1 files changed, 0 insertions, 1478 deletions

diff --git a/src/cmd/5c/peep.c b/src/cmd/5c/peep.c
deleted file mode 100644
index 1de56b594..000000000
--- a/src/cmd/5c/peep.c
+++ /dev/null
@@ -1,1478 +0,0 @@
-// Inferno utils/5c/peep.c
-// http://code.google.com/p/inferno-os/source/browse/utils/5c/peep.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"
-
-int xtramodes(Reg*, Addr*);
-
-void
-peep(void)
-{
-	Reg *r, *r1, *r2;
-	Prog *p, *p1;
-	int t;
-/*
- * complete R structure
- */
-	t = 0;
-	for(r=firstr; r!=R; r=r1) {
-		r1 = r->link;
-		if(r1 == R)
-			break;
-		p = r->prog->link;
-		while(p != r1->prog)
-		switch(p->as) {
-		default:
-			r2 = rega();
-			r->link = r2;
-			r2->link = r1;
-
-			r2->prog = p;
-			r2->p1 = r;
-			r->s1 = r2;
-			r2->s1 = r1;
-			r1->p1 = r2;
-
-			r = r2;
-			t++;
-
-		case ADATA:
-		case AGLOBL:
-		case ANAME:
-		case ASIGNAME:
-			p = p->link;
-		}
-	}
-
-loop1:
-	t = 0;
-	for(r=firstr; r!=R; r=r->link) {
-		p = r->prog;
-		if(p->as == ASLL || p->as == ASRL || p->as == ASRA) {
-			/*
-			 * elide shift into D_SHIFT operand of subsequent instruction
-			 */
-			if(shiftprop(r)) {
-				excise(r);
-				t++;
-			}
-		}
-		if(p->as == AMOVW || p->as == AMOVF || p->as == AMOVD)
-		if(regtyp(&p->to)) {
-			if(p->from.type == D_CONST)
-				constprop(&p->from, &p->to, r->s1);
-			else if(regtyp(&p->from))
-			if(p->from.type == p->to.type) {
-				if(copyprop(r)) {
-					excise(r);
-					t++;
-				} else
-				if(subprop(r) && copyprop(r)) {
-					excise(r);
-					t++;
-				}
-			}
-		}
-	}
-	if(t)
-		goto loop1;
-	/*
-	 * look for MOVB x,R; MOVB R,R
-	 */
-	for(r=firstr; r!=R; r=r->link) {
-		p = r->prog;
-		switch(p->as) {
-		default:
-			continue;
-		case AEOR:
-			/*
-			 * EOR -1,x,y => MVN x,y
-			 */
-			if(p->from.type == D_CONST && p->from.offset == -1) {
-				p->as = AMVN;
-				p->from.type = D_REG;
-				if(p->reg != NREG)
-					p->from.reg = p->reg;
-				else
-					p->from.reg = p->to.reg;
-				p->reg = NREG;
-			}
-			continue;
-		case AMOVH:
-		case AMOVHS:
-		case AMOVHU:
-		case AMOVB:
-		case AMOVBS:
-		case AMOVBU:
-			if(p->to.type != D_REG)
-				continue;
-			break;
-		}
-		r1 = r->link;
-		if(r1 == R)
-			continue;
-		p1 = r1->prog;
-		if(p1->as != p->as)
-			continue;
-		if(p1->from.type != D_REG || p1->from.reg != p->to.reg)
-			continue;
-		if(p1->to.type != D_REG || p1->to.reg != p->to.reg)
-			continue;
-		excise(r1);
-	}
-
-	for(r=firstr; r!=R; r=r->link) {
-		p = r->prog;
-		switch(p->as) {
-		case AMOVW:
-		case AMOVB:
-		case AMOVBS:
-		case AMOVBU:
-			if(p->from.type == D_OREG && p->from.offset == 0)
-				xtramodes(r, &p->from);
-			else if(p->to.type == D_OREG && p->to.offset == 0)
-				xtramodes(r, &p->to);
-			else
-				continue;
-			break;
-		case ACMP:
-			/*
-			 * elide CMP $0,x if calculation of x can set condition codes
-			 */
-			if(p->from.type != D_CONST || p->from.offset != 0)
-				continue;
-			r2 = r->s1;
-			if(r2 == R)
-				continue;
-			t = r2->prog->as;
-			switch(t) {
-			default:
-				continue;
-			case ABEQ:
-			case ABNE:
-			case ABMI:
-			case ABPL:
-				break;
-			case ABGE:
-				t = ABPL;
-				break;
-			case ABLT:
-				t = ABMI;
-				break;
-			case ABHI:
-				t = ABNE;
-				break;
-			case ABLS:
-				t = ABEQ;
-				break;
-			}
-			r1 = r;
-			do
-				r1 = uniqp(r1);
-			while (r1 != R && r1->prog->as == ANOP);
-			if(r1 == R)
-				continue;
-			p1 = r1->prog;
