84d9c625bf
- Fix for possible unset uid/gid in toproto - Fix for default mtree style - Update libelf - Importing libexecinfo - Resynchronize GCC, mpc, gmp, mpfr - build.sh: Replace params with show-params. This has been done as the make target has been renamed in the same way, while a new target named params has been added. This new target generates a file containing all the parameters, instead of printing it on the console. - Update test48 with new etc/services (Fix by Ben Gras <ben@minix3.org) get getservbyport() out of the inner loop Change-Id: Ie6ad5226fa2621ff9f0dee8782ea48f9443d2091
158 lines
4.1 KiB
C
158 lines
4.1 KiB
C
/* @(#)e_fmod.c 1.3 95/01/18 */
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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 SunSoft, 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 <sys/cdefs.h>
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__RCSID("$NetBSD: e_fmodl.c,v 1.2 2013/11/14 15:25:22 martin Exp $");
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#if 0
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__FBSDID("$FreeBSD: head/lib/msun/src/e_fmodl.c 181063 2008-07-31 20:09:47Z das $");
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#endif
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#include "namespace.h"
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#include <float.h>
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#include <stdint.h>
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#include "math.h"
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#include "math_private.h"
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#include <machine/ieee.h>
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#ifdef __HAVE_LONG_DOUBLE
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#define BIAS (LDBL_MAX_EXP - 1)
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#if EXT_FRACLBITS > 32
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typedef uint64_t manl_t;
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#else
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typedef uint32_t manl_t;
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#endif
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#if EXT_FRACHBITS > 32
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typedef uint64_t manh_t;
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#else
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typedef uint32_t manh_t;
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#endif
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/*
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* These macros add and remove an explicit integer bit in front of the
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* fractional mantissa, if the architecture doesn't have such a bit by
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* default already.
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*/
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#ifdef LDBL_IMPLICIT_NBIT
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#define SET_NBIT(hx) ((hx) | (1ULL << EXT_FRACHBITS))
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#define HFRAC_BITS EXT_FRACHBITS
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#define LDBL_NBIT 0
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#else
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#define SET_NBIT(hx) (hx)
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#define HFRAC_BITS (EXT_FRACHBITS - 1)
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#endif
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#define MANL_SHIFT (EXT_FRACLBITS - 1)
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static const long double one = 1.0, Zero[] = {0.0, -0.0,};
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/*
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* fmodl(x,y)
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* Return x mod y in exact arithmetic
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* Method: shift and subtract
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*
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* Assumptions:
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* - The low part of the mantissa fits in a manl_t exactly.
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* - The high part of the mantissa fits in an int64_t with enough room
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* for an explicit integer bit in front of the fractional bits.
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*/
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long double
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__ieee754_fmodl(long double x, long double y)
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{
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union ieee_ext_u ux = { .extu_ld = x, };
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union ieee_ext_u uy = { .extu_ld = y, };
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int64_t hx,hz; /* We need a carry bit even if EXT_FRACHBITS is 32. */
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manh_t hy;
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manl_t lx,ly,lz;
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int ix,iy,n,sx;
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sx = ux.extu_sign;
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/* purge off exception values */
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if((uy.extu_exp|uy.extu_frach|uy.extu_fracl)==0 || /* y=0 */
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(ux.extu_exp == BIAS + LDBL_MAX_EXP) || /* or x not finite */
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(uy.extu_exp == BIAS + LDBL_MAX_EXP &&
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((uy.extu_frach&~LDBL_NBIT)|uy.extu_fracl)!=0)) /* or y is NaN */
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return (x*y)/(x*y);
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if(ux.extu_exp<=uy.extu_exp) {
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if((ux.extu_exp<uy.extu_exp) ||
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(ux.extu_frach<=uy.extu_frach &&
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(ux.extu_frach<uy.extu_frach ||
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ux.extu_fracl<uy.extu_fracl))) {
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return x; /* |x|<|y| return x or x-y */
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}
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if(ux.extu_frach==uy.extu_frach && ux.extu_fracl==uy.extu_fracl) {
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return Zero[sx]; /* |x|=|y| return x*0*/
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}
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}
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/* determine ix = ilogb(x) */
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if(ux.extu_exp == 0) { /* subnormal x */
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ux.extu_ld *= 0x1.0p512;
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ix = ux.extu_exp - (BIAS + 512);
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} else {
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ix = ux.extu_exp - BIAS;
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}
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/* determine iy = ilogb(y) */
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if(uy.extu_exp == 0) { /* subnormal y */
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uy.extu_ld *= 0x1.0p512;
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iy = uy.extu_exp - (BIAS + 512);
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} else {
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iy = uy.extu_exp - BIAS;
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}
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/* set up {hx,lx}, {hy,ly} and align y to x */
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hx = SET_NBIT(ux.extu_frach);
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hy = SET_NBIT(uy.extu_frach);
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lx = ux.extu_fracl;
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ly = uy.extu_fracl;
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/* fix point fmod */
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n = ix - iy;
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while(n--) {
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hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;
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if(hz<0){hx = hx+hx+(lx>>MANL_SHIFT); lx = lx+lx;}
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else {
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if ((hz|lz)==0) /* return sign(x)*0 */
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return Zero[sx];
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hx = hz+hz+(lz>>MANL_SHIFT); lx = lz+lz;
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}
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}
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hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;
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if(hz>=0) {hx=hz;lx=lz;}
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/* convert back to floating value and restore the sign */
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if((hx|lx)==0) /* return sign(x)*0 */
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return Zero[sx];
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while(hx<(1LL<<HFRAC_BITS)) { /* normalize x */
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hx = hx+hx+(lx>>MANL_SHIFT); lx = lx+lx;
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iy -= 1;
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}
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ux.extu_frach = hx; /* The mantissa is truncated here if needed. */
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ux.extu_fracl = lx;
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if (iy < LDBL_MIN_EXP) {
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ux.extu_exp = iy + (BIAS + 512);
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ux.extu_ld *= 0x1p-512;
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} else {
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ux.extu_exp = iy + BIAS;
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}
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x = ux.extu_ld * one; /* create necessary signal */
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return x; /* exact output */
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}
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#endif /* __HAVE_LONG_DOUBLE */
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