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86 lines
2.0 KiB
C
86 lines
2.0 KiB
C
/* s_ceill.c -- long double version of s_ceil.c.
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* Conversion to long double by Ulrich Drepper,
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* Cygnus Support, drepper@cygnus.com.
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*/
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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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#if defined(LIBM_SCCS) && !defined(lint)
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static char rcsid[] = "$NetBSD: $";
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#endif
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/*
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* ceill(x)
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* Return x rounded toward -inf to integral value
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* Method:
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* Bit twiddling.
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* Exception:
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* Inexact flag raised if x not equal to ceil(x).
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*/
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#include <math.h>
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#include <math_private.h>
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static const long double huge = 1.0e4930;
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long double __ceill(long double x)
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{
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int32_t i1,j0;
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u_int32_t i,j,se,i0,sx;
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GET_LDOUBLE_WORDS(se,i0,i1,x);
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sx = (se>>15)&1;
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j0 = (se&0x7fff)-0x3fff;
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if(j0<31) {
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if(j0<0) { /* raise inexact if x != 0 */
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if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */
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if(sx) {se=0x8000;i0=0;i1=0;}
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else if((i0|i1)!=0) { se=0x3fff;i0=0;i1=0;}
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}
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} else {
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i = (0x7fffffff)>>j0;
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if(((i0&i)|i1)==0) return x; /* x is integral */
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if(huge+x>0.0) { /* raise inexact flag */
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if(sx==0) {
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if (j0>0 && (i0+(0x80000000>>j0))>i0)
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i0+=0x80000000>>j0;
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else
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{
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i = 0x7fffffff;
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++se;
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}
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}
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i0 &= (~i); i1=0;
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}
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}
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} else if (j0>62) {
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if(j0==0x4000) return x+x; /* inf or NaN */
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else return x; /* x is integral */
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} else {
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i = ((u_int32_t)(0xffffffff))>>(j0-31);
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if((i1&i)==0) return x; /* x is integral */
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if(huge+x>0.0) { /* raise inexact flag */
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if(sx==0) {
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if(j0==31) i0+=1;
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else {
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j = i1 + (1<<(63-j0));
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if(j<i1) i0+=1; /* got a carry */
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i1 = j;
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}
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}
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i1 &= (~i);
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}
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}
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SET_LDOUBLE_WORDS(x,se,i0,i1);
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return x;
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}
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weak_alias (__ceill, ceill)
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