[dev.cc] cmd/9c: remove

LGTM=rsc
R=rsc
CC=golang-codereviews
https://codereview.appspot.com/175940043

1 files changed, 0 insertions, 1163 deletions

diff --git a/src/cmd/9c/reg.c b/src/cmd/9c/reg.c
deleted file mode 100644
index 81a7c7fe4..000000000
--- a/src/cmd/9c/reg.c
+++ /dev/null
@@ -1,1163 +0,0 @@
-// cmd/9c/reg.c from Vita Nuova.
-//
-//	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 © 2000-2008 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 © 2000-2008 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"
-
-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)
-{
-	const Rgn *p1, *p2;
-	int c1, c2;
-
-	p1 = a1;
-	p2 = 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 = 0;
-	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 ARETURN:
-		case ABR:
-		case ARFI:
-		case ARFCI:
-		case ARFID:
-			r->p1 = R;
-			r1->s1 = R;
-		}
-
-		/*
-		 * left side always read
-		 */
-		bit = mkvar(&p->from, p->as==AMOVW || p->as == AMOVWZ || p->as == AMOVD);
-		for(z=0; z<BITS; z++)
-			r->use1.b[z] |= bit.b[z];
-
-		/*
-		 * right side depends on opcode
-		 */
-		bit = mkvar(&p->to, 0);
-		if(bany(&bit))
-		switch(p->as) {
-		default:
-			diag(Z, "reg: unknown asop: %A", p->as);
-			break;
-
-		/*
-		 * right side write
-		 */
-		case ANOP:
-		case AMOVB:
-		case AMOVBU:
-		case AMOVBZ:
-		case AMOVBZU:
-		case AMOVH:
-		case AMOVHBR:
-		case AMOVWBR:
-		case AMOVHU:
-		case AMOVHZ:
-		case AMOVHZU:
-		case AMOVW:
-		case AMOVWU:
-		case AMOVWZ:
-		case AMOVWZU:
-		case AMOVD:
-		case AMOVDU:
-		case AFMOVD:
-		case AFMOVDCC:
-		case AFMOVDU:
-		case AFMOVS:
-		case AFMOVSU:
-		case AFRSP:
-			for(z=0; z<BITS; z++)
-				r->set.b[z] |= bit.b[z];
-			break;
-
-		/*
-		 * funny
-		 */
-		case ABL:
-			for(z=0; z<BITS; z++)
-				addrs.b[z] |= bit.b[z];
-			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 2.5
-	 * 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("%ld:%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 == ARETURN)
-			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\n	set = %B; rah = %B; cal = %B\n",
-				r->prog, r->set, r->refahead, r->calahead);
-		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 an 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$%d: %B\n",
-						r->prog->lineno, change, blsh(i));
-				continue;
-			}
-			rgp->cost = change;
-			nregion++;
-			if(nregion >= NRGN)
-				fatal(Z, "too many regions");
-			rgp++;
-		}
-	}
-	qsort(region, nregion, sizeof(region[0]), rcmp);
-
-	/*
-	 * pass 6
-	 * determine used registers (paint2)
-	 * replace code (paint3)
-	 */
-	rgp = region;
-	for(i=0; i<nregion; i++) {
-		bit = blsh(rgp->varno);
-		vreg = paint2(rgp->enter, rgp->varno);
-		vreg = allreg(vreg, rgp);
-		if(debug['R']) {
-			if(rgp->regno >= NREG)
-				print("%L$%d F%d: %B\n",
-					rgp->enter->prog->lineno,
-					rgp->cost,
-					rgp->regno-NREG,
-					bit);
-			else
-				print("%L$%d R%d: %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();
-
-	/*
-	 * 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(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->name = v->name;
-	a->offset = v->offset;
-	a->etype = v->etype;
-	a->type = D_OREG;
-	if(a->etype == TARRAY || a->sym == nil)
-		a->type = D_CONST;
-
-	p1->as = AMOVW;
-	if(v->etype == TCHAR || v->etype == TUCHAR)
-		p1->as = AMOVB;
-	if(v->etype == TSHORT || v->etype == TUSHORT)
-		p1->as = AMOVH;
-	if(v->etype == TVLONG || v->etype == TUVLONG || v->etype == TIND)
-		p1->as = AMOVD;
-	if(v->etype == TFLOAT)
-		p1->as = AFMOVS;
-	if(v->etype == TDOUBLE)
-		p1->as = AFMOVD;
-
-	p1->from.type = D_REG;
-	p1->from.reg = rn;
-	if(rn >= NREG) {
-		p1->from.type = D_FREG;
-		p1->from.reg = rn-NREG;
-	}
-	if(!f) {
-		p1->from = *a;
