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-rw-r--r--src/cmd/8c/reg.c1438
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diff --git a/src/cmd/8c/reg.c b/src/cmd/8c/reg.c
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--- a/src/cmd/8c/reg.c
+++ /dev/null
@@ -1,1438 +0,0 @@
-// Inferno utils/8c/reg.c
-// http://code.google.com/p/inferno-os/source/browse/utils/8c/reg.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"
-
-static void fixjmp(Reg*);
-
-Reg*
-rega(void)
-{
- Reg *r;
-
- r = freer;
- if(r == R) {
- r = alloc(sizeof(*r));
- } else
- freer = r->link;
-
- *r = zreg;
- return r;
-}
-
-int
-rcmp(const void *a1, const void *a2)
-{
- Rgn *p1, *p2;
- int c1, c2;
-
- p1 = (Rgn*)a1;
- p2 = (Rgn*)a2;
- c1 = p2->cost;
- c2 = p1->cost;
- if(c1 -= c2)
- return c1;
- return p2->varno - p1->varno;
-}
-
-void
-regopt(Prog *p)
-{
- Reg *r, *r1, *r2;
- Prog *p1;
- int i, z;
- int32 initpc, val, npc;
- uint32 vreg;
- Bits bit;
- struct
- {
- int32 m;
- int32 c;
- Reg* p;
- } log5[6], *lp;
-
- firstr = R;
- lastr = R;
- nvar = 0;
- regbits = RtoB(D_SP) | RtoB(D_AX);
- for(z=0; z<BITS; z++) {
- externs.b[z] = 0;
- params.b[z] = 0;
- consts.b[z] = 0;
- addrs.b[z] = 0;
- }
-
- /*
- * pass 1
- * build aux data structure
- * allocate pcs
- * find use and set of variables
- */
- val = 5L * 5L * 5L * 5L * 5L;
- lp = log5;
- for(i=0; i<5; i++) {
- lp->m = val;
- lp->c = 0;
- lp->p = R;
- val /= 5L;
- lp++;
- }
- val = 0;
- for(; p != P; p = p->link) {
- switch(p->as) {
- case ADATA:
- case AGLOBL:
- case ANAME:
- case ASIGNAME:
- case AFUNCDATA:
- continue;
- }
- r = rega();
- if(firstr == R) {
- firstr = r;
- lastr = r;
- } else {
- lastr->link = r;
- r->p1 = lastr;
- lastr->s1 = r;
- lastr = r;
- }
- r->prog = p;
- r->pc = val;
- val++;
-
- lp = log5;
- for(i=0; i<5; i++) {
- lp->c--;
- if(lp->c <= 0) {
- lp->c = lp->m;
- if(lp->p != R)
- lp->p->log5 = r;
- lp->p = r;
- (lp+1)->c = 0;
- break;
- }
- lp++;
- }
-
- r1 = r->p1;
- if(r1 != R)
- switch(r1->prog->as) {
- case ARET:
- case AJMP:
- case AIRETL:
- r->p1 = R;
- r1->s1 = R;
- }
- bit = mkvar(r, &p->from);
- if(bany(&bit))
- switch(p->as) {
- /*
- * funny
- */
- case ALEAL:
- for(z=0; z<BITS; z++)
- addrs.b[z] |= bit.b[z];
- break;
-
- /*
- * left side read
- */
- default:
- for(z=0; z<BITS; z++)
- r->use1.b[z] |= bit.b[z];
- break;
- }
-
- bit = mkvar(r, &p->to);
- if(bany(&bit))
- switch(p->as) {
- default:
- diag(Z, "reg: unknown op: %A", p->as);
- break;
-
- /*
- * right side read
- */
- case ACMPB:
- case ACMPL:
- case ACMPW:
- case APREFETCHT0:
- case APREFETCHT1:
- case APREFETCHT2:
- case APREFETCHNTA:
- for(z=0; z<BITS; z++)
- r->use2.b[z] |= bit.b[z];
- break;
-
- /*
- * right side write
- */
- case ANOP:
- case AMOVL:
- case AMOVB:
- case AMOVW:
- case AMOVBLSX:
- case AMOVBLZX:
- case AMOVWLSX:
- case AMOVWLZX:
- for(z=0; z<BITS; z++)
- r->set.b[z] |= bit.b[z];
- break;
-
- /*
- * right side read+write
- */
