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Diffstat (limited to 'src/cmd/8c/div.c')
| -rw-r--r-- | src/cmd/8c/div.c | 236 |
1 files changed, 0 insertions, 236 deletions
diff --git a/src/cmd/8c/div.c b/src/cmd/8c/div.c deleted file mode 100644 index 14945052e..000000000 --- a/src/cmd/8c/div.c +++ /dev/null @@ -1,236 +0,0 @@ -// 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); -} |