xref: /netbsd-src/external/gpl3/gcc.old/dist/libgcc/config/i386/sfp-exceptions.c (revision 8feb0f0b7eaff0608f8350bbfa3098827b4bb91b)
1 /*
2  * Copyright (C) 2012-2020 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 };
43 
44 void
__sfp_handle_exceptions(int _fex)45 __sfp_handle_exceptions (int _fex)
46 {
47   if (_fex & FP_EX_INVALID)
48     {
49       float f = 0.0f;
50 #ifdef __SSE_MATH__
51       asm volatile ("%vdivss\t{%0, %d0|%d0, %0}" : "+x" (f));
52 #else
53       asm volatile ("fdiv\t{%y0, %0|%0, %y0}" : "+t" (f));
54       /* No need for fwait, exception is triggered by emitted fstp.  */
55 #endif
56     }
57   if (_fex & FP_EX_DENORM)
58     {
59       struct fenv temp;
60       asm volatile ("fnstenv\t%0" : "=m" (temp));
61       temp.__status_word |= FP_EX_DENORM;
62       asm volatile ("fldenv\t%0" : : "m" (temp));
63       asm volatile ("fwait");
64     }
65   if (_fex & FP_EX_DIVZERO)
66     {
67       float f = 1.0f, g = 0.0f;
68 #ifdef __SSE_MATH__
69       asm volatile ("%vdivss\t{%1, %d0|%d0, %1}" : "+x" (f) : "xm" (g));
70 #else
71       asm volatile ("fdivs\t%1" : "+t" (f) : "m" (g));
72       /* No need for fwait, exception is triggered by emitted fstp.  */
73 #endif
74     }
75   if (_fex & FP_EX_OVERFLOW)
76     {
77       struct fenv temp;
78       asm volatile ("fnstenv\t%0" : "=m" (temp));
79       temp.__status_word |= FP_EX_OVERFLOW;
80       asm volatile ("fldenv\t%0" : : "m" (temp));
81       asm volatile ("fwait");
82     }
83   if (_fex & FP_EX_UNDERFLOW)
84     {
85       struct fenv temp;
86       asm volatile ("fnstenv\t%0" : "=m" (temp));
87       temp.__status_word |= FP_EX_UNDERFLOW;
88       asm volatile ("fldenv\t%0" : : "m" (temp));
89       asm volatile ("fwait");
90     }
91   if (_fex & FP_EX_INEXACT)
92     {
93       float f = 1.0f, g = 3.0f;
94 #ifdef __SSE_MATH__
95       asm volatile ("%vdivss\t{%1, %d0|%d0, %1}" : "+x" (f) : "xm" (g));
96 #else
97       asm volatile ("fdivs\t%1" : "+t" (f) : "m" (g));
98       /* No need for fwait, exception is triggered by emitted fstp.  */
99 #endif
100     }
101 }
102 #endif
103