /*
2 * Copyright (C) 2012-2022 Free Software Foundation, Inc.
3 *
4 * This file is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the
6 * Free Software Foundation; either version 3, or (at your option) any
7 * later version.
8 *
9 * This file is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * Under Section 7 of GPL version 3, you are granted additional
15 * permissions described in the GCC Runtime Library Exception, version
16 * 3.1, as published by the Free Software Foundation.
17 *
18 * You should have received a copy of the GNU General Public License and
19 * a copy of the GCC Runtime Library Exception along with this program;
20 * see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
21 * <http://www.gnu.org/licenses/>.
22 */
23
24 #ifndef _SOFT_FLOAT
25 #include "sfp-machine.h"
26
27 struct fenv
28 {
29 unsigned short int __control_word;
30 unsigned short int __unused1;
31 unsigned short int __status_word;
32 unsigned short int __unused2;
33 unsigned short int __tags;
34 unsigned short int __unused3;
35 unsigned int __eip;
36 unsigned short int __cs_selector;
37 unsigned int __opcode:11;
38 unsigned int __unused4:5;
39 unsigned int __data_offset;
40 unsigned short int __data_selector;
41 unsigned short int __unused5;
42 } __attribute__ ((gcc_struct));
43
44 #ifdef __SSE_MATH__
45 # define __math_force_eval_div(x, y) \
46 do { asm ("" : "+x" (x)); asm volatile ("" : : "x" (x / y)); } while (0)
47 #else
48 # define __math_force_eval_div(x, y) \
49 do { asm ("" : "+t" (x)); asm volatile ("" : : "f" (x / y)); } while (0)
50 #endif
51
52 void
__sfp_handle_exceptions(int _fex)53 __sfp_handle_exceptions (int _fex)
54 {
55 struct fenv temp;
56
57 if (_fex & FP_EX_INVALID)
58 {
59 float f = 0.0f;
60 __math_force_eval_div (f, f);
61 }
62 if (_fex & FP_EX_DENORM)
63 {
64 asm volatile ("fnstenv\t%0" : "=m" (temp));
65 temp.__status_word |= FP_EX_DENORM;
66 asm volatile ("fldenv\t%0" : : "m" (temp));
67 asm volatile ("fwait");
68 }
69 if (_fex & FP_EX_DIVZERO)
70 {
71 float f = 1.0f, g = 0.0f;
72 __math_force_eval_div (f, g);
73 }
74 if (_fex & FP_EX_OVERFLOW)
75 {
76 asm volatile ("fnstenv\t%0" : "=m" (temp));
77 temp.__status_word |= FP_EX_OVERFLOW;
78 asm volatile ("fldenv\t%0" : : "m" (temp));
79 asm volatile ("fwait");
80 }
81 if (_fex & FP_EX_UNDERFLOW)
82 {
83 asm volatile ("fnstenv\t%0" : "=m" (temp));
84 temp.__status_word |= FP_EX_UNDERFLOW;
85 asm volatile ("fldenv\t%0" : : "m" (temp));
86 asm volatile ("fwait");
87 }
88 if (_fex & FP_EX_INEXACT)
89 {
90 float f = 1.0f, g = 3.0f;
91 __math_force_eval_div (f, g);
92 }
93 }
94 #endif
95