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/* origin: FreeBSD /usr/src/lib/msun/src/s_floorf.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.
* ====================================================
*/
/*
* floorf(x)
* Return x rounded toward -inf to integral value
* Method:
* Bit twiddling.
* Exception:
* Inexact flag raised if x not equal to floorf(x).
*/
#include "libm.h"
static const float huge = 1.0e30;
float floorf(float x)
{
int32_t i0,j0;
uint32_t i;
GET_FLOAT_WORD(i0, x);
// FIXME: signed shift
j0 = ((i0>>23)&0xff) - 0x7f;
if (j0 < 23) {
if (j0 < 0) { /* |x| < 1 */
/* raise inexact if x != 0 */
if (huge+x > (float)0.0) {
if (i0 >= 0) /* x >= 0 */
i0 = 0;
else if ((i0&0x7fffffff) != 0)
i0 = 0xbf800000;
}
} else {
i = 0x007fffff>>j0;
if ((i0&i) == 0)
return x; /* x is integral */
/* raise inexact flag */
if (huge+x > (float)0.0) {
if (i0 < 0)
i0 += 0x00800000>>j0;
i0 &= ~i;
}
}
} else {
if (j0 == 0x80) /* inf or NaN */
return x+x;
else
return x; /* x is integral */
}
SET_FLOAT_WORD(x, i0);
return x;
}
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