mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-27 14:50:23 +00:00
81 lines
1.7 KiB
C
81 lines
1.7 KiB
C
/* sf_floor.c -- float version of s_floor.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 "fdlibm.h"
|
|
|
|
#ifdef __STDC__
|
|
static const float huge = 1.0e30;
|
|
#else
|
|
static float huge = 1.0e30;
|
|
#endif
|
|
|
|
#ifdef __STDC__
|
|
float floorf(float x)
|
|
#else
|
|
float floorf(x)
|
|
float x;
|
|
#endif
|
|
{
|
|
__int32_t i0,j0;
|
|
__uint32_t i,ix;
|
|
GET_FLOAT_WORD(i0,x);
|
|
ix = (i0&0x7fffffff);
|
|
j0 = (ix>>23)-0x7f;
|
|
if(j0<23) {
|
|
if(j0<0) { /* raise inexact if x != 0 */
|
|
if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
|
|
if(i0>=0) {i0=0;}
|
|
else if(!FLT_UWORD_IS_ZERO(ix))
|
|
{ i0=0xbf800000;}
|
|
}
|
|
} else {
|
|
i = (0x007fffff)>>j0;
|
|
if((i0&i)==0) return x; /* x is integral */
|
|
if(huge+x>(float)0.0) { /* raise inexact flag */
|
|
if(i0<0) i0 += (0x00800000)>>j0;
|
|
i0 &= (~i);
|
|
}
|
|
}
|
|
} else {
|
|
if(!FLT_UWORD_IS_FINITE(ix)) return x+x; /* inf or NaN */
|
|
else return x; /* x is integral */
|
|
}
|
|
SET_FLOAT_WORD(x,i0);
|
|
return x;
|
|
}
|
|
|
|
#ifdef _DOUBLE_IS_32BITS
|
|
|
|
#ifdef __STDC__
|
|
double floor(double x)
|
|
#else
|
|
double floor(x)
|
|
double x;
|
|
#endif
|
|
{
|
|
return (double) floorf((float) x);
|
|
}
|
|
|
|
#endif /* defined(_DOUBLE_IS_32BITS) */
|