-			if(p1->to.type != D_REG)
-				continue;
-			if(p1->to.reg != p->reg)
-			if(!(p1->as == AMOVW && p1->from.type == D_REG && p1->from.reg == p->reg))
-				continue;
-			switch(p1->as) {
-			default:
-				continue;
-			case AMOVW:
-				if(p1->from.type != D_REG)
-					continue;
-			case AAND:
-			case AEOR:
-			case AORR:
-			case ABIC:
-			case AMVN:
-			case ASUB:
-			case ARSB:
-			case AADD:
-			case AADC:
-			case ASBC:
-			case ARSC:
-				break;
-			}
-			p1->scond |= C_SBIT;
-			r2->prog->as = t;
-			excise(r);
-			continue;
-		}
-	}
-
-	predicate();
-}
-
-void
-excise(Reg *r)
-{
-	Prog *p;
-
-	p = r->prog;
-	p->as = ANOP;
-	p->scond = zprog.scond;
-	p->from = zprog.from;
-	p->to = zprog.to;
-	p->reg = zprog.reg; /**/
-}
-
-Reg*
-uniqp(Reg *r)
-{
-	Reg *r1;
-
-	r1 = r->p1;
-	if(r1 == R) {
-		r1 = r->p2;
-		if(r1 == R || r1->p2link != R)
-			return R;
-	} else
-		if(r->p2 != R)
-			return R;
-	return r1;
-}
-
-Reg*
-uniqs(Reg *r)
-{
-	Reg *r1;
-
-	r1 = r->s1;
-	if(r1 == R) {
-		r1 = r->s2;
-		if(r1 == R)
-			return R;
-	} else
-		if(r->s2 != R)
-			return R;
-	return r1;
-}
-
-int
-regtyp(Addr *a)
-{
-
-	if(a->type == D_REG)
-		return 1;
-	if(a->type == D_FREG)
-		return 1;
-	return 0;
-}
-
-/*
- * the idea is to substitute
- * one register for another
- * from one MOV to another
- *	MOV	a, R0
- *	ADD	b, R0	/ no use of R1
- *	MOV	R0, R1
- * would be converted to
- *	MOV	a, R1
- *	ADD	b, R1
- *	MOV	R1, R0
- * hopefully, then the former or latter MOV
- * will be eliminated by copy propagation.
- */
-int
-subprop(Reg *r0)
-{
-	Prog *p;
-	Addr *v1, *v2;
-	Reg *r;
-	int t;
-
-	p = r0->prog;
-	v1 = &p->from;
-	if(!regtyp(v1))
-		return 0;
-	v2 = &p->to;
-	if(!regtyp(v2))
-		return 0;
-	for(r=uniqp(r0); r!=R; r=uniqp(r)) {
-		if(uniqs(r) == R)
-			break;
-		p = r->prog;
-		switch(p->as) {
-		case ABL:
-			return 0;
-
-		case ACMP:
-		case ACMN:
-		case AADD:
-		case ASUB:
-		case ARSB:
-		case ASLL:
-		case ASRL:
-		case ASRA:
-		case AORR:
-		case AAND:
-		case AEOR:
-		case AMUL:
-		case ADIV:
-		case ADIVU:
-
-		case ACMPF:
-		case ACMPD:
-		case AADDD:
-		case AADDF:
-		case ASUBD:
-		case ASUBF:
-		case AMULD:
-		case AMULF:
-		case ADIVD:
-		case ADIVF:
-			if(p->to.type == v1->type)
-			if(p->to.reg == v1->reg) {
-				if(p->reg == NREG)
-					p->reg = p->to.reg;
-				goto gotit;
-			}
-			break;
-
-		case AMOVF:
-		case AMOVD:
-		case AMOVW:
-			if(p->to.type == v1->type)
-			if(p->to.reg == v1->reg)
-				goto gotit;
-			break;
-
-		case AMOVM:
-			t = 1<<v2->reg;
-			if((p->from.type == D_CONST && (p->from.offset&t)) ||
-			   (p->to.type == D_CONST && (p->to.offset&t)))
-				return 0;
-			break;
-		}
-		if(copyau(&p->from, v2) ||
-		   copyau1(p, v2) ||
-		   copyau(&p->to, v2))
-			break;
-		if(copysub(&p->from, v1, v2, 0) ||
-		   copysub1(p, v1, v2, 0) ||
-		   copysub(&p->to, v1, v2, 0))
-			break;
-	}
-	return 0;
-
-gotit:
-	copysub(&p->to, v1, v2, 1);
-	if(debug['P']) {
-		print("gotit: %D->%D\n%P", v1, v2, r->prog);
-		if(p->from.type == v2->type)
-			print(" excise");
-		print("\n");
-	}
-	for(r=uniqs(r); r!=r0; r=uniqs(r)) {
-		p = r->prog;
-		copysub(&p->from, v1, v2, 1);
-		copysub1(p, v1, v2, 1);
-		copysub(&p->to, v1, v2, 1);
-		if(debug['P'])
-			print("%P\n", r->prog);
-	}
-	t = v1->reg;
-	v1->reg = v2->reg;
-	v2->reg = t;
-	if(debug['P'])
-		print("%P last\n", r->prog);
-	return 1;
-}
-
-/*
- * The idea is to remove redundant copies.
