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d967237443
The functions in the nexttoward family are special, in the sense that they always have a long double argument, regardless of their suffix (i.e.: nexttowardf and nexttoward have a long double argument, besides the float and double arguments). On top of that, they are also special because nexttoward functions are not part of the _FloatN API, hence __nexttowardf128 do not exist. This patch adds 4 new function implementations for the new long double format: __nexttoward_to_ieee128 __nexttowardf_to_ieee128 __nexttowardieee128 (as an alias to __nextafterieee128) Likewise, rename "long double" "_Float128" in shared ldbl-128 files to ensure correct type is used irrespective of ABI switches. Thank you to those who helped out with this patch: Co-Authored-By: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
91 lines
2.2 KiB
C
91 lines
2.2 KiB
C
/* s_nexttoward.c
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* Conversion from s_nextafter.c by Ulrich Drepper, Cygnus Support,
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* drepper@cygnus.com and Jakub Jelinek, jj@ultra.linux.cz.
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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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/* IEEE functions
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* nexttoward(x,y)
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* return the next machine floating-point number of x in the
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* direction toward y.
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* Special cases:
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*/
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#include <errno.h>
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#include <math.h>
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#include <math-barriers.h>
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#include <math_private.h>
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#include <float.h>
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double __nexttoward(double x, _Float128 y)
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{
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int32_t hx,ix;
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int64_t hy,iy;
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uint32_t lx;
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uint64_t ly;
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EXTRACT_WORDS(hx,lx,x);
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GET_LDOUBLE_WORDS64(hy,ly,y);
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ix = hx&0x7fffffff; /* |x| */
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iy = hy&0x7fffffffffffffffLL; /* |y| */
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if(((ix>=0x7ff00000)&&((ix-0x7ff00000)|lx)!=0) || /* x is nan */
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((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0))
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/* y is nan */
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return x+y;
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if((_Float128) x==y) return y; /* x=y, return y */
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if((ix|lx)==0) { /* x == 0 */
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double u;
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INSERT_WORDS(x,(uint32_t)((hy>>32)&0x80000000),1);/* return +-minsub */
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u = math_opt_barrier (x);
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u = u * u;
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math_force_eval (u); /* raise underflow flag */
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return x;
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}
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if(hx>=0) { /* x > 0 */
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if (x > y) { /* x -= ulp */
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if(lx==0) hx -= 1;
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lx -= 1;
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} else { /* x < y, x += ulp */
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lx += 1;
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if(lx==0) hx += 1;
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}
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} else { /* x < 0 */
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if (x < y) { /* x -= ulp */
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if(lx==0) hx -= 1;
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lx -= 1;
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} else { /* x > y, x += ulp */
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lx += 1;
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if(lx==0) hx += 1;
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}
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}
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hy = hx&0x7ff00000;
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if(hy>=0x7ff00000) {
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double u = x+x; /* overflow */
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math_force_eval (u);
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__set_errno (ERANGE);
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}
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if(hy<0x00100000) {
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double u = x*x; /* underflow */
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math_force_eval (u); /* raise underflow flag */
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__set_errno (ERANGE);
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}
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INSERT_WORDS(x,hx,lx);
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return x;
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}
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weak_alias (__nexttoward, nexttoward)
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