-		*a = zprog.from;
-		a->type = D_REG;
-		a->reg = rn;
-		if(rn >= NREG) {
-			a->type = D_FREG;
-			a->reg = rn-NREG;
-		}
-		if(v->etype == TUCHAR)
-			p1->as = AMOVBZ;
-		if(v->etype == TUSHORT)
-			p1->as = AMOVHZ;
-		if(v->etype == TUINT || v->etype == TULONG)
-			p1->as = AMOVWZ;
-	}
-	if(debug['R'])
-		print("%P\t.a%P\n", p, p1);
-}
-
-Bits
-mkvar(Addr *a, int docon)
-{
-	Var *v;
-	int i, t, n, et, z;
-	int64 o;
-	Bits bit;
-	LSym *s;
-
-	t = a->type;
-	if(t == D_REG && a->reg != NREG)
-		regbits |= RtoB(a->reg);
-	if(t == D_FREG && a->reg != NREG)
-		regbits |= FtoB(a->reg);
-	s = a->sym;
-	o = a->offset;
-	et = a->etype;
-	if(s == nil) {
-		if(t != D_CONST || !docon || a->reg != NREG)
-			goto none;
-		et = TLONG;
-	}
-	if(t == D_CONST) {
-		if(s == nil && sval(o))
-			goto none;
-	}
-	n = a->name;
-	v = var;
-	for(i=0; i<nvar; i++) {
-		if(s == v->sym)
-		if(n == v->name)
-		if(o == v->offset)
-			goto out;
-		v++;
-	}
-	if(s)
-		if(s->name[0] == '.')
-			goto none;
-	if(nvar >= NVAR)
-		fatal(Z, "variable not optimized: %s", s->name);
-	i = nvar;
-	nvar++;
-	v = &var[i];
-	v->sym = s;
-	v->offset = o;
-	v->etype = et;
-	v->name = n;
-	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] || typev[et]))	/* funny punning */
-		for(z=0; z<BITS; z++)
-			addrs.b[z] |= bit.b[z];
-	if(t == D_CONST) {
-		if((int32)o != o)
-			v->etype = TVLONG;
-		if(s == nil) {
-			for(z=0; z<BITS; z++)
-				consts.b[z] |= bit.b[z];
-			return bit;
-		}
-		if(et != TARRAY)
-			for(z=0; z<BITS; z++)
-				addrs.b[z] |= bit.b[z];
-		for(z=0; z<BITS; z++)
-			params.b[z] |= bit.b[z];
-		return bit;
-	}
-	if(t == D_OREG)
-		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 ABL:
-			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 ARETURN:
-			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 TVLONG:
-	case TUVLONG:
-	case TARRAY:
-		i = BtoR(~b);
-		if(i && r->cost > 0) {
-			r->regno = i;
-			return RtoB(i);
-		}
-		break;
-
-	case TDOUBLE:
-	case TFLOAT:
-		i = BtoF(~b);
-		if(i && r->cost > 0) {
-			r->regno = i+NREG;
-			return FtoB(i);
-		}
-		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("%ld%P\tld %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->to.type == D_FREG && (p->as == AMOVW || p->as == AMOVD))
-				change = -CINF;		/* cant go Rreg to Freg */
-			if(debug['R'] && debug['v'])
-				print("%ld%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->from.type == D_FREG && (p->as == AMOVW || p->as == AMOVD))
-				change = -CINF;		/* cant go Rreg to Freg */
-			if(debug['R'] && debug['v'])
-				print("%ld%P\tu2 %B $%d\n", r->loop,
-					p, blsh(bn), change);
-		}
-
-		if(STORE(r) & r->regdiff.b[z] & bb) {
-			change -= CLOAD * r->loop;
-			if(debug['R'] && debug['v'])
-				print("%ld%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
-paint2(Reg *r, int bn)
-{
-	Reg *r1;
-	int z;
-	uint32 bb, vreg;
-
-	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;
-	}
-	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->name = D_NONE;
-	a->type = D_REG;
-	a->reg = rn;
-	if(rn >= NREG) {
-		a->type = D_FREG;
-		a->reg = rn-NREG;
-	}
-}
-
-/*
- * track register variables including external registers:
- *	bit	reg
- *	0	R7
- *	1	R8
- *	...	...
- *	21	R28
- */
-int32
-RtoB(int r)
-{
-
-	if(r >= REGMIN && r <= REGMAX)
-		return 1L << (r-REGMIN);
-	return 0;
-}
-
-int
-BtoR(int32 b)
-{
-	b &= 0x001fffffL;
-	if(b == 0)
-		return 0;
-	return bitno(b) + REGMIN;
-}
-
-/*
- *	bit	reg
- *	22	F17
- *	23	F18
- *	...	...
- *	31	F26
- */
-int32
-FtoB(int f)
-{
-	if(f < FREGMIN || f > FREGEXT)
-		return 0;
-	return 1L << (f - FREGMIN + 22);
-}
-
-int
-BtoF(int32 b)
-{
-
-	b &= 0xffc00000L;
-	if(b == 0)
-		return 0;
-	return bitno(b) - 22 + FREGMIN;
-}