- *	v1->v2	F=0
- *	(use v2	s/v2/v1/)*
- *	set v1	F=1
- *	use v2	return fail
- *	-----------------
- *	v1->v2	F=0
- *	(use v2	s/v2/v1/)*
- *	set v1	F=1
- *	set v2	return success
- */
-int
-copyprop(Reg *r0)
-{
-	Prog *p;
-	Addr *v1, *v2;
-	Reg *r;
-
-	p = r0->prog;
-	v1 = &p->from;
-	v2 = &p->to;
-	if(copyas(v1, v2))
-		return 1;
-	for(r=firstr; r!=R; r=r->link)
-		r->active = 0;
-	return copy1(v1, v2, r0->s1, 0);
-}
-
-int
-copy1(Addr *v1, Addr *v2, Reg *r, int f)
-{
-	int t;
-	Prog *p;
-
-	if(r->active) {
-		if(debug['P'])
-			print("act set; return 1\n");
-		return 1;
-	}
-	r->active = 1;
-	if(debug['P'])
-		print("copy %D->%D f=%d\n", v1, v2, f);
-	for(; r != R; r = r->s1) {
-		p = r->prog;
-		if(debug['P'])
-			print("%P", p);
-		if(!f && uniqp(r) == R) {
-			f = 1;
-			if(debug['P'])
-				print("; merge; f=%d", f);
-		}
-		t = copyu(p, v2, A);
-		switch(t) {
-		case 2:	/* rar, can't split */
-			if(debug['P'])
-				print("; %Drar; return 0\n", v2);
-			return 0;
-
-		case 3:	/* set */
-			if(debug['P'])
-				print("; %Dset; return 1\n", v2);
-			return 1;
-
-		case 1:	/* used, substitute */
-		case 4:	/* use and set */
-			if(f) {
-				if(!debug['P'])
-					return 0;
-				if(t == 4)
-					print("; %Dused+set and f=%d; return 0\n", v2, f);
-				else
-					print("; %Dused and f=%d; return 0\n", v2, f);
-				return 0;
-			}
-			if(copyu(p, v2, v1)) {
-				if(debug['P'])
-					print("; sub fail; return 0\n");
-				return 0;
-			}
-			if(debug['P'])
-				print("; sub%D/%D", v2, v1);
-			if(t == 4) {
-				if(debug['P'])
-					print("; %Dused+set; return 1\n", v2);
-				return 1;
-			}
-			break;
-		}
-		if(!f) {
-			t = copyu(p, v1, A);
-			if(!f && (t == 2 || t == 3 || t == 4)) {
-				f = 1;
-				if(debug['P'])
-					print("; %Dset and !f; f=%d", v1, f);
-			}
-		}
-		if(debug['P'])
-			print("\n");
-		if(r->s2)
-			if(!copy1(v1, v2, r->s2, f))
-				return 0;
-	}
-	return 1;
-}
-
-/*
- * The idea is to remove redundant constants.
- *	$c1->v1
- *	($c1->v2 s/$c1/v1)*
- *	set v1  return
- * The v1->v2 should be eliminated by copy propagation.
- */
-void
-constprop(Addr *c1, Addr *v1, Reg *r)
-{
-	Prog *p;
-
-	if(debug['C'])
-		print("constprop %D->%D\n", c1, v1);
-	for(; r != R; r = r->s1) {
-		p = r->prog;
-		if(debug['C'])
-			print("%P", p);
-		if(uniqp(r) == R) {
-			if(debug['C'])
-				print("; merge; return\n");
-			return;
-		}
-		if(p->as == AMOVW && copyas(&p->from, c1)) {
-				if(debug['C'])
-					print("; sub%D/%D", &p->from, v1);
-				p->from = *v1;
-		} else if(copyu(p, v1, A) > 1) {
-			if(debug['C'])
-				print("; %Dset; return\n", v1);
-			return;
-		}
-		if(debug['C'])
-			print("\n");
-		if(r->s2)
-			constprop(c1, v1, r->s2);
-	}
-}
-
-/*
- * ASLL x,y,w
- * .. (not use w, not set x y w)
- * AXXX w,a,b (a != w)
- * .. (not use w)
- * (set w)
- * ----------- changed to
- * ..
- * AXXX (x<<y),a,b
- * ..
