Imported Upstream version 60upstream/60

13 files changed, 8543 insertions, 0 deletions

diff --git a/src/cmd/6c/Makefile b/src/cmd/6c/Makefile
new file mode 100644
index 000000000..484e16def
--- /dev/null
+++ b/src/cmd/6c/Makefile
@@ -0,0 +1,36 @@
+# Copyright 2009 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+include ../../Make.inc
+O:=$(HOST_O)
+
+TARG=6c
+
+HFILES=\
+	gc.h\
+	../6l/6.out.h\
+	../cc/cc.h\
+
+OFILES=\
+	cgen.$O\
+	list.$O\
+	sgen.$O\
+	swt.$O\
+	txt.$O\
+	pgen.$O\
+	pswt.$O\
+	div.$O\
+	mul.$O\
+	reg.$O\
+	peep.$O\
+	machcap.$O\
+	../6l/enam.$O\
+
+LIB=\
+	../cc/cc.a\
+
+include ../../Make.ccmd
+
+%.$O: ../cc/%.c
+	$(HOST_CC) $(HOST_CFLAGS) -c -I. -o $@ ../cc/$*.c
diff --git a/src/cmd/6c/cgen.c b/src/cmd/6c/cgen.c
new file mode 100644
index 000000000..7f717dcbb
--- /dev/null
+++ b/src/cmd/6c/cgen.c
@@ -0,0 +1,1976 @@
+// Inferno utils/6c/cgen.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6c/cgen.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"
+
+/* ,x/^(print|prtree)\(/i/\/\/ */
+int castup(Type*, Type*);
+int vaddr(Node *n, int a);
+
+void
+cgen(Node *n, Node *nn)
+{
+	Node *l, *r, *t;
+	Prog *p1;
+	Node nod, nod1, nod2, nod3, nod4;
+	int o, hardleft;
+	int32 v, curs;
+	vlong c;
+
+	if(debug['g']) {
+		prtree(nn, "cgen lhs");
+		prtree(n, "cgen");
+	}
+	if(n == Z || n->type == T)
+		return;
+	if(typesu[n->type->etype]) {
+		sugen(n, nn, n->type->width);
+		return;
+	}
+	l = n->left;
+	r = n->right;
+	o = n->op;
+	
+	if(n->op == OEXREG || (nn != Z && nn->op == OEXREG)) {
+		gmove(n, nn);
+		return;
+	}
+
+	if(n->addable >= INDEXED) {
+		if(nn == Z) {
+			switch(o) {
+			default:
+				nullwarn(Z, Z);
+				break;
+			case OINDEX:
+				nullwarn(l, r);
+				break;
+			}
+			return;
+		}
+		gmove(n, nn);
+		return;
+	}
+	curs = cursafe;
+
+	if(l->complex >= FNX)
+	if(r != Z && r->complex >= FNX)
+	switch(o) {
+	default:
+		if(cond(o) && typesu[l->type->etype])
+			break;
+
+		regret(&nod, r);
+		cgen(r, &nod);
+
+		regsalloc(&nod1, r);
+		gmove(&nod, &nod1);
+
+		regfree(&nod);
+		nod = *n;
+		nod.right = &nod1;
+
+		cgen(&nod, nn);
+		return;
+
+	case OFUNC:
+	case OCOMMA:
+	case OANDAND:
+	case OOROR:
+	case OCOND:
+	case ODOT:
+		break;
+	}
+
+	hardleft = l->addable < INDEXED || l->complex >= FNX;
+	switch(o) {
+	default:
+		diag(n, "unknown op in cgen: %O", o);
+		break;
+
+	case ONEG:
+	case OCOM:
+		if(nn == Z) {
+			nullwarn(l, Z);
+			break;
+		}
+		regalloc(&nod, l, nn);
+		cgen(l, &nod);
+		gopcode(o, n->type, Z, &nod);
+		gmove(&nod, nn);
+		regfree(&nod);
+		break;
+
+	case OAS:
+		if(l->op == OBIT)
+			goto bitas;
+		if(!hardleft) {
+			if(nn != Z || r->addable < INDEXED || hardconst(r)) {
+				if(r->complex >= FNX && nn == Z)
+					regret(&nod, r);
+				else
+					regalloc(&nod, r, nn);
+				cgen(r, &nod);
+				gmove(&nod, l);
+				if(nn != Z)
+					gmove(&nod, nn);
+				regfree(&nod);
+			} else
+				gmove(r, l);
+			break;
+		}
+		if(l->complex >= r->complex) {
+			if(l->op == OINDEX && immconst(r)) {
+				gmove(r, l);
+				break;
+			}
+			reglcgen(&nod1, l, Z);
+			if(r->addable >= INDEXED && !hardconst(r)) {
+				gmove(r, &nod1);
+				if(nn != Z)
+					gmove(r, nn);
+				regfree(&nod1);
+				break;
+			}
+			regalloc(&nod, r, nn);
+			cgen(r, &nod);
+		} else {
+			regalloc(&nod, r, nn);
+			cgen(r, &nod);
+			reglcgen(&nod1, l, Z);
+		}
+		gmove(&nod, &nod1);
+		regfree(&nod);
+		regfree(&nod1);
+		break;
+
+	bitas:
+		n = l->left;
+		regalloc(&nod, r, nn);
+		if(l->complex >= r->complex) {
+			reglcgen(&nod1, n, Z);
+			cgen(r, &nod);
+		} else {
+			cgen(r, &nod);
+			reglcgen(&nod1, n, Z);
+		}
+		regalloc(&nod2, n, Z);
+		gmove(&nod1, &nod2);
+		bitstore(l, &nod, &nod1, &nod2, nn);
+		break;
+
+	case OBIT:
+		if(nn == Z) {
+			nullwarn(l, Z);
+			break;
+		}
+		bitload(n, &nod, Z, Z, nn);
+		gmove(&nod, nn);
+		regfree(&nod);
+		break;
+
+	case OLSHR:
+	case OASHL:
+	case OASHR:
+		if(nn == Z) {
+			nullwarn(l, r);
+			break;
+		}
+		if(r->op == OCONST) {
+			if(r->vconst == 0) {
+				cgen(l, nn);
+				break;
+			}
+			regalloc(&nod, l, nn);
+			cgen(l, &nod);
+			if(o == OASHL && r->vconst == 1)
+				gopcode(OADD, n->type, &nod, &nod);
+			else
+				gopcode(o, n->type, r, &nod);
+			gmove(&nod, nn);
+			regfree(&nod);
+			break;
+		}
+
+		/*
+		 * get nod to be D_CX
+		 */
+		if(nodreg(&nod, nn, D_CX)) {
+			regsalloc(&nod1, n);
+			gmove(&nod, &nod1);
+			cgen(n, &nod);		/* probably a bug */
+			gmove(&nod, nn);
+			gmove(&nod1, &nod);
+			break;
+		}
+		reg[D_CX]++;
+		if(nn->op == OREGISTER && nn->reg == D_CX)
+			regalloc(&nod1, l, Z);
+		else
+			regalloc(&nod1, l, nn);
+		if(r->complex >= l->complex) {
+			cgen(r, &nod);
+			cgen(l, &nod1);
+		} else {
+			cgen(l, &nod1);
+			cgen(r, &nod);
+		}
+		gopcode(o, n->type, &nod, &nod1);
+		gmove(&nod1, nn);
+		regfree(&nod);
+		regfree(&nod1);
+		break;
+
+	case OADD:
+	case OSUB:
+	case OOR:
+	case OXOR:
+	case OAND:
+		if(nn == Z) {
+			nullwarn(l, r);
+			break;
+		}
+		if(typefd[n->type->etype])
+			goto fop;
+		if(r->op == OCONST) {
+			if(r->vconst == 0 && o != OAND) {
+				cgen(l, nn);
+				break;
+			}
+		}
+		if(n->op == OADD && l->op == OASHL && l->right->op == OCONST
+		&& (r->op != OCONST || r->vconst < -128 || r->vconst > 127)) {
+			c = l->right->vconst;
+			if(c > 0 && c <= 3) {
+				if(l->left->complex >= r->complex) {
+					regalloc(&nod, l->left, nn);
+					cgen(l->left, &nod);
+					if(r->addable < INDEXED) {
+						regalloc(&nod1, r, Z);
+						cgen(r, &nod1);
+						genmuladd(&nod, &nod, 1 << c, &nod1);
+						regfree(&nod1);
+					}
+					else
+						genmuladd(&nod, &nod, 1 << c, r);
+				}
+				else {
+					regalloc(&nod, r, nn);
+					cgen(r, &nod);
+					regalloc(&nod1, l->left, Z);
+					cgen(l->left, &nod1);
+					genmuladd(&nod, &nod1, 1 << c, &nod);
+					regfree(&nod1);
+				}
+				gmove(&nod, nn);
+				regfree(&nod);
+				break;
+			}
+		}
+		if(r->addable >= INDEXED && !hardconst(r)) {
+			regalloc(&nod, l, nn);
+			cgen(l, &nod);
+			gopcode(o, n->type, r, &nod);
+			gmove(&nod, nn);
+			regfree(&nod);
+			break;
+		}
+		if(l->complex >= r->complex) {
+			regalloc(&nod, l, nn);
+			cgen(l, &nod);
+			regalloc(&nod1, r, Z);
+			cgen(r, &nod1);
+			gopcode(o, n->type, &nod1, &nod);
+		} else {
+			regalloc(&nod1, r, nn);
+			cgen(r, &nod1);
+			regalloc(&nod, l, Z);
+			cgen(l, &nod);
+			gopcode(o, n->type, &nod1, &nod);
+		}
+		gmove(&nod, nn);
+		regfree(&nod);
+		regfree(&nod1);
+		break;
+
+	case OLMOD:
+	case OMOD:
+	case OLMUL:
+	case OLDIV:
+	case OMUL:
+	case ODIV:
+		if(nn == Z) {
+			nullwarn(l, r);
+			break;
+		}
+		if(typefd[n->type->etype])
+			goto fop;
+		if(r->op == OCONST && typechl[n->type->etype]) {	/* TO DO */
+			SET(v);
+			switch(o) {
+			case ODIV:
+			case OMOD:
+				c = r->vconst;
+				if(c < 0)
+					c = -c;
+				v = xlog2(c);
+				if(v < 0)
+					break;
+				/* fall thru */
+			case OMUL:
+			case OLMUL:
+				regalloc(&nod, l, nn);
+				cgen(l, &nod);
+				switch(o) {
+				case OMUL:
+				case OLMUL:
+					mulgen(n->type, r, &nod);
+					break;
+				case ODIV:
+					sdiv2(r->vconst, v, l, &nod);
+					break;
+				case OMOD:
+					smod2(r->vconst, v, l, &nod);
+					break;
+				}
+				gmove(&nod, nn);
+				regfree(&nod);
+				goto done;
+			case OLDIV:
+				c = r->vconst;
+				if((c & 0x80000000) == 0)
+					break;
+				regalloc(&nod1, l, Z);
+				cgen(l, &nod1);
+				regalloc(&nod, l, nn);
+				zeroregm(&nod);
+				gins(ACMPL, &nod1, nodconst(c));
+				gins(ASBBL, nodconst(-1), &nod);
+				regfree(&nod1);
+				gmove(&nod, nn);
+				regfree(&nod);
+				goto done;
+			}
+		}
+
+		if(o == OMUL) {
+			if(l->addable >= INDEXED) {
+				t = l;
+				l = r;
+				r = t;
+			}
+			/* should favour AX */
+			regalloc(&nod, l, nn);
+			cgen(l, &nod);
+			if(r->addable < INDEXED || hardconst(r)) {
+				regalloc(&nod1, r, Z);
+				cgen(r, &nod1);
+				gopcode(OMUL, n->type, &nod1, &nod);
+				regfree(&nod1);
+			}else
+				gopcode(OMUL, n->type, r, &nod);	/* addressible */
+			gmove(&nod, nn);
+			regfree(&nod);
+			break;
+		}
+
+		/*
+		 * get nod to be D_AX
+		 * get nod1 to be D_DX
+		 */
+		if(nodreg(&nod, nn, D_AX)) {
+			regsalloc(&nod2, n);
+			gmove(&nod, &nod2);
+			v = reg[D_AX];
+			reg[D_AX] = 0;
+
+			if(isreg(l, D_AX)) {
+				nod3 = *n;
+				nod3.left = &nod2;
+				cgen(&nod3, nn);
+			} else
+			if(isreg(r, D_AX)) {
+				nod3 = *n;
+				nod3.right = &nod2;
+				cgen(&nod3, nn);
+			} else
+				cgen(n, nn);
+
+			gmove(&nod2, &nod);
+			reg[D_AX] = v;
+			break;
+		}
+		if(nodreg(&nod1, nn, D_DX)) {
+			regsalloc(&nod2, n);
+			gmove(&nod1, &nod2);
+			v = reg[D_DX];
+			reg[D_DX] = 0;
+
+			if(isreg(l, D_DX)) {
+				nod3 = *n;
+				nod3.left = &nod2;
+				cgen(&nod3, nn);
+			} else
+			if(isreg(r, D_DX)) {
+				nod3 = *n;
+				nod3.right = &nod2;
+				cgen(&nod3, nn);
+			} else
+				cgen(n, nn);
+
+			gmove(&nod2, &nod1);
+			reg[D_DX] = v;
+			break;
+		}
+		reg[D_AX]++;
+
+		if(r->op == OCONST && (o == ODIV || o == OLDIV) && immconst(r) && typechl[r->type->etype]) {
+			reg[D_DX]++;
+			if(l->addable < INDEXED) {
+				regalloc(&nod2, l, Z);
+				cgen(l, &nod2);
+				l = &nod2;
+			}
+			if(o == ODIV)
+				sdivgen(l, r, &nod, &nod1);
+			else
+				udivgen(l, r, &nod, &nod1);
+			gmove(&nod1, nn);
+			if(l == &nod2)
+				regfree(l);
+			goto freeaxdx;
+		}
+
+		if(l->complex >= r->complex) {
+			cgen(l, &nod);
+			reg[D_DX]++;
+			if(o == ODIV || o == OMOD)
+				gins(typechl[l->type->etype]? ACDQ: ACQO, Z, Z);
+			if(o == OLDIV || o == OLMOD)
+				zeroregm(&nod1);
+			if(r->addable < INDEXED || r->op == OCONST) {
+				regsalloc(&nod3, r);
+				cgen(r, &nod3);
+				gopcode(o, n->type, &nod3, Z);
+			} else
+				gopcode(o, n->type, r, Z);
+		} else {
+			regsalloc(&nod3, r);
+			cgen(r, &nod3);
+			cgen(l, &nod);
+			reg[D_DX]++;
+			if(o == ODIV || o == OMOD)
+				gins(typechl[l->type->etype]? ACDQ: ACQO, Z, Z);
+			if(o == OLDIV || o == OLMOD)
+				zeroregm(&nod1);
+			gopcode(o, n->type, &nod3, Z);
+		}
+		if(o == OMOD || o == OLMOD)
+			gmove(&nod1, nn);
+		else
+			gmove(&nod, nn);
+	freeaxdx:
+		regfree(&nod);
+		regfree(&nod1);
+		break;
+
+	case OASLSHR:
+	case OASASHL:
+	case OASASHR:
+		if(r->op == OCONST)
+			goto asand;
+		if(l->op == OBIT)
+			goto asbitop;
+		if(typefd[n->type->etype])
+			goto asand;	/* can this happen? */
+
+		/*
+		 * get nod to be D_CX
+		 */
+		if(nodreg(&nod, nn, D_CX)) {
+			regsalloc(&nod1, n);
+			gmove(&nod, &nod1);
+			cgen(n, &nod);
+			if(nn != Z)
+				gmove(&nod, nn);
+			gmove(&nod1, &nod);
+			break;
+		}
+		reg[D_CX]++;
+
+		if(r->complex >= l->complex) {
+			cgen(r, &nod);
+			if(hardleft)
+				reglcgen(&nod1, l, Z);
+			else
+				nod1 = *l;
+		} else {
+			if(hardleft)
+				reglcgen(&nod1, l, Z);
+			else
+				nod1 = *l;
+			cgen(r, &nod);
+		}
+
+		gopcode(o, l->type, &nod, &nod1);
+		regfree(&nod);
+		if(nn != Z)
+			gmove(&nod1, nn);
+		if(hardleft)
+			regfree(&nod1);
+		break;
+
+	case OASAND:
+	case OASADD:
+	case OASSUB:
+	case OASXOR:
+	case OASOR:
+	asand:
+		if(l->op == OBIT)
+			goto asbitop;
+		if(typefd[l->type->etype] || typefd[r->type->etype])
+			goto asfop;
+		if(l->complex >= r->complex) {
+			if(hardleft)
+				reglcgen(&nod, l, Z);
+			else
+				nod = *l;
+			if(!immconst(r)) {
+				regalloc(&nod1, r, nn);
+				cgen(r, &nod1);
+				gopcode(o, l->type, &nod1, &nod);
+				regfree(&nod1);
+			} else
+				gopcode(o, l->type, r, &nod);
+		} else {
+			regalloc(&nod1, r, nn);
+			cgen(r, &nod1);
+			if(hardleft)
+				reglcgen(&nod, l, Z);
+			else
+				nod = *l;
+			gopcode(o, l->type, &nod1, &nod);
+			regfree(&nod1);
+		}
+		if(nn != Z)
+			gmove(&nod, nn);
+		if(hardleft)
+			regfree(&nod);
+		break;
+
+	asfop:
+		if(l->complex >= r->complex) {
+			if(hardleft)
+				reglcgen(&nod, l, Z);
+			else
+				nod = *l;
+			if(r->addable < INDEXED){
+				regalloc(&nod1, r, nn);
+				cgen(r, &nod1);
+			}else
+				nod1 = *r;
+			regalloc(&nod2, r, Z);
+			gmove(&nod, &nod2);
+			gopcode(o, r->type, &nod1, &nod2);
+			gmove(&nod2, &nod);
+			regfree(&nod2);
+			if(r->addable < INDEXED)
+				regfree(&nod1);
+		} else {
+			regalloc(&nod1, r, nn);
+			cgen(r, &nod1);
+			if(hardleft)
+				reglcgen(&nod, l, Z);
+			else
+				nod = *l;
+			if(o != OASMUL && o != OASADD) {
+				regalloc(&nod2, r, Z);
+				gmove(&nod, &nod2);
+				gopcode(o, r->type, &nod1, &nod2);
+				regfree(&nod1);
+				gmove(&nod2, &nod);
+				regfree(&nod2);
+			} else {
+				gopcode(o, r->type, &nod, &nod1);
+				gmove(&nod1, &nod);
+				regfree(&nod1);
+			}
+		}
+		if(nn != Z)
+			gmove(&nod, nn);
+		if(hardleft)
+			regfree(&nod);
+		break;
+
+	case OASLMUL:
+	case OASLDIV:
+	case OASLMOD:
+	case OASMUL:
+	case OASDIV:
+	case OASMOD:
+		if(l->op == OBIT)
+			goto asbitop;
+		if(typefd[n->type->etype] || typefd[r->type->etype])
+			goto asfop;
+		if(r->op == OCONST && typechl[n->type->etype]) {
+			SET(v);
+			switch(o) {
+			case OASDIV:
+			case OASMOD:
+				c = r->vconst;
+				if(c < 0)
+					c = -c;
+				v = xlog2(c);
+				if(v < 0)
+					break;
+				/* fall thru */
+			case OASMUL:
+			case OASLMUL:
+				if(hardleft)
+					reglcgen(&nod2, l, Z);
+				else
+					nod2 = *l;
+				regalloc(&nod, l, nn);
+				cgen(&nod2, &nod);
+				switch(o) {
+				case OASMUL:
+				case OASLMUL:
+					mulgen(n->type, r, &nod);
+					break;
+				case OASDIV:
+					sdiv2(r->vconst, v, l, &nod);
+					break;
+				case OASMOD:
+					smod2(r->vconst, v, l, &nod);
+					break;
+				}
+			havev:
+				gmove(&nod, &nod2);
+				if(nn != Z)
+					gmove(&nod, nn);
+				if(hardleft)
+					regfree(&nod2);
+				regfree(&nod);
+				goto done;
+			case OASLDIV:
+				c = r->vconst;
+				if((c & 0x80000000) == 0)
+					break;
+				if(hardleft)
+					reglcgen(&nod2, l, Z);
+				else
+					nod2 = *l;
+				regalloc(&nod1, l, nn);
+				cgen(&nod2, &nod1);
+				regalloc(&nod, l, nn);
+				zeroregm(&nod);
+				gins(ACMPL, &nod1, nodconst(c));
+				gins(ASBBL, nodconst(-1), &nod);
+				regfree(&nod1);
+				goto havev;
+			}
+		}
+
+		if(o == OASMUL) {
+			/* should favour AX */
+			regalloc(&nod, l, nn);
+			if(r->complex >= FNX) {
+				regalloc(&nod1, r, Z);
+				cgen(r, &nod1);
+				r = &nod1;
+			}
+			if(hardleft)
+				reglcgen(&nod2, l, Z);
+			else
+				nod2 = *l;
+			cgen(&nod2, &nod);
+			if(r->addable < INDEXED || hardconst(r)) {
+				if(r->complex < FNX) {
+					regalloc(&nod1, r, Z);
+					cgen(r, &nod1);
+				}
+				gopcode(OASMUL, n->type, &nod1, &nod);
+				regfree(&nod1);
+			}
+			else
+				gopcode(OASMUL, n->type, r, &nod);
+			if(r == &nod1)
+				regfree(r);
+			gmove(&nod, &nod2);
+			if(nn != Z)
+				gmove(&nod, nn);
+			regfree(&nod);
+			if(hardleft)
+				regfree(&nod2);
+			break;
+		}
+
+		/*
+		 * get nod to be D_AX
+		 * get nod1 to be D_DX
+		 */
+		if(nodreg(&nod, nn, D_AX)) {
+			regsalloc(&nod2, n);
+			gmove(&nod, &nod2);
+			v = reg[D_AX];
+			reg[D_AX] = 0;
+
+			if(isreg(l, D_AX)) {
+				nod3 = *n;
+				nod3.left = &nod2;
+				cgen(&nod3, nn);
+			} else
+			if(isreg(r, D_AX)) {
+				nod3 = *n;
+				nod3.right = &nod2;
+				cgen(&nod3, nn);
+			} else
+				cgen(n, nn);
+
+			gmove(&nod2, &nod);
+			reg[D_AX] = v;
+			break;
+		}
+		if(nodreg(&nod1, nn, D_DX)) {
+			regsalloc(&nod2, n);
+			gmove(&nod1, &nod2);
+			v = reg[D_DX];
+			reg[D_DX] = 0;
+
+			if(isreg(l, D_DX)) {
+				nod3 = *n;
+				nod3.left = &nod2;
+				cgen(&nod3, nn);
+			} else
+			if(isreg(r, D_DX)) {
+				nod3 = *n;
+				nod3.right = &nod2;
+				cgen(&nod3, nn);
+			} else
+				cgen(n, nn);
+
+			gmove(&nod2, &nod1);
+			reg[D_DX] = v;
+			break;
+		}
+		reg[D_AX]++;
+		reg[D_DX]++;
+
+		if(l->complex >= r->complex) {
+			if(hardleft)
+				reglcgen(&nod2, l, Z);
+			else
+				nod2 = *l;
+			cgen(&nod2, &nod);
+			if(r->op == OCONST && typechl[r->type->etype]) {
+				switch(o) {
+				case OASDIV:
+					sdivgen(&nod2, r, &nod, &nod1);
+					goto divdone;
+				case OASLDIV:
+					udivgen(&nod2, r, &nod, &nod1);
+				divdone:
+					gmove(&nod1, &nod2);
+					if(nn != Z)
+						gmove(&nod1, nn);
+					goto freelxaxdx;
+				}
+			}
+			if(o == OASDIV || o == OASMOD)
+				gins(typechl[l->type->etype]? ACDQ: ACQO, Z, Z);
+			if(o == OASLDIV || o == OASLMOD)
+				zeroregm(&nod1);
+			if(r->addable < INDEXED || r->op == OCONST ||
+			   !typeil[r->type->etype]) {
+				regalloc(&nod3, r, Z);
+				cgen(r, &nod3);
+				gopcode(o, l->type, &nod3, Z);
+				regfree(&nod3);
+			} else
+				gopcode(o, n->type, r, Z);
+		} else {
+			regalloc(&nod3, r, Z);
+			cgen(r, &nod3);
+			if(hardleft)
+				reglcgen(&nod2, l, Z);
+			else
+				nod2 = *l;
+			cgen(&nod2, &nod);
+			if(o == OASDIV || o == OASMOD)
+				gins(typechl[l->type->etype]? ACDQ: ACQO, Z, Z);
+			if(o == OASLDIV || o == OASLMOD)
+				zeroregm(&nod1);
+			gopcode(o, l->type, &nod3, Z);
+			regfree(&nod3);
+		}
+		if(o == OASMOD || o == OASLMOD) {
+			gmove(&nod1, &nod2);
+			if(nn != Z)
+				gmove(&nod1, nn);
+		} else {
+			gmove(&nod, &nod2);
+			if(nn != Z)
+				gmove(&nod, nn);
+		}
+	freelxaxdx:
+		if(hardleft)
+			regfree(&nod2);
+		regfree(&nod);
+		regfree(&nod1);
+		break;
+
+	fop:
+		if(l->complex >= r->complex) {
+			regalloc(&nod, l, nn);
+			cgen(l, &nod);
+			if(r->addable < INDEXED) {
+				regalloc(&nod1, r, Z);
+				cgen(r, &nod1);
+				gopcode(o, n->type, &nod1, &nod);
+				regfree(&nod1);
+			} else
+				gopcode(o, n->type, r, &nod);
+		} else {
+			/* TO DO: could do better with r->addable >= INDEXED */
+			regalloc(&nod1, r, Z);
+			cgen(r, &nod1);
+			regalloc(&nod, l, nn);
+			cgen(l, &nod);
+			gopcode(o, n->type, &nod1, &nod);
+			regfree(&nod1);
+		}
+		gmove(&nod, nn);
+		regfree(&nod);
+		break;
+
+	asbitop:
+		regalloc(&nod4, n, nn);
+		if(l->complex >= r->complex) {
+			bitload(l, &nod, &nod1, &nod2, &nod4);
+			regalloc(&nod3, r, Z);
+			cgen(r, &nod3);
+		} else {
+			regalloc(&nod3, r, Z);
+			cgen(r, &nod3);
+			bitload(l, &nod, &nod1, &nod2, &nod4);
+		}
+		gmove(&nod, &nod4);
+
+		{	/* TO DO: check floating point source */
+			Node onod;
+
+			/* incredible grot ... */
+			onod = nod3;
+			onod.op = o;
+			onod.complex = 2;
+			onod.addable = 0;
+			onod.type = tfield;
+			onod.left = &nod4;
+			onod.right = &nod3;
+			cgen(&onod, Z);
+		}
+		regfree(&nod3);
+		gmove(&nod4, &nod);
+		regfree(&nod4);
+		bitstore(l, &nod, &nod1, &nod2, nn);
+		break;
+
+	case OADDR:
+		if(nn == Z) {
+			nullwarn(l, Z);
+			break;
+		}
+		lcgen(l, nn);
+		break;
+
+	case OFUNC:
+		if(l->complex >= FNX) {
+			if(l->op != OIND)
+				diag(n, "bad function call");
+
+			regret(&nod, l->left);
+			cgen(l->left, &nod);
+			regsalloc(&nod1, l->left);
+			gmove(&nod, &nod1);
+			regfree(&nod);
+
+			nod = *n;
+			nod.left = &nod2;
+			nod2 = *l;
+			nod2.left = &nod1;
+			nod2.complex = 1;
+			cgen(&nod, nn);
+
+			return;
+		}
+		gargs(r, &nod, &nod1);
+		if(l->addable < INDEXED) {
+			reglcgen(&nod, l, nn);
+			nod.op = OREGISTER;
+			gopcode(OFUNC, n->type, Z, &nod);
+			regfree(&nod);
+		} else
+			gopcode(OFUNC, n->type, Z, l);
+		if(REGARG >= 0 && reg[REGARG])
+			reg[REGARG]--;
+		if(nn != Z) {
+			regret(&nod, n);
+			gmove(&nod, nn);
+			regfree(&nod);
+		}
+		break;
+
+	case OIND:
+		if(nn == Z) {
+			nullwarn(l, Z);
+			break;
+		}
+		regialloc(&nod, n, nn);
+		r = l;
+		while(r->op == OADD)
+			r = r->right;
+		if(sconst(r)) {
+			v = r->vconst;
+			r->vconst = 0;
+			cgen(l, &nod);
+			nod.xoffset += v;
+			r->vconst = v;
+		} else
+			cgen(l, &nod);
+		regind(&nod, n);
+		gmove(&nod, nn);
+		regfree(&nod);
+		break;
+
+	case OEQ:
+	case ONE:
+	case OLE:
+	case OLT:
+	case OGE:
+	case OGT:
+	case OLO:
+	case OLS:
+	case OHI:
+	case OHS:
+		if(nn == Z) {
+			nullwarn(l, r);
+			break;
+		}
+		boolgen(n, 1, nn);
+		break;
+
+	case OANDAND:
+	case OOROR:
+		boolgen(n, 1, nn);
+		if(nn == Z)
+			patch(p, pc);
+		break;
+
+	case ONOT:
+		if(nn == Z) {
+			nullwarn(l, Z);
+			break;
+		}
+		boolgen(n, 1, nn);
+		break;
+
+	case OCOMMA:
+		cgen(l, Z);
+		cgen(r, nn);
+		break;
+
+	case OCAST:
+		if(nn == Z) {
+			nullwarn(l, Z);
+			break;
+		}
+		/*
+		 * convert from types l->n->nn
+		 */
+		if(nocast(l->type, n->type) && nocast(n->type, nn->type)) {
+			/* both null, gen l->nn */
+			cgen(l, nn);
+			break;
+		}
+		if(ewidth[n->type->etype] < ewidth[l->type->etype]){
+			if(l->type->etype == TIND && typechlp[n->type->etype])
+				warn(n, "conversion of pointer to shorter integer");
+		}else if(0){
+			if(nocast(n->type, nn->type) || castup(n->type, nn->type)){
+				if(typefd[l->type->etype] != typefd[nn->type->etype])
+					regalloc(&nod, l, nn);
+				else
+					regalloc(&nod, nn, nn);
+				cgen(l, &nod);
+				gmove(&nod, nn);
+				regfree(&nod);
+				break;
+			}
+		}
+		regalloc(&nod, l, nn);
+		cgen(l, &nod);
+		regalloc(&nod1, n, &nod);
+		gmove(&nod, &nod1);
+		gmove(&nod1, nn);
+		regfree(&nod1);
+		regfree(&nod);
+		break;
+
+	case ODOT:
+		sugen(l, nodrat, l->type->width);
+		if(nn == Z)
+			break;
+		warn(n, "non-interruptable temporary");
+		nod = *nodrat;
+		if(!r || r->op != OCONST) {
+			diag(n, "DOT and no offset");
+			break;
+		}
+		nod.xoffset += (int32)r->vconst;
+		nod.type = n->type;
+		cgen(&nod, nn);
+		break;
+
+	case OCOND:
+		bcgen(l, 1);
+		p1 = p;
+		cgen(r->left, nn);
+		gbranch(OGOTO);
+		patch(p1, pc);
+		p1 = p;
+		cgen(r->right, nn);
+		patch(p1, pc);
+		break;
+
+	case OPOSTINC:
+	case OPOSTDEC:
+		v = 1;
+		if(l->type->etype == TIND)
+			v = l->type->link->width;
+		if(o == OPOSTDEC)
+			v = -v;
+		if(l->op == OBIT)
+			goto bitinc;
+		if(nn == Z)
+			goto pre;
+
+		if(hardleft)
+			reglcgen(&nod, l, Z);
+		else
+			nod = *l;
+
+		gmove(&nod, nn);
+		if(typefd[n->type->etype]) {
+			regalloc(&nod1, l, Z);
+			gmove(&nod, &nod1);
+			if(v < 0)
+				gopcode(OSUB, n->type, nodfconst(-v), &nod1);
+			else
+				gopcode(OADD, n->type, nodfconst(v), &nod1);
+			gmove(&nod1, &nod);
+			regfree(&nod1);
+		} else
+			gopcode(OADD, n->type, nodconst(v), &nod);
+		if(hardleft)
+			regfree(&nod);
+		break;
+
+	case OPREINC:
+	case OPREDEC:
+		v = 1;
+		if(l->type->etype == TIND)
+			v = l->type->link->width;
+		if(o == OPREDEC)
+			v = -v;
+		if(l->op == OBIT)
+			goto bitinc;
+
+	pre:
+		if(hardleft)
+			reglcgen(&nod, l, Z);
+		else
+			nod = *l;
+		if(typefd[n->type->etype]) {
+			regalloc(&nod1, l, Z);
+			gmove(&nod, &nod1);
+			if(v < 0)
+				gopcode(OSUB, n->type, nodfconst(-v), &nod1);
+			else
+				gopcode(OADD, n->type, nodfconst(v), &nod1);
+			gmove(&nod1, &nod);
+			regfree(&nod1);
+		} else
+			gopcode(OADD, n->type, nodconst(v), &nod);
+		if(nn != Z)
+			gmove(&nod, nn);
+		if(hardleft)
+			regfree(&nod);
+		break;
+
+	bitinc:
+		if(nn != Z && (o == OPOSTINC || o == OPOSTDEC)) {
+			bitload(l, &nod, &nod1, &nod2, Z);
+			gmove(&nod, nn);
+			gopcode(OADD, tfield, nodconst(v), &nod);
+			bitstore(l, &nod, &nod1, &nod2, Z);
+			break;
+		}
+		bitload(l, &nod, &nod1, &nod2, nn);
+		gopcode(OADD, tfield, nodconst(v), &nod);
+		bitstore(l, &nod, &nod1, &nod2, nn);
+		break;
+	}
+done:
+	cursafe = curs;
+}
+
+void
+reglcgen(Node *t, Node *n, Node *nn)
+{
+	Node *r;
+	int32 v;
+
+	regialloc(t, n, nn);
+	if(n->op == OIND) {
+		r = n->left;
+		while(r->op == OADD)
+			r = r->right;
+		if(sconst(r)) {
+			v = r->vconst;
+			r->vconst = 0;
+			lcgen(n, t);
+			t->xoffset += v;
+			r->vconst = v;
+			regind(t, n);
+			return;
+		}
+	}
+	lcgen(n, t);
+	regind(t, n);
+}
+
+void
+lcgen(Node *n, Node *nn)
+{
+	Prog *p1;
+	Node nod;
+
+	if(debug['g']) {
+		prtree(nn, "lcgen lhs");
+		prtree(n, "lcgen");
+	}
+	if(n == Z || n->type == T)
+		return;
+	if(nn == Z) {
+		nn = &nod;
+		regalloc(&nod, n, Z);
+	}
+	switch(n->op) {
+	default:
+		if(n->addable < INDEXED) {
+			diag(n, "unknown op in lcgen: %O", n->op);
+			break;
+		}
+		gopcode(OADDR, n->type, n, nn);
+		break;
+
+	case OCOMMA:
+		cgen(n->left, n->left);
+		lcgen(n->right, nn);
+		break;
+
+	case OIND:
+		cgen(n->left, nn);
+		break;
+
+	case OCOND:
+		bcgen(n->left, 1);
+		p1 = p;
+		lcgen(n->right->left, nn);
+		gbranch(OGOTO);
+		patch(p1, pc);
+		p1 = p;
+		lcgen(n->right->right, nn);
+		patch(p1, pc);
+		break;
+	}
+}
+
+void
+bcgen(Node *n, int true)
+{
+
+	if(n->type == T)
+		gbranch(OGOTO);
+	else
+		boolgen(n, true, Z);
+}
+
+void
+boolgen(Node *n, int true, Node *nn)
+{
+	int o;
+	Prog *p1, *p2;
+	Node *l, *r, nod, nod1;
+	int32 curs;
+
+	if(debug['g']) {
+		prtree(nn, "boolgen lhs");
+		prtree(n, "boolgen");
+	}
+	curs = cursafe;
+	l = n->left;
+	r = n->right;
+	switch(n->op) {
+
+	default:
+		o = ONE;
+		if(true)
+			o = OEQ;
+		/* bad, 13 is address of external that becomes constant */
+		if(n->addable >= INDEXED && n->addable != 13) {
+			if(typefd[n->type->etype]) {
+				regalloc(&nod1, n, Z);
+				gmove(nodfconst(0.0), &nod1);	/* TO DO: FREGZERO */
+				gopcode(o, n->type, n, &nod1);
+				regfree(&nod1);
+			} else
+				gopcode(o, n->type, n, nodconst(0));
+			goto com;
+		}
+		regalloc(&nod, n, nn);
+		cgen(n, &nod);
+		if(typefd[n->type->etype]) {
+			regalloc(&nod1, n, Z);
+			gmove(nodfconst(0.0), &nod1);	/* TO DO: FREGZERO */
+			gopcode(o, n->type, &nod, &nod1);
+			regfree(&nod1);
+		} else
+			gopcode(o, n->type, &nod, nodconst(0));
+		regfree(&nod);
+		goto com;
+
+	case OCONST:
+		o = vconst(n);
+		if(!true)
+			o = !o;
+		gbranch(OGOTO);
+		if(o) {
+			p1 = p;
+			gbranch(OGOTO);
+			patch(p1, pc);
+		}
+		goto com;
+
+	case OCOMMA:
+		cgen(l, Z);
+		boolgen(r, true, nn);