- case AADDB:
- case AADDL:
- case AADDW:
- case AANDB:
- case AANDL:
- case AANDW:
- case ASUBB:
- case ASUBL:
- case ASUBW:
- case AORB:
- case AORL:
- case AORW:
- case AXORB:
- case AXORL:
- case AXORW:
- case ASALB:
- case ASALL:
- case ASALW:
- case ASARB:
- case ASARL:
- case ASARW:
- case AROLB:
- case AROLL:
- case AROLW:
- case ARORB:
- case ARORL:
- case ARORW:
- case ASHLB:
- case ASHLL:
- case ASHLW:
- case ASHRB:
- case ASHRL:
- case ASHRW:
- case AIMULL:
- case AIMULW:
- case ANEGL:
- case ANOTL:
- case AADCL:
- case ASBBL:
- for(z=0; z<BITS; z++) {
- r->set.b[z] |= bit.b[z];
- r->use2.b[z] |= bit.b[z];
- }
- break;
-
- /*
- * funny
- */
- case AFMOVDP:
- case AFMOVFP:
- case AFMOVLP:
- case AFMOVVP:
- case AFMOVWP:
- case ACALL:
- for(z=0; z<BITS; z++)
- addrs.b[z] |= bit.b[z];
- break;
- }
-
- switch(p->as) {
- case AIMULL:
- case AIMULW:
- if(p->to.type != D_NONE)
- break;
-
- case AIDIVB:
- case AIDIVL:
- case AIDIVW:
- case AIMULB:
- case ADIVB:
- case ADIVL:
- case ADIVW:
- case AMULB:
- case AMULL:
- case AMULW:
-
- case ACWD:
- case ACDQ:
- r->regu |= RtoB(D_AX) | RtoB(D_DX);
- break;
-
- case AREP:
- case AREPN:
- case ALOOP:
- case ALOOPEQ:
- case ALOOPNE:
- r->regu |= RtoB(D_CX);
- break;
-
- case AMOVSB:
- case AMOVSL:
- case AMOVSW:
- case ACMPSB:
- case ACMPSL:
- case ACMPSW:
- r->regu |= RtoB(D_SI) | RtoB(D_DI);
- break;
-
- case ASTOSB:
- case ASTOSL:
- case ASTOSW:
- case ASCASB:
- case ASCASL:
- case ASCASW:
- r->regu |= RtoB(D_AX) | RtoB(D_DI);
- break;
-
- case AINSB:
- case AINSL:
- case AINSW:
- case AOUTSB:
- case AOUTSL:
- case AOUTSW:
- r->regu |= RtoB(D_DI) | RtoB(D_DX);
- break;
-
- case AFSTSW:
- case ASAHF:
- r->regu |= RtoB(D_AX);
- break;
- }
- }
- if(firstr == R)
- return;
- initpc = pc - val;
- npc = val;
-
- /*
- * pass 2
- * turn branch references to pointers
- * build back pointers
- */
- for(r = firstr; r != R; r = r->link) {
- p = r->prog;
- if(p->to.type == D_BRANCH) {
- val = p->to.offset - initpc;
- r1 = firstr;
- while(r1 != R) {
- r2 = r1->log5;
- if(r2 != R && val >= r2->pc) {
- r1 = r2;
- continue;
- }
- if(r1->pc == val)
- break;
- r1 = r1->link;
- }
- if(r1 == R) {
- nearln = p->lineno;
- diag(Z, "ref not found\n%P", p);
- continue;
- }
- if(r1 == r) {
- nearln = p->lineno;
- diag(Z, "ref to self\n%P", p);
- continue;
- }
- r->s2 = r1;
- r->p2link = r1->p2;
- r1->p2 = r;
- }
- }
- if(debug['R']) {
- p = firstr->prog;
- print("\n%L %D\n", p->lineno, &p->from);
- }
-
- /*
- * pass 2.1
- * fix jumps
- */
- fixjmp(firstr);
-
- /*
- * pass 2.5
- * find looping structure
- */
- for(r = firstr; r != R; r = r->link)
- r->active = 0;
- change = 0;
- loopit(firstr, npc);
- if(debug['R'] && debug['v']) {
- print("\nlooping structure:\n");
- for(r = firstr; r != R; r = r->link) {
- print("%d:%P", r->loop, r->prog);
- for(z=0; z<BITS; z++)
- bit.b[z] = r->use1.b[z] |
- r->use2.b[z] |
- r->set.b[z];
- if(bany(&bit)) {
- print("\t");
