| /* |
| * ==================================================== |
| * 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. |
| * ==================================================== |
| */ |
| |
| /* |
| * modf(double x, double *iptr) |
| * return fraction part of x, and return x's integral part in *iptr. |
| * Method: |
| * Bit twiddling. |
| * |
| * Exception: |
| * No exception. |
| */ |
| |
| #include <math.h> |
| #include <math_private.h> |
| |
| static const double one = 1.0; |
| |
| double |
| __modf (double x, double *iptr) |
| { |
| int32_t i0, i1, j0; |
| u_int32_t i; |
| EXTRACT_WORDS (i0, i1, x); |
| j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; /* exponent of x */ |
| if (j0 < 20) /* integer part in high x */ |
| { |
| if (j0 < 0) /* |x|<1 */ |
| { |
| INSERT_WORDS (*iptr, i0 & 0x80000000, 0); /* *iptr = +-0 */ |
| return x; |
| } |
| else |
| { |
| i = (0x000fffff) >> j0; |
| if (((i0 & i) | i1) == 0) /* x is integral */ |
| { |
| *iptr = x; |
| INSERT_WORDS (x, i0 & 0x80000000, 0); /* return +-0 */ |
| return x; |
| } |
| else |
| { |
| INSERT_WORDS (*iptr, i0 & (~i), 0); |
| return x - *iptr; |
| } |
| } |
| } |
| else if (__builtin_expect (j0 > 51, 0)) /* no fraction part */ |
| { |
| *iptr = x * one; |
| /* We must handle NaNs separately. */ |
| if (j0 == 0x400 && ((i0 & 0xfffff) | i1)) |
| return x * one; |
| INSERT_WORDS (x, i0 & 0x80000000, 0); /* return +-0 */ |
| return x; |
| } |
| else /* fraction part in low x */ |
| { |
| i = ((u_int32_t) (0xffffffff)) >> (j0 - 20); |
| if ((i1 & i) == 0) /* x is integral */ |
| { |
| *iptr = x; |
| INSERT_WORDS (x, i0 & 0x80000000, 0); /* return +-0 */ |
| return x; |
| } |
| else |
| { |
| INSERT_WORDS (*iptr, i0, i1 & (~i)); |
| return x - *iptr; |
| } |
| } |
| } |
| weak_alias (__modf, modf) |
| #ifdef NO_LONG_DOUBLE |
| strong_alias (__modf, __modfl) |
| weak_alias (__modf, modfl) |
| #endif |