+		break;
+
+	case ONOT:
+		boolgen(l, !true, nn);
+		break;
+
+	case OCOND:
+		bcgen(l, 1);
+		p1 = p;
+		bcgen(r->left, true);
+		p2 = p;
+		gbranch(OGOTO);
+		patch(p1, pc);
+		p1 = p;
+		bcgen(r->right, !true);
+		patch(p2, pc);
+		p2 = p;
+		gbranch(OGOTO);
+		patch(p1, pc);
+		patch(p2, pc);
+		goto com;
+
+	case OANDAND:
+		if(!true)
+			goto caseor;
+
+	caseand:
+		bcgen(l, true);
+		p1 = p;
+		bcgen(r, !true);
+		p2 = p;
+		patch(p1, pc);
+		gbranch(OGOTO);
+		patch(p2, pc);
+		goto com;
+
+	case OOROR:
+		if(!true)
+			goto caseand;
+
+	caseor:
+		bcgen(l, !true);
+		p1 = p;
+		bcgen(r, !true);
+		p2 = p;
+		gbranch(OGOTO);
+		patch(p1, pc);
+		patch(p2, pc);
+		goto com;
+
+	case OEQ:
+	case ONE:
+	case OLE:
+	case OLT:
+	case OGE:
+	case OGT:
+	case OHI:
+	case OHS:
+	case OLO:
+	case OLS:
+		o = n->op;
+		if(true)
+			o = comrel[relindex(o)];
+		if(l->complex >= FNX && r->complex >= FNX) {
+			regret(&nod, r);
+			cgen(r, &nod);
+			regsalloc(&nod1, r);
+			gmove(&nod, &nod1);
+			regfree(&nod);
+			nod = *n;
+			nod.right = &nod1;
+			boolgen(&nod, true, nn);
+			break;
+		}
+		if(immconst(l)) {
+			o = invrel[relindex(o)];
+			/* bad, 13 is address of external that becomes constant */
+			if(r->addable < INDEXED || r->addable == 13) {
+				regalloc(&nod, r, nn);
+				cgen(r, &nod);
+				gopcode(o, l->type, &nod, l);
+				regfree(&nod);
+			} else
+				gopcode(o, l->type, r, l);
+			goto com;
+		}
+		if(typefd[l->type->etype])
+			o = invrel[relindex(logrel[relindex(o)])];
+		if(l->complex >= r->complex) {
+			regalloc(&nod, l, nn);
+			cgen(l, &nod);
+			if(r->addable < INDEXED || hardconst(r) || typefd[l->type->etype]) {
+				regalloc(&nod1, r, Z);
+				cgen(r, &nod1);
+				gopcode(o, l->type, &nod, &nod1);
+				regfree(&nod1);
+			} else
+				gopcode(o, l->type, &nod, r);
+			regfree(&nod);
+			goto com;
+		}
+		regalloc(&nod, r, nn);
+		cgen(r, &nod);
+		if(l->addable < INDEXED || l->addable == 13 || hardconst(l)) {
+			regalloc(&nod1, l, Z);
+			cgen(l, &nod1);
+			if(typechl[l->type->etype] && ewidth[l->type->etype] <= ewidth[TINT])
+				gopcode(o, types[TINT], &nod1, &nod);
+			else
+				gopcode(o, l->type, &nod1, &nod);
+			regfree(&nod1);
+		} else
+			gopcode(o, l->type, l, &nod);
+		regfree(&nod);
+
+	com:
+		if(nn != Z) {
+			p1 = p;
+			gmove(nodconst(1L), nn);
+			gbranch(OGOTO);
+			p2 = p;
+			patch(p1, pc);
+			gmove(nodconst(0L), nn);
+			patch(p2, pc);
+		}
+		break;
+	}
+	cursafe = curs;
+}
+
+void
+sugen(Node *n, Node *nn, int32 w)
+{
+	Prog *p1;
+	Node nod0, nod1, nod2, nod3, nod4, *l, *r;
+	Type *t;
+	int c, mt, mo;
+	vlong o0, o1;
+
+	if(n == Z || n->type == T)
+		return;
+	if(debug['g']) {
+		prtree(nn, "sugen lhs");
+		prtree(n, "sugen");
+	}
+	if(nn == nodrat)
+		if(w > nrathole)
+			nrathole = w;
+	switch(n->op) {
+	case OIND:
+		if(nn == Z) {
+			nullwarn(n->left, Z);
+			break;
+		}
+
+	default:
+		goto copy;
+
+	case OCONST:
+		goto copy;
+
+	case ODOT:
+		l = n->left;
+		sugen(l, nodrat, l->type->width);
+		if(nn == Z)
+			break;
+		warn(n, "non-interruptable temporary");
+		nod1 = *nodrat;
+		r = n->right;
+		if(!r || r->op != OCONST) {
+			diag(n, "DOT and no offset");
+			break;
+		}
+		nod1.xoffset += (int32)r->vconst;
+		nod1.type = n->type;
+		sugen(&nod1, nn, w);
+		break;
+
+	case OSTRUCT:
+		/*
+		 * rewrite so lhs has no fn call
+		 */
+		if(nn != Z && side(nn)) {
+			nod1 = *n;
+			nod1.type = typ(TIND, n->type);
+			regret(&nod2, &nod1);
+			lcgen(nn, &nod2);
+			regsalloc(&nod0, &nod1);
+			cgen(&nod2, &nod0);
+			regfree(&nod2);
+
+			nod1 = *n;
+			nod1.op = OIND;
+			nod1.left = &nod0;
+			nod1.right = Z;
+			nod1.complex = 1;
+
+			sugen(n, &nod1, w);
+			return;
+		}
+
+		r = n->left;
+		for(t = n->type->link; t != T; t = t->down) {
+			l = r;
+			if(r->op == OLIST) {
+				l = r->left;
+				r = r->right;
+			}
+			if(nn == Z) {
+				cgen(l, nn);
+				continue;
+			}
+			/*
+			 * hand craft *(&nn + o) = l
+			 */
+			nod0 = znode;
+			nod0.op = OAS;
+			nod0.type = t;
+			nod0.left = &nod1;
+			nod0.right = nil;
+
+			nod1 = znode;
+			nod1.op = OIND;
+			nod1.type = t;
+			nod1.left = &nod2;
+
+			nod2 = znode;
+			nod2.op = OADD;
+			nod2.type = typ(TIND, t);
+			nod2.left = &nod3;
+			nod2.right = &nod4;
+
+			nod3 = znode;
+			nod3.op = OADDR;
+			nod3.type = nod2.type;
+			nod3.left = nn;
+
+			nod4 = znode;
+			nod4.op = OCONST;
+			nod4.type = nod2.type;
+			nod4.vconst = t->offset;
+
+			ccom(&nod0);
+			acom(&nod0);
+			xcom(&nod0);
+			nod0.addable = 0;
+			nod0.right = l;
+
+			// prtree(&nod0, "hand craft");
+			cgen(&nod0, Z);
+		}
+		break;
+
+	case OAS:
+		if(nn == Z) {
+			if(n->addable < INDEXED)
+				sugen(n->right, n->left, w);
+			break;
+		}
+
+		sugen(n->right, nodrat, w);
+		warn(n, "non-interruptable temporary");
+		sugen(nodrat, n->left, w);
+		sugen(nodrat, nn, w);
+		break;
+
+	case OFUNC:
+		if(nn == Z) {
+			sugen(n, nodrat, w);
+			break;
+		}
+		if(nn->op != OIND) {
+			nn = new1(OADDR, nn, Z);
+			nn->type = types[TIND];
+			nn->addable = 0;
+		} else
+			nn = nn->left;
+		n = new(OFUNC, n->left, new(OLIST, nn, n->right));
+		n->type = types[TVOID];
+		n->left->type = types[TVOID];
+		cgen(n, Z);
+		break;
+
+	case OCOND:
+		bcgen(n->left, 1);
+		p1 = p;
+		sugen(n->right->left, nn, w);
+		gbranch(OGOTO);
+		patch(p1, pc);
+		p1 = p;
+		sugen(n->right->right, nn, w);
+		patch(p1, pc);
+		break;
+
+	case OCOMMA:
+		cgen(n->left, Z);
+		sugen(n->right, nn, w);
+		break;
+	}
+	return;
+
+copy:
+	if(nn == Z) {
+		switch(n->op) {
+		case OASADD:
+		case OASSUB:
+		case OASAND:
+		case OASOR:
+		case OASXOR:
+
+		case OASMUL:
+		case OASLMUL:
+
+
+		case OASASHL:
+		case OASASHR:
+		case OASLSHR:
+			break;
+
+		case OPOSTINC:
+		case OPOSTDEC:
+		case OPREINC:
+		case OPREDEC:
+			break;
+
+		default:
+			return;
+		}
+	}
+
+	if(n->complex >= FNX && nn != nil && nn->complex >= FNX) {
+		t = nn->type;
+		nn->type = types[TLONG];
+		regialloc(&nod1, nn, Z);
+		lcgen(nn, &nod1);
+		regsalloc(&nod2, nn);
+		nn->type = t;
+
+		gins(AMOVL, &nod1, &nod2);
+		regfree(&nod1);
+
+		nod2.type = typ(TIND, t);
+
+		nod1 = nod2;
+		nod1.op = OIND;
+		nod1.left = &nod2;
+		nod1.right = Z;
+		nod1.complex = 1;
+		nod1.type = t;
+
+		sugen(n, &nod1, w);
+		return;
+	}
+
+	if(w <= 32) {
+		c = cursafe;
+		if(n->left != Z && n->left->complex >= FNX
+		&& n->right != Z && n->right->complex >= FNX) {
+			regsalloc(&nod1, n->right);
+			cgen(n->right, &nod1);
+			nod2 = *n;
+			nod2.right = &nod1;
+			cgen(&nod2, nn);
+			cursafe = c;
+			return;
+		}
+		if(w & 7) {
+			mt = TLONG;
+			mo = AMOVL;
+		} else {
+			mt = TVLONG;
+			mo = AMOVQ;
+		}
+		if(n->complex > nn->complex) {
+			t = n->type;
+			n->type = types[mt];
+			regalloc(&nod0, n, Z);
+			if(!vaddr(n, 0)) {
+				reglcgen(&nod1, n, Z);
+				n->type = t;
+				n = &nod1;
+			}
+			else
+				n->type = t;
+
+			t = nn->type;
+			nn->type = types[mt];
+			if(!vaddr(nn, 0)) {
+				reglcgen(&nod2, nn, Z);
+				nn->type = t;
+				nn = &nod2;
+			}
+			else
+				nn->type = t;
+		} else {
+			t = nn->type;
+			nn->type = types[mt];
+			regalloc(&nod0, nn, Z);
+			if(!vaddr(nn, 0)) {
+				reglcgen(&nod2, nn, Z);
+				nn->type = t;
+				nn = &nod2;
+			}
+			else
+				nn->type = t;
+
+			t = n->type;
+			n->type = types[mt];
+			if(!vaddr(n, 0)) {
+				reglcgen(&nod1, n, Z);
+				n->type = t;
+				n = &nod1;
+			}
+			else
+				n->type = t;
+		}
+		o0 = n->xoffset;
+		o1 = nn->xoffset;
+		w /= ewidth[mt];
+		while(--w >= 0) {
+			gins(mo, n, &nod0);
+			gins(mo, &nod0, nn);
+			n->xoffset += ewidth[mt];
+			nn->xoffset += ewidth[mt];
+		}
+		n->xoffset = o0;
+		nn->xoffset = o1;
+		if(nn == &nod2)
+			regfree(&nod2);
+		if(n == &nod1)
+			regfree(&nod1);
+		regfree(&nod0);
+		return;
+	}
+
+	/* botch, need to save in .safe */
+	c = 0;
+	if(n->complex > nn->complex) {
+		t = n->type;
+		n->type = types[TLONG];
+		nodreg(&nod1, n, D_SI);
+		if(reg[D_SI]) {
+			gins(APUSHQ, &nod1, Z);
+			c |= 1;
+			reg[D_SI]++;
+		}
+		lcgen(n, &nod1);
+		n->type = t;
+
+		t = nn->type;
+		nn->type = types[TLONG];
+		nodreg(&nod2, nn, D_DI);
+		if(reg[D_DI]) {
+warn(Z, "DI botch");
+			gins(APUSHQ, &nod2, Z);
+			c |= 2;
+			reg[D_DI]++;
+		}
+		lcgen(nn, &nod2);
+		nn->type = t;
+	} else {
+		t = nn->type;
+		nn->type = types[TLONG];
+		nodreg(&nod2, nn, D_DI);
+		if(reg[D_DI]) {
+warn(Z, "DI botch");
+			gins(APUSHQ, &nod2, Z);
+			c |= 2;
+			reg[D_DI]++;
+		}
+		lcgen(nn, &nod2);
+		nn->type = t;
+
+		t = n->type;
+		n->type = types[TLONG];
+		nodreg(&nod1, n, D_SI);
+		if(reg[D_SI]) {
+			gins(APUSHQ, &nod1, Z);
+			c |= 1;
+			reg[D_SI]++;
+		}
+		lcgen(n, &nod1);
+		n->type = t;
+	}
+	nodreg(&nod3, n, D_CX);
+	if(reg[D_CX]) {
+		gins(APUSHQ, &nod3, Z);
+		c |= 4;
+		reg[D_CX]++;
+	}
+	gins(AMOVL, nodconst(w/SZ_INT), &nod3);
+	gins(ACLD, Z, Z);
+	gins(AREP, Z, Z);
+	gins(AMOVSL, Z, Z);
+	if(c & 4) {
+		gins(APOPQ, Z, &nod3);
+		reg[D_CX]--;
+	}
+	if(c & 2) {
+		gins(APOPQ, Z, &nod2);
+		reg[nod2.reg]--;
+	}
+	if(c & 1) {
+		gins(APOPQ, Z, &nod1);
+		reg[nod1.reg]--;
+	}
+}
+
+/*
+ * TO DO
+ */
+void
+layout(Node *f, Node *t, int c, int cv, Node *cn)
+{
+	Node t1, t2;
+
+	while(c > 3) {
+		layout(f, t, 2, 0, Z);
+		c -= 2;
+	}
+
+	regalloc(&t1, &lregnode, Z);
+	regalloc(&t2, &lregnode, Z);
+	if(c > 0) {
+		gmove(f, &t1);
+		f->xoffset += SZ_INT;
+	}
+	if(cn != Z)
+		gmove(nodconst(cv), cn);
+	if(c > 1) {
+		gmove(f, &t2);
+		f->xoffset += SZ_INT;
+	}
+	if(c > 0) {
+		gmove(&t1, t);
+		t->xoffset += SZ_INT;
+	}
+	if(c > 2) {
+		gmove(f, &t1);
+		f->xoffset += SZ_INT;
+	}
+	if(c > 1) {
+		gmove(&t2, t);
+		t->xoffset += SZ_INT;
+	}
+	if(c > 2) {
+		gmove(&t1, t);
+		t->xoffset += SZ_INT;
+	}
+	regfree(&t1);
+	regfree(&t2);
+}
+
+/*
+ * constant is not vlong or fits as 32-bit signed immediate
+ */
+int
+immconst(Node *n)
+{
+	int32 v;
+
+	if(n->op != OCONST || !typechlpv[n->type->etype])
+		return 0;
+	if(typechl[n->type->etype])
+		return 1;
+	v = n->vconst;
+	return n->vconst == (vlong)v;
+}
+
+/*
+ * if a constant and vlong, doesn't fit as 32-bit signed immediate
+ */
+int
+hardconst(Node *n)
+{
+	return n->op == OCONST && !immconst(n);
+}
+
+/*
+ * casting up to t2 covers an intermediate cast to t1
+ */
+int
+castup(Type *t1, Type *t2)
+{
+	int ft;
+
+	if(!nilcast(t1, t2))
+		return 0;
+	/* known to be small to large */
+	ft = t1->etype;
+	switch(t2->etype){
+	case TINT:
+	case TLONG:
+		return ft == TLONG || ft == TINT || ft == TSHORT || ft == TCHAR;
+	case TUINT:
+	case TULONG:
+		return ft == TULONG || ft == TUINT || ft == TUSHORT || ft == TUCHAR;
+	case TVLONG:
+		return ft == TLONG || ft == TINT || ft == TSHORT;
+	case TUVLONG:
+		return ft == TULONG || ft == TUINT || ft == TUSHORT;
+	}
+	return 0;
+}
+
+void
+zeroregm(Node *n)
+{
+	gins(AMOVL, nodconst(0), n);
+}
+
+/* do we need to load the address of a vlong? */
+int
+vaddr(Node *n, int a)
+{
+	switch(n->op) {
+	case ONAME:
+		if(a)
+			return 1;
+		return !(n->class == CEXTERN || n->class == CGLOBL || n->class == CSTATIC);
+
+	case OCONST:
+	case OREGISTER:
+	case OINDREG:
+		return 1;
+	}
+	return 0;
+}
+
+int32
+hi64v(Node *n)
+{
+	if(align(0, types[TCHAR], Aarg1, nil))	/* isbigendian */
+		return (int32)(n->vconst) & ~0L;
+	else
+		return (int32)((uvlong)n->vconst>>32) & ~0L;
+}
+
+int32
+lo64v(Node *n)
+{
+	if(align(0, types[TCHAR], Aarg1, nil))	/* isbigendian */
+		return (int32)((uvlong)n->vconst>>32) & ~0L;
+	else
+		return (int32)(n->vconst) & ~0L;
+}
+
+Node *
+hi64(Node *n)
+{
+	return nodconst(hi64v(n));
+}
+
+Node *
+lo64(Node *n)
+{
+	return nodconst(lo64v(n));
+}
+
+int
+cond(int op)
+{
+	switch(op) {
+	case OANDAND:
+	case OOROR:
+	case ONOT:
+		return 1;
+
+	case OEQ:
+	case ONE:
+	case OLE:
+	case OLT:
+	case OGE:
+	case OGT:
+	case OHI:
+	case OHS:
+	case OLO:
+	case OLS:
+		return 1;
+	}
+	return 0;
+}
diff --git a/src/cmd/6c/div.c b/src/cmd/6c/div.c
new file mode 100644
index 000000000..bad6c5e27
--- /dev/null
+++ b/src/cmd/6c/div.c
@@ -0,0 +1,236 @@
+// Inferno utils/6c/div.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6c/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, (long)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, (long)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);
+}
diff --git a/src/cmd/6c/doc.go b/src/cmd/6c/doc.go
new file mode 100644
index 000000000..249a8ed80
--- /dev/null
+++ b/src/cmd/6c/doc.go
@@ -0,0 +1,14 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+
+6c is a version of the Plan 9 C compiler.  The original is documented at
+
+	http://plan9.bell-labs.com/magic/man2html/1/2c
+
+Its target architecture is the x86-64, referred to by these tools as amd64.
