ubuntu-buildroot/output/build/glibc-2.36-81-g4f4d7a13edfd.../sysdeps/ieee754/flt-32/s_modff.c

55 lines
1.4 KiB
C

/* s_modff.c -- float version of s_modf.c.
*/
/*
* ====================================================
* 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>
#include <libm-alias-float.h>
static const float one = 1.0;
float
__modff(float x, float *iptr)
{
int32_t i0,j0;
uint32_t i;
GET_FLOAT_WORD(i0,x);
j0 = ((i0>>23)&0xff)-0x7f; /* exponent of x */
if(__builtin_expect(j0<23, 1)) { /* integer part in x */
if(j0<0) { /* |x|<1 */
SET_FLOAT_WORD(*iptr,i0&0x80000000); /* *iptr = +-0 */
return x;
} else {
i = (0x007fffff)>>j0;
if((i0&i)==0) { /* x is integral */
uint32_t ix;
*iptr = x;
GET_FLOAT_WORD(ix,x);
SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */
return x;
} else {
SET_FLOAT_WORD(*iptr,i0&(~i));
return x - *iptr;
}
}
} else { /* no fraction part */
*iptr = x*one;
/* We must handle NaNs separately. */
if (j0 == 0x80 && (i0 & 0x7fffff))
return x*one;
SET_FLOAT_WORD(x,i0&0x80000000); /* return +-0 */
return x;
}
}
libm_alias_float (__modf, modf)