- if(bany(&r->use1))
- print(" u1=%B", r->use1);
- if(bany(&r->use2))
- print(" u2=%B", r->use2);
- if(bany(&r->set))
- print(" st=%B", r->set);
- }
- print("\n");
- }
- }
-
- /*
- * pass 3
- * iterate propagating usage
- * back until flow graph is complete
- */
-loop1:
- change = 0;
- for(r = firstr; r != R; r = r->link)
- r->active = 0;
- for(r = firstr; r != R; r = r->link)
- if(r->prog->as == ARET)
- prop(r, zbits, zbits);
-loop11:
- /* pick up unreachable code */
- i = 0;
- for(r = firstr; r != R; r = r1) {
- r1 = r->link;
- if(r1 && r1->active && !r->active) {
- prop(r, zbits, zbits);
- i = 1;
- }
- }
- if(i)
- goto loop11;
- if(change)
- goto loop1;
-
-
- /*
- * pass 4
- * iterate propagating register/variable synchrony
- * forward until graph is complete
- */
-loop2:
- change = 0;
- for(r = firstr; r != R; r = r->link)
- r->active = 0;
- synch(firstr, zbits);
- if(change)
- goto loop2;
-
-
- /*
- * pass 5
- * isolate regions
- * calculate costs (paint1)
- */
- r = firstr;
- if(r) {
- for(z=0; z<BITS; z++)
- bit.b[z] = (r->refahead.b[z] | r->calahead.b[z]) &
- ~(externs.b[z] | params.b[z] | addrs.b[z] | consts.b[z]);
- if(bany(&bit)) {
- nearln = r->prog->lineno;
- warn(Z, "used and not set: %B", bit);
- if(debug['R'] && !debug['w'])
- print("used and not set: %B\n", bit);
- }
- }
- if(debug['R'] && debug['v'])
- print("\nprop structure:\n");
- for(r = firstr; r != R; r = r->link)
- r->act = zbits;
- rgp = region;
- nregion = 0;
- for(r = firstr; r != R; r = r->link) {
- if(debug['R'] && debug['v']) {
- print("%P\t", r->prog);
- if(bany(&r->set))
- print("s:%B ", r->set);
- if(bany(&r->refahead))
- print("ra:%B ", r->refahead);
- if(bany(&r->calahead))
- print("ca:%B ", r->calahead);
- print("\n");
- }
- for(z=0; z<BITS; z++)
- bit.b[z] = r->set.b[z] &
- ~(r->refahead.b[z] | r->calahead.b[z] | addrs.b[z]);
- if(bany(&bit)) {
- nearln = r->prog->lineno;
- warn(Z, "set and not used: %B", bit);
- if(debug['R'])
- print("set and not used: %B\n", bit);
- excise(r);
- }
- for(z=0; z<BITS; z++)
- bit.b[z] = LOAD(r) & ~(r->act.b[z] | addrs.b[z]);
- while(bany(&bit)) {
- i = bnum(bit);
- rgp->enter = r;
- rgp->varno = i;
- change = 0;
- if(debug['R'] && debug['v'])
- print("\n");
- paint1(r, i);
- bit.b[i/32] &= ~(1L<<(i%32));
- if(change <= 0) {
- if(debug['R'])
- print("%L$%d: %B\n",
- r->prog->lineno, change, blsh(i));
- continue;
- }
- rgp->cost = change;
- nregion++;
- if(nregion >= NRGN) {
- fatal(Z, "too many regions");
- goto brk;
- }
- rgp++;
- }
- }
-brk:
- qsort(region, nregion, sizeof(region[0]), rcmp);
-
- /*
- * pass 6
- * determine used registers (paint2)
- * replace code (paint3)
- */
- rgp = region;
- for(i=0; i<nregion; i++) {
- bit = blsh(rgp->varno);
- vreg = paint2(rgp->enter, rgp->varno);
- vreg = allreg(vreg, rgp);
- if(debug['R']) {
- print("%L$%d %R: %B\n",
- rgp->enter->prog->lineno,
- rgp->cost,
- rgp->regno,
- bit);
- }
- if(rgp->regno != 0)
- paint3(rgp->enter, rgp->varno, vreg, rgp->regno);