+
+*/
+package documentation
diff --git a/src/cmd/6c/gc.h b/src/cmd/6c/gc.h
new file mode 100644
index 000000000..0c23b115c
--- /dev/null
+++ b/src/cmd/6c/gc.h
@@ -0,0 +1,408 @@
+// Inferno utils/6c/gc.h
+// http://code.google.com/p/inferno-os/source/browse/utils/6c/gc.h
+//
+//	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	<u.h>
+#include	"../cc/cc.h"
+#include	"../6l/6.out.h"
+
+/*
+ * 6c/amd64
+ * Intel 386 with AMD64 extensions
+ */
+#define	SZ_CHAR		1
+#define	SZ_SHORT	2
+#define	SZ_INT		4
+#define	SZ_LONG		4
+#define	SZ_IND		8
+#define	SZ_FLOAT	4
+#define	SZ_VLONG	8
+#define	SZ_DOUBLE	8
+#define	FNX		100
+
+typedef	struct	Adr	Adr;
+typedef	struct	Prog	Prog;
+typedef	struct	Case	Case;
+typedef	struct	C1	C1;
+typedef	struct	Var	Var;
+typedef	struct	Reg	Reg;
+typedef	struct	Rgn	Rgn;
+typedef	struct	Renv	Renv;
+
+EXTERN	struct
+{
+	Node*	regtree;
+	Node*	basetree;
+	short	scale;
+	short	reg;
+	short	ptr;
+} idx;
+
+struct	Adr
+{
+	vlong	offset;
+	double	dval;
+	char	sval[NSNAME];
+
+	Sym*	sym;
+	uchar	type;
+	uchar	index;
+	uchar	etype;
+	uchar	scale;	/* doubles as width in DATA op */
+};
+#define	A	((Adr*)0)
+
+#define	INDEXED	9
+struct	Prog
+{
+	Adr	from;
+	Adr	to;
+	Prog*	link;
+	int32	lineno;
+	short	as;
+};
+#define	P	((Prog*)0)
+
+struct	Case
+{
+	Case*	link;
+	vlong	val;
+	int32	label;
+	char	def;
+	char	isv;
+};
+#define	C	((Case*)0)
+
+struct	C1
+{
+	vlong	val;
+	int32	label;
+};
+
+struct	Var
+{
+	vlong	offset;
+	Sym*	sym;
+	char	name;
+	char	etype;
+};
+
+struct	Reg
+{
+	int32	pc;
+	int32	rpo;		/* reverse post ordering */
+
+	Bits	set;
+	Bits	use1;
+	Bits	use2;
+
+	Bits	refbehind;
+	Bits	refahead;
+	Bits	calbehind;
+	Bits	calahead;
+	Bits	regdiff;
+	Bits	act;
+
+	int32	regu;
+	int32	loop;		/* could be shorter */
+
+	Reg*	log5;
+	int32	active;
+
+	Reg*	p1;
+	Reg*	p2;
+	Reg*	p2link;
+	Reg*	s1;
+	Reg*	s2;
+	Reg*	link;
+	Prog*	prog;
+};
+#define	R	((Reg*)0)
+
+struct	Renv
+{
+	int	safe;
+	Node	base;
+	Node*	saved;
+	Node*	scope;
+};
+
+#define	NRGN	600
+struct	Rgn
+{
+	Reg*	enter;
+	short	cost;
+	short	varno;
+	short	regno;
+};
+
+EXTERN	int32	breakpc;
+EXTERN	int32	nbreak;
+EXTERN	Case*	cases;
+EXTERN	Node	constnode;
+EXTERN	Node	fconstnode;
+EXTERN	Node	vconstnode;
+EXTERN	int32	continpc;
+EXTERN	int32	curarg;
+EXTERN	int32	cursafe;
+EXTERN	Prog*	firstp;
+EXTERN	Prog*	lastp;
+EXTERN	int32	maxargsafe;
+EXTERN	int	mnstring;
+EXTERN	int	retok;
+EXTERN	Node*	nodrat;
+EXTERN	Node*	nodret;
+EXTERN	Node*	nodsafe;
+EXTERN	int32	nrathole;
+EXTERN	int32	nstring;
+EXTERN	Prog*	p;
+EXTERN	int32	pc;
+EXTERN	Node	lregnode;
+EXTERN	Node	qregnode;
+EXTERN	char	string[NSNAME];
+EXTERN	Sym*	symrathole;
+EXTERN	Node	znode;
+EXTERN	Prog	zprog;
+EXTERN	int	reg[D_NONE];
+EXTERN	int32	exregoffset;
+EXTERN	int32	exfregoffset;
+EXTERN	uchar	typechlpv[NTYPE];
+
+#define	BLOAD(r)	band(bnot(r->refbehind), r->refahead)
+#define	BSTORE(r)	band(bnot(r->calbehind), r->calahead)
+#define	LOAD(r)		(~r->refbehind.b[z] & r->refahead.b[z])
+#define	STORE(r)	(~r->calbehind.b[z] & r->calahead.b[z])
+
+#define	bset(a,n)	((a).b[(n)/32]&(1L<<(n)%32))
+
+#define	CLOAD	5
+#define	CREF	5
+#define	CINF	1000
+#define	LOOP	3
+
+EXTERN	Rgn	region[NRGN];
+EXTERN	Rgn*	rgp;
+EXTERN	int	nregion;
+EXTERN	int	nvar;
+
+EXTERN	Bits	externs;
+EXTERN	Bits	params;
+EXTERN	Bits	consts;
+EXTERN	Bits	addrs;
+
+EXTERN	int32	regbits;
+EXTERN	int32	exregbits;
+
+EXTERN	int	change;
+EXTERN	int	suppress;
+
+EXTERN	Reg*	firstr;
+EXTERN	Reg*	lastr;
+EXTERN	Reg	zreg;
+EXTERN	Reg*	freer;
+EXTERN	Var	var[NVAR];
+EXTERN	int32*	idom;
+EXTERN	Reg**	rpo2r;
+EXTERN	int32	maxnr;
+
+extern	char*	anames[];
+
+/*
+ * sgen.c
+ */
+void	codgen(Node*, Node*);
+void	gen(Node*);
+void	noretval(int);
+void	usedset(Node*, int);
+void	xcom(Node*);
+void	indx(Node*);
+int	bcomplex(Node*, Node*);
+Prog*	gtext(Sym*, int32);
+vlong	argsize(void);
+
+/*
+ * cgen.c
+ */
+void	zeroregm(Node*);
+void	cgen(Node*, Node*);
+void	reglcgen(Node*, Node*, Node*);
+void	lcgen(Node*, Node*);
+void	bcgen(Node*, int);
+void	boolgen(Node*, int, Node*);
+void	sugen(Node*, Node*, int32);
+int	needreg(Node*, int);
+int	hardconst(Node*);
+int	immconst(Node*);
+
+/*
+ * txt.c
+ */
+void	ginit(void);
+void	gclean(void);
+void	nextpc(void);
+void	gargs(Node*, Node*, Node*);
+void	garg1(Node*, Node*, Node*, int, Node**);
+Node*	nodconst(int32);
+Node*	nodfconst(double);
+Node*	nodgconst(vlong, Type*);
+int	nodreg(Node*, Node*, int);
+int	isreg(Node*, int);
+void	regret(Node*, Node*);
+void	regalloc(Node*, Node*, Node*);
+void	regfree(Node*);
+void	regialloc(Node*, Node*, Node*);
+void	regsalloc(Node*, Node*);
+void	regaalloc1(Node*, Node*);
+void	regaalloc(Node*, Node*);
+void	regind(Node*, Node*);
+void	gprep(Node*, Node*);
+void	naddr(Node*, Adr*);
+void	gcmp(int, Node*, vlong);
+void	gmove(Node*, Node*);
+void	gins(int a, Node*, Node*);
+void	gopcode(int, Type*, Node*, Node*);
+int	samaddr(Node*, Node*);
+void	gbranch(int);
+void	patch(Prog*, int32);
+int	sconst(Node*);
+void	gpseudo(int, Sym*, Node*);
+
+/*
+ * swt.c
+ */
+int	swcmp(const void*, const void*);
+void	doswit(Node*);
+void	swit1(C1*, int, int32, Node*);
+void	cas(void);
+void	bitload(Node*, Node*, Node*, Node*, Node*);
+void	bitstore(Node*, Node*, Node*, Node*, Node*);
+int32	outstring(char*, int32);
+void	nullwarn(Node*, Node*);
+void	sextern(Sym*, Node*, int32, int32);
+void	gextern(Sym*, Node*, int32, int32);
+void	outcode(void);
+void	ieeedtod(Ieee*, double);
+
+/*
+ * list
+ */
+void	listinit(void);
+int	Pconv(Fmt*);
+int	Aconv(Fmt*);
+int	Dconv(Fmt*);
+int	Sconv(Fmt*);
+int	Rconv(Fmt*);
+int	Xconv(Fmt*);
+int	Bconv(Fmt*);
+
+/*
+ * reg.c
+ */
+Reg*	rega(void);
+int	rcmp(const void*, const void*);
+void	regopt(Prog*);
+void	addmove(Reg*, int, int, int);
+Bits	mkvar(Reg*, Adr*);
+void	prop(Reg*, Bits, Bits);
+void	loopit(Reg*, int32);
+void	synch(Reg*, Bits);
+uint32	allreg(uint32, Rgn*);
+void	paint1(Reg*, int);
+uint32	paint2(Reg*, int);
+void	paint3(Reg*, int, int32, int);
+void	addreg(Adr*, int);
+
+/*
+ * peep.c
+ */
+void	peep(void);
+void	excise(Reg*);
+Reg*	uniqp(Reg*);
+Reg*	uniqs(Reg*);
+int	regtyp(Adr*);
+int	anyvar(Adr*);
+int	subprop(Reg*);
+int	copyprop(Reg*);
+int	copy1(Adr*, Adr*, Reg*, int);
+int	copyu(Prog*, Adr*, Adr*);
+
+int	copyas(Adr*, Adr*);
+int	copyau(Adr*, Adr*);
+int	copysub(Adr*, Adr*, Adr*, int);
+int	copysub1(Prog*, Adr*, Adr*, int);
+
+int32	RtoB(int);
+int32	FtoB(int);
+int	BtoR(int32);
+int	BtoF(int32);
+
+#define	D_HI	D_NONE
+#define	D_LO	D_NONE
+
+#define	isregtype(t)	((t)>= D_AX && (t)<=D_R15)
+
+/*
+ * bound
+ */
+void	comtarg(void);
+
+/*
+ * com64
+ */
+int	cond(int);
+int	com64(Node*);
+void	com64init(void);
+void	bool64(Node*);
+int32	lo64v(Node*);
+int32	hi64v(Node*);
+Node*	lo64(Node*);
+Node*	hi64(Node*);
+
+/*
+ * div/mul
+ */
+void	sdivgen(Node*, Node*, Node*, Node*);
+void	udivgen(Node*, Node*, Node*, Node*);
+void	sdiv2(int32, int, Node*, Node*);
+void	smod2(int32, int, Node*, Node*);
+void	mulgen(Type*, Node*, Node*);
+void	genmuladd(Node*, Node*, int, Node*);
+void	shiftit(Type*, Node*, Node*);
+
+#pragma	varargck	type	"A"	int
+#pragma	varargck	type	"B"	Bits
+#pragma	varargck	type	"D"	Adr*
+#pragma	varargck	type	"lD"	Adr*
+#pragma	varargck	type	"P"	Prog*
+#pragma	varargck	type	"R"	int
+#pragma	varargck	type	"S"	char*
+
+#define	D_X7	(D_X0+7)
+
+void	fgopcode(int, Node*, Node*, int, int);
diff --git a/src/cmd/6c/list.c b/src/cmd/6c/list.c
new file mode 100644
index 000000000..4293203c0
--- /dev/null
+++ b/src/cmd/6c/list.c
@@ -0,0 +1,396 @@
+// Inferno utils/6c/list.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6c/list.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.
