| /* Rewritten for 64-bit machines by Ulrich Drepper <drepper@gmail.com>. */ |
| /* |
| * ==================================================== |
| * 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> |
| #include <stdint.h> |
| |
| static const double one = 1.0; |
| |
| double |
| __modf(double x, double *iptr) |
| { |
| int64_t i0; |
| int32_t j0; |
| EXTRACT_WORDS64(i0,x); |
| j0 = ((i0>>52)&0x7ff)-0x3ff; /* exponent of x */ |
| if(j0<52) { /* integer part in x */ |
| if(j0<0) { /* |x|<1 */ |
| /* *iptr = +-0 */ |
| INSERT_WORDS64(*iptr,i0&UINT64_C(0x8000000000000000)); |
| return x; |
| } else { |
| uint64_t i = UINT64_C(0x000fffffffffffff)>>j0; |
| if((i0&i)==0) { /* x is integral */ |
| *iptr = x; |
| /* return +-0 */ |
| INSERT_WORDS64(x,i0&UINT64_C(0x8000000000000000)); |
| return x; |
| } else { |
| INSERT_WORDS64(*iptr,i0&(~i)); |
| return x - *iptr; |
| } |
| } |
| } else { /* no fraction part */ |
| *iptr = x*one; |
| /* We must handle NaNs separately. */ |
| if (j0 == 0x400 && (i0 & UINT64_C(0xfffffffffffff))) |
| return x*one; |
| INSERT_WORDS64(x,i0&UINT64_C(0x8000000000000000)); /* return +-0 */ |
| return x; |
| } |
| } |
| weak_alias (__modf, modf) |
| #ifdef NO_LONG_DOUBLE |
| strong_alias (__modf, __modfl) |
| weak_alias (__modf, modfl) |
| #endif |
