175 lines
4.3 KiB
C
Executable File
175 lines
4.3 KiB
C
Executable File
/*
|
|
====================================================
|
|
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_ */
|