- rgp++;
- }
- /*
- * pass 7
- * peep-hole on basic block
- */
- if(!debug['R'] || debug['P'])
- peep();
-
- if(debug['R'] && debug['v']) {
- print("after pass 7 (peep)\n");
- for(r=firstr; r; r=r->link)
- print("%04d %P\n", (int)r->pc, r->prog);
- print("\n");
- }
-
- /*
- * pass 8
- * recalculate pc
- */
- val = initpc;
- for(r = firstr; r != R; r = r1) {
- r->pc = val;
- p = r->prog;
- p1 = P;
- r1 = r->link;
- if(r1 != R)
- p1 = r1->prog;
- for(; p != p1; p = p->link) {
- switch(p->as) {
- default:
- val++;
- break;
-
- case ANOP:
- case ADATA:
- case AGLOBL:
- case ANAME:
- case ASIGNAME:
- case AFUNCDATA:
- break;
- }
- }
- }
- pc = val;
-
- /*
- * fix up branches
- */
- if(debug['R'])
- if(bany(&addrs))
- print("addrs: %B\n", addrs);
-
- r1 = 0; /* set */
- for(r = firstr; r != R; r = r->link) {
- p = r->prog;
- if(p->to.type == D_BRANCH) {
- p->to.offset = r->s2->pc;
- p->to.u.branch = r->s2->prog;
- }
- r1 = r;
- }
-
- /*
- * last pass
- * eliminate nops
- * free aux structures
- */
- for(p = firstr->prog; p != P; p = p->link){
- while(p->link && p->link->as == ANOP)
- p->link = p->link->link;
- }
-
- if(debug['R'] && debug['v']) {
- print("after pass 8 (fixup pc)\n");
- for(p1=firstr->prog; p1!=P; p1=p1->link)
- print("%P\n", p1);
- print("\n");
- }
-
- if(r1 != R) {
- r1->link = freer;
- freer = firstr;
- }
-}
-
-/*
- * add mov b,rn
- * just after r
- */
-void
-addmove(Reg *r, int bn, int rn, int f)
-{
- Prog *p, *p1;
- Addr *a;
- Var *v;
-
- p1 = alloc(sizeof(*p1));
- *p1 = zprog;
- p = r->prog;
-
- p1->link = p->link;
- p->link = p1;
- p1->lineno = p->lineno;
-
- v = var + bn;
-
- a = &p1->to;
- a->sym = v->sym;
- a->offset = v->offset;
- a->etype = v->etype;
- a->type = v->name;
-
- p1->as = AMOVL;
- if(v->etype == TCHAR || v->etype == TUCHAR)
- p1->as = AMOVB;
- if(v->etype == TSHORT || v->etype == TUSHORT)
- p1->as = AMOVW;
-
- p1->from.type = rn;
- if(!f) {
- p1->from = *a;
- *a = zprog.from;
- a->type = rn;
- if(v->etype == TUCHAR)
- p1->as = AMOVB;
- if(v->etype == TUSHORT)
- p1->as = AMOVW;
- }
- if(debug['R'])
- print("%P\t.a%P\n", p, p1);
-}
-
-uint32
-doregbits(int r)
-{
- uint32 b;
-
- b = 0;
- if(r >= D_INDIR)
- r -= D_INDIR;
- if(r >= D_AX && r <= D_DI)
- b |= RtoB(r);
- else
- if(r >= D_AL && r <= D_BL)
- b |= RtoB(r-D_AL+D_AX);
- else
- if(r >= D_AH && r <= D_BH)
- b |= RtoB(r-D_AH+D_AX);
- return b;
-}
-
-Bits
-mkvar(Reg *r, Addr *a)
-{
- Var *v;
- int i, t, n, et, z;
- int32 o;
- Bits bit;
- LSym *s;
-
- /*
- * mark registers used
- */
- t = a->type;
- r->regu |= doregbits(t);
- r->regu |= doregbits(a->index);
-
- switch(t) {
- default:
- goto none;
- case D_ADDR:
- a->type = a->index;
- bit = mkvar(r, a);
- for(z=0; z<BITS; z++)
- addrs.b[z] |= bit.b[z];
- a->type = t;
- goto none;
- case D_EXTERN:
- case D_STATIC:
- case D_PARAM:
- case D_AUTO:
- n = t;
- break;
- }
- s = a->sym;
- if(s == nil)
- goto none;
- if(s->name[0] == '.')
