glibc/sysdeps/ieee754/flt-32/s_rintf.c
2012-02-22 13:01:20 +00:00

51 lines
1.1 KiB
C

/* s_rintf.c -- float version of s_rint.c.
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.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.
* ====================================================
*/
#include "math.h"
#include "math_private.h"
static const float
TWO23[2]={
8.3886080000e+06, /* 0x4b000000 */
-8.3886080000e+06, /* 0xcb000000 */
};
float
__rintf(float x)
{
int32_t i0,j0,sx;
float w,t;
GET_FLOAT_WORD(i0,x);
sx = (i0>>31)&1;
j0 = ((i0>>23)&0xff)-0x7f;
if(j0<23) {
if(j0<0) {
w = TWO23[sx]+x;
t = w-TWO23[sx];
GET_FLOAT_WORD(i0,t);
SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31));
return t;
}
} else {
if(j0==0x80) return x+x; /* inf or NaN */
else return x; /* x is integral */
}
w = TWO23[sx]+x;
return w-TWO23[sx];
}
#ifndef __rintf
weak_alias (__rintf, rintf)
#endif