- */
-#define FAIL(msg) { if(debug['H']) print("\t%s; FAILURE\n", msg); return 0; }
-int
-shiftprop(Reg *r)
-{
-	Reg *r1;
-	Prog *p, *p1, *p2;
-	int n, o;
-	Addr a;
-
-	p = r->prog;
-	if(p->to.type != D_REG)
-		FAIL("BOTCH: result not reg");
-	n = p->to.reg;
-	a = zprog.from;
-	if(p->reg != NREG && p->reg != p->to.reg) {
-		a.type = D_REG;
-		a.reg = p->reg;
-	}
-	if(debug['H'])
-		print("shiftprop\n%P", p);
-	r1 = r;
-	for(;;) {
-		/* find first use of shift result; abort if shift operands or result are changed */
-		r1 = uniqs(r1);
-		if(r1 == R)
-			FAIL("branch");
-		if(uniqp(r1) == R)
-			FAIL("merge");
-		p1 = r1->prog;
-		if(debug['H'])
-			print("\n%P", p1);
-		switch(copyu(p1, &p->to, A)) {
-		case 0:	/* not used or set */
-			if((p->from.type == D_REG && copyu(p1, &p->from, A) > 1) ||
-			   (a.type == D_REG && copyu(p1, &a, A) > 1))
-				FAIL("args modified");
-			continue;
-		case 3:	/* set, not used */
-			FAIL("BOTCH: noref");
-		}
-		break;
-	}
-	/* check whether substitution can be done */
-	switch(p1->as) {
-	default:
-		FAIL("non-dpi");
-	case AAND:
-	case AEOR:
-	case AADD:
-	case AADC:
-	case AORR:
-	case ASUB:
-	case ARSB:
-	case ASBC:
-	case ARSC:
-		if(p1->reg == n || (p1->reg == NREG && p1->to.type == D_REG && p1->to.reg == n)) {
-			if(p1->from.type != D_REG)
-				FAIL("can't swap");
-			p1->reg = p1->from.reg;
-			p1->from.reg = n;
-			switch(p1->as) {
-			case ASUB:
-				p1->as = ARSB;
-				break;
-			case ARSB:
-				p1->as = ASUB;
-				break;
-			case ASBC:
-				p1->as = ARSC;
-				break;
-			case ARSC:
-				p1->as = ASBC;
-				break;
-			}
-			if(debug['H'])
-				print("\t=>%P", p1);
-		}
-	case ABIC:
-	case ACMP:
-	case ACMN:
-		if(p1->reg == n)
-			FAIL("can't swap");
-		if(p1->reg == NREG && p1->to.reg == n)
-			FAIL("shift result used twice");
-	case AMVN:
-		if(p1->from.type == D_SHIFT)
-			FAIL("shift result used in shift");
-		if(p1->from.type != D_REG || p1->from.reg != n)
-			FAIL("BOTCH: where is it used?");
-		break;
-	}
-	/* check whether shift result is used subsequently */
-	p2 = p1;
-	if(p1->to.reg != n)
-	for (;;) {
-		r1 = uniqs(r1);
-		if(r1 == R)
-			FAIL("inconclusive");
-		p1 = r1->prog;
-		if(debug['H'])
-			print("\n%P", p1);
-		switch(copyu(p1, &p->to, A)) {
-		case 0:	/* not used or set */
-			continue;
-		case 3: /* set, not used */
-			break;
-		default:/* used */
-			FAIL("reused");
-		}
-		break;
-	}
-	/* make the substitution */
-	p2->from.type = D_SHIFT;
-	p2->from.reg = NREG;
-	o = p->reg;
-	if(o == NREG)
-		o = p->to.reg;
-	switch(p->from.type){
-	case D_CONST:
-		o |= (p->from.offset&0x1f)<<7;
-		break;
-	case D_REG:
-		o |= (1<<4) | (p->from.reg<<8);
-		break;
-	}
-	switch(p->as){
-	case ASLL:
-		o |= 0<<5;
-		break;
-	case ASRL:
-		o |= 1<<5;
-		break;
-	case ASRA:
-		o |= 2<<5;
-		break;
-	}
-	p2->from.offset = o;
-	if(debug['H'])
-		print("\t=>%P\tSUCCEED\n", p2);
-	return 1;
-}
-
-Reg*
-findpre(Reg *r, Addr *v)
-{
-	Reg *r1;
-
-	for(r1=uniqp(r); r1!=R; r=r1,r1=uniqp(r)) {
-		if(uniqs(r1) != r)
-			return R;
-		switch(copyu(r1->prog, v, A)) {
-		case 1: /* used */
-		case 2: /* read-alter-rewrite */
-			return R;
-		case 3: /* set */
-		case 4: /* set and used */
-			return r1;
-		}
-	}
-	return R;
-}
-
-Reg*
-findinc(Reg *r, Reg *r2, Addr *v)
-{
-	Reg *r1;
-	Prog *p;
-
-
-	for(r1=uniqs(r); r1!=R && r1!=r2; r=r1,r1=uniqs(r)) {
-		if(uniqp(r1) != r)
-			return R;
-		switch(copyu(r1->prog, v, A)) {
-		case 0: /* not touched */
-			continue;
-		case 4: /* set and used */