+
+#define EXTERN
+#include "gc.h"
+
+void
+listinit(void)
+{
+
+	fmtinstall('A', Aconv);
+	fmtinstall('B', Bconv);
+	fmtinstall('P', Pconv);
+	fmtinstall('S', Sconv);
+	fmtinstall('D', Dconv);
+	fmtinstall('R', Rconv);
+}
+
+int
+Bconv(Fmt *fp)
+{
+	char str[STRINGSZ], ss[STRINGSZ], *s;
+	Bits bits;
+	int i;
+
+	str[0] = 0;
+	bits = va_arg(fp->args, Bits);
+	while(bany(&bits)) {
+		i = bnum(bits);
+		if(str[0])
+			strcat(str, " ");
+		if(var[i].sym == S) {
+			sprint(ss, "$%lld", var[i].offset);
+			s = ss;
+		} else
+			s = var[i].sym->name;
+		if(strlen(str) + strlen(s) + 1 >= STRINGSZ)
+			break;
+		strcat(str, s);
+		bits.b[i/32] &= ~(1L << (i%32));
+	}
+	return fmtstrcpy(fp, str);
+}
+
+int
+Pconv(Fmt *fp)
+{
+	char str[STRINGSZ];
+	Prog *p;
+
+	p = va_arg(fp->args, Prog*);
+	switch(p->as) {
+	case ADATA:
+		sprint(str, "(%L)	%A	%D/%d,%D",
+			p->lineno, p->as, &p->from, p->from.scale, &p->to);
+		break;
+
+	case ATEXT:
+		if(p->from.scale) {
+			sprint(str, "(%L)	%A	%D,%d,%lD",
+				p->lineno, p->as, &p->from, p->from.scale, &p->to);
+			break;
+		}
+		sprint(str, "(%L)	%A	%D,%lD",
+			p->lineno, p->as, &p->from, &p->to);
+		break;
+
+	default:
+		sprint(str, "(%L)	%A	%D,%lD",
+			p->lineno, p->as, &p->from, &p->to);
+		break;
+	}
+	return fmtstrcpy(fp, str);
+}
+
+int
+Aconv(Fmt *fp)
+{
+	int i;
+
+	i = va_arg(fp->args, int);
+	return fmtstrcpy(fp, anames[i]);
+}
+
+int
+Dconv(Fmt *fp)
+{
+	char str[STRINGSZ], s[STRINGSZ];
+	Adr *a;
+	int i;
+
+	a = va_arg(fp->args, Adr*);
+	i = a->type;
+
+	if(fp->flags & FmtLong) {
+		if(i != D_CONST) {
+			// ATEXT dst is not constant
+			sprint(str, "!!%D", a);
+			goto brk;
+		}
+		sprint(str, "$%lld-%lld", a->offset&0xffffffffLL,
+			(a->offset>>32)&0xffffffffLL);
+		goto brk;
+	}
+
+	if(i >= D_INDIR) {
+		if(a->offset)
+			sprint(str, "%lld(%R)", a->offset, i-D_INDIR);
+		else
+			sprint(str, "(%R)", i-D_INDIR);
+		goto brk;
+	}
+	switch(i) {
+
+	default:
+		if(a->offset)
+			sprint(str, "$%lld,%R", a->offset, i);
+		else
+			sprint(str, "%R", i);
+		break;
+
+	case D_NONE:
+		str[0] = 0;
+		break;
+
+	case D_BRANCH:
+		sprint(str, "%lld(PC)", a->offset-pc);
+		break;
+
+	case D_EXTERN:
+		sprint(str, "%s+%lld(SB)", a->sym->name, a->offset);
+		break;
+
+	case D_STATIC:
+		sprint(str, "%s<>+%lld(SB)", a->sym->name,
+			a->offset);
+		break;
+
+	case D_AUTO:
+		if(a->sym) {
+			sprint(str, "%s+%lld(SP)", a->sym->name, a->offset);
+			break;
+		}
+		sprint(str, "%lld(SP)", a->offset);
+		break;
+
+	case D_PARAM:
+		if(a->sym) {
+			sprint(str, "%s+%lld(FP)", a->sym->name, a->offset);
+			break;
+		}
+		sprint(str, "%lld(FP)", a->offset);
+		break;
+
+	case D_CONST:
+		sprint(str, "$%lld", a->offset);
+		break;
+
+	case D_FCONST:
+		sprint(str, "$(%.17e)", a->dval);
+		break;
+
+	case D_SCONST:
+		sprint(str, "$\"%S\"", a->sval);
+		break;
+
+	case D_ADDR:
+		a->type = a->index;
+		a->index = D_NONE;
+		sprint(str, "$%D", a);
+		a->index = a->type;
+		a->type = D_ADDR;
+		goto conv;
+	}
+brk:
+	if(a->index != D_NONE) {
+		sprint(s, "(%R*%d)", (int)a->index, (int)a->scale);
+		strcat(str, s);
+	}
+conv:
+	return fmtstrcpy(fp, str);
+}
+
+char*	regstr[] =
+{
+	"AL",		/* [D_AL] */
+	"CL",
+	"DL",
+	"BL",
+	"SPB",
+	"BPB",
+	"SIB",
+	"DIB",
+	"R8B",
+	"R9B",
+	"R10B",
+	"R11B",
+	"R12B",
+	"R13B",
+	"R14B",
+	"R15B",
+
+	"AX",		/* [D_AX] */
+	"CX",
+	"DX",
+	"BX",
+	"SP",
+	"BP",
+	"SI",
+	"DI",
+	"R8",
+	"R9",
+	"R10",
+	"R11",
+	"R12",
+	"R13",
+	"R14",
+	"R15",
+
+	"AH",
+	"CH",
+	"DH",
+	"BH",
+
+	"F0",		/* [D_F0] */
+	"F1",
+	"F2",
+	"F3",
+	"F4",
+	"F5",
+	"F6",
+	"F7",
+
+	"M0",
+	"M1",
+	"M2",
+	"M3",
+	"M4",
+	"M5",
+	"M6",
+	"M7",
+
+	"X0",
+	"X1",
+	"X2",
+	"X3",
+	"X4",
+	"X5",
+	"X6",
+	"X7",
+	"X8",
+	"X9",
+	"X10",
+	"X11",
+	"X12",
+	"X13",
+	"X14",
+	"X15",
+
+	"CS",		/* [D_CS] */
+	"SS",
+	"DS",
+	"ES",
+	"FS",
+	"GS",
+
+	"GDTR",		/* [D_GDTR] */
+	"IDTR",		/* [D_IDTR] */
+	"LDTR",		/* [D_LDTR] */
+	"MSW",		/* [D_MSW] */
+	"TASK",		/* [D_TASK] */
+
+	"CR0",		/* [D_CR] */
+	"CR1",
+	"CR2",
+	"CR3",
+	"CR4",
+	"CR5",
+	"CR6",
+	"CR7",
+	"CR8",
+	"CR9",
+	"CR10",
+	"CR11",
+	"CR12",
+	"CR13",
+	"CR14",
+	"CR15",
+
+	"DR0",		/* [D_DR] */
+	"DR1",
+	"DR2",
+	"DR3",
+	"DR4",
+	"DR5",
+	"DR6",
+	"DR7",
+
+	"TR0",		/* [D_TR] */
+	"TR1",
+	"TR2",
+	"TR3",
+	"TR4",
+	"TR5",
+	"TR6",
+	"TR7",
+
+	"NONE",		/* [D_NONE] */
+};
+
+int
+Rconv(Fmt *fp)
+{
+	char str[STRINGSZ];
+	int r;
+
+	r = va_arg(fp->args, int);
+	if(r >= D_AL && r <= D_NONE)
+		sprint(str, "%s", regstr[r-D_AL]);
+	else
+		sprint(str, "gok(%d)", r);
+
+	return fmtstrcpy(fp, str);
+}
+
+int
+Sconv(Fmt *fp)
+{
+	int i, c;
+	char str[STRINGSZ], *p, *a;
+
+	a = va_arg(fp->args, char*);
+	p = str;
+	for(i=0; i<sizeof(double); i++) {
+		c = a[i] & 0xff;
+		if(c >= 'a' && c <= 'z' ||
+		   c >= 'A' && c <= 'Z' ||
+		   c >= '0' && c <= '9') {
+			*p++ = c;
+			continue;
+		}
+		*p++ = '\\';
+		switch(c) {
+		default:
+			if(c < 040 || c >= 0177)
+				break;	/* not portable */
+			p[-1] = c;
+			continue;
+		case 0:
+			*p++ = 'z';
+			continue;
+		case '\\':
+		case '"':
+			*p++ = c;
+			continue;
+		case '\n':
+			*p++ = 'n';
+			continue;
+		case '\t':
+			*p++ = 't';
+			continue;
+		}
+		*p++ = (c>>6) + '0';
+		*p++ = ((c>>3) & 7) + '0';
+		*p++ = (c & 7) + '0';
+	}
+	*p = 0;
+	return fmtstrcpy(fp, str);
+}
diff --git a/src/cmd/6c/machcap.c b/src/cmd/6c/machcap.c
new file mode 100644
index 000000000..820d9a0aa
--- /dev/null
+++ b/src/cmd/6c/machcap.c
@@ -0,0 +1,107 @@
+// Inferno utils/6c/machcap.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6c/machcap.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
+machcap(Node *n)
+{
+
+	if(n == Z)
+		return 1;	/* test */
+
+	switch(n->op) {
+	case OMUL:
+	case OLMUL:
+	case OASMUL:
+	case OASLMUL:
+		if(typechl[n->type->etype])
+			return 1;
+		if(typev[n->type->etype])
+			return 1;
+		break;
+
+	case OCOM:
+	case ONEG:
+	case OADD:
+	case OAND:
+	case OOR:
+	case OSUB:
+	case OXOR:
+	case OASHL:
+	case OLSHR:
+	case OASHR:
+		if(typechlv[n->left->type->etype])
+			return 1;
+		break;
+
+	case OCAST:
+		return 1;
+
+	case OCOND:
+	case OCOMMA:
+	case OLIST:
+	case OANDAND:
+	case OOROR:
+	case ONOT:
+		return 1;
+
+	case OASADD:
+	case OASSUB:
+	case OASAND:
+	case OASOR:
+	case OASXOR:
+		return 1;
+
+	case OASASHL:
+	case OASASHR:
+	case OASLSHR:
+		return 1;
+
+	case OPOSTINC:
+	case OPOSTDEC:
+	case OPREINC:
+	case OPREDEC:
+		return 1;
+
+	case OEQ:
+	case ONE:
+	case OLE:
+	case OGT:
+	case OLT:
+	case OGE:
+	case OHI:
+	case OHS:
+	case OLO:
+	case OLS:
+		return 1;
+	}
+	return 0;
+}
diff --git a/src/cmd/6c/mul.c b/src/cmd/6c/mul.c
new file mode 100644
index 000000000..ab6883e7a
--- /dev/null
+++ b/src/cmd/6c/mul.c
@@ -0,0 +1,458 @@
+// Inferno utils/6c/mul.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6c/mul.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"
+
+typedef struct	Malg	Malg;
+typedef struct	Mparam	Mparam;
+
+struct	Malg
+{
+	char	vals[10];
+};
+
+struct	Mparam
+{
+	uint32	value;
+	char	alg;
+	char	neg;
+	char	shift;
+	char	arg;
+	char	off;
+};
+
+static	Mparam	multab[32];
+static	int	mulptr;
+
+static	Malg	malgs[]	=
+{
+	{0, 100},
+	{-1, 1, 100},
+	{-9, -5, -3, 3, 5, 9, 100},
+	{6, 10, 12, 18, 20, 24, 36, 40, 72, 100},
+	{-8, -4, -2, 2, 4, 8, 100},
+};
+
+/*
+ * return position of lowest 1
+ */
+int
+lowbit(uint32 v)
+{
+	int s, i;
+	uint32 m;
+
+	s = 0;
+	m = 0xFFFFFFFFUL;
+	for(i = 16; i > 0; i >>= 1) {
+		m >>= i;
+		if((v & m) == 0) {
+			v >>= i;
+			s += i;
+		}
+	}
+	return s;
+}
+
+void
+genmuladd(Node *d, Node *s, int m, Node *a)
+{
+	Node nod;
+
+	nod.op = OINDEX;
+	nod.left = a;
+	nod.right = s;
+	nod.scale = m;
+	nod.type = types[TIND];
+	nod.xoffset = 0;
+	xcom(&nod);
+	gopcode(OADDR, d->type, &nod, d);
+}
+
+void
+mulparam(uint32 m, Mparam *mp)
+{
+	int c, i, j, n, o, q, s;
+	int bc, bi, bn, bo, bq, bs, bt;
+	char *p;
+	int32 u;
+	uint32 t;
+
+	bc = bq = 10;
+	bi = bn = bo = bs = bt = 0;
+	for(i = 0; i < nelem(malgs); i++) {
+		for(p = malgs[i].vals, j = 0; (o = p[j]) < 100; j++)
+		for(s = 0; s < 2; s++) {
+			c = 10;
+			q = 10;
+			u = m - o;
+			if(u == 0)
+				continue;
+			if(s) {
+				o = -o;
+				if(o > 0)
+					continue;
+				u = -u;
+			}
+			n = lowbit(u);
+			t = (uint32)u >> n;
+			switch(i) {
+			case 0:
+				if(t == 1) {
+					c = s + 1;
+					q = 0;
+					break;
+				}
+				switch(t) {
+				case 3:
+				case 5:
+				case 9:
+					c = s + 1;
+					if(n)
+						c++;
+					q = 0;
+					break;
+				}
+				if(s)
+					break;
+				switch(t) {
+				case 15:
+				case 25:
+				case 27:
+				case 45:
+				case 81:
+					c = 2;
+					if(n)
+						c++;
+					q = 1;
+					break;
+				}
+				break;
+			case 1:
+				if(t == 1) {
+					c = 3;
+					q = 3;
+					break;
+				}
+				switch(t) {
+				case 3:
+				case 5:
+				case 9:
+					c = 3;
+					q = 2;
+					break;
+				}
+				break;
+			case 2:
+				if(t == 1) {
+					c = 3;
+					q = 2;
+					break;
+				}
+				break;
+			case 3:
+				if(s)
+					break;
+				if(t == 1) {
+					c = 3;
+					q = 1;
+					break;
+				}
+				break;
+			case 4:
+				if(t == 1) {
+					c = 3;
+					q = 0;
+					break;
+				}
+				break;
+			}
+			if(c < bc || (c == bc && q > bq)) {
+				bc = c;
+				bi = i;
+				bn = n;
+				bo = o;
+				bq = q;
+				bs = s;
+				bt = t;
+			}
+		}
+	}
+	mp->value = m;
+	if(bc <= 3) {
+		mp->alg = bi;
+		mp->shift = bn;
+		mp->off = bo;
+		mp->neg = bs;
+		mp->arg = bt;
+	}
+	else
+		mp->alg = -1;
+}
+
+int
+m0(int a)
+{
+	switch(a) {
+	case -2:
+	case 2:
+		return 2;
+	case -3:
+	case 3:
+		return 2;
+	case -4:
+	case 4:
+		return 4;
+	case -5:
+	case 5:
+		return 4;
+	case 6:
+		return 2;
+	case -8:
+	case 8:
+		return 8;
+	case -9:
+	case 9:
+		return 8;
+	case 10:
+		return 4;
+	case 12:
+		return 2;
+	case 15:
+		return 2;
+	case 18:
+		return 8;
+	case 20:
+		return 4;
+	case 24:
+		return 2;
+	case 25:
+		return 4;
+	case 27:
+		return 2;
+	case 36:
+		return 8;
+	case 40:
+		return 4;
+	case 45:
+		return 4;
+	case 72:
+		return 8;
+	case 81:
+		return 8;
+	}
+	diag(Z, "bad m0");
+	return 0;
+}
+
+int
+m1(int a)
+{
+	switch(a) {
+	case 15:
+		return 4;
+	case 25:
+		return 4;
+	case 27:
+		return 8;
+	case 45:
+		return 8;
+	case 81:
+		return 8;
+	}
+	diag(Z, "bad m1");
+	return 0;
+}
+
+int
+m2(int a)
+{
+	switch(a) {
+	case 6:
+		return 2;
+	case 10:
+		return 2;
+	case 12:
+		return 4;
+	case 18:
+		return 2;
+	case 20:
+		return 4;
+	case 24:
+		return 8;
+	case 36:
+		return 4;
+	case 40:
+		return 8;
+	case 72:
+		return 8;
+	}
+	diag(Z, "bad m2");
+	return 0;
+}
+
+void
+shiftit(Type *t, Node *s, Node *d)
+{
+	int32 c;
+
+	c = (int32)s->vconst & 31;
+	switch(c) {
+	case 0:
+		break;
+	case 1:
+		gopcode(OADD, t, d, d);
+		break;
+	default:
+		gopcode(OASHL, t, s, d);
+	}
+}
+
+static int
+mulgen1(uint32 v, Node *n)
+{
+	int i, o;
+	Mparam *p;
+	Node nod, nods;
+
+	for(i = 0; i < nelem(multab); i++) {
+		p = &multab[i];
+		if(p->value == v)
+			goto found;
+	}
+
+	p = &multab[mulptr];
+	if(++mulptr == nelem(multab))
+		mulptr = 0;
+
+	mulparam(v, p);
+
+found:
+//	print("v=%.x a=%d n=%d s=%d g=%d o=%d \n", p->value, p->alg, p->neg, p->shift, p->arg, p->off);
+	if(p->alg < 0)
+		return 0;
+
+	nods = *nodconst(p->shift);
+
+	o = OADD;
+	if(p->alg > 0) {
+		regalloc(&nod, n, Z);
+		if(p->off < 0)
+			o = OSUB;
+	}
+
+	switch(p->alg) {
+	case 0:
+		switch(p->arg) {
+		case 1:
+			shiftit(n->type, &nods, n);
+			break;
+		case 15:
+		case 25:
+		case 27:
+		case 45:
+		case 81:
+			genmuladd(n, n, m1(p->arg), n);
+			/* fall thru */
+		case 3:
+		case 5:
+		case 9:
+			genmuladd(n, n, m0(p->arg), n);
+			shiftit(n->type, &nods, n);
+			break;
+		default:
+			goto bad;
+		}
+		if(p->neg == 1)
+			gins(ANEGL, Z, n);
+		break;
+	case 1:
+		switch(p->arg) {
+		case 1:
+			gmove(n, &nod);
+			shiftit(n->type, &nods, &nod);
+			break;
+		case 3:
+		case 5:
+		case 9:
+			genmuladd(&nod, n, m0(p->arg), n);
+			shiftit(n->type, &nods, &nod);
+			break;
+		default:
+			goto bad;
+		}
+		if(p->neg)
+			gopcode(o, n->type, &nod, n);
+		else {
+			gopcode(o, n->type, n, &nod);
+			gmove(&nod, n);
+		}
+		break;
+	case 2:
+		genmuladd(&nod, n, m0(p->off), n);
+		shiftit(n->type, &nods, n);
+		goto comop;
+	case 3:
+		genmuladd(&nod, n, m0(p->off), n);
+		shiftit(n->type, &nods, n);
+		genmuladd(n, &nod, m2(p->off), n);
+		break;
+	case 4:
+		genmuladd(&nod, n, m0(p->off), nodconst(0));
+		shiftit(n->type, &nods, n);
+		goto comop;
+	default:
+		diag(Z, "bad mul alg");
+		break;
+	comop:
+		if(p->neg) {
+			gopcode(o, n->type, n, &nod);
+			gmove(&nod, n);
+		}
+		else
+			gopcode(o, n->type, &nod, n);
+	}
+
+	if(p->alg > 0)
+		regfree(&nod);
+
+	return 1;
+
+bad:
+	diag(Z, "mulgen botch");
+	return 1;
+}
+
+void
+mulgen(Type *t, Node *r, Node *n)
+{
+	if(!mulgen1(r->vconst, n))
+		gopcode(OMUL, t, r, n);
+}
diff --git a/src/cmd/6c/peep.c b/src/cmd/6c/peep.c
new file mode 100644
index 000000000..8b82adbf5
--- /dev/null
+++ b/src/cmd/6c/peep.c
@@ -0,0 +1,890 @@
+// Inferno utils/6c/peep.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6c/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"
+
+static int
+needc(Prog *p)
+{
+	while(p != P) {
+		switch(p->as) {
+		case AADCL:
+		case AADCQ:
+		case ASBBL:
+		case ASBBQ:
+		case ARCRL:
+		case ARCRQ:
+			return 1;
+		case AADDL:
+		case AADDQ:
+		case ASUBL:
+		case ASUBQ:
+		case AJMP:
+		case ARET:
+		case ACALL:
+			return 0;
+		default:
+			if(p->to.type == D_BRANCH)
