OpenBSD-4.6/lib/libm/src/math_private.h
/* $OpenBSD: math_private.h,v 1.11 2008/12/09 20:00:35 martynas Exp $ */
/*
* ====================================================
* 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 <sys/types.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 arm32 port is little endian except for the FP word order which is
* big endian.
*/
#if (BYTE_ORDER == BIG_ENDIAN) || defined(arm32)
typedef union
{
double value;
struct
{
u_int32_t msw;
u_int32_t lsw;
} parts;
} ieee_double_shape_type;
typedef union
{
long double value;
struct {
u_int32_t msw;
u_int32_t nsw;
u_int32_t lsw;
} parts;
} ieee_extended_shape_type;
typedef union
{
long double value;
struct {
u_int32_t mswhi;
u_int32_t mswlo;
u_int32_t lswhi;
u_int32_t lswlo;
} parts;
} ieee_quad_shape_type;
#endif
#if (BYTE_ORDER == LITTLE_ENDIAN) && !defined(arm32)
typedef union
{
double value;
struct
{
u_int32_t lsw;
u_int32_t msw;
} parts;
} ieee_double_shape_type;
typedef union
{
long double value;
struct {
u_int32_t lswlo;
u_int32_t lswhi;
u_int32_t mswlo;
u_int32_t mswhi;
} parts;
} ieee_quad_shape_type;
typedef union
{
long double value;
struct {
u_int32_t lsw;
u_int32_t nsw;
u_int32_t msw;
} parts;
} ieee_extended_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)
/* 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) \
do { \
ieee_float_shape_type gf_u; \
gf_u.value = (d); \
(i) = gf_u.word; \
} while (0)
/* Set a float from a 32 bit int. */
#define SET_FLOAT_WORD(d,i) \
do { \
ieee_float_shape_type sf_u; \
sf_u.word = (i); \
(d) = sf_u.value; \
} while (0)
#ifdef FLT_EVAL_METHOD
/*
* Attempt to get strict C99 semantics for assignment with non-C99 compilers.
*/
#if FLT_EVAL_METHOD == 0 || __GNUC__ == 0
#define STRICT_ASSIGN(type, lval, rval) ((lval) = (rval))
#else /* FLT_EVAL_METHOD == 0 || __GNUC__ == 0 */
#define STRICT_ASSIGN(type, lval, rval) do { \
volatile type __lval; \
\
if (sizeof(type) >= sizeof(double)) \
(lval) = (rval); \
else { \
__lval = (rval); \
(lval) = __lval; \
} \
} while (0)
#endif /* FLT_EVAL_METHOD == 0 || __GNUC__ == 0 */
#endif /* FLT_EVAL_METHOD */
/* fdlibm kernel function */
extern int __ieee754_rem_pio2(double,double*);
extern double __kernel_sin(double,double,int);
extern double __kernel_cos(double,double);
extern double __kernel_tan(double,double,int);
extern int __kernel_rem_pio2(double*,double*,int,int,int);
/* float versions of fdlibm kernel functions */
extern int __ieee754_rem_pio2f(float,float*);
extern float __kernel_sinf(float,float,int);
extern float __kernel_cosf(float,float);
extern float __kernel_tanf(float,float,int);
extern int __kernel_rem_pio2f(float*,float*,int,int,int,const int*);
/* long double precision kernel functions */
long double __kernel_sinl(long double, long double, int);
long double __kernel_cosl(long double, long double);
long double __kernel_tanl(long double, long double, int);
/*
* Common routine to process the arguments to nan(), nanf(), and nanl().
*/
void _scan_nan(uint32_t *__words, int __num_words, const char *__s);
/*
* TRUNC() is a macro that sets the trailing 27 bits in the mantissa
* of an IEEE double variable to zero. It must be expression-like
* for syntactic reasons, and we implement this expression using
* an inline function instead of a pure macro to avoid depending
* on the gcc feature of statement-expressions.
*/
#define TRUNC(d) (_b_trunc(&(d)))
static __inline void
_b_trunc(volatile double *_dp)
{
uint32_t _lw;
GET_LOW_WORD(_lw, *_dp);
SET_LOW_WORD(*_dp, _lw & 0xf8000000);
}
struct Double {
double a;
double b;
};
/*
* Functions internal to the math package, yet not static.
*/
double __exp__D(double, double);
struct Double __log__D(double);
#endif /* _MATH_PRIVATE_H_ */