mirror of
https://github.com/fluencelabs/musl
synced 2025-07-01 15:42:05 +00:00
53 lines
1.2 KiB
C
53 lines
1.2 KiB
C
|
/* origin: FreeBSD /usr/src/lib/msun/src/s_truncf.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.
|
||
|
|
* ====================================================
|
||
|
|
*/
|
||
|
|
/*
|
||
|
|
* truncf(x)
|
||
|
|
* Return x rounded toward 0 to integral value
|
||
|
|
* Method:
|
||
|
|
* Bit twiddling.
|
||
|
|
* Exception:
|
||
|
|
* Inexact flag raised if x not equal to truncf(x).
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "libm.h"
|
||
|
|
|
||
|
|
static const float huge = 1.0e30F;
|
||
|
|
|
||
|
|
float truncf(float x)
|
||
|
|
{
|
||
|
|
int32_t i0,j0;
|
||
|
|
uint32_t i;
|
||
|
|
|
||
|
|
GET_FLOAT_WORD(i0, x);
|
||
|
|
j0 = ((i0>>23)&0xff) - 0x7f;
|
||
|
|
if (j0 < 23) {
|
||
|
|
if (j0 < 0) { /* |x|<1, return 0*sign(x) */
|
||
|
|
/* raise inexact if x != 0 */
|
||
|
|
if (huge+x > 0.0F)
|
||
|
|
i0 &= 0x80000000;
|
||
|
|
} else {
|
||
|
|
i = 0x007fffff>>j0;
|
||
|
|
if ((i0&i) == 0)
|
||
|
|
return x; /* x is integral */
|
||
|
|
/* raise inexact */
|
||
|
|
if (huge+x > 0.0F)
|
||
|
|
i0 &= ~i;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
if (j0 == 0x80)
|
||
|
|
return x + x; /* inf or NaN */
|
||
|
|
return x; /* x is integral */
|
||
|
|
}
|
||
|
|
SET_FLOAT_WORD(x, i0);
|
||
|
|
return x;
|
||
|
|
}
|