-			p = r1->prog;
-			if(p->as == AADD)
-			if(p->from.type == D_CONST)
-			if(p->from.offset > -4096 && p->from.offset < 4096)
-				return r1;
-		default:
-			return R;
-		}
-	}
-	return R;
-}
-
-int
-nochange(Reg *r, Reg *r2, Prog *p)
-{
-	Addr a[3];
-	int i, n;
-
-	if(r == r2)
-		return 1;
-	n = 0;
-	if(p->reg != NREG && p->reg != p->to.reg) {
-		a[n].type = D_REG;
-		a[n++].reg = p->reg;
-	}
-	switch(p->from.type) {
-	case D_SHIFT:
-		a[n].type = D_REG;
-		a[n++].reg = p->from.offset&0xf;
-	case D_REG:
-		a[n].type = D_REG;
-		a[n++].reg = p->from.reg;
-	}
-	if(n == 0)
-		return 1;
-	for(; r!=R && r!=r2; r=uniqs(r)) {
-		p = r->prog;
-		for(i=0; i<n; i++)
-			if(copyu(p, &a[i], A) > 1)
-				return 0;
-	}
-	return 1;
-}
-
-int
-findu1(Reg *r, Addr *v)
-{
-	for(; r != R; r = r->s1) {
-		if(r->active)
-			return 0;
-		r->active = 1;
-		switch(copyu(r->prog, v, A)) {
-		case 1: /* used */
-		case 2: /* read-alter-rewrite */
-		case 4: /* set and used */
-			return 1;
-		case 3: /* set */
-			return 0;
-		}
-		if(r->s2)
-			if (findu1(r->s2, v))
-				return 1;
-	}
-	return 0;
-}
-
-int
-finduse(Reg *r, Addr *v)
-{
-	Reg *r1;
-
-	for(r1=firstr; r1!=R; r1=r1->link)
-		r1->active = 0;
-	return findu1(r, v);
-}
-
-int
-xtramodes(Reg *r, Addr *a)
-{
-	Reg *r1, *r2, *r3;
-	Prog *p, *p1;
-	Addr v;
-
-	p = r->prog;
-	if((p->as == AMOVB || p->as == AMOVBS) && p->from.type == D_OREG)	/* byte load */
-		return 0;
-	v = *a;
-	v.type = D_REG;
-	r1 = findpre(r, &v);
-	if(r1 != R) {
-		p1 = r1->prog;
-		if(p1->to.type == D_REG && p1->to.reg == v.reg)
-		switch(p1->as) {
-		case AADD:
-			if(p1->from.type == D_REG ||
-			   (p1->from.type == D_SHIFT && (p1->from.offset&(1<<4)) == 0 &&
-			    ((p->as != AMOVB && p->as != AMOVBS) || (a == &p->from && (p1->from.offset&~0xf) == 0))) ||
-			   (p1->from.type == D_CONST &&
-			    p1->from.offset > -4096 && p1->from.offset < 4096))
-			if(nochange(uniqs(r1), r, p1)) {
-				if(a != &p->from || v.reg != p->to.reg)
-				if (finduse(r->s1, &v)) {
-					if(p1->reg == NREG || p1->reg == v.reg)
-						/* pre-indexing */
-						p->scond |= C_WBIT;
-					else return 0;
-				}
-				switch (p1->from.type) {
-				case D_REG:
-					/* register offset */
-					if(nacl)
-						return 0;
-					a->type = D_SHIFT;
-					a->offset = p1->from.reg;
-					break;
-				case D_SHIFT:
-					/* scaled register offset */
-					if(nacl)
-						return 0;
-					a->type = D_SHIFT;
-				case D_CONST:
-					/* immediate offset */
-					a->offset = p1->from.offset;
-					break;
-				}
-				if(p1->reg != NREG)
-					a->reg = p1->reg;
-				excise(r1);
-				return 1;
-			}
-			break;
-		case AMOVW:
-			if(p1->from.type == D_REG)
-			if((r2 = findinc(r1, r, &p1->from)) != R) {
-			for(r3=uniqs(r2); r3->prog->as==ANOP; r3=uniqs(r3))
-				;
-			if(r3 == r) {
-				/* post-indexing */
-				p1 = r2->prog;
-				a->reg = p1->to.reg;
-				a->offset = p1->from.offset;
-				p->scond |= C_PBIT;
-				if(!finduse(r, &r1->prog->to))
-					excise(r1);
-				excise(r2);
-				return 1;
-			}
-			}
-			break;
-		}
-	}
-	if(a != &p->from || a->reg != p->to.reg)
-	if((r1 = findinc(r, R, &v)) != R) {
-		/* post-indexing */
-		p1 = r1->prog;
-		a->offset = p1->from.offset;
-		p->scond |= C_PBIT;
-		excise(r1);
-		return 1;
-	}
-	return 0;
-}
-
-/*
- * return
- * 1 if v only used (and substitute),
- * 2 if read-alter-rewrite
- * 3 if set
- * 4 if set and used
- * 0 otherwise (not touched)
- */
-int
-copyu(Prog *p, Addr *v, Addr *s)
-{
-
-	switch(p->as) {
-
-	default:
