1 /* s_floorf.c -- float version of s_floor.c. 2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian (at) 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 <sys/cdefs.h> 17 __FBSDID("$FreeBSD$"); 18 19 /* 20 * floorf(x) 21 * Return x rounded toward -inf to integral value 22 * Method: 23 * Bit twiddling. 24 * Exception: 25 * Inexact flag raised if x not equal to floorf(x). 26 */ 27 28 #include "math.h" 29 #include "math_private.h" 30 31 static const float huge = 1.0e30; 32 33 float 34 floorf(float x) 35 { 36 int32_t i0,j0; 37 u_int32_t i; 38 GET_FLOAT_WORD(i0,x); 39 j0 = ((i0>>23)&0xff)-0x7f; 40 if(j0<23) { 41 if(j0<0) { /* raise inexact if x != 0 */ 42 if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */ 43 if(i0>=0) {i0=0;} 44 else if((i0&0x7fffffff)!=0) 45 { i0=0xbf800000;} 46 } 47 } else { 48 i = (0x007fffff)>>j0; 49 if((i0&i)==0) return x; /* x is integral */ 50 if(huge+x>(float)0.0) { /* raise inexact flag */ 51 if(i0<0) i0 += (0x00800000)>>j0; 52 i0 &= (~i); 53 } 54 } 55 } else { 56 if(j0==0x80) return x+x; /* inf or NaN */ 57 else return x; /* x is integral */ 58 } 59 SET_FLOAT_WORD(x,i0); 60 return x; 61 } 62