- goto none;
- et = a->etype;
- o = a->offset;
- v = var;
- for(i=0; i<nvar; i++) {
- if(s == v->sym)
- if(n == v->name)
- if(o == v->offset)
- goto out;
- v++;
- }
- if(nvar >= NVAR)
- fatal(Z, "variable not optimized: %s", s->name);
- i = nvar;
- nvar++;
- v = &var[i];
- v->sym = s;
- v->offset = o;
- v->name = n;
- v->etype = et;
- if(debug['R'])
- print("bit=%2d et=%2d %D\n", i, et, a);
-
-out:
- bit = blsh(i);
- if(n == D_EXTERN || n == D_STATIC)
- for(z=0; z<BITS; z++)
- externs.b[z] |= bit.b[z];
- if(n == D_PARAM)
- for(z=0; z<BITS; z++)
- params.b[z] |= bit.b[z];
- if(v->etype != et || !typechlpfd[et]) /* funny punning */
- for(z=0; z<BITS; z++)
- addrs.b[z] |= bit.b[z];
- return bit;
-
-none:
- return zbits;
-}
-
-void
-prop(Reg *r, Bits ref, Bits cal)
-{
- Reg *r1, *r2;
- int z;
-
- for(r1 = r; r1 != R; r1 = r1->p1) {
- for(z=0; z<BITS; z++) {
- ref.b[z] |= r1->refahead.b[z];
- if(ref.b[z] != r1->refahead.b[z]) {
- r1->refahead.b[z] = ref.b[z];
- change++;
- }
- cal.b[z] |= r1->calahead.b[z];
- if(cal.b[z] != r1->calahead.b[z]) {
- r1->calahead.b[z] = cal.b[z];
- change++;
- }
- }
- switch(r1->prog->as) {
- case ACALL:
- for(z=0; z<BITS; z++) {
- cal.b[z] |= ref.b[z] | externs.b[z];
- ref.b[z] = 0;
- }
- break;
-
- case ATEXT:
- for(z=0; z<BITS; z++) {
- cal.b[z] = 0;
- ref.b[z] = 0;
- }
- break;
-
- case ARET:
- for(z=0; z<BITS; z++) {
- cal.b[z] = externs.b[z];
- ref.b[z] = 0;
- }
- }
- for(z=0; z<BITS; z++) {
- ref.b[z] = (ref.b[z] & ~r1->set.b[z]) |
- r1->use1.b[z] | r1->use2.b[z];
- cal.b[z] &= ~(r1->set.b[z] | r1->use1.b[z] | r1->use2.b[z]);
- r1->refbehind.b[z] = ref.b[z];
- r1->calbehind.b[z] = cal.b[z];
- }
- if(r1->active)
- break;
- r1->active = 1;
- }
- for(; r != r1; r = r->p1)
- for(r2 = r->p2; r2 != R; r2 = r2->p2link)
- prop(r2, r->refbehind, r->calbehind);
-}
-
-/*
- * find looping structure
- *
- * 1) find reverse postordering
- * 2) find approximate dominators,
- * the actual dominators if the flow graph is reducible
- * otherwise, dominators plus some other non-dominators.
- * See Matthew S. Hecht and Jeffrey D. Ullman,
- * "Analysis of a Simple Algorithm for Global Data Flow Problems",
- * Conf. Record of ACM Symp. on Principles of Prog. Langs, Boston, Massachusetts,
- * Oct. 1-3, 1973, pp. 207-217.
- * 3) find all nodes with a predecessor dominated by the current node.
- * such a node is a loop head.
- * recursively, all preds with a greater rpo number are in the loop
- */
-int32
-postorder(Reg *r, Reg **rpo2r, int32 n)
-{
- Reg *r1;
-
- r->rpo = 1;
- r1 = r->s1;
- if(r1 && !r1->rpo)
- n = postorder(r1, rpo2r, n);
- r1 = r->s2;
- if(r1 && !r1->rpo)
- n = postorder(r1, rpo2r, n);
- rpo2r[n] = r;
- n++;
- return n;
-}
-
-int32
-rpolca(int32 *idom, int32 rpo1, int32 rpo2)
-{
- int32 t;
-
- if(rpo1 == -1)
- return rpo2;
- while(rpo1 != rpo2){
- if(rpo1 > rpo2){
- t = rpo2;
- rpo2 = rpo1;
- rpo1 = t;
- }
- while(rpo1 < rpo2){
- t = idom[rpo2];
- if(t >= rpo2)
- fatal(Z, "bad idom");
- rpo2 = t;
- }
- }
- return rpo1;
-}
-
-int
-doms(int32 *idom, int32 r, int32 s)
-{
- while(s > r)
- s = idom[s];
- return s == r;
-}
-
-int
-loophead(int32 *idom, Reg *r)
