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/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
/*
* from: @(#)fdlibm.h 5.1 93/09/24
*/
#ifndef _MATH_PRIVATE_H_
#define _MATH_PRIVATE_H_
#include "wcclibm.h"
//#include <endian.h>
//#include <sys/types.h>
/* A representation of a double as a union. */
union ieee754_double
{
double d;
/* This is the IEEE 754 double-precision format. */
struct {
/* Together these comprise the mantissa. */
unsigned int mantissa1:32;
unsigned int mantissa0:20;
unsigned int exponent:11;
unsigned int negative:1;
} ieee;
/* This format makes it easier to see if a NaN is a signalling NaN. */
struct {
/* Together these comprise the mantissa. */
unsigned int mantissa1:32;
unsigned int mantissa0:19;
unsigned int quiet_nan:1;
unsigned int exponent:11;
unsigned int negative:1;
} ieee_nan;
};
/* The original fdlibm code used statements like:
n0 = ((*(int*)&one)>>29)^1; * index of high word *
ix0 = *(n0+(int*)&x); * high word of x *
ix1 = *((1-n0)+(int*)&x); * low word of x *
to dig two 32 bit words out of the 64 bit IEEE floating point
value. That is non-ANSI, and, moreover, the gcc instruction
scheduler gets it wrong. We instead use the following macros.
Unlike the original code, we determine the endianness at compile
time, not at run time; I don't see much benefit to selecting
endianness at run time. */
/* A union which permits us to convert between a double and two 32 bit
ints. */
/* #if __FLOAT_WORD_ORDER == BIG_ENDIAN */
/* #warning USING Big Endian float word order */
/* typedef union */
/* { */
/* double value; */
/* struct */
/* { */
/* u_int16_t msw; */
/* u_int16_t lsw; */
/* } parts; */
/* } ieeeDoubleShapeType; */
/* #endif */
/* #if __FLOAT_WORD_ORDER == LITTLE_ENDIAN */
/* #warning USING Little Endian float word order */
typedef union
{
double value;
struct
{
u_int16_t lsw;
u_int16_t msw;
} parts;
} ieeeDoubleShapeType;
/* #endif */
/* Get two 32 bit ints from a double. */
#define EXTRACT_WORDS(ix0,ix1,d) \
{ \
ieeeDoubleShapeType ew_u; \
ew_u.value = (d); \
(ix0) = ew_u.parts.msw; \
(ix1) = ew_u.parts.lsw; \
}
/* Get the more significant 32 bit int from a double. */
#define GET_HIGH_WORD(i,d) \
{ \
ieeeDoubleShapeType gh_u; \
gh_u.value = (d); \
(i) = gh_u.parts.msw; \
}
/* Get the less significant 32 bit int from a double. */
#define GET_LOW_WORD(i,d) \
{ \
ieeeDoubleShapeType gl_u; \
gl_u.value = (d); \
(i) = gl_u.parts.lsw; \
}
/* Set a double from two 32 bit ints. */
#define INSERT_WORDS(d,ix0,ix1) \
{ \
ieeeDoubleShapeType iw_u; \
iw_u.parts.msw = (ix0); \
iw_u.parts.lsw = (ix1); \
(d) = iw_u.value; \
}
/* Set the more significant 32 bits of a double from an int. */
#define SET_HIGH_WORD(d,v) \
{ \
ieeeDoubleShapeType sh_u; \
sh_u.value = (d); \
sh_u.parts.msw = (v); \
(d) = sh_u.value; \
}
/* Set the less significant 32 bits of a double from an int. */
#define SET_LOW_WORD(d,v) \
{ \
ieeeDoubleShapeType sl_u; \
sl_u.value = (d); \
sl_u.parts.lsw = (v); \
(d) = sl_u.value; \
}
/* A union which permits us to convert between a float and a 32 bit
int. */
typedef union
{
float value;
u_int32_t word;
} ieee_float_shape_type;
/* Get a 32 bit int from a float. */
#define GET_FLOAT_WORD(i,d) \
{ \
ieee_float_shape_type gf_u; \
gf_u.value = (d); \
(i) = gf_u.word; \
}
/* Set a float from a 32 bit int. */
#define SET_FLOAT_WORD(d,i) \
{ \
ieee_float_shape_type sf_u; \
sf_u.word = (i); \
(d) = sf_u.value; \
}
#endif /* _MATH_PRIVATE_H_ */
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