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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.
* ====================================================
*/
#ifndef _MATH_PRIVATE_H_
#define _MATH_PRIVATE_H_
#include <endian.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. */
/*
* Math on arm is special (read: stupid):
* For FPA, float words are always big-endian.
* For VFP, float words follow the memory system mode.
* For Maverick, float words are always little-endian.
*/
#if !defined(__MAVERICK__) && ((__BYTE_ORDER == __BIG_ENDIAN) || \
(!defined(__VFP_FP__) && (defined(__arm__) || defined(__thumb__))))
typedef union
{
double value;
struct
{
u_int32_t msw;
u_int32_t lsw;
} parts;
} ieee_double_shape_type;
#else
typedef union
{
double value;
struct
{
u_int32_t lsw;
u_int32_t 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)
/* 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)
/* ieee style elementary functions */
extern double __ieee754_sqrt (double) attribute_hidden;
extern double __ieee754_acos (double) attribute_hidden;
extern double __ieee754_acosh (double) attribute_hidden;
extern double __ieee754_log (double) attribute_hidden;
extern double __ieee754_log2 (double) attribute_hidden;
extern double __ieee754_atanh (double) attribute_hidden;
extern double __ieee754_asin (double) attribute_hidden;
extern double __ieee754_atan2 (double,double) attribute_hidden;
extern double __ieee754_exp (double) attribute_hidden;
extern double __ieee754_exp10 (double) attribute_hidden;
extern double __ieee754_cosh (double) attribute_hidden;
extern double __ieee754_fmod (double,double) attribute_hidden;
extern double __ieee754_pow (double,double) attribute_hidden;
extern double __ieee754_lgamma_r (double,int *) attribute_hidden;
/*extern double __ieee754_gamma_r (double,int *) attribute_hidden;*/
extern double __ieee754_lgamma (double) attribute_hidden;
/*extern double __ieee754_gamma (double) attribute_hidden;*/
extern double __ieee754_log10 (double) attribute_hidden;
extern double __ieee754_sinh (double) attribute_hidden;
extern double __ieee754_hypot (double,double) attribute_hidden;
extern double __ieee754_j0 (double) attribute_hidden;
extern double __ieee754_j1 (double) attribute_hidden;
extern double __ieee754_y0 (double) attribute_hidden;
extern double __ieee754_y1 (double) attribute_hidden;
extern double __ieee754_jn (int,double) attribute_hidden;
extern double __ieee754_yn (int,double) attribute_hidden;
extern double __ieee754_remainder (double,double) attribute_hidden;
extern int __ieee754_rem_pio2 (double,double*) attribute_hidden;
extern double __ieee754_scalb (double,double) attribute_hidden;
/* fdlibm kernel function */
#ifndef _IEEE_LIBM
extern double __kernel_standard (double,double,int) attribute_hidden;
#endif
extern double __kernel_sin (double,double,int) attribute_hidden;
extern double __kernel_cos (double,double) attribute_hidden;
extern double __kernel_tan (double,double,int) attribute_hidden;
extern int __kernel_rem_pio2 (double*,double*,int,int,int,const int*) attribute_hidden;
/*
* math_opt_barrier(x): safely load x, even if it was manipulated
* by non-floationg point operations. This macro returns the value of x.
* This ensures compiler does not (ab)use its knowledge about x value
* and don't optimize future operations. Example:
* float x;
* SET_FLOAT_WORD(x, 0x80000001); // sets a bit pattern
* y = math_opt_barrier(x); // "compiler, do not cheat!"
* y = y * y; // compiler can't optimize, must use real multiply insn
*
* math_force_eval(x): force expression x to be evaluated.
* Useful if otherwise compiler may eliminate the expression
* as unused. This macro returns no value.
* Example: "void fn(float f) { f = f * f; }"
* versus "void fn(float f) { f = f * f; math_force_eval(f); }"
*
* Currently, math_force_eval(x) stores x into
* a floating point register or memory *of the appropriate size*.
* There is no guarantee this will not change.
*/
#if defined(__i386__)
#define math_opt_barrier(x) ({ \
__typeof(x) __x = (x); \
/* "t": load x into top-of-stack fpreg */ \
__asm__ ("" : "=t" (__x) : "0" (__x)); \
__x; \
})
#define math_force_eval(x) do { \
__typeof(x) __x = (x); \
if (sizeof(__x) <= sizeof(double)) \
/* "m": store x into a memory location */ \
__asm__ __volatile__ ("" : : "m" (__x)); \
else /* long double */ \
/* "f": load x into (any) fpreg */ \
__asm__ __volatile__ ("" : : "f" (__x)); \
} while (0)
#endif
#if defined(__x86_64__)
#define math_opt_barrier(x) ({ \
__typeof(x) __x = (x); \
if (sizeof(__x) <= sizeof(double)) \
/* "x": load into XMM SSE register */ \
__asm__ ("" : "=x" (__x) : "0" (__x)); \
else /* long double */ \
/* "t": load x into top-of-stack fpreg */ \
__asm__ ("" : "=t" (__x) : "0" (__x)); \
__x; \
})
#define math_force_eval(x) do { \
__typeof(x) __x = (x); \
if (sizeof(__x) <= sizeof(double)) \
/* "x": load into XMM SSE register */ \
__asm__ __volatile__ ("" : : "x" (__x)); \
else /* long double */ \
/* "f": load x into (any) fpreg */ \
__asm__ __volatile__ ("" : : "f" (__x)); \
} while (0)
#endif
/* Default implementations force store to a memory location */
#ifndef math_opt_barrier
#define math_opt_barrier(x) ({ __typeof(x) __x = (x); __asm__ ("" : "+m" (__x)); __x; })
#endif
#ifndef math_force_eval
#define math_force_eval(x) do { __typeof(x) __x = (x); __asm__ __volatile__ ("" : : "m" (__x)); } while (0)
#endif
#endif /* _MATH_PRIVATE_H_ */
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