| /* @(#)s_ceil.c 5.1 93/09/24 */ |
| /* |
| * ==================================================== |
| * 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. |
| * ==================================================== |
| */ |
| |
| /* |
| * ceil(x) |
| * Return x rounded toward -inf to integral value |
| * Method: |
| * Bit twiddling. |
| */ |
| |
| #include <math.h> |
| #include <math_private.h> |
| #include <libm-alias-double.h> |
| |
| double |
| __ceil(double x) |
| { |
| int64_t i0,i; |
| int32_t j0; |
| EXTRACT_WORDS64(i0,x); |
| j0 = ((i0>>52)&0x7ff)-0x3ff; |
| if(j0<=51) { |
| if(j0<0) { |
| /* return 0*sign(x) if |x|<1 */ |
| if(i0<0) {i0=INT64_C(0x8000000000000000);} |
| else if(i0!=0) { i0=INT64_C(0x3ff0000000000000);} |
| } else { |
| i = INT64_C(0x000fffffffffffff)>>j0; |
| if((i0&i)==0) return x; /* x is integral */ |
| if(i0>0) i0 += UINT64_C(0x0010000000000000)>>j0; |
| i0 &= (~i); |
| } |
| } else { |
| if(j0==0x400) return x+x; /* inf or NaN */ |
| else return x; /* x is integral */ |
| } |
| INSERT_WORDS64(x,i0); |
| return x; |
| } |
| #ifndef __ceil |
| libm_alias_double (__ceil, ceil) |
| #endif |
