79 lines
1.6 KiB
C
79 lines
1.6 KiB
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 "fdlibm.h"
|
|
|
|
#ifdef __STDC__
|
|
float roundf(float x)
|
|
#else
|
|
float roundf(x)
|
|
float x;
|
|
#endif
|
|
{
|
|
int signbit;
|
|
int w;
|
|
/* Most significant word, least significant word. */
|
|
int exponent_less_127;
|
|
|
|
GET_FLOAT_WORD(w, x);
|
|
|
|
/* Extract sign bit. */
|
|
signbit = w & 0x80000000;
|
|
|
|
/* Extract exponent field. */
|
|
exponent_less_127 = ((w & 0x7f800000) >> 23) - 127;
|
|
|
|
if (exponent_less_127 < 23)
|
|
{
|
|
if (exponent_less_127 < 0)
|
|
{
|
|
w &= 0x80000000;
|
|
if (exponent_less_127 == -1)
|
|
/* Result is +1.0 or -1.0. */
|
|
w |= (127 << 23);
|
|
}
|
|
else
|
|
{
|
|
unsigned int exponent_mask = 0x007fffff >> exponent_less_127;
|
|
if ((w & exponent_mask) == 0)
|
|
/* x has an integral value. */
|
|
return x;
|
|
|
|
w += 0x00400000 >> exponent_less_127;
|
|
w &= ~exponent_mask;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (exponent_less_127 == 128)
|
|
/* x is NaN or infinite. */
|
|
return x + x;
|
|
else
|
|
return x;
|
|
}
|
|
SET_FLOAT_WORD(x, w);
|
|
return x;
|
|
}
|
|
|
|
#ifdef _DOUBLE_IS_32BITS
|
|
|
|
#ifdef __STDC__
|
|
double round(double x)
|
|
#else
|
|
double round(x)
|
|
double x;
|
|
#endif
|
|
{
|
|
return (double) roundf((float) x);
|
|
}
|
|
|
|
#endif /* defined(_DOUBLE_IS_32BITS) */
|