1/*-
2 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/lib/msun/arm/fenv.h,v 1.5 2005/03/16 19:03:45 das Exp $
27 */
28
29/*
30 * Rewritten for Android.
31 *
32 * The ARM FPSCR is described here:
33 * http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0344b/Chdfafia.html
34 */
35
36#ifndef _FENV_H_
37#define _FENV_H_
38
39#include <sys/types.h>
40
41__BEGIN_DECLS
42
43typedef __uint32_t fenv_t;
44typedef __uint32_t fexcept_t;
45
46/* Exception flags. */
47#define FE_INVALID    0x01
48#define FE_DIVBYZERO  0x02
49#define FE_OVERFLOW   0x04
50#define FE_UNDERFLOW  0x08
51#define FE_INEXACT    0x10
52#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
53#define _FPSCR_ENABLE_SHIFT 8
54#define _FPSCR_ENABLE_MASK (FE_ALL_EXCEPT << _FPSCR_ENABLE_SHIFT)
55
56/* Rounding modes. */
57#define FE_TONEAREST  0x0
58#define FE_UPWARD     0x1
59#define FE_DOWNWARD   0x2
60#define FE_TOWARDZERO 0x3
61#define _FPSCR_RMODE_SHIFT 22
62
63/* Default floating-point environment. */
64extern const fenv_t __fe_dfl_env;
65#define FE_DFL_ENV (&__fe_dfl_env)
66
67static __inline int fegetenv(fenv_t* __envp) {
68  fenv_t _fpscr;
69#if !defined(__SOFTFP__)
70  #if !defined(__thumb__) || defined(__thumb2__)
71  __asm__ __volatile__("vmrs %0,fpscr" : "=r" (_fpscr));
72  #else
73   /* Switching from thumb1 to arm, do vmrs, then switch back */
74  __asm__ __volatile__(
75    ".balign 4           \n\t"
76    "mov     ip, pc      \n\t"
77    "bx      ip          \n\t"
78    ".arm                \n\t"
79    "vmrs    %0, fpscr   \n\t"
80    "add     ip, pc, #1  \n\t"
81    "bx      ip          \n\t"
82    ".thumb              \n\t"
83    : "=r" (_fpscr) : : "ip");
84  #endif
85#else
86  _fpscr = 0;
87#endif
88  *__envp = _fpscr;
89  return 0;
90}
91
92static __inline int fesetenv(const fenv_t* __envp) {
93  fenv_t _fpscr = *__envp;
94#if !defined(__SOFTFP__)
95  #if !defined(__thumb__) || defined(__thumb2__)
96  __asm__ __volatile__("vmsr fpscr,%0" : :"ri" (_fpscr));
97  #else
98   /* Switching from thumb1 to arm, do vmsr, then switch back */
99  __asm__ __volatile__(
100    ".balign 4           \n\t"
101    "mov     ip, pc      \n\t"
102    "bx      ip          \n\t"
103    ".arm                \n\t"
104    "vmsr    fpscr, %0   \n\t"
105    "add     ip, pc, #1  \n\t"
106    "bx      ip          \n\t"
107    ".thumb              \n\t"
108    : : "ri" (_fpscr) : "ip");
109  #endif
110#else
111  _fpscr = _fpscr;
112#endif
113  return 0;
114}
115
116static __inline int feclearexcept(int __excepts) {
117  fexcept_t __fpscr;
118  fegetenv(&__fpscr);
119  __fpscr &= ~__excepts;
120  fesetenv(&__fpscr);
121  return 0;
122}
123
124static __inline int fegetexceptflag(fexcept_t* __flagp, int __excepts) {
125  fexcept_t __fpscr;
126  fegetenv(&__fpscr);
127  *__flagp = __fpscr & __excepts;
128  return 0;
129}
130
131static __inline int fesetexceptflag(const fexcept_t* __flagp, int __excepts) {
132  fexcept_t __fpscr;
133  fegetenv(&__fpscr);
134  __fpscr &= ~__excepts;
135  __fpscr |= *__flagp & __excepts;
136  fesetenv(&__fpscr);
137  return 0;
138}
139
140static __inline int feraiseexcept(int __excepts) {
141  fexcept_t __ex = __excepts;
142  fesetexceptflag(&__ex, __excepts);
143  return 0;
144}
145
146static __inline int fetestexcept(int __excepts) {
147  fexcept_t __fpscr;
148  fegetenv(&__fpscr);
149  return (__fpscr & __excepts);
150}
151
152static __inline int fegetround(void) {
153  fenv_t _fpscr;
154  fegetenv(&_fpscr);
155  return ((_fpscr >> _FPSCR_RMODE_SHIFT) & 0x3);
156}
157
158static __inline int fesetround(int __round) {
159  fenv_t _fpscr;
160  fegetenv(&_fpscr);
161  _fpscr &= ~(0x3 << _FPSCR_RMODE_SHIFT);
162  _fpscr |= (__round << _FPSCR_RMODE_SHIFT);
163  fesetenv(&_fpscr);
164  return 0;
165}
166
167static __inline int feholdexcept(fenv_t* __envp) {
168  fenv_t __env;
169  fegetenv(&__env);
170  *__envp = __env;
171  __env &= ~(FE_ALL_EXCEPT | _FPSCR_ENABLE_MASK);
172  fesetenv(&__env);
173  return 0;
174}
175
176static __inline int feupdateenv(const fenv_t* __envp) {
177  fexcept_t __fpscr;
178  fegetenv(&__fpscr);
179  fesetenv(__envp);
180  feraiseexcept(__fpscr & FE_ALL_EXCEPT);
181  return 0;
182}
183
184#if __BSD_VISIBLE
185
186static __inline int feenableexcept(int __mask) {
187  fenv_t __old_fpscr, __new_fpscr;
188  fegetenv(&__old_fpscr);
189  __new_fpscr = __old_fpscr | (__mask & FE_ALL_EXCEPT) << _FPSCR_ENABLE_SHIFT;
190  fesetenv(&__new_fpscr);
191  return ((__old_fpscr >> _FPSCR_ENABLE_SHIFT) & FE_ALL_EXCEPT);
192}
193
194static __inline int fedisableexcept(int __mask) {
195  fenv_t __old_fpscr, __new_fpscr;
196  fegetenv(&__old_fpscr);
197  __new_fpscr = __old_fpscr & ~((__mask & FE_ALL_EXCEPT) << _FPSCR_ENABLE_SHIFT);
198  fesetenv(&__new_fpscr);
199  return ((__old_fpscr >> _FPSCR_ENABLE_SHIFT) & FE_ALL_EXCEPT);
200}
201
202static __inline int fegetexcept(void) {
203  fenv_t __fpscr;
204  fegetenv(&__fpscr);
205  return ((__fpscr & _FPSCR_ENABLE_MASK) >> _FPSCR_ENABLE_SHIFT);
206}
207
208#endif /* __BSD_VISIBLE */
209
210__END_DECLS
211
212#endif /* !_FENV_H_ */
213