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1/*
2 * ====================================================
3 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
4 *
5 * Developed at SunPro, a Sun Microsystems, Inc. business.
6 * Permission to use, copy, modify, and distribute this
7 * software is freely granted, provided that this notice
8 * is preserved.
9 * ====================================================
10 */
11
12/*
13 * from: @(#)fdlibm.h 5.1 93/09/24
14 * $Id: math_private.h,v 1.1 2002/01/28 23:27:44 scp Exp $
15 */
16
17#ifndef _MATH_PRIVATE_H_
18#define _MATH_PRIVATE_H_
19
20#include <sys/types.h>
21
22/* The original fdlibm code used statements like:
23 n0 = ((*(int*)&one)>>29)^1; * index of high word *
24 ix0 = *(n0+(int*)&x); * high word of x *
25 ix1 = *((1-n0)+(int*)&x); * low word of x *
26 to dig two 32 bit words out of the 64 bit IEEE floating point
27 value. That is non-ANSI, and, moreover, the gcc instruction
28 scheduler gets it wrong. We instead use the following macros.
29 Unlike the original code, we determine the endianness at compile
30 time, not at run time; I don't see much benefit to selecting
31 endianness at run time. */
32
33/* A union which permits us to convert between a double and two 32 bit
34 ints. */
35
36/*
37 * The arm32 port is little endian except for the FP word order which is
38 * big endian.
39 */
40
41#if (BYTE_ORDER == BIG_ENDIAN) || defined(arm32)
42
43typedef union
44{
45 double value;
46 struct
47 {
48 u_int32_t msw;
49 u_int32_t lsw;
50 } parts;
51} ieee_double_shape_type;
52
53#endif
54
55#if (BYTE_ORDER == LITTLE_ENDIAN) && !defined(arm32)
56
57typedef union
58{
59 double value;
60 struct
61 {
62 u_int32_t lsw;
63 u_int32_t msw;
64 } parts;
65} ieee_double_shape_type;
66
67#endif
68
69/* Get two 32 bit ints from a double. */
70
71#define EXTRACT_WORDS(ix0,ix1,d) \
72do { \
73 ieee_double_shape_type ew_u; \
74 ew_u.value = (d); \
75 (ix0) = ew_u.parts.msw; \
76 (ix1) = ew_u.parts.lsw; \
77} while (0)
78
79/* Get the more significant 32 bit int from a double. */
80
81#define GET_HIGH_WORD(i,d) \
82do { \
83 ieee_double_shape_type gh_u; \
84 gh_u.value = (d); \
85 (i) = gh_u.parts.msw; \
86} while (0)
87
88/* Get the less significant 32 bit int from a double. */
89
90#define GET_LOW_WORD(i,d) \
91do { \
92 ieee_double_shape_type gl_u; \
93 gl_u.value = (d); \
94 (i) = gl_u.parts.lsw; \
95} while (0)
96
97/* Set a double from two 32 bit ints. */
98
99#define INSERT_WORDS(d,ix0,ix1) \
100do { \
101 ieee_double_shape_type iw_u; \
102 iw_u.parts.msw = (ix0); \
103 iw_u.parts.lsw = (ix1); \
104 (d) = iw_u.value; \
105} while (0)
106
107/* Set the more significant 32 bits of a double from an int. */
108
109#define SET_HIGH_WORD(d,v) \
110do { \
111 ieee_double_shape_type sh_u; \
112 sh_u.value = (d); \
113 sh_u.parts.msw = (v); \
114 (d) = sh_u.value; \
115} while (0)
116
117/* Set the less significant 32 bits of a double from an int. */
118
119#define SET_LOW_WORD(d,v) \
120do { \
121 ieee_double_shape_type sl_u; \
122 sl_u.value = (d); \
123 sl_u.parts.lsw = (v); \
124 (d) = sl_u.value; \
125} while (0)
126
127/* A union which permits us to convert between a float and a 32 bit
128 int. */
129
130typedef union
131{
132 float value;
133 u_int32_t word;
134} ieee_float_shape_type;
135
136/* Get a 32 bit int from a float. */
137
138#define GET_FLOAT_WORD(i,d) \
139do { \
140 ieee_float_shape_type gf_u; \
141 gf_u.value = (d); \
142 (i) = gf_u.word; \
143} while (0)
144
145/* Set a float from a 32 bit int. */
146
147#define SET_FLOAT_WORD(d,i) \
148do { \
149 ieee_float_shape_type sf_u; \
150 sf_u.word = (i); \
151 (d) = sf_u.value; \
152} while (0)
153
154#endif /* _MATH_PRIVATE_H_ */