-{
- int32 src;
-
- src = r->rpo;
- if(r->p1 != R && doms(idom, src, r->p1->rpo))
- return 1;
- for(r = r->p2; r != R; r = r->p2link)
- if(doms(idom, src, r->rpo))
- return 1;
- return 0;
-}
-
-void
-loopmark(Reg **rpo2r, int32 head, Reg *r)
-{
- if(r->rpo < head || r->active == head)
- return;
- r->active = head;
- r->loop += LOOP;
- if(r->p1 != R)
- loopmark(rpo2r, head, r->p1);
- for(r = r->p2; r != R; r = r->p2link)
- loopmark(rpo2r, head, r);
-}
-
-void
-loopit(Reg *r, int32 nr)
-{
- Reg *r1;
- int32 i, d, me;
-
- if(nr > maxnr) {
- rpo2r = alloc(nr * sizeof(Reg*));
- idom = alloc(nr * sizeof(int32));
- maxnr = nr;
- }
-
- d = postorder(r, rpo2r, 0);
- if(d > nr)
- fatal(Z, "too many reg nodes");
- nr = d;
- for(i = 0; i < nr / 2; i++){
- r1 = rpo2r[i];
- rpo2r[i] = rpo2r[nr - 1 - i];
- rpo2r[nr - 1 - i] = r1;
- }
- for(i = 0; i < nr; i++)
- rpo2r[i]->rpo = i;
-
- idom[0] = 0;
- for(i = 0; i < nr; i++){
- r1 = rpo2r[i];
- me = r1->rpo;
- d = -1;
- if(r1->p1 != R && r1->p1->rpo < me)
- d = r1->p1->rpo;
- for(r1 = r1->p2; r1 != nil; r1 = r1->p2link)
- if(r1->rpo < me)
- d = rpolca(idom, d, r1->rpo);
- idom[i] = d;
- }
-
- for(i = 0; i < nr; i++){
- r1 = rpo2r[i];
- r1->loop++;
- if(r1->p2 != R && loophead(idom, r1))
- loopmark(rpo2r, i, r1);
- }
-}
-
-void
-synch(Reg *r, Bits dif)
-{
- Reg *r1;
- int z;
-
- for(r1 = r; r1 != R; r1 = r1->s1) {
- for(z=0; z<BITS; z++) {
- dif.b[z] = (dif.b[z] &
- ~(~r1->refbehind.b[z] & r1->refahead.b[z])) |
- r1->set.b[z] | r1->regdiff.b[z];
- if(dif.b[z] != r1->regdiff.b[z]) {
- r1->regdiff.b[z] = dif.b[z];
- change++;
- }
- }
- if(r1->active)
- break;
- r1->active = 1;
- for(z=0; z<BITS; z++)
- dif.b[z] &= ~(~r1->calbehind.b[z] & r1->calahead.b[z]);
- if(r1->s2 != R)
- synch(r1->s2, dif);
- }
-}
-
-uint32
-allreg(uint32 b, Rgn *r)
-{
- Var *v;
- int i;
-
- v = var + r->varno;
- r->regno = 0;
- switch(v->etype) {
-
- default:
- diag(Z, "unknown etype %d/%d", bitno(b), v->etype);
- break;
-
- case TCHAR:
- case TUCHAR:
- case TSHORT:
- case TUSHORT:
- case TINT:
- case TUINT:
- case TLONG:
- case TULONG:
- case TIND:
- case TARRAY:
- i = BtoR(~b);
- if(i && r->cost > 0) {
- r->regno = i;
- return RtoB(i);
- }
- break;
-
- case TDOUBLE:
- case TFLOAT:
- break;
- }
- return 0;
-}
-
-void
-paint1(Reg *r, int bn)
-{
- Reg *r1;
- Prog *p;
- int z;
- uint32 bb;
-
- z = bn/32;
- bb = 1L<<(bn%32);
- if(r->act.b[z] & bb)
- return;
- for(;;) {
- if(!(r->refbehind.b[z] & bb))
- break;
- r1 = r->p1;
- if(r1 == R)
- break;
- if(!(r1->refahead.b[z] & bb))
- break;
- if(r1->act.b[z] & bb)
- break;
- r = r1;
- }
-
- if(LOAD(r) & ~(r->set.b[z]&~(r->use1.b[z]|r->use2.b[z])) & bb) {
- change -= CLOAD * r->loop;
- if(debug['R'] && debug['v'])
- print("%d%P\td %B $%d\n", r->loop,
- r->prog, blsh(bn), change);
- }
- for(;;) {
- r->act.b[z] |= bb;
- p = r->prog;
-
- if(r->use1.b[z] & bb) {
- change += CREF * r->loop;
- if(p->as == AFMOVL)
- if(BtoR(bb) != D_F0)
- change = -CINF;
- if(debug['R'] && debug['v'])
- print("%d%P\tu1 %B $%d\n", r->loop,
- p, blsh(bn), change);
- }
-
- if((r->use2.b[z]|r->set.b[z]) & bb) {
- change += CREF * r->loop;
- if(p->as == AFMOVL)
