72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
/* s_rintf.c -- float version of s_rint.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 <fenv.h>
|
|
#include <math.h>
|
|
#include <math-barriers.h>
|
|
#include <math_private.h>
|
|
#include <fenv_private.h>
|
|
#include <libm-alias-float.h>
|
|
#include <math-use-builtins.h>
|
|
|
|
float
|
|
__nearbyintf (float x)
|
|
{
|
|
#if USE_NEARBYINTF_BUILTIN
|
|
return __builtin_nearbyintf (x);
|
|
#else
|
|
/* Use generic implementation. */
|
|
static const float
|
|
TWO23[2] = {
|
|
8.3886080000e+06, /* 0x4b000000 */
|
|
-8.3886080000e+06, /* 0xcb000000 */
|
|
};
|
|
fenv_t env;
|
|
int32_t i0, j0, sx;
|
|
float w, t;
|
|
GET_FLOAT_WORD (i0, x);
|
|
sx = (i0 >> 31) & 1;
|
|
j0 = ((i0 >> 23) & 0xff) - 0x7f;
|
|
if (j0 < 23)
|
|
{
|
|
if (j0 < 0)
|
|
{
|
|
libc_feholdexceptf (&env);
|
|
w = TWO23[sx] + math_opt_barrier (x);
|
|
t = w - TWO23[sx];
|
|
math_force_eval (t);
|
|
libc_fesetenvf (&env);
|
|
GET_FLOAT_WORD (i0, t);
|
|
SET_FLOAT_WORD (t, (i0 & 0x7fffffff) | (sx << 31));
|
|
return t;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (__glibc_unlikely (j0 == 0x80))
|
|
return x + x; /* inf or NaN */
|
|
else
|
|
return x; /* x is integral */
|
|
}
|
|
libc_feholdexceptf (&env);
|
|
w = TWO23[sx] + math_opt_barrier (x);
|
|
t = w - TWO23[sx];
|
|
math_force_eval (t);
|
|
libc_fesetenvf (&env);
|
|
return t;
|
|
#endif /* ! USE_NEARBYINT_BUILTIN */
|
|
}
|
|
libm_alias_float (__nearbyint, nearbyint)
|