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60 lines
1.4 KiB
C
60 lines
1.4 KiB
C
/* s_rintf.c -- float version of s_rint.c.
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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*/
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/* Adapted for use as nearbyint by Ulrich Drepper <drepper@cygnus.com>. */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include <fenv.h>
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#include <math.h>
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#include <math_private.h>
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static const float
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TWO23[2]={
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8.3886080000e+06, /* 0x4b000000 */
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-8.3886080000e+06, /* 0xcb000000 */
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};
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float
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__nearbyintf(float x)
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{
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fenv_t env;
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int32_t i0,j0,sx;
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float w,t;
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GET_FLOAT_WORD(i0,x);
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sx = (i0>>31)&1;
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j0 = ((i0>>23)&0xff)-0x7f;
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if(j0<23) {
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if(j0<0) {
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libc_feholdexceptf (&env);
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w = TWO23[sx]+x;
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t = w-TWO23[sx];
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math_force_eval (t);
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libc_fesetenvf (&env);
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GET_FLOAT_WORD(i0,t);
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SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31));
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return t;
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}
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} else {
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if(__builtin_expect(j0==0x80, 0)) return x+x; /* inf or NaN */
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else return x; /* x is integral */
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}
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libc_feholdexceptf (&env);
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w = TWO23[sx]+x;
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t = w-TWO23[sx];
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math_force_eval (t);
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libc_fesetenvf (&env);
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return t;
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}
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weak_alias (__nearbyintf, nearbyintf)
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