- if(BtoR(bb) != D_F0)
- change = -CINF;
- if(debug['R'] && debug['v'])
- print("%d%P\tu2 %B $%d\n", r->loop,
- p, blsh(bn), change);
- }
-
- if(STORE(r) & r->regdiff.b[z] & bb) {
- change -= CLOAD * r->loop;
- if(p->as == AFMOVL)
- if(BtoR(bb) != D_F0)
- change = -CINF;
- if(debug['R'] && debug['v'])
- print("%d%P\tst %B $%d\n", r->loop,
- p, blsh(bn), change);
- }
-
- if(r->refbehind.b[z] & bb)
- for(r1 = r->p2; r1 != R; r1 = r1->p2link)
- if(r1->refahead.b[z] & bb)
- paint1(r1, bn);
-
- if(!(r->refahead.b[z] & bb))
- break;
- r1 = r->s2;
- if(r1 != R)
- if(r1->refbehind.b[z] & bb)
- paint1(r1, bn);
- r = r->s1;
- if(r == R)
- break;
- if(r->act.b[z] & bb)
- break;
- if(!(r->refbehind.b[z] & bb))
- break;
- }
-}
-
-uint32
-regset(Reg *r, uint32 bb)
-{
- uint32 b, set;
- Addr v;
- int c;
-
- set = 0;
- v = zprog.from;
- while(b = bb & ~(bb-1)) {
- v.type = BtoR(b);
- c = copyu(r->prog, &v, A);
- if(c == 3)
- set |= b;
- bb &= ~b;
- }
- return set;
-}
-
-uint32
-reguse(Reg *r, uint32 bb)
-{
- uint32 b, set;
- Addr v;
- int c;
-
- set = 0;
- v = zprog.from;
- while(b = bb & ~(bb-1)) {
- v.type = BtoR(b);
- c = copyu(r->prog, &v, A);
- if(c == 1 || c == 2 || c == 4)
- set |= b;
- bb &= ~b;
- }
- return set;
-}
-
-uint32
-paint2(Reg *r, int bn)
-{
- Reg *r1;
- int z;
- uint32 bb, vreg, x;
-
- z = bn/32;
- bb = 1L << (bn%32);
- vreg = regbits;
- if(!(r->act.b[z] & bb))
- return vreg;
- for(;;) {
- if(!(r->refbehind.b[z] & bb))
- break;
- r1 = r->p1;
- if(r1 == R)
- break;
- if(!(r1->refahead.b[z] & bb))
- break;
- if(!(r1->act.b[z] & bb))
- break;
- r = r1;
- }
- for(;;) {
- r->act.b[z] &= ~bb;
-
- vreg |= r->regu;
-
- if(r->refbehind.b[z] & bb)
- for(r1 = r->p2; r1 != R; r1 = r1->p2link)
- if(r1->refahead.b[z] & bb)
- vreg |= paint2(r1, bn);
-
- if(!(r->refahead.b[z] & bb))
- break;
- r1 = r->s2;
- if(r1 != R)
- if(r1->refbehind.b[z] & bb)
- vreg |= paint2(r1, bn);
- r = r->s1;
- if(r == R)
- break;
- if(!(r->act.b[z] & bb))
- break;
- if(!(r->refbehind.b[z] & bb))
- break;
- }
-
- bb = vreg;
- for(; r; r=r->s1) {
- x = r->regu & ~bb;
- if(x) {
- vreg |= reguse(r, x);
- bb |= regset(r, x);
- }
- }
- return vreg;
-}
-
-void
-paint3(Reg *r, int bn, int32 rb, int rn)
-{
- Reg *r1;
- Prog *p;
- int z;
- uint32 bb;
-
- z = bn/32;
- bb = 1L << (bn%32);
- if(r->act.b[z] & bb)
- return;
- for(;;) {
- if(!(r->refbehind.b[z] & bb))
- break;
- r1 = r->p1;
- if(r1 == R)
- break;
- if(!(r1->refahead.b[z] & bb))
- break;
- if(r1->act.b[z] & bb)
- break;
- r = r1;
- }
-
- if(LOAD(r) & ~(r->set.b[z] & ~(r->use1.b[z]|r->use2.b[z])) & bb)
- addmove(r, bn, rn, 0);
- for(;;) {
- r->act.b[z] |= bb;
- p = r->prog;
-
- if(r->use1.b[z] & bb) {
- if(debug['R'])
- print("%P", p);
- addreg(&p->from, rn);
- if(debug['R'])
- print("\t.c%P\n", p);
- }
- if((r->use2.b[z]|r->set.b[z]) & bb) {
- if(debug['R'])
- print("%P", p);
- addreg(&p->to, rn);
- if(debug['R'])
- print("\t.c%P\n", p);
- }
-
- if(STORE(r) & r->regdiff.b[z] & bb)
- addmove(r, bn, rn, 1);
- r->regu |= rb;
-
- if(r->refbehind.b[z] & bb)
- for(r1 = r->p2; r1 != R; r1 = r1->p2link)
- if(r1->refahead.b[z] & bb)
- paint3(r1, bn, rb, rn);
-