+				return 0;
+		}
+		p = p->link;
+	}
+	return 0;
+}
+
+static Reg*
+rnops(Reg *r)
+{
+	Prog *p;
+	Reg *r1;
+
+	if(r != R)
+	for(;;){
+		p = r->prog;
+		if(p->as != ANOP || p->from.type != D_NONE || p->to.type != D_NONE)
+			break;
+		r1 = uniqs(r);
+		if(r1 == R)
+			break;
+		r = r1;
+	}
+	return r;
+}
+
+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;
+		}
+	}
+
+	pc = 0;	/* speculating it won't kill */
+
+loop1:
+
+	t = 0;
+	for(r=firstr; r!=R; r=r->link) {
+		p = r->prog;
+		switch(p->as) {
+		case AMOVL:
+		case AMOVQ:
+		case AMOVSS:
+		case AMOVSD:
+			if(regtyp(&p->to))
+			if(regtyp(&p->from)) {
+				if(copyprop(r)) {
+					excise(r);
+					t++;
+				} else
+				if(subprop(r) && copyprop(r)) {
+					excise(r);
+					t++;
+				}
+			}
+			break;
+
+		case AMOVBLZX:
+		case AMOVWLZX:
+		case AMOVBLSX:
+		case AMOVWLSX:
+			if(regtyp(&p->to)) {
+				r1 = rnops(uniqs(r));
+				if(r1 != R) {
+					p1 = r1->prog;
+					if(p->as == p1->as && p->to.type == p1->from.type){
+						p1->as = AMOVL;
+						t++;
+					}
+				}
+			}
+			break;
+
+		case AMOVBQSX:
+		case AMOVBQZX:
+		case AMOVWQSX:
+		case AMOVWQZX:
+		case AMOVLQSX:
+		case AMOVLQZX:
+			if(regtyp(&p->to)) {
+				r1 = rnops(uniqs(r));
+				if(r1 != R) {
+					p1 = r1->prog;
+					if(p->as == p1->as && p->to.type == p1->from.type){
+						p1->as = AMOVQ;
+						t++;
+					}
+				}
+			}
+			break;
+
+		case AADDL:
+		case AADDQ:
+		case AADDW:
+			if(p->from.type != D_CONST || needc(p->link))
+				break;
+			if(p->from.offset == -1){
+				if(p->as == AADDQ)
+					p->as = ADECQ;
+				else if(p->as == AADDL)
+					p->as = ADECL;
+				else
+					p->as = ADECW;
+				p->from = zprog.from;
+			}
+			else if(p->from.offset == 1){
+				if(p->as == AADDQ)
+					p->as = AINCQ;
+				else if(p->as == AADDL)
+					p->as = AINCL;
+				else
+					p->as = AINCW;
+				p->from = zprog.from;
+			}
+			break;
+
+		case ASUBL:
+		case ASUBQ:
+		case ASUBW:
+			if(p->from.type != D_CONST || needc(p->link))
+				break;
+			if(p->from.offset == -1) {
+				if(p->as == ASUBQ)
+					p->as = AINCQ;
+				else if(p->as == ASUBL)
+					p->as = AINCL;
+				else
+					p->as = AINCW;
+				p->from = zprog.from;
+			}
+			else if(p->from.offset == 1){
+				if(p->as == ASUBQ)
+					p->as = ADECQ;
+				else if(p->as == ASUBL)
+					p->as = ADECL;
+				else
+					p->as = ADECW;
+				p->from = zprog.from;
+			}
+			break;
+		}
+	}
+	if(t)
+		goto loop1;
+}
+
+void
+excise(Reg *r)
+{
+	Prog *p;
+
+	p = r->prog;
+	p->as = ANOP;
+	p->from = zprog.from;
+	p->to = zprog.to;
+}
+
+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(Adr *a)
+{
+	int t;
+
+	t = a->type;
+	if(t >= D_AX && t <= D_R15)
+		return 1;
+	if(t >= D_X0 && t <= D_X0+15)
+		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;
+	Adr *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 ACALL:
+			return 0;
+
+		case AIMULL:
+		case AIMULQ:
+		case AIMULW:
+			if(p->to.type != D_NONE)
+				break;
+
+		case ADIVB:
+		case ADIVL:
+		case ADIVQ:
+		case ADIVW:
+		case AIDIVB:
+		case AIDIVL:
+		case AIDIVQ:
+		case AIDIVW:
+		case AIMULB:
+		case AMULB:
+		case AMULL:
+		case AMULQ:
+		case AMULW:
+
+		case AROLB:
+		case AROLL:
+		case AROLQ:
+		case AROLW:
+		case ARORB:
+		case ARORL:
+		case ARORQ:
+		case ARORW:
+		case ASALB:
+		case ASALL:
+		case ASALQ:
+		case ASALW:
+		case ASARB:
+		case ASARL:
+		case ASARQ:
+		case ASARW:
+		case ASHLB:
+		case ASHLL:
+		case ASHLQ:
+		case ASHLW:
+		case ASHRB:
+		case ASHRL:
+		case ASHRQ:
+		case ASHRW:
+
+		case AREP:
+		case AREPN:
+
+		case ACWD:
+		case ACDQ:
+		case ACQO:
+
+		case ASTOSB:
+		case ASTOSL:
+		case ASTOSQ:
+		case AMOVSB:
+		case AMOVSL:
+		case AMOVSQ:
+			return 0;
+
+		case AMOVL:
+		case AMOVQ:
+			if(p->to.type == v1->type)
+				goto gotit;
+			break;
+		}
+		if(copyau(&p->from, v2) ||
+		   copyau(&p->to, v2))
+			break;
+		if(copysub(&p->from, 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);
+		copysub(&p->to, v1, v2, 1);
+		if(debug['P'])
+			print("%P\n", r->prog);
+	}
+	t = v1->type;
+	v1->type = v2->type;
+	v2->type = 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;
+	Adr *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(Adr *v1, Adr *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, cant split */
+			if(debug['P'])
+				print("; %D rar; return 0\n", v2);
+			return 0;
+
+		case 3:	/* set */
+			if(debug['P'])
+				print("; %D set; 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("; %D used+set and f=%d; return 0\n", v2, f);
+				else
+					print("; %D used 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("; %D used+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("; %D set 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;
+}
+
+/*
+ * 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, Adr *v, Adr *s)
+{
+
+	switch(p->as) {
+
+	default:
+		if(debug['P'])
+			print("unknown op %A\n", p->as);
+		/* SBBL; ADCL; FLD1; SAHF */
+		return 2;
+
+
+	case ANEGB:
+	case ANEGW:
+	case ANEGL:
+	case ANEGQ:
+	case ANOTB:
+	case ANOTW:
+	case ANOTL:
+	case ANOTQ:
+		if(copyas(&p->to, v))
+			return 2;
+		break;
+
+	case ALEAL:	/* lhs addr, rhs store */
+	case ALEAQ:
+		if(copyas(&p->from, v))
+			return 2;
+
+
+	case ANOP:	/* rhs store */
+	case AMOVL:
+	case AMOVQ:
+	case AMOVBLSX:
+	case AMOVBLZX:
+	case AMOVBQSX:
+	case AMOVBQZX:
+	case AMOVLQSX:
+	case AMOVLQZX:
+	case AMOVWLSX:
+	case AMOVWLZX:
+	case AMOVWQSX:
+	case AMOVWQZX:
+
+	case AMOVSS:
+	case AMOVSD:
+	case ACVTSD2SL:
+	case ACVTSD2SQ:
+	case ACVTSD2SS:
+	case ACVTSL2SD:
+	case ACVTSL2SS:
+	case ACVTSQ2SD:
+	case ACVTSQ2SS:
+	case ACVTSS2SD:
+	case ACVTSS2SL:
+	case ACVTSS2SQ:
+	case ACVTTSD2SL:
+	case ACVTTSD2SQ:
+	case ACVTTSS2SL:
+	case ACVTTSS2SQ:
+		if(copyas(&p->to, v)) {
+			if(s != A)
+				return copysub(&p->from, v, s, 1);
+			if(copyau(&p->from, v))
+				return 4;
+			return 3;
+		}
+		goto caseread;
+
+	case AROLB:
+	case AROLL:
+	case AROLQ:
+	case AROLW:
+	case ARORB:
+	case ARORL:
+	case ARORQ:
+	case ARORW:
+	case ASALB:
+	case ASALL:
+	case ASALQ:
+	case ASALW:
+	case ASARB:
+	case ASARL:
+	case ASARQ:
+	case ASARW:
+	case ASHLB:
+	case ASHLL:
+	case ASHLQ:
+	case ASHLW:
+	case ASHRB:
+	case ASHRL:
+	case ASHRQ:
+	case ASHRW:
+		if(copyas(&p->to, v))
+			return 2;
+		if(copyas(&p->from, v))
+			if(p->from.type == D_CX)
+				return 2;
+		goto caseread;
+
+	case AADDB:	/* rhs rar */
+	case AADDL:
+	case AADDQ:
+	case AADDW:
+	case AANDB:
+	case AANDL:
+	case AANDQ:
+	case AANDW:
+	case ADECL:
+	case ADECQ:
+	case ADECW:
+	case AINCL:
+	case AINCQ:
+	case AINCW:
+	case ASUBB:
+	case ASUBL:
+	case ASUBQ:
+	case ASUBW:
+	case AORB:
+	case AORL:
+	case AORQ:
+	case AORW:
+	case AXORB:
+	case AXORL:
+	case AXORQ:
+	case AXORW:
+	case AMOVB:
+	case AMOVW:
+
+	case AADDSD:
+	case AADDSS:
+	case ACMPSD:
+	case ACMPSS:
+	case ADIVSD:
+	case ADIVSS:
+	case AMAXSD:
+	case AMAXSS:
+	case AMINSD:
+	case AMINSS:
+	case AMULSD:
+	case AMULSS:
+	case ARCPSS:
+	case ARSQRTSS:
+	case ASQRTSD:
+	case ASQRTSS:
+	case ASUBSD:
+	case ASUBSS:
+	case AXORPD:
+		if(copyas(&p->to, v))
+			return 2;
+		goto caseread;
+
+	case ACMPL:	/* read only */
+	case ACMPW:
+	case ACMPB:
+	case ACMPQ:
+
+	case ACOMISD:
+	case ACOMISS:
+	case AUCOMISD:
+	case AUCOMISS:
+	caseread:
+		if(s != A) {
+			if(copysub(&p->from, v, s, 1))
+				return 1;
+			return copysub(&p->to, v, s, 1);
+		}
+		if(copyau(&p->from, v))
+			return 1;
+		if(copyau(&p->to, v))
+			return 1;
+		break;
+
+	case AJGE:	/* no reference */
+	case AJNE:
+	case AJLE:
+	case AJEQ:
+	case AJHI:
+	case AJLS:
+	case AJMI:
+	case AJPL:
+	case AJGT:
+	case AJLT:
+	case AJCC:
+	case AJCS:
+
+	case AADJSP:
+	case AWAIT:
+	case ACLD:
+		break;
+
+	case AIMULL:
+	case AIMULQ:
+	case AIMULW:
+		if(p->to.type != D_NONE) {
+			if(copyas(&p->to, v))
+				return 2;
+			goto caseread;
+		}
+
+	case ADIVB:
+	case ADIVL:
+	case ADIVQ:
+	case ADIVW:
+	case AIDIVB:
+	case AIDIVL:
+	case AIDIVQ:
+	case AIDIVW:
+	case AIMULB:
+	case AMULB:
+	case AMULL:
+	case AMULQ:
+	case AMULW:
+
+	case ACWD:
+	case ACDQ:
+	case ACQO:
+		if(v->type == D_AX || v->type == D_DX)
+			return 2;
+		goto caseread;
+
+	case AREP:
+	case AREPN:
+		if(v->type == D_CX)
+			return 2;
+		goto caseread;
+
+	case AMOVSB:
+	case AMOVSL:
+	case AMOVSQ:
+		if(v->type == D_DI || v->type == D_SI)
+			return 2;
+		goto caseread;
+
+	case ASTOSB:
+	case ASTOSL:
+	case ASTOSQ:
+		if(v->type == D_AX || v->type == D_DI)
+			return 2;
+		goto caseread;
+
+	case AJMP:	/* 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 == REGRET || v->type == FREGRET)
+			return 2;
+		if(s != A)
+			return 1;
+		return 3;
+
+	case ACALL:	/* funny */
+		if(REGARG >= 0 && v->type == (uchar)REGARG)
+			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(REGARG >= 0 && v->type == (uchar)REGARG)
+			return 3;
+		return 0;
+	}
+	return 0;
+}
+
+/*
+ * direct reference,
+ * could be set/use depending on
+ * semantics
+ */
+int
+copyas(Adr *a, Adr *v)
+{
+	if(a->type != v->type)
+		return 0;
+	if(regtyp(v))
+		return 1;
+	if(v->type == D_AUTO || v->type == D_PARAM)
+		if(v->offset == a->offset)
+			return 1;
+	return 0;
+}
+
+/*
+ * either direct or indirect
+ */
+int
+copyau(Adr *a, Adr *v)
+{
+
+	if(copyas(a, v))
+		return 1;
+	if(regtyp(v)) {
+		if(a->type-D_INDIR == v->type)
+			return 1;
+		if(a->index == v->type)
+			return 1;
+	}
+	return 0;
+}
+
+/*
+ * substitute s for v in a
+ * return failure to substitute
+ */
+int
+copysub(Adr *a, Adr *v, Adr *s, int f)
+{
+	int t;
+
+	if(copyas(a, v)) {
+		t = s->type;
+		if(t >= D_AX && t <= D_R15 || t >= D_X0 && t <= D_X0+15) {
+			if(f)
+				a->type = t;
+		}
+		return 0;
+	}
+	if(regtyp(v)) {
+		t = v->type;
+		if(a->type == t+D_INDIR) {
+			if((s->type == D_BP || s->type == D_R13) && a->index != D_NONE)
+				return 1;	/* can't use BP-base with index */
+			if(f)
+				a->type = s->type+D_INDIR;
+//			return 0;
+		}
+		if(a->index == t) {
+			if(f)
+				a->index = s->type;
+			return 0;
+		}
+		return 0;
+	}
+	return 0;
+}
diff --git a/src/cmd/6c/reg.c b/src/cmd/6c/reg.c
new file mode 100644
index 000000000..996128f75
--- /dev/null
+++ b/src/cmd/6c/reg.c
@@ -0,0 +1,1386 @@
+// Inferno utils/6c/reg.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6c/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"
+
+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) | RtoB(D_X0);
+	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:
+			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:
+		case AIRETQ:
+			r->p1 = R;
+			r1->s1 = R;
+		}
+
+		bit = mkvar(r, &p->from);
+		if(bany(&bit))
+		switch(p->as) {
+		/*
+		 * funny
+		 */
+		case ALEAL:
+		case ALEAQ:
+			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 ACMPQ:
+		case ACMPW:
+		case ACOMISS:
+		case ACOMISD:
+		case AUCOMISS:
+		case AUCOMISD:
+			for(z=0; z<BITS; z++)
+				r->use2.b[z] |= bit.b[z];
+			break;
+
+		/*
+		 * right side write
+		 */
+		case ANOP:
+		case AMOVL:
+		case AMOVQ:
+		case AMOVB:
+		case AMOVW:
+		case AMOVBLSX:
+		case AMOVBLZX:
+		case AMOVBQSX:
+		case AMOVBQZX:
+		case AMOVLQSX:
+		case AMOVLQZX:
+		case AMOVWLSX:
+		case AMOVWLZX:
+		case AMOVWQSX:
+		case AMOVWQZX:
+
+		case AMOVSS:
+		case AMOVSD:
+		case ACVTSD2SL:
+		case ACVTSD2SQ:
+		case ACVTSD2SS:
+		case ACVTSL2SD:
+		case ACVTSL2SS:
+		case ACVTSQ2SD:
+		case ACVTSQ2SS:
+		case ACVTSS2SD:
+		case ACVTSS2SL:
+		case ACVTSS2SQ:
+		case ACVTTSD2SL:
+		case ACVTTSD2SQ:
+		case ACVTTSS2SL:
+		case ACVTTSS2SQ:
+			for(z=0; z<BITS; z++)
+				r->set.b[z] |= bit.b[z];
+			break;
+
+		/*
+		 * right side read+write
+		 */
+		case AADDB:
+		case AADDL:
+		case AADDQ:
+		case AADDW:
+		case AANDB:
+		case AANDL:
+		case AANDQ:
+		case AANDW:
+		case ASUBB:
+		case ASUBL:
+		case ASUBQ:
+		case ASUBW:
+		case AORB:
+		case AORL:
+		case AORQ:
+		case AORW:
+		case AXORB:
+		case AXORL:
+		case AXORQ:
+		case AXORW:
+		case ASALB:
+		case ASALL:
+		case ASALQ:
+		case ASALW:
+		case ASARB:
+		case ASARL:
+		case ASARQ:
+		case ASARW:
+		case AROLB:
+		case AROLL:
+		case AROLQ:
+		case AROLW:
+		case ARORB:
+		case ARORL:
+		case ARORQ:
+		case ARORW:
+		case ASHLB:
+		case ASHLL:
+		case ASHLQ:
+		case ASHLW:
+		case ASHRB:
+		case ASHRL:
+		case ASHRQ:
+		case ASHRW:
+		case AIMULL:
+		case AIMULQ:
+		case AIMULW:
+		case ANEGL:
+		case ANEGQ:
+		case ANOTL:
+		case ANOTQ:
+		case AADCL:
+		case AADCQ:
+		case ASBBL:
+		case ASBBQ:
+
+		case AADDSD:
+		case AADDSS:
+		case ACMPSD:
+		case ACMPSS:
+		case ADIVSD:
+		case ADIVSS:
+		case AMAXSD:
+		case AMAXSS:
+		case AMINSD:
+		case AMINSS:
+		case AMULSD:
+		case AMULSS:
+		case ARCPSS:
+		case ARSQRTSS:
+		case ASQRTSD:
+		case ASQRTSS:
+		case ASUBSD:
+		case ASUBSS:
+		case AXORPD:
+			for(z=0; z<BITS; z++) {
+				r->set.b[z] |= bit.b[z];
+				r->use2.b[z] |= bit.b[z];
+			}
+			break;
+
+		/*
+		 * funny
+		 */
+		case ACALL:
+			for(z=0; z<BITS; z++)
+				addrs.b[z] |= bit.b[z];
+			break;
+		}
+
+		switch(p->as) {
+		case AIMULL:
+		case AIMULQ:
+		case AIMULW:
+			if(p->to.type != D_NONE)
+				break;
+
+		case AIDIVB:
+		case AIDIVL:
+		case AIDIVQ:
+		case AIDIVW:
+		case AIMULB:
+		case ADIVB:
+		case ADIVL:
+		case ADIVQ:
+		case ADIVW:
+		case AMULB:
+		case AMULL:
+		case AMULQ:
+		case AMULW:
+
+		case ACWD:
+		case ACDQ:
+		case ACQO:
+			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 AMOVSQ:
+		case AMOVSW:
+		case ACMPSB:
+		case ACMPSL:
+		case ACMPSQ:
+		case ACMPSW:
+			r->regu |= RtoB(D_SI) | RtoB(D_DI);
+			break;
+
+		case ASTOSB:
+		case ASTOSL:
+		case ASTOSQ:
+		case ASTOSW:
+		case ASCASB:
+		case ASCASL:
+		case ASCASQ:
+		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;
+		}
+	}
+	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("%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) {
+				warn(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();
+
+	/*
+	 * 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:
+				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;
+		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;
+	Adr *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;
+	if(v->etype == TVLONG || v->etype == TUVLONG || v->etype == TIND)
+		p1->as = AMOVQ;
+	if(v->etype == TFLOAT)
+		p1->as = AMOVSS;
+	if(v->etype == TDOUBLE)
+		p1->as = AMOVSD;
+
+	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_R15)
+		b |= RtoB(r);
+	else
+	if(r >= D_AL && r <= D_R15B)
+		b |= RtoB(r-D_AL+D_AX);
+	else
+	if(r >= D_AH && r <= D_BH)
+		b |= RtoB(r-D_AH+D_AX);
+	else
+	if(r >= D_X0 && r <= D_X0+15)
+		b |= FtoB(r);
+	return b;
+}
+
+Bits
+mkvar(Reg *r, Adr *a)
+{
+	Var *v;
+	int i, t, n, et, z;
+	int32 o;
+	Bits bit;
+	Sym *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 == S)
+		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) {
+		if(debug['w'] > 1 && s)
+			warn(Z, "variable not optimized: %s", s->name);
+		goto none;
+	}
+	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] || typev[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 TVLONG:
+	case TUVLONG:
+	case TIND:
+	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;
+			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("%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(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(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(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;
+	Adr v;
+	int c;
+
+	set = 0;
+	v = zprog.from;
+	while(b = bb & ~(bb-1)) {
+		v.type = b & 0xFFFF? BtoR(b): BtoF(b);
+		if(v.type == 0)
+			diag(Z, "zero v.type for %#ux", 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;
+	Adr v;
+	int c;
+
+	set = 0;
+	v = zprog.from;
+	while(b = bb & ~(bb-1)) {
+		v.type = b & 0xFFFF? BtoR(b): BtoF(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(Adr *a, int rn)
+{
+
+	a->sym = 0;
+	a->offset = 0;
+	a->type = rn;
+}
+
+int32
+RtoB(int r)
+{
+
+	if(r < D_AX || r > D_R15)
+		return 0;
+	return 1L << (r-D_AX);
+}
+
+int
+BtoR(int32 b)
+{
+
+	b &= 0xffffL;
+	if(b == 0)
+		return 0;
+	return bitno(b) + D_AX;
+}
+
+/*
+ *	bit	reg
+ *	16	X5
+ *	17	X6
+ *	18	X7
+ */
+int32
+FtoB(int f)
+{
+	if(f < FREGMIN || f > FREGEXT)
+		return 0;
+	return 1L << (f - FREGMIN + 16);
+}
+
+int
+BtoF(int32 b)
+{
+
+	b &= 0x70000L;
+	if(b == 0)
+		return 0;
+	return bitno(b) - 16 + FREGMIN;
+}
diff --git a/src/cmd/6c/sgen.c b/src/cmd/6c/sgen.c
new file mode 100644
index 000000000..42045f8fa
--- /dev/null
+++ b/src/cmd/6c/sgen.c
@@ -0,0 +1,485 @@
+// Inferno utils/6c/sgen.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6c/sgen.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"
+
+Prog*
+gtext(Sym *s, int32 stkoff)
+{
+	vlong v;
+	
+	v = 0;
+	if(!(textflag & NOSPLIT))
+		v |= argsize() << 32;
+	v |= stkoff & 0xffffffff;
+	if((textflag & NOSPLIT) && stkoff >= 128)
+		yyerror("stack frame too large for NOSPLIT function");
+
+	gpseudo(ATEXT, s, nodgconst(v, types[TVLONG]));
+	return p;
+}
+
+void
+noretval(int n)
+{
+
+	if(n & 1) {
+		gins(ANOP, Z, Z);
+		p->to.type = REGRET;
+	}
+	if(n & 2) {
+		gins(ANOP, Z, Z);
+		p->to.type = FREGRET;
+	}
+}
+
+/* welcome to commute */
+static void
+commute(Node *n)
+{
+	Node *l, *r;
+
+	l = n->left;
+	r = n->right;
+	if(r->complex > l->complex) {
+		n->left = r;
+		n->right = l;
+	}
+}
+
+void
+indexshift(Node *n)
+{
+	int g;
+
+	if(!typechlpv[n->type->etype])
+		return;
+	simplifyshift(n);
+	if(n->op == OASHL && n->right->op == OCONST){
+		g = vconst(n->right);
+		if(g >= 0 && g <= 3)
+			n->addable = 7;
+	}
+}
+
+/*
+ *	calculate addressability as follows
+ *		NAME ==> 10/11		name+value(SB/SP)
+ *		REGISTER ==> 12		register
+ *		CONST ==> 20		$value
+ *		*(20) ==> 21		value
+ *		&(10) ==> 13		$name+value(SB)
+ *		&(11) ==> 1		$name+value(SP)
+ *		(13) + (20) ==> 13	fold constants
+ *		(1) + (20) ==> 1	fold constants
+ *		*(13) ==> 10		back to name
+ *		*(1) ==> 11		back to name
+ *
+ *		(20) * (X) ==> 7	multiplier in indexing
+ *		(X,7) + (13,1) ==> 8	adder in indexing (addresses)
+ *		(8) ==> &9(OINDEX)	index, almost addressable
+ *
+ *	calculate complexity (number of registers)
+ */
+void
+xcom(Node *n)
+{
+	Node *l, *r;
+	int g;
+
+	if(n == Z)
+		return;
+	l = n->left;
+	r = n->right;
+	n->complex = 0;
+	n->addable = 0;
+	switch(n->op) {
+	case OCONST:
+		n->addable = 20;
+		break;
+
+	case ONAME:
+		n->addable = 10;
+		if(n->class == CPARAM || n->class == CAUTO)
+			n->addable = 11;
+		break;
+
+	case OEXREG:
+		n->addable = 0;
+		break;
+
+	case OREGISTER:
+		n->addable = 12;
+		break;
+
+	case OINDREG:
+		n->addable = 12;
+		break;
+
+	case OADDR:
+		xcom(l);
+		if(l->addable == 10)
+			n->addable = 13;
+		else
+		if(l->addable == 11)
+			n->addable = 1;
+		break;
+
+	case OADD:
+		xcom(l);
+		xcom(r);
+		if(n->type->etype != TIND)
+			break;
+
+		switch(r->addable) {
+		case 20:
+			switch(l->addable) {
+			case 1:
+			case 13:
+			commadd:
+				l->type = n->type;
+				*n = *l;
+				l = new(0, Z, Z);
+				*l = *(n->left);
+				l->xoffset += r->vconst;
+				n->left = l;
+				r = n->right;
+				goto brk;
+			}
+			break;
+
+		case 1:
+		case 13:
+		case 10:
+		case 11:
+			/* l is the base, r is the index */
+			if(l->addable != 20)
+				n->addable = 8;
+			break;
+		}
+		switch(l->addable) {
+		case 20:
+			switch(r->addable) {
+			case 13:
+			case 1:
+				r = n->left;
+				l = n->right;
+				n->left = l;
+				n->right = r;
+				goto commadd;
+			}
+			break;
+
+		case 13:
+		case 1:
+		case 10:
+		case 11:
+			/* r is the base, l is the index */
+			if(r->addable != 20)
+				n->addable = 8;
+			break;
+		}
+		if(n->addable == 8 && !side(n)) {
+			indx(n);
+			l = new1(OINDEX, idx.basetree, idx.regtree);
+			l->scale = idx.scale;
+			l->addable = 9;
+			l->complex = l->right->complex;
+			l->type = l->left->type;
+			n->op = OADDR;
+			n->left = l;
+			n->right = Z;
+			n->addable = 8;
+			break;
+		}
+		break;
+
+	case OINDEX:
+		xcom(l);
+		xcom(r);
+		n->addable = 9;
+		break;
+
+	case OIND:
+		xcom(l);
+		if(l->op == OADDR) {
+			l = l->left;
+			l->type = n->type;
+			*n = *l;
+			return;
+		}
+		switch(l->addable) {
+		case 20:
+			n->addable = 21;
+			break;
+		case 1:
+			n->addable = 11;
+			break;
+		case 13:
+			n->addable = 10;
+			break;
+		}
+		break;
+
+	case OASHL:
+		xcom(l);
+		xcom(r);
+		indexshift(n);
+		break;
+
+	case OMUL:
+	case OLMUL:
+		xcom(l);
+		xcom(r);
+		g = vlog(l);
+		if(g >= 0) {
+			n->left = r;
+			n->right = l;
+			l = r;
+			r = n->right;
+		}
+		g = vlog(r);
+		if(g >= 0) {
+			n->op = OASHL;
+			r->vconst = g;
+			r->type = types[TINT];
+			indexshift(n);
+			break;
+		}
+		commute(n);
+		break;
+
+	case OASLDIV:
+		xcom(l);
+		xcom(r);
+		g = vlog(r);
+		if(g >= 0) {
+			n->op = OASLSHR;
+			r->vconst = g;
+			r->type = types[TINT];
+		}
+		break;
+
+	case OLDIV:
+		xcom(l);
+		xcom(r);
+		g = vlog(r);
+		if(g >= 0) {
+			n->op = OLSHR;
+			r->vconst = g;
+			r->type = types[TINT];
+			indexshift(n);
+			break;
+		}
+		break;
+
+	case OASLMOD:
+		xcom(l);
+		xcom(r);
+		g = vlog(r);
+		if(g >= 0) {
+			n->op = OASAND;
+			r->vconst--;
+		}
+		break;
+
+	case OLMOD:
+		xcom(l);
+		xcom(r);
+		g = vlog(r);
+		if(g >= 0) {
+			n->op = OAND;
+			r->vconst--;
+		}
+		break;
+
+	case OASMUL:
+	case OASLMUL:
+		xcom(l);
+		xcom(r);
+		g = vlog(r);
+		if(g >= 0) {
+			n->op = OASASHL;
+			r->vconst = g;
+		}
+		break;
+
+	case OLSHR:
+	case OASHR:
+		xcom(l);
+		xcom(r);
+		indexshift(n);
+		break;
+
+	default:
+		if(l != Z)
+			xcom(l);
+		if(r != Z)
+			xcom(r);
+		break;
+	}
+brk:
+	if(n->addable >= 10)
+		return;
+	if(l != Z)
+		n->complex = l->complex;
+	if(r != Z) {
+		if(r->complex == n->complex)
+			n->complex = r->complex+1;
+		else
+		if(r->complex > n->complex)
+			n->complex = r->complex;
+	}
+	if(n->complex == 0)
+		n->complex++;
+
+	switch(n->op) {
+
+	case OFUNC:
+		n->complex = FNX;
+		break;
+
+	case OCAST:
+		if(l->type->etype == TUVLONG && typefd[n->type->etype])
+			n->complex += 2;
+		break;
+
+	case OLMOD:
+	case OMOD:
+	case OLMUL:
+	case OLDIV:
+	case OMUL:
+	case ODIV:
+	case OASLMUL:
+	case OASLDIV:
+	case OASLMOD:
+	case OASMUL:
+	case OASDIV:
+	case OASMOD:
+		if(r->complex >= l->complex) {
+			n->complex = l->complex + 3;
+			if(r->complex > n->complex)
+				n->complex = r->complex;
+		} else {
+			n->complex = r->complex + 3;
+			if(l->complex > n->complex)
+				n->complex = l->complex;
+		}
+		break;
+
+	case OLSHR:
+	case OASHL:
+	case OASHR:
+	case OASLSHR:
+	case OASASHL:
+	case OASASHR:
+		if(r->complex >= l->complex) {
+			n->complex = l->complex + 2;
+			if(r->complex > n->complex)
+				n->complex = r->complex;
+		} else {
+			n->complex = r->complex + 2;
+			if(l->complex > n->complex)
+				n->complex = l->complex;
+		}
+		break;
+
+	case OADD:
+	case OXOR:
+	case OAND:
+	case OOR:
+		/*
+		 * immediate operators, make const on right
+		 */
+		if(l->op == OCONST) {
+			n->left = r;
+			n->right = l;
+		}
+		break;
+
+	case OEQ:
+	case ONE:
+	case OLE:
+	case OLT:
+	case OGE:
+	case OGT:
+	case OHI:
+	case OHS:
+	case OLO:
+	case OLS:
+		/*
+		 * compare operators, make const on left
+		 */
+		if(r->op == OCONST) {
+			n->left = r;
+			n->right = l;
+			n->op = invrel[relindex(n->op)];
+		}
+		break;
+	}
+}
+
+void
+indx(Node *n)
+{
+	Node *l, *r;
+
+	if(debug['x'])
+		prtree(n, "indx");
+
+	l = n->left;
+	r = n->right;
+	if(l->addable == 1 || l->addable == 13 || r->complex > l->complex) {
+		n->right = l;
+		n->left = r;
+		l = r;
+		r = n->right;
+	}
+	if(l->addable != 7) {
+		idx.regtree = l;
+		idx.scale = 1;
+	} else
+	if(l->right->addable == 20) {
+		idx.regtree = l->left;
+		idx.scale = 1 << l->right->vconst;
+	} else
+	if(l->left->addable == 20) {
+		idx.regtree = l->right;
+		idx.scale = 1 << l->left->vconst;
+	} else
+		diag(n, "bad index");
+
+	idx.basetree = r;
+	if(debug['x']) {
+		print("scale = %d\n", idx.scale);
+		prtree(idx.regtree, "index");
+		prtree(idx.basetree, "base");
+	}
+}
diff --git a/src/cmd/6c/swt.c b/src/cmd/6c/swt.c
new file mode 100644
index 000000000..d7a917043
--- /dev/null
+++ b/src/cmd/6c/swt.c
@@ -0,0 +1,587 @@
+// Inferno utils/6c/swt.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6c/swt.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"
+
+void
+swit1(C1 *q, int nc, int32 def, Node *n)
+{
+	C1 *r;
+	int i;
+	Prog *sp;
+
+	if(nc < 5) {
+		for(i=0; i<nc; i++) {
+			if(debug['W'])
+				print("case = %.8llux\n", q->val);
+			gcmp(OEQ, n, q->val);
+			patch(p, q->label);
+			q++;
+		}
+		gbranch(OGOTO);
+		patch(p, def);
+		return;
+	}
+	i = nc / 2;
+	r = q+i;
+	if(debug['W'])
+		print("case > %.8llux\n", r->val);
+	gcmp(OGT, n, r->val);
+	sp = p;
+	gbranch(OGOTO);
+	p->as = AJEQ;
+	patch(p, r->label);
+	swit1(q, i, def, n);
+
+	if(debug['W'])
+		print("case < %.8llux\n", r->val);
+	patch(sp, pc);
+	swit1(r+1, nc-i-1, def, n);
+}
+
+void
+bitload(Node *b, Node *n1, Node *n2, Node *n3, Node *nn)
+{
+	int sh;
+	int32 v;
+	Node *l;
+
+	/*
+	 * n1 gets adjusted/masked value
+	 * n2 gets address of cell
+	 * n3 gets contents of cell
+	 */
+	l = b->left;
+	if(n2 != Z) {
+		regalloc(n1, l, nn);
+		reglcgen(n2, l, Z);
+		regalloc(n3, l, Z);
+		gmove(n2, n3);
+		gmove(n3, n1);
+	} else {
+		regalloc(n1, l, nn);
+		cgen(l, n1);
+	}
+	if(b->type->shift == 0 && typeu[b->type->etype]) {
+		v = ~0 + (1L << b->type->nbits);
+		gopcode(OAND, tfield, nodconst(v), n1);
+	} else {
+		sh = 32 - b->type->shift - b->type->nbits;
+		if(sh > 0)
+			gopcode(OASHL, tfield, nodconst(sh), n1);
+		sh += b->type->shift;
+		if(sh > 0)
+			if(typeu[b->type->etype])
+				gopcode(OLSHR, tfield, nodconst(sh), n1);
+			else
+				gopcode(OASHR, tfield, nodconst(sh), n1);
+	}
+}
+
+void
+bitstore(Node *b, Node *n1, Node *n2, Node *n3, Node *nn)
+{
+	int32 v;
+	Node nod;
+	int sh;
+
+	regalloc(&nod, b->left, Z);
+	v = ~0 + (1L << b->type->nbits);
+	gopcode(OAND, types[TLONG], nodconst(v), n1);
+	gmove(n1, &nod);
+	if(nn != Z)
+		gmove(n1, nn);
+	sh = b->type->shift;
+	if(sh > 0)
+		gopcode(OASHL, types[TLONG], nodconst(sh), &nod);
+	v <<= sh;
+	gopcode(OAND, types[TLONG], nodconst(~v), n3);
+	gopcode(OOR, types[TLONG], n3, &nod);
+	gmove(&nod, n2);
+
+	regfree(&nod);
+	regfree(n1);
+	regfree(n2);
+	regfree(n3);
+}
+
+int32
+outstring(char *s, int32 n)
+{
+	int32 r;
+
+	if(suppress)
+		return nstring;
+	r = nstring;
+	while(n) {
+		string[mnstring] = *s++;
+		mnstring++;
+		nstring++;
+		if(mnstring >= NSNAME) {
+			gpseudo(ADATA, symstring, nodconst(0L));
+			p->from.offset += nstring - NSNAME;
+			p->from.scale = NSNAME;
+			p->to.type = D_SCONST;
+			memmove(p->to.sval, string, NSNAME);
+			mnstring = 0;
+		}
+		n--;
+	}
+	return r;
+}
+
+void
+sextern(Sym *s, Node *a, int32 o, int32 w)
+{
+	int32 e, lw;
+
+	for(e=0; e<w; e+=NSNAME) {
+		lw = NSNAME;
+		if(w-e < lw)
+			lw = w-e;
+		gpseudo(ADATA, s, nodconst(0L));
+		p->from.offset += o+e;
+		p->from.scale = lw;
+		p->to.type = D_SCONST;
+		memmove(p->to.sval, a->cstring+e, lw);
+	}
+}
+
+void