-		if(debug['P'])
-			print(" (?)");
-		return 2;
-
-	case AMOVM:
-		if(v->type != D_REG)
-			return 0;
-		if(p->from.type == D_CONST) {	/* read reglist, read/rar */
-			if(s != A) {
-				if(p->from.offset&(1<<v->reg))
-					return 1;
-				if(copysub(&p->to, v, s, 1))
-					return 1;
-				return 0;
-			}
-			if(copyau(&p->to, v)) {
-				if(p->scond&C_WBIT)
-					return 2;
-				return 1;
-			}
-			if(p->from.offset&(1<<v->reg))
-				return 1;
-		} else {			/* read/rar, write reglist */
-			if(s != A) {
-				if(p->to.offset&(1<<v->reg))
-					return 1;
-				if(copysub(&p->from, v, s, 1))
-					return 1;
-				return 0;
-			}
-			if(copyau(&p->from, v)) {
-				if(p->scond&C_WBIT)
-					return 2;
-				if(p->to.offset&(1<<v->reg))
-					return 4;
-				return 1;
-			}
-			if(p->to.offset&(1<<v->reg))
-				return 3;
-		}
-		return 0;
-
-	case ANOP:	/* read, write */
-	case AMOVW:
-	case AMOVF:
-	case AMOVD:
-	case AMOVH:
-	case AMOVHS:
-	case AMOVHU:
-	case AMOVB:
-	case AMOVBS:
-	case AMOVBU:
-	case AMOVDW:
-	case AMOVWD:
-	case AMOVFD:
-	case AMOVDF:
-		if(p->scond&(C_WBIT|C_PBIT))
-		if(v->type == D_REG) {
-			if(p->from.type == D_OREG || p->from.type == D_SHIFT) {
-				if(p->from.reg == v->reg)
-					return 2;
-			} else {
-		  		if(p->to.reg == v->reg)
-				return 2;
-			}
-		}
-		if(s != A) {
-			if(copysub(&p->from, v, s, 1))
-				return 1;
-			if(!copyas(&p->to, v))
-				if(copysub(&p->to, v, s, 1))
-					return 1;
-			return 0;
-		}
-		if(copyas(&p->to, v)) {
-			if(copyau(&p->from, v))
-				return 4;
-			return 3;
-		}
-		if(copyau(&p->from, v))
-			return 1;
-		if(copyau(&p->to, v))
-			return 1;
-		return 0;
-
-
-	case AADD:	/* read, read, write */
-	case ASUB:
-	case ARSB:
-	case ASLL:
-	case ASRL:
-	case ASRA:
-	case AORR:
-	case AAND:
-	case AEOR:
-	case AMUL:
-	case ADIV:
-	case ADIVU:
-	case AADDF:
-	case AADDD:
-	case ASUBF:
-	case ASUBD:
-	case AMULF:
-	case AMULD:
-	case ADIVF:
-	case ADIVD:
-
-	case ACMPF:
-	case ACMPD:
-	case ACMP:
-	case ACMN:
-	case ACASE:
-		if(s != A) {
-			if(copysub(&p->from, v, s, 1))
-				return 1;
-			if(copysub1(p, v, s, 1))
-				return 1;
-			if(!copyas(&p->to, v))
-				if(copysub(&p->to, v, s, 1))
-					return 1;
-			return 0;
-		}
-		if(copyas(&p->to, v)) {
-			if(p->reg == NREG)
-				p->reg = p->to.reg;
-			if(copyau(&p->from, v))
-				return 4;
-			if(copyau1(p, v))
-				return 4;
-			return 3;
-		}
-		if(copyau(&p->from, v))
-			return 1;
-		if(copyau1(p, v))
-			return 1;
-		if(copyau(&p->to, v))
-			return 1;
-		return 0;
-
-	case ABEQ:	/* read, read */
-	case ABNE:
-	case ABCS:
-	case ABHS:
-	case ABCC:
-	case ABLO:
-	case ABMI:
-	case ABPL:
-	case ABVS:
-	case ABVC:
-	case ABHI:
-	case ABLS:
-	case ABGE:
-	case ABLT:
-	case ABGT:
-	case ABLE:
-	case APLD:
-		if(s != A) {
-			if(copysub(&p->from, v, s, 1))
-				return 1;
-			return copysub1(p, v, s, 1);
-		}
-		if(copyau(&p->from, v))
-			return 1;
-		if(copyau1(p, v))
-			return 1;
-		return 0;
-
-	case AB:	/* funny */
-		if(s != A) {
-			if(copysub(&p->to, v, s, 1))
-				return 1;
-			return 0;
-		}
-		if(copyau(&p->to, v))
-			return 1;
-		return 0;
-
-	case ARET:	/* funny */
-		if(v->type == D_REG)
-		if(v->reg == REGRET)
-			return 2;
-		if(v->type == D_FREG)
-		if(v->reg == FREGRET)
-			return 2;
-
-	case ABL:	/* funny */
-		if(v->type == D_REG) {
-			if(v->reg <= REGEXT && v->reg > exregoffset)
-				return 2;
-			if(v->reg == REGARG)
-				return 2;
-		}
-		if(v->type == D_FREG)
-			if(v->reg <= FREGEXT && v->reg > exfregoffset)
