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aclock-efi/math_private.h

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C

/*
* ====================================================
* 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
* $NetBSD: math_private.h,v 1.12 2005/07/21 12:55:58 christos Exp $
*/
#ifndef _MATH_PRIVATE_H_
#define _MATH_PRIVATE_H_
/* 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. */
/*
* The ARM ports are little endian except for the FPA word order which is
* big endian.
*/
#if (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) || (defined(__arm__) && !defined(__VFP_FP__))
typedef union
{
double value;
struct
{
unsigned int msw;
unsigned int lsw;
} parts;
} ieee_double_shape_type;
#endif
#if (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) && !(defined(__arm__) && !defined(__VFP_FP__))
typedef union
{
double value;
struct
{
unsigned int lsw;
unsigned int msw;
} parts;
} ieee_double_shape_type;
#endif
/* Get two 32 bit ints from a double. */
#define EXTRACT_WORDS(ix0,ix1,d) \
do { \
ieee_double_shape_type ew_u; \
ew_u.value = (d); \
(ix0) = ew_u.parts.msw; \
(ix1) = ew_u.parts.lsw; \
} while (0)
/* Get the more significant 32 bit int from a double. */
#define GET_HIGH_WORD(i,d) \
do { \
ieee_double_shape_type gh_u; \
gh_u.value = (d); \
(i) = gh_u.parts.msw; \
} while (0)
/* Get the less significant 32 bit int from a double. */
#define GET_LOW_WORD(i,d) \
do { \
ieee_double_shape_type gl_u; \
gl_u.value = (d); \
(i) = gl_u.parts.lsw; \
} while (0)
/* Set a double from two 32 bit ints. */
#define INSERT_WORDS(d,ix0,ix1) \
do { \
ieee_double_shape_type iw_u; \
iw_u.parts.msw = (ix0); \
iw_u.parts.lsw = (ix1); \
(d) = iw_u.value; \
} while (0)
/* Set the more significant 32 bits of a double from an int. */
#define SET_HIGH_WORD(d,v) \
do { \
ieee_double_shape_type sh_u; \
sh_u.value = (d); \
sh_u.parts.msw = (v); \
(d) = sh_u.value; \
} while (0)
/* Set the less significant 32 bits of a double from an int. */
#define SET_LOW_WORD(d,v) \
do { \
ieee_double_shape_type sl_u; \
sl_u.value = (d); \
sl_u.parts.lsw = (v); \
(d) = sl_u.value; \
} while (0)
/** Compute the value of the cosine of Arg, measured in radians.
@param[in] Arg The value to compute the cosine of.
@return The computed value of the cosine of Arg.
**/
double cos(double Arg);
/** Compute the value of the sine of Arg.
@param[in] Arg The value to compute the sine of.
@return The computed value of the sine of Arg.
**/
double sin(double Arg);
/** Compute the absolute value of Arg.
@param[in] Arg The value to compute the absolute value of.
@return The absolute value of Arg.
**/
double fabs(double Arg);
/** Compute the largest integer value not greater than Arg.
@param[in] Arg The value to compute the floor of.
@return The largest integer value not greater than Arg, expressed as a floating-point number.
**/
double floor(double);
/* ieee style elementary functions */
extern int __ieee754_rem_pio2 (double,double*);
/* fdlibm kernel function */
extern double __kernel_sin (double, double, int);
extern double __kernel_cos (double, double);
extern int __kernel_rem_pio2 (double*,double*,int,int,int,const int*);
/**@{
C99, Posix, or NetBSD functions that are not part of the C95 specification.
**/
/*
* Functions callable from C, intended to support IEEE arithmetic.
*/
double scalbn(double, int);
double copysign(double, double);
#endif /* _MATH_PRIVATE_H_ */