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diff --git a/src/cmd/8c/div.c b/src/cmd/8c/div.c
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-// Inferno utils/8c/div.c
-// http://code.google.com/p/inferno-os/source/browse/utils/8c/div.c
-//
-// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
-// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-// Portions Copyright © 1997-1999 Vita Nuova Limited
-// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-// Portions Copyright © 2004,2006 Bruce Ellis
-// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-// Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-#include "gc.h"
-
-/*
- * Based on: Granlund, T.; Montgomery, P.L.
- * "Division by Invariant Integers using Multiplication".
- * SIGPLAN Notices, Vol. 29, June 1994, page 61.
- */
-
-#define TN(n) ((uvlong)1 << (n))
-#define T31 TN(31)
-#define T32 TN(32)
-
-int
-multiplier(uint32 d, int p, uvlong *mp)
-{
- int l;
- uvlong mlo, mhi, tlo, thi;
-
- l = topbit(d - 1) + 1;
- mlo = (((TN(l) - d) << 32) / d) + T32;
- if(l + p == 64)
- mhi = (((TN(l) + 1 - d) << 32) / d) + T32;
- else
- mhi = (TN(32 + l) + TN(32 + l - p)) / d;
- /*assert(mlo < mhi);*/
- while(l > 0) {
- tlo = mlo >> 1;
- thi = mhi >> 1;
- if(tlo == thi)
- break;
- mlo = tlo;
- mhi = thi;
- l--;
- }
- *mp = mhi;
- return l;
-}
-
-int
-sdiv(uint32 d, uint32 *mp, int *sp)
-{
- int s;
- uvlong m;
-
- s = multiplier(d, 32 - 1, &m);
- *mp = m;
- *sp = s;
- if(m >= T31)
- return 1;
- else
- return 0;
-}
-
-int
-udiv(uint32 d, uint32 *mp, int *sp, int *pp)
-{
- int p, s;
- uvlong m;
-
- s = multiplier(d, 32, &m);
- p = 0;
- if(m >= T32) {
- while((d & 1) == 0) {
- d >>= 1;
- p++;
- }
- s = multiplier(d, 32 - p, &m);
- }
- *mp = m;
- *pp = p;
- if(m >= T32) {
- /*assert(p == 0);*/
- *sp = s - 1;
- return 1;
- }
- else {
- *sp = s;
- return 0;
- }
-}
-
-void
-sdivgen(Node *l, Node *r, Node *ax, Node *dx)
-{
- int a, s;
- uint32 m;
- vlong c;
-
- c = r->vconst;
- if(c < 0)
- c = -c;
- a = sdiv(c, &m, &s);
-//print("a=%d i=%d s=%d m=%ux\n", a, (int32)r->vconst, s, m);
- gins(AMOVL, nodconst(m), ax);
- gins(AIMULL, l, Z);
- gins(AMOVL, l, ax);
- if(a)
- gins(AADDL, ax, dx);
- gins(ASHRL, nodconst(31), ax);
- gins(ASARL, nodconst(s), dx);
- gins(AADDL, ax, dx);
- if(r->vconst < 0)
- gins(ANEGL, Z, dx);
-}
-
-void
-udivgen(Node *l, Node *r, Node *ax, Node *dx)
-{
- int a, s, t;
- uint32 m;
- Node nod;
-
- a = udiv(r->vconst, &m, &s, &t);
-//print("a=%ud i=%d p=%d s=%d m=%ux\n", a, (int32)r->vconst, t, s, m);
- if(t != 0) {
- gins(AMOVL, l, ax);
- gins(ASHRL, nodconst(t), ax);
- gins(AMOVL, nodconst(m), dx);
- gins(AMULL, dx, Z);
- }
- else if(a) {
- if(l->op != OREGISTER) {
- regalloc(&nod, l, Z);
- gins(AMOVL, l, &nod);
- l = &nod;
- }
- gins(AMOVL, nodconst(m), ax);
- gins(AMULL, l, Z);
- gins(AADDL, l, dx);
- gins(ARCRL, nodconst(1), dx);
- if(l == &nod)
- regfree(l);
- }
- else {
- gins(AMOVL, nodconst(m), ax);
- gins(AMULL, l, Z);
- }
- if(s != 0)
- gins(ASHRL, nodconst(s), dx);
-}
-
-void
-sext(Node *d, Node *s, Node *l)
-{
- if(s->reg == D_AX && !nodreg(d, Z, D_DX)) {
- reg[D_DX]++;
- gins(ACDQ, Z, Z);
- }
- else {
- regalloc(d, l, Z);
- gins(AMOVL, s, d);
- gins(ASARL, nodconst(31), d);
- }
-}
-
-void
-sdiv2(int32 c, int v, Node *l, Node *n)
-{
- Node nod;
-
- if(v > 0) {
- if(v > 1) {
- sext(&nod, n, l);
- gins(AANDL, nodconst((1 << v) - 1), &nod);
- gins(AADDL, &nod, n);
- regfree(&nod);
- }
- else {
- gins(ACMPL, n, nodconst(0x80000000));
- gins(ASBBL, nodconst(-1), n);
- }
- gins(ASARL, nodconst(v), n);
- }
- if(c < 0)
- gins(ANEGL, Z, n);
-}
-
-void
-smod2(int32 c, int v, Node *l, Node *n)
-{
- Node nod;
-
- if(c == 1) {
- zeroregm(n);
- return;
- }
-
- sext(&nod, n, l);
- if(v == 0) {
- zeroregm(n);
- gins(AXORL, &nod, n);
- gins(ASUBL, &nod, n);
- }
- else if(v > 1) {
- gins(AANDL, nodconst((1 << v) - 1), &nod);
- gins(AADDL, &nod, n);
- gins(AANDL, nodconst((1 << v) - 1), n);
- gins(ASUBL, &nod, n);
- }
- else {
- gins(AANDL, nodconst(1), n);
- gins(AXORL, &nod, n);
- gins(ASUBL, &nod, n);
- }
- regfree(&nod);
-}