/* * ==================================================== * 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_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_ */