- if(!(r->refahead.b[z] & bb))
- break;
- r1 = r->s2;
- if(r1 != R)
- if(r1->refbehind.b[z] & bb)
- paint3(r1, bn, rb, rn);
- r = r->s1;
- if(r == R)
- break;
- if(r->act.b[z] & bb)
- break;
- if(!(r->refbehind.b[z] & bb))
- break;
- }
-}
-
-void
-addreg(Addr *a, int rn)
-{
-
- a->sym = 0;
- a->offset = 0;
- a->type = rn;
-}
-
-int32
-RtoB(int r)
-{
-
- if(r < D_AX || r > D_DI)
- return 0;
- return 1L << (r-D_AX);
-}
-
-int
-BtoR(int32 b)
-{
-
- b &= 0xffL;
- if(b == 0)
- return 0;
- return bitno(b) + D_AX;
-}
-
-/* what instruction does a JMP to p eventually land on? */
-static Reg*
-chasejmp(Reg *r, int *jmploop)
-{
- int n;
-
- n = 0;
- for(; r; r=r->s2) {
- if(r->prog->as != AJMP || r->prog->to.type != D_BRANCH)
- break;
- if(++n > 10) {
- *jmploop = 1;
- break;
- }
- }
- return r;
-}
-
-/* mark all code reachable from firstp as alive */
-static void
-mark(Reg *firstr)
-{
- Reg *r;
- Prog *p;
-
- for(r=firstr; r; r=r->link) {
- if(r->active)
- break;
- r->active = 1;
- p = r->prog;
- if(p->as != ACALL && p->to.type == D_BRANCH)
- mark(r->s2);
- if(p->as == AJMP || p->as == ARET || p->as == AUNDEF)
- break;
- }
-}
-
-/*
- * the code generator depends on being able to write out JMP
- * instructions that it can jump to now but fill in later.
- * the linker will resolve them nicely, but they make the code
- * longer and more difficult to follow during debugging.
- * remove them.
- */
-static void
-fixjmp(Reg *firstr)
-{
- int jmploop;
- Reg *r;
- Prog *p;
-
- if(debug['R'] && debug['v'])
- print("\nfixjmp\n");
-
- // pass 1: resolve jump to AJMP, mark all code as dead.
- jmploop = 0;
- for(r=firstr; r; r=r->link) {
- p = r->prog;
- if(debug['R'] && debug['v'])
- print("%04d %P\n", (int)r->pc, p);
- if(p->as != ACALL && p->to.type == D_BRANCH && r->s2 && r->s2->prog->as == AJMP) {
- r->s2 = chasejmp(r->s2, &jmploop);
- p->to.offset = r->s2->pc;
- p->to.u.branch = r->s2->prog;
- if(debug['R'] && debug['v'])
- print("->%P\n", p);
- }
- r->active = 0;
- }
- if(debug['R'] && debug['v'])
- print("\n");
-
- // pass 2: mark all reachable code alive
- mark(firstr);
-
- // pass 3: delete dead code (mostly JMPs).
- for(r=firstr; r; r=r->link) {
- if(!r->active) {
- p = r->prog;
- if(p->link == P && p->as == ARET && r->p1 && r->p1->prog->as != ARET) {
- // This is the final ARET, and the code so far doesn't have one.
- // Let it stay.
- } else {
- if(debug['R'] && debug['v'])
- print("del %04d %P\n", (int)r->pc, p);
- p->as = ANOP;
- }
- }
- }
-
- // pass 4: elide JMP to next instruction.
- // only safe if there are no jumps to JMPs anymore.
- if(!jmploop) {
- for(r=firstr; r; r=r->link) {
- p = r->prog;
- if(p->as == AJMP && p->to.type == D_BRANCH && r->s2 == r->link) {
- if(debug['R'] && debug['v'])
- print("del %04d %P\n", (int)r->pc, p);
- p->as = ANOP;
- }
- }
- }
-
- // fix back pointers.
- for(r=firstr; r; r=r->link) {
- r->p2 = R;
- r->p2link = R;
- }
- for(r=firstr; r; r=r->link) {
- if(r->s2) {
- r->p2link = r->s2->p2;
- r->s2->p2 = r;
- }
- }
-
- if(debug['R'] && debug['v']) {
- print("\n");
- for(r=firstr; r; r=r->link)
- print("%04d %P\n", (int)r->pc, r->prog);
- print("\n");
- }
-}
-