xref: /illumos-gate/usr/src/lib/libm/common/m9x/feexcept.c (revision 9498083eeaed1aacdde41369b7fa6f3b84870791)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
24  */
25 /*
26  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #pragma weak __feclearexcept = feclearexcept
31 #pragma weak __feraiseexcept = feraiseexcept
32 #pragma weak __fetestexcept = fetestexcept
33 #pragma weak __fegetexceptflag = fegetexceptflag
34 #pragma weak __fesetexceptflag = fesetexceptflag
35 
36 #pragma weak feclearexcept96 = feclearexcept
37 #pragma weak feraiseexcept96 = feraiseexcept
38 #pragma weak fetestexcept96 = fetestexcept
39 #pragma weak fegetexceptflag96 = fegetexceptflag
40 #pragma weak fesetexceptflag96 = fesetexceptflag
41 
42 #include <fenv.h>
43 #include <sys/ieeefp.h>
44 #include <ucontext.h>
45 #include <thread.h>
46 #include "fex_handler.h"
47 #include "fenv_inlines.h"
48 
49 
50 int feclearexcept(int e)
51 {
52 	unsigned long	fsr;
53 
54 	__fenv_getfsr(&fsr);
55 	__fenv_set_ex(fsr, __fenv_get_ex(fsr) & ~e);
56 	__fenv_setfsr(&fsr);
57 	if (fex_get_log())
58 		__fex_update_te();
59 	return 0;
60 }
61 
62 /*
63 *  note - __fex_hdlr depends on fetestexcept following feraiseexcept
64 */
65 int feraiseexcept(int e)
66 {
67 	volatile double	t;
68 	unsigned long	fsr;
69 
70 	if (e & FE_INVALID) {
71 		t = 0.0;
72 		t /= 0.0;
73 	}
74 	if (e & FE_DIVBYZERO) {
75 		t = 1.0e300;
76 		t /= 0.0;
77 	}
78 	if (e & FE_OVERFLOW) {
79 		/* if overflow is not trapped, avoid raising inexact */
80 		__fenv_getfsr(&fsr);
81 		if (!(__fenv_get_te(fsr) & (1 << fp_trap_overflow))) {
82 			__fenv_set_ex(fsr, __fenv_get_ex(fsr) | FE_OVERFLOW);
83 			__fenv_setfsr(&fsr);
84 		}
85 		else {
86 			t = 1.0e300;
87 			t *= 1.0e300;
88 		}
89 	}
90 	if (e & FE_UNDERFLOW) {
91 		/* if underflow is not trapped, avoid raising inexact */
92 		__fenv_getfsr(&fsr);
93 		if (!(__fenv_get_te(fsr) & (1 << fp_trap_underflow))) {
94 			__fenv_set_ex(fsr, __fenv_get_ex(fsr) | FE_UNDERFLOW);
95 			__fenv_setfsr(&fsr);
96 		}
97 		else {
98 			t = 1.0e-307;
99 			t -= 1.001e-307;
100 		}
101 	}
102 	if (e & FE_INEXACT) {
103 		t = 1.0e300;
104 		t += 1.0e-307;
105 	}
106 	return 0;
107 }
108 
109 int fetestexcept(int e)
110 {
111 	unsigned long	fsr;
112 
113 	__fenv_getfsr(&fsr);
114 	return (int)__fenv_get_ex(fsr) & e;
115 }
116 
117 int fegetexceptflag(fexcept_t *p, int e)
118 {
119 	unsigned long	fsr;
120 
121 	__fenv_getfsr(&fsr);
122 	*p = (int)__fenv_get_ex(fsr) & e;
123 	return 0;
124 }
125 
126 int fesetexceptflag(const fexcept_t *p, int e)
127 {
128 	unsigned long	fsr;
129 
130 	__fenv_getfsr(&fsr);
131 	__fenv_set_ex(fsr, (((int)__fenv_get_ex(fsr) & ~e) | (*p & e)) &
132 		FE_ALL_EXCEPT);
133 	__fenv_setfsr(&fsr);
134 	if (fex_get_log())
135 		__fex_update_te();
136 	return 0;
137 }
138