-				return 2;
-
-		if(s != A) {
-			if(copysub(&p->to, v, s, 1))
-				return 1;
-			return 0;
-		}
-		if(copyau(&p->to, v))
-			return 4;
-		return 3;
-
-	case ATEXT:	/* funny */
-		if(v->type == D_REG)
-			if(v->reg == REGARG)
-				return 3;
-		return 0;
-	}
-}
-
-int
-a2type(Prog *p)
-{
-
-	switch(p->as) {
-
-	case ACMP:
-	case ACMN:
-
-	case AADD:
-	case ASUB:
-	case ARSB:
-	case ASLL:
-	case ASRL:
-	case ASRA:
-	case AORR:
-	case AAND:
-	case AEOR:
-	case AMUL:
-	case ADIV:
-	case ADIVU:
-		return D_REG;
-
-	case ACMPF:
-	case ACMPD:
-
-	case AADDF:
-	case AADDD:
-	case ASUBF:
-	case ASUBD:
-	case AMULF:
-	case AMULD:
-	case ADIVF:
-	case ADIVD:
-		return D_FREG;
-	}
-	return D_NONE;
-}
-
-/*
- * direct reference,
- * could be set/use depending on
- * semantics
- */
-int
-copyas(Addr *a, Addr *v)
-{
-
-	if(regtyp(v)) {
-		if(a->type == v->type)
-		if(a->reg == v->reg)
-			return 1;
-	} else if(v->type == D_CONST) {		/* for constprop */
-		if(a->type == v->type)
-		if(a->name == v->name)
-		if(a->sym == v->sym)
-		if(a->reg == v->reg)
-		if(a->offset == v->offset)
-			return 1;
-	}
-	return 0;
-}
-
-/*
- * either direct or indirect
- */
-int
-copyau(Addr *a, Addr *v)
-{
-
-	if(copyas(a, v))
-		return 1;
-	if(v->type == D_REG) {
-		if(a->type == D_OREG) {
-			if(v->reg == a->reg)
-				return 1;
-		} else if(a->type == D_SHIFT) {
-			if((a->offset&0xf) == v->reg)
-				return 1;
-			if((a->offset&(1<<4)) && (a->offset>>8) == v->reg)
-				return 1;
-		}
-	}
-	return 0;
-}
-
-int
-copyau1(Prog *p, Addr *v)
-{
-
-	if(regtyp(v)) {
-		if(a2type(p) == v->type)
-		if(p->reg == v->reg) {
-			if(a2type(p) != v->type)
-				print("botch a2type %P\n", p);
-			return 1;
-		}
-	}
-	return 0;
-}
-
-/*
- * substitute s for v in a
- * return failure to substitute
- */
-int
-copysub(Addr *a, Addr *v, Addr *s, int f)
-{
-
-	if(f)
-	if(copyau(a, v)) {
-		if(a->type == D_SHIFT) {
-			if((a->offset&0xf) == v->reg)
-				a->offset = (a->offset&~0xf)|s->reg;
-			if((a->offset&(1<<4)) && (a->offset>>8) == v->reg)
-				a->offset = (a->offset&~(0xf<<8))|(s->reg<<8);
-		} else
-			a->reg = s->reg;
-	}
-	return 0;
-}
-
-int
-copysub1(Prog *p1, Addr *v, Addr *s, int f)
-{
-
-	if(f)
-	if(copyau1(p1, v))
-		p1->reg = s->reg;
-	return 0;
-}
-
-struct {
-	int opcode;
-	int notopcode;
-	int scond;
-	int notscond;
-} predinfo[]  = {
-	{ ABEQ,	ABNE,	0x0,	0x1, },
-	{ ABNE,	ABEQ,	0x1,	0x0, },
-	{ ABCS,	ABCC,	0x2,	0x3, },
-	{ ABHS,	ABLO,	0x2,	0x3, },
-	{ ABCC,	ABCS,	0x3,	0x2, },
-	{ ABLO,	ABHS,	0x3,	0x2, },
-	{ ABMI,	ABPL,	0x4,	0x5, },
-	{ ABPL,	ABMI,	0x5,	0x4, },
-	{ ABVS,	ABVC,	0x6,	0x7, },
-	{ ABVC,	ABVS,	0x7,	0x6, },
-	{ ABHI,	ABLS,	0x8,	0x9, },
-	{ ABLS,	ABHI,	0x9,	0x8, },
-	{ ABGE,	ABLT,	0xA,	0xB, },
-	{ ABLT,	ABGE,	0xB,	0xA, },
-	{ ABGT,	ABLE,	0xC,	0xD, },
-	{ ABLE,	ABGT,	0xD,	0xC, },
-};
-
-typedef struct {
-	Reg *start;
-	Reg *last;
-	Reg *end;
-	int len;
-} Joininfo;
-
-enum {
-	Join,
-	Split,
-	End,
-	Branch,
-	Setcond,
-	Toolong
-};
-
-enum {
-	Falsecond,
-	Truecond,
-	Delbranch,
-	Keepbranch
-};
-
-int
-isbranch(Prog *p)
-{
-	return (ABEQ <= p->as) && (p->as <= ABLE);
-}
-
-int
-predicable(Prog *p)
-{
-	if (isbranch(p)
-		|| p->as == ANOP
-		|| p->as == AXXX
-		|| p->as == ADATA
-		|| p->as == AGLOBL
-		|| p->as == AGOK
-		|| p->as == AHISTORY
-		|| p->as == ANAME
-		|| p->as == ASIGNAME
-		|| p->as == ATEXT
-		|| p->as == AWORD
-		|| p->as == ABCASE
-		|| p->as == ACASE)
-		return 0;
-	return 1;
-}
-
-/*
- * Depends on an analysis of the encodings performed by 5l.
