| 1 | /* s_modff.c -- float version of s_modf.c. |
| 2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
| 3 | */ |
| 4 | |
| 5 | /* |
| 6 | * ==================================================== |
| 7 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
| 8 | * |
| 9 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
| 10 | * Permission to use, copy, modify, and distribute this |
| 11 | * software is freely granted, provided that this notice |
| 12 | * is preserved. |
| 13 | * ==================================================== |
| 14 | */ |
| 15 | |
| 16 | #include <math.h> |
| 17 | #include <math_private.h> |
| 18 | #include <libm-alias-float.h> |
| 19 | |
| 20 | static const float one = 1.0; |
| 21 | |
| 22 | float |
| 23 | __modff(float x, float *iptr) |
| 24 | { |
| 25 | int32_t i0,j0; |
| 26 | uint32_t i; |
| 27 | GET_FLOAT_WORD(i0,x); |
| 28 | j0 = ((i0>>23)&0xff)-0x7f; /* exponent of x */ |
| 29 | if(__builtin_expect(j0<23, 1)) { /* integer part in x */ |
| 30 | if(j0<0) { /* |x|<1 */ |
| 31 | SET_FLOAT_WORD(*iptr,i0&0x80000000); /* *iptr = +-0 */ |
| 32 | return x; |
| 33 | } else { |
| 34 | i = (0x007fffff)>>j0; |
| 35 | if((i0&i)==0) { /* x is integral */ |
| 36 | uint32_t ix; |
| 37 | *iptr = x; |
| 38 | GET_FLOAT_WORD(ix,x); |
| 39 | SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */ |
| 40 | return x; |
| 41 | } else { |
| 42 | SET_FLOAT_WORD(*iptr,i0&(~i)); |
| 43 | return x - *iptr; |
| 44 | } |
| 45 | } |
| 46 | } else { /* no fraction part */ |
| 47 | *iptr = x*one; |
| 48 | /* We must handle NaNs separately. */ |
| 49 | if (j0 == 0x80 && (i0 & 0x7fffff)) |
| 50 | return x*one; |
| 51 | SET_FLOAT_WORD(x,i0&0x80000000); /* return +-0 */ |
| 52 | return x; |
| 53 | } |
| 54 | } |
| 55 | libm_alias_float (__modf, modf) |
| 56 | |