217 lines
4.6 KiB
C
217 lines
4.6 KiB
C
/****************************************************************
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The author of this software is David M. Gay.
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Copyright (C) 1998 by Lucent Technologies
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All Rights Reserved
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Permission to use, copy, modify, and distribute this software and
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its documentation for any purpose and without fee is hereby
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granted, provided that the above copyright notice appear in all
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copies and that both that the copyright notice and this
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permission notice and warranty disclaimer appear in supporting
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documentation, and that the name of Lucent or any of its entities
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not be used in advertising or publicity pertaining to
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distribution of the software without specific, written prior
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permission.
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LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
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INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
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IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
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SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
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IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
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ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
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THIS SOFTWARE.
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****************************************************************/
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/* Please send bug reports to David M. Gay (dmg at acm dot org,
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* with " at " changed at "@" and " dot " changed to "."). */
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#include "gdtoaimp.h"
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#ifndef MULTIPLE_THREADS
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char *dtoa_result;
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#endif
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char *
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#ifdef KR_headers
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rv_alloc(i) int i;
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#else
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rv_alloc(int i)
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#endif
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{
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int j, k, *r;
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j = sizeof(ULong);
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for(k = 0;
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sizeof(Bigint) - sizeof(ULong) - sizeof(int) + j <= i;
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j <<= 1)
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k++;
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r = (int*)Balloc(k);
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*r = k;
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return
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#ifndef MULTIPLE_THREADS
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dtoa_result =
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#endif
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(char *)(r+1);
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}
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char *
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#ifdef KR_headers
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nrv_alloc(s, rve, n) char *s, **rve; int n;
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#else
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nrv_alloc(char *s, char **rve, int n)
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#endif
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{
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char *rv, *t;
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t = rv = rv_alloc(n);
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while((*t = *s++) !=0)
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t++;
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if (rve)
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*rve = t;
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return rv;
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}
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/* freedtoa(s) must be used to free values s returned by dtoa
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* when MULTIPLE_THREADS is #defined. It should be used in all cases,
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* but for consistency with earlier versions of dtoa, it is optional
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* when MULTIPLE_THREADS is not defined.
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*/
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void
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#ifdef KR_headers
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freedtoa(s) char *s;
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#else
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freedtoa(char *s)
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#endif
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{
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Bigint *b = (Bigint *)((int *)s - 1);
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b->maxwds = 1 << (b->k = *(int*)b);
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Bfree(b);
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#ifndef MULTIPLE_THREADS
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if (s == dtoa_result)
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dtoa_result = 0;
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#endif
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}
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int
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quorem
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#ifdef KR_headers
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(b, S) Bigint *b, *S;
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#else
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(Bigint *b, Bigint *S)
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#endif
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{
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int n;
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ULong *bx, *bxe, q, *sx, *sxe;
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#ifdef ULLong
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ULLong borrow, carry, y, ys;
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#else
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ULong borrow, carry, y, ys;
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#ifdef Pack_32
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ULong si, z, zs;
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#endif
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#endif
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n = S->wds;
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#ifdef DEBUG
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/*debug*/ if (b->wds > n)
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/*debug*/ Bug("oversize b in quorem");
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#endif
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if (b->wds < n)
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return 0;
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sx = S->x;
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sxe = sx + --n;
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bx = b->x;
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bxe = bx + n;
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q = *bxe / (*sxe + 1); /* ensure q <= true quotient */
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#ifdef DEBUG
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/*debug*/ if (q > 9)
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/*debug*/ Bug("oversized quotient in quorem");
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#endif
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if (q) {
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borrow = 0;
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carry = 0;
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do {
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#ifdef ULLong
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ys = *sx++ * (ULLong)q + carry;
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carry = ys >> 32;
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y = *bx - (ys & 0xffffffffUL) - borrow;
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borrow = y >> 32 & 1UL;
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*bx++ = y & 0xffffffffUL;
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#else
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#ifdef Pack_32
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si = *sx++;
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ys = (si & 0xffff) * q + carry;
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zs = (si >> 16) * q + (ys >> 16);
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carry = zs >> 16;
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y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
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borrow = (y & 0x10000) >> 16;
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z = (*bx >> 16) - (zs & 0xffff) - borrow;
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borrow = (z & 0x10000) >> 16;
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Storeinc(bx, z, y);
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#else
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ys = *sx++ * q + carry;
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carry = ys >> 16;
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y = *bx - (ys & 0xffff) - borrow;
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borrow = (y & 0x10000) >> 16;
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*bx++ = y & 0xffff;
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#endif
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#endif
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}
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while(sx <= sxe);
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if (!*bxe) {
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bx = b->x;
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while(--bxe > bx && !*bxe)
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--n;
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b->wds = n;
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}
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}
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if (cmp(b, S) >= 0) {
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q++;
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borrow = 0;
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carry = 0;
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bx = b->x;
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sx = S->x;
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do {
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#ifdef ULLong
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ys = *sx++ + carry;
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carry = ys >> 32;
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y = *bx - (ys & 0xffffffffUL) - borrow;
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borrow = y >> 32 & 1UL;
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*bx++ = y & 0xffffffffUL;
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#else
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#ifdef Pack_32
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si = *sx++;
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ys = (si & 0xffff) + carry;
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zs = (si >> 16) + (ys >> 16);
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carry = zs >> 16;
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y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
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borrow = (y & 0x10000) >> 16;
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z = (*bx >> 16) - (zs & 0xffff) - borrow;
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borrow = (z & 0x10000) >> 16;
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Storeinc(bx, z, y);
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#else
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ys = *sx++ + carry;
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carry = ys >> 16;
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y = *bx - (ys & 0xffff) - borrow;
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borrow = (y & 0x10000) >> 16;
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*bx++ = y & 0xffff;
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#endif
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#endif
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}
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while(sx <= sxe);
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bx = b->x;
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bxe = bx + n;
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if (!*bxe) {
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while(--bxe > bx && !*bxe)
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--n;
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b->wds = n;
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}
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}
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return q;
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}
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