- * These seem to be all of the opcodes that lead to the "S" bit
- * being set in the instruction encodings.
- *
- * C_SBIT may also have been set explicitly in p->scond.
- */
-int
-modifiescpsr(Prog *p)
-{
-	return (p->scond&C_SBIT)
-		|| p->as == ATST
-		|| p->as == ATEQ
-		|| p->as == ACMN
-		|| p->as == ACMP
-		|| p->as == AMULU
-		|| p->as == ADIVU
-		|| p->as == AMUL
-		|| p->as == ADIV
-		|| p->as == AMOD
-		|| p->as == AMODU
-		|| p->as == ABL;
-}
-
-/*
- * Find the maximal chain of instructions starting with r which could
- * be executed conditionally
- */
-int
-joinsplit(Reg *r, Joininfo *j)
-{
-	j->start = r;
-	j->last = r;
-	j->len = 0;
-	do {
-		if (r->p2 && (r->p1 || r->p2->p2link)) {
-			j->end = r;
-			return Join;
-		}
-		if (r->s1 && r->s2) {
-			j->end = r;
-			return Split;
-		}
-		j->last = r;
-		if (r->prog->as != ANOP)
-			j->len++;
-		if (!r->s1 && !r->s2) {
-			j->end = r->link;
-			return End;
-		}
-		if (r->s2) {
-			j->end = r->s2;
-			return Branch;
-		}
-		if (modifiescpsr(r->prog)) {
-			j->end = r->s1;
-			return Setcond;
-		}
-		r = r->s1;
-	} while (j->len < 4);
-	j->end = r;
-	return Toolong;
-}
-
-Reg *
-successor(Reg *r)
-{
-	if (r->s1)
-		return r->s1;
-	else
-		return r->s2;
-}
-
-void
-applypred(Reg *rstart, Joininfo *j, int cond, int branch)
-{
-	int pred;
-	Reg *r;
-
-	if(j->len == 0)
-		return;
-	if (cond == Truecond)
-		pred = predinfo[rstart->prog->as - ABEQ].scond;
-	else
-		pred = predinfo[rstart->prog->as - ABEQ].notscond;
-
-	for (r = j->start; ; r = successor(r)) {
-		if (r->prog->as == AB) {
-			if (r != j->last || branch == Delbranch)
-				excise(r);
-			else {
-			  if (cond == Truecond)
-				r->prog->as = predinfo[rstart->prog->as - ABEQ].opcode;
-			  else
-				r->prog->as = predinfo[rstart->prog->as - ABEQ].notopcode;
-			}
-		}
-		else if (predicable(r->prog))
-			r->prog->scond = (r->prog->scond&~C_SCOND)|pred;
-		if (r->s1 != r->link) {
-			r->s1 = r->link;
-			r->link->p1 = r;
-		}
-		if (r == j->last)
-			break;
-	}
-}
-
-void
-predicate(void)
-{
-	Reg *r;
-	int t1, t2;
-	Joininfo j1, j2;
-
-	for(r=firstr; r!=R; r=r->link) {
-		if (isbranch(r->prog)) {
-			t1 = joinsplit(r->s1, &j1);
-			t2 = joinsplit(r->s2, &j2);
-			if(j1.last->link != j2.start)
-				continue;
-			if(j1.end == j2.end)
-			if((t1 == Branch && (t2 == Join || t2 == Setcond)) ||
-			   (t2 == Join && (t1 == Join || t1 == Setcond))) {
-				applypred(r, &j1, Falsecond, Delbranch);
-				applypred(r, &j2, Truecond, Delbranch);
-				excise(r);
-				continue;
-			}
-			if(t1 == End || t1 == Branch) {
-				applypred(r, &j1, Falsecond, Keepbranch);
-				excise(r);
-				continue;
-			}
-		}
-	}
-}