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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. |
| * ==================================================== |
| */ |
| |
| /* |
| * from: @(#)fdlibm.h 5.1 93/09/24 |
| * $Id: math_private.h,v 1.8 1998/11/27 11:33:46 drepper 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. */ |
| |
| typedef int int32_t; |
| typedef unsigned int u_int32_t; |
| |
| typedef union |
| { |
| double value; |
| struct |
| { |
| u_int32_t lsw; |
| u_int32_t msw; |
| } parts; |
| } ieee_double_shape_type; |
| |
| /* 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) |
| |
| /* A union which permits us to convert between a long double and |
| three 32 bit ints. */ |
| |
| |
| typedef union |
| { |
| long double value; |
| struct |
| { |
| u_int32_t lsw; |
| u_int32_t msw; |
| unsigned int sign_exponent:16; |
| unsigned int empty:16; |
| } parts; |
| } ieee_long_double_shape_type; |
| |
| /* Get three 32 bit ints from a double. */ |
| |
| #define GET_LDOUBLE_WORDS(exp,ix0,ix1,d) \ |
| do { \ |
| ieee_long_double_shape_type ew_u; \ |
| ew_u.value = (d); \ |
| (exp) = ew_u.parts.sign_exponent; \ |
| (ix0) = ew_u.parts.msw; \ |
| (ix1) = ew_u.parts.lsw; \ |
| } while (0) |
| |
| /* Set a double from two 32 bit ints. */ |
| |
| #define SET_LDOUBLE_WORDS(d,exp,ix0,ix1) \ |
| do { \ |
| ieee_long_double_shape_type iw_u; \ |
| iw_u.parts.sign_exponent = (exp); \ |
| iw_u.parts.msw = (ix0); \ |
| iw_u.parts.lsw = (ix1); \ |
| (d) = iw_u.value; \ |
| } while (0) |
| |
| /* Get the more significant 32 bits of a long double mantissa. */ |
| |
| #define GET_LDOUBLE_MSW(v,d) \ |
| do { \ |
| ieee_long_double_shape_type sh_u; \ |
| sh_u.value = (d); \ |
| (v) = sh_u.parts.msw; \ |
| } while (0) |
| |
| /* Set the more significant 32 bits of a long double mantissa from an int. */ |
| |
| #define SET_LDOUBLE_MSW(d,v) \ |
| do { \ |
| ieee_long_double_shape_type sh_u; \ |
| sh_u.value = (d); \ |
| sh_u.parts.msw = (v); \ |
| (d) = sh_u.value; \ |
| } while (0) |
| |
| /* Get int from the exponent of a long double. */ |
| |
| #define GET_LDOUBLE_EXP(exp,d) \ |
| do { \ |
| ieee_long_double_shape_type ge_u; \ |
| ge_u.value = (d); \ |
| (exp) = ge_u.parts.sign_exponent; \ |
| } while (0) |
| |
| /* Set exponent of a long double from an int. */ |
| |
| #define SET_LDOUBLE_EXP(d,exp) \ |
| do { \ |
| ieee_long_double_shape_type se_u; \ |
| se_u.value = (d); \ |
| se_u.parts.sign_exponent = (exp); \ |
| (d) = se_u.value; \ |
| } while (0) |
| |
| #endif /* _MATH_PRIVATE_H_ */ |