+gextern(Sym *s, Node *a, int32 o, int32 w)
+{
+	if(0 && a->op == OCONST && typev[a->type->etype]) {
+		gpseudo(ADATA, s, lo64(a));
+		p->from.offset += o;
+		p->from.scale = 4;
+		gpseudo(ADATA, s, hi64(a));
+		p->from.offset += o + 4;
+		p->from.scale = 4;
+		return;
+	}
+	gpseudo(ADATA, s, a);
+	p->from.offset += o;
+	p->from.scale = w;
+	switch(p->to.type) {
+	default:
+		p->to.index = p->to.type;
+		p->to.type = D_ADDR;
+	case D_CONST:
+	case D_FCONST:
+	case D_ADDR:
+		break;
+	}
+}
+
+void	zname(Biobuf*, Sym*, int);
+void	zaddr(Biobuf*, Adr*, int);
+void	outhist(Biobuf*);
+
+void
+outcode(void)
+{
+	struct { Sym *sym; short type; } h[NSYM];
+	Prog *p;
+	Sym *s;
+	int f, sf, st, t, sym;
+	Biobuf b;
+
+	if(debug['S']) {
+		for(p = firstp; p != P; p = p->link)
+			if(p->as != ADATA && p->as != AGLOBL)
+				pc--;
+		for(p = firstp; p != P; p = p->link) {
+			print("%P\n", p);
+			if(p->as != ADATA && p->as != AGLOBL)
+				pc++;
+		}
+	}
+
+	f = open(outfile, OWRITE);
+	if(f < 0) {
+		diag(Z, "cannot open %s", outfile);
+		return;
+	}
+	Binit(&b, f, OWRITE);
+
+	Bprint(&b, "go object %s %s %s\n", getgoos(), thestring, getgoversion());
+	if(ndynimp > 0 || ndynexp > 0) {
+		int i;
+
+		Bprint(&b, "\n");
+		Bprint(&b, "$$  // exports\n\n");
+		Bprint(&b, "$$  // local types\n\n");
+		Bprint(&b, "$$  // dynimport\n");
+		for(i=0; i<ndynimp; i++)
+			Bprint(&b, "dynimport %s %s %s\n", dynimp[i].local, dynimp[i].remote, dynimp[i].path);
+		Bprint(&b, "\n$$  // dynexport\n");
+		for(i=0; i<ndynexp; i++)
+			Bprint(&b, "dynexport %s %s\n", dynexp[i].local, dynexp[i].remote);
+		Bprint(&b, "\n$$\n\n");
+	}
+	Bprint(&b, "!\n");
+
+	outhist(&b);
+	for(sym=0; sym<NSYM; sym++) {
+		h[sym].sym = S;
+		h[sym].type = 0;
+	}
+	sym = 1;
+	for(p = firstp; p != P; p = p->link) {
+	jackpot:
+		sf = 0;
+		s = p->from.sym;
+		while(s != S) {
+			sf = s->sym;
+			if(sf < 0 || sf >= NSYM)
+				sf = 0;
+			t = p->from.type;
+			if(t == D_ADDR)
+				t = p->from.index;
+			if(h[sf].type == t)
+			if(h[sf].sym == s)
+				break;
+			s->sym = sym;
+			zname(&b, s, t);
+			h[sym].sym = s;
+			h[sym].type = t;
+			sf = sym;
+			sym++;
+			if(sym >= NSYM)
+				sym = 1;
+			break;
+		}
+		st = 0;
+		s = p->to.sym;
+		while(s != S) {
+			st = s->sym;
+			if(st < 0 || st >= NSYM)
+				st = 0;
+			t = p->to.type;
+			if(t == D_ADDR)
+				t = p->to.index;
+			if(h[st].type == t)
+			if(h[st].sym == s)
+				break;
+			s->sym = sym;
+			zname(&b, s, t);
+			h[sym].sym = s;
+			h[sym].type = t;
+			st = sym;
+			sym++;
+			if(sym >= NSYM)
+				sym = 1;
+			if(st == sf)
+				goto jackpot;
+			break;
+		}
+		Bputc(&b, p->as);
+		Bputc(&b, p->as>>8);
+		Bputc(&b, p->lineno);
+		Bputc(&b, p->lineno>>8);
+		Bputc(&b, p->lineno>>16);
+		Bputc(&b, p->lineno>>24);
+		zaddr(&b, &p->from, sf);
+		zaddr(&b, &p->to, st);
+	}
+	Bflush(&b);
+	close(f);
+	firstp = P;
+	lastp = P;
+}
+
+void
+outhist(Biobuf *b)
+{
+	Hist *h;
+	char *p, *q, *op, c;
+	Prog pg;
+	int n;
+
+	pg = zprog;
+	pg.as = AHISTORY;
+	c = pathchar();
+	for(h = hist; h != H; h = h->link) {
+		p = h->name;
+		op = 0;
+		/* on windows skip drive specifier in pathname */
+		if(systemtype(Windows) && p && p[1] == ':'){
+			p += 2;
+			c = *p;
+		}
+		if(p && p[0] != c && h->offset == 0 && pathname){
+			/* on windows skip drive specifier in pathname */
+			if(systemtype(Windows) && pathname[1] == ':') {
+				op = p;
+				p = pathname+2;
+				c = *p;
+			} else if(pathname[0] == c){
+				op = p;
+				p = pathname;
+			}
+		}
+		while(p) {
+			q = utfrune(p, c);
+			if(q) {
+				n = q-p;
+				if(n == 0){
+					n = 1;	/* leading "/" */
+					*p = '/';	/* don't emit "\" on windows */
+				}
+				q++;
+			} else {
+				n = strlen(p);
+				q = 0;
+			}
+			if(n) {
+				Bputc(b, ANAME);
+				Bputc(b, ANAME>>8);
+				Bputc(b, D_FILE);
+				Bputc(b, 1);
+				Bputc(b, '<');
+				Bwrite(b, p, n);
+				Bputc(b, 0);
+			}
+			p = q;
+			if(p == 0 && op) {
+				p = op;
+				op = 0;
+			}
+		}
+		pg.lineno = h->line;
+		pg.to.type = zprog.to.type;
+		pg.to.offset = h->offset;
+		if(h->offset)
+			pg.to.type = D_CONST;
+
+		Bputc(b, pg.as);
+		Bputc(b, pg.as>>8);
+		Bputc(b, pg.lineno);
+		Bputc(b, pg.lineno>>8);
+		Bputc(b, pg.lineno>>16);
+		Bputc(b, pg.lineno>>24);
+		zaddr(b, &pg.from, 0);
+		zaddr(b, &pg.to, 0);
+	}
+}
+
+void
+zname(Biobuf *b, Sym *s, int t)
+{
+	char *n;
+	uint32 sig;
+
+	if(debug['T'] && t == D_EXTERN && s->sig != SIGDONE && s->type != types[TENUM] && s != symrathole){
+		sig = sign(s);
+		Bputc(b, ASIGNAME);
+		Bputc(b, ASIGNAME>>8);
+		Bputc(b, sig);
+		Bputc(b, sig>>8);
+		Bputc(b, sig>>16);
+		Bputc(b, sig>>24);
+		s->sig = SIGDONE;
+	}
+	else{
+		Bputc(b, ANAME);	/* as */
+		Bputc(b, ANAME>>8);	/* as */
+	}
+	Bputc(b, t);			/* type */
+	Bputc(b, s->sym);		/* sym */
+	n = s->name;
+	while(*n) {
+		Bputc(b, *n);
+		n++;
+	}
+	Bputc(b, 0);
+}
+
+void
+zaddr(Biobuf *b, Adr *a, int s)
+{
+	int32 l;
+	int i, t;
+	char *n;
+	Ieee e;
+
+	t = 0;
+	if(a->index != D_NONE || a->scale != 0)
+		t |= T_INDEX;
+	if(s != 0)
+		t |= T_SYM;
+
+	switch(a->type) {
+	default:
+		t |= T_TYPE;
+	case D_NONE:
+		if(a->offset != 0) {
+			t |= T_OFFSET;
+			l = a->offset;
+			if((vlong)l != a->offset)
+				t |= T_64;
+		}
+		break;
+	case D_FCONST:
+		t |= T_FCONST;
+		break;
+	case D_SCONST:
+		t |= T_SCONST;
+		break;
+	}
+	Bputc(b, t);
+
+	if(t & T_INDEX) {	/* implies index, scale */
+		Bputc(b, a->index);
+		Bputc(b, a->scale);
+	}
+	if(t & T_OFFSET) {	/* implies offset */
+		l = a->offset;
+		Bputc(b, l);
+		Bputc(b, l>>8);
+		Bputc(b, l>>16);
+		Bputc(b, l>>24);
+		if(t & T_64) {
+			l = a->offset>>32;
+			Bputc(b, l);
+			Bputc(b, l>>8);
+			Bputc(b, l>>16);
+			Bputc(b, l>>24);
+		}
+	}
+	if(t & T_SYM)		/* implies sym */
+		Bputc(b, s);
+	if(t & T_FCONST) {
+		ieeedtod(&e, a->dval);
+		l = e.l;
+		Bputc(b, l);
+		Bputc(b, l>>8);
+		Bputc(b, l>>16);
+		Bputc(b, l>>24);
+		l = e.h;
+		Bputc(b, l);
+		Bputc(b, l>>8);
+		Bputc(b, l>>16);
+		Bputc(b, l>>24);
+		return;
+	}
+	if(t & T_SCONST) {
+		n = a->sval;
+		for(i=0; i<NSNAME; i++) {
+			Bputc(b, *n);
+			n++;
+		}
+		return;
+	}
+	if(t & T_TYPE)
+		Bputc(b, a->type);
+}
+
+int32
+align(int32 i, Type *t, int op, int32 *maxalign)
+{
+	int32 o;
+	Type *v;
+	int w;
+
+	o = i;
+	w = 1;
+	switch(op) {
+	default:
+		diag(Z, "unknown align opcode %d", op);
+		break;
+
+	case Asu2:	/* padding at end of a struct */
+		w = *maxalign;
+		if(w < 1)
+			w = 1;
+		if(packflg)
+			w = packflg;
+		break;
+
+	case Ael1:	/* initial align of struct element */
+		for(v=t; v->etype==TARRAY; v=v->link)
+			;
+		if(v->etype == TSTRUCT || v->etype == TUNION)
+			w = v->align;
+		else
+			w = ewidth[v->etype];
+		if(w < 1 || w > SZ_VLONG)
+			fatal(Z, "align");
+		if(packflg) 
+			w = packflg;
+		break;
+
+	case Ael2:	/* width of a struct element */
+		o += t->width;
+		break;
+
+	case Aarg0:	/* initial passbyptr argument in arg list */
+		if(typesu[t->etype]) {
+			o = align(o, types[TIND], Aarg1, nil);
+			o = align(o, types[TIND], Aarg2, nil);
+		}
+		break;
+
+	case Aarg1:	/* initial align of parameter */
+		w = ewidth[t->etype];
+		if(w <= 0 || w >= SZ_VLONG) {
+			w = SZ_VLONG;
+			break;
+		}
+		w = 1;		/* little endian no adjustment */
+		break;
+
+	case Aarg2:	/* width of a parameter */
+		o += t->width;
+		w = t->width;
+		if(w > SZ_VLONG)
+			w = SZ_VLONG;
+		break;
+
+	case Aaut3:	/* total align of automatic */
+		o = align(o, t, Ael1, nil);
+		o = align(o, t, Ael2, nil);
+		break;
+	}
+	o = xround(o, w);
+	if(maxalign && *maxalign < w)
+		*maxalign = w;
+	if(debug['A'])
+		print("align %s %d %T = %d\n", bnames[op], i, t, o);
+	return o;
+}
+
+int32
+maxround(int32 max, int32 v)
+{
+	v += SZ_VLONG-1;
+	if(v > max)
+		max = xround(v, SZ_VLONG);
+	return max;
+}
diff --git a/src/cmd/6c/txt.c b/src/cmd/6c/txt.c
new file mode 100644
index 000000000..12fc5b498
--- /dev/null
+++ b/src/cmd/6c/txt.c
@@ -0,0 +1,1564 @@
+// Inferno utils/6c/txt.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6c/txt.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"
+
+void
+ginit(void)
+{
+	int i;
+	Type *t;
+
+	thechar = '6';
+	thestring = "amd64";
+	dodefine("_64BIT");
+	listinit();
+	nstring = 0;
+	mnstring = 0;
+	nrathole = 0;
+	pc = 0;
+	breakpc = -1;
+	continpc = -1;
+	cases = C;
+	firstp = P;
+	lastp = P;
+	tfield = types[TINT];
+
+	typeword = typechlvp;
+	typecmplx = typesu;
+
+	/* TO DO */
+	memmove(typechlpv, typechlp, sizeof(typechlpv));
+	typechlpv[TVLONG] = 1;
+	typechlpv[TUVLONG] = 1;
+
+	zprog.link = P;
+	zprog.as = AGOK;
+	zprog.from.type = D_NONE;
+	zprog.from.index = D_NONE;
+	zprog.from.scale = 0;
+	zprog.to = zprog.from;
+
+	lregnode.op = OREGISTER;
+	lregnode.class = CEXREG;
+	lregnode.reg = REGTMP;
+	lregnode.complex = 0;
+	lregnode.addable = 11;
+	lregnode.type = types[TLONG];
+
+	qregnode = lregnode;
+	qregnode.type = types[TVLONG];
+
+	constnode.op = OCONST;
+	constnode.class = CXXX;
+	constnode.complex = 0;
+	constnode.addable = 20;
+	constnode.type = types[TLONG];
+
+	vconstnode = constnode;
+	vconstnode.type = types[TVLONG];
+
+	fconstnode.op = OCONST;
+	fconstnode.class = CXXX;
+	fconstnode.complex = 0;
+	fconstnode.addable = 20;
+	fconstnode.type = types[TDOUBLE];
+
+	nodsafe = new(ONAME, Z, Z);
+	nodsafe->sym = slookup(".safe");
+	nodsafe->type = types[TINT];
+	nodsafe->etype = types[TINT]->etype;
+	nodsafe->class = CAUTO;
+	complex(nodsafe);
+
+	t = typ(TARRAY, types[TCHAR]);
+	symrathole = slookup(".rathole");
+	symrathole->class = CGLOBL;
+	symrathole->type = t;
+
+	nodrat = new(ONAME, Z, Z);
+	nodrat->sym = symrathole;
+	nodrat->type = types[TIND];
+	nodrat->etype = TVOID;
+	nodrat->class = CGLOBL;
+	complex(nodrat);
+	nodrat->type = t;
+
+	nodret = new(ONAME, Z, Z);
+	nodret->sym = slookup(".ret");
+	nodret->type = types[TIND];
+	nodret->etype = TIND;
+	nodret->class = CPARAM;
+	nodret = new(OIND, nodret, Z);
+	complex(nodret);
+
+	if(0)
+		com64init();
+
+	for(i=0; i<nelem(reg); i++) {
+		reg[i] = 1;
+		if(i >= D_AX && i <= D_R15 && i != D_SP)
+			reg[i] = 0;
+		if(i >= D_X0 && i <= D_X7)
+			reg[i] = 0;
+	}
+}
+
+void
+gclean(void)
+{
+	int i;
+	Sym *s;
+
+	reg[D_SP]--;
+	for(i=D_AX; i<=D_R15; i++)
+		if(reg[i])
+			diag(Z, "reg %R left allocated", i);
+	for(i=D_X0; i<=D_X7; i++)
+		if(reg[i])
+			diag(Z, "reg %R left allocated", i);
+	while(mnstring)
+		outstring("", 1L);
+	symstring->type->width = nstring;
+	symrathole->type->width = nrathole;
+	for(i=0; i<NHASH; i++)
+	for(s = hash[i]; s != S; s = s->link) {
+		if(s->type == T)
+			continue;
+		if(s->type->width == 0)
+			continue;
+		if(s->class != CGLOBL && s->class != CSTATIC)
+			continue;
+		if(s->type == types[TENUM])
+			continue;
+		gpseudo(AGLOBL, s, nodconst(s->type->width));
+	}
+	nextpc();
+	p->as = AEND;
+	outcode();
+}
+
+void
+nextpc(void)
+{
+
+	p = alloc(sizeof(*p));
+	*p = zprog;
+	p->lineno = nearln;
+	pc++;
+	if(firstp == P) {
+		firstp = p;
+		lastp = p;
+		return;
+	}
+	lastp->link = p;
+	lastp = p;
+}
+
+void
+gargs(Node *n, Node *tn1, Node *tn2)
+{
+	int32 regs;
+	Node fnxargs[20], *fnxp;
+
+	regs = cursafe;
+
+	fnxp = fnxargs;
+	garg1(n, tn1, tn2, 0, &fnxp);	/* compile fns to temps */
+
+	curarg = 0;
+	fnxp = fnxargs;
+	garg1(n, tn1, tn2, 1, &fnxp);	/* compile normal args and temps */
+
+	cursafe = regs;
+}
+
+int
+nareg(void)
+{
+	int i, n;
+
+	n = 0;
+	for(i=D_AX; i<=D_R15; i++)
+		if(reg[i] == 0)
+			n++;
+	return n;
+}
+
+void
+garg1(Node *n, Node *tn1, Node *tn2, int f, Node **fnxp)
+{
+	Node nod;
+
+	if(n == Z)
+		return;
+	if(n->op == OLIST) {
+		garg1(n->left, tn1, tn2, f, fnxp);
+		garg1(n->right, tn1, tn2, f, fnxp);
+		return;
+	}
+	if(f == 0) {
+		if(n->complex >= FNX) {
+			regsalloc(*fnxp, n);
+			nod = znode;
+			nod.op = OAS;
+			nod.left = *fnxp;
+			nod.right = n;
+			nod.type = n->type;
+			cgen(&nod, Z);
+			(*fnxp)++;
+		}
+		return;
+	}
+	if(typesu[n->type->etype]) {
+		regaalloc(tn2, n);
+		if(n->complex >= FNX) {
+			sugen(*fnxp, tn2, n->type->width);
+			(*fnxp)++;
+		} else
+			sugen(n, tn2, n->type->width);
+		return;
+	}
+	if(REGARG >= 0 && curarg == 0 && typechlpv[n->type->etype]) {
+		regaalloc1(tn1, n);
+		if(n->complex >= FNX) {
+			cgen(*fnxp, tn1);
+			(*fnxp)++;
+		} else
+			cgen(n, tn1);
+		return;
+	}
+	if(vconst(n) == 0) {
+		regaalloc(tn2, n);
+		gmove(n, tn2);
+		return;
+	}
+	regalloc(tn1, n, Z);
+	if(n->complex >= FNX) {
+		cgen(*fnxp, tn1);
+		(*fnxp)++;
+	} else
+		cgen(n, tn1);
+	regaalloc(tn2, n);
+	gmove(tn1, tn2);
+	regfree(tn1);
+}
+
+Node*
+nodgconst(vlong v, Type *t)
+{
+	if(!typev[t->etype])
+		return nodconst((int32)v);
+	vconstnode.vconst = v;
+	return &vconstnode;
+}
+
+Node*
+nodconst(int32 v)
+{
+	constnode.vconst = v;
+	return &constnode;
+}
+
+Node*
+nodfconst(double d)
+{
+	fconstnode.fconst = d;
+	return &fconstnode;
+}
+
+int
+isreg(Node *n, int r)
+{
+
+	if(n->op == OREGISTER)
+		if(n->reg == r)
+			return 1;
+	return 0;
+}
+
+int
+nodreg(Node *n, Node *nn, int r)
+{
+	int et;
+
+	*n = qregnode;
+	n->reg = r;
+	if(nn != Z){
+		et = nn->type->etype;
+		if(!typefd[et] && nn->type->width <= SZ_LONG && 0)
+			n->type = typeu[et]? types[TUINT]: types[TINT];
+		else
+			n->type = nn->type;
+//print("nodreg %s [%s]\n", tnames[et], tnames[n->type->etype]);
+		n->lineno = nn->lineno;
+	}
+	if(reg[r] == 0)
+		return 0;
+	if(nn != Z) {
+		if(nn->op == OREGISTER)
+		if(nn->reg == r)
+			return 0;
+	}
+	return 1;
+}
+
+void
+regret(Node *n, Node *nn)
+{
+	int r;
+
+	r = REGRET;
+	if(typefd[nn->type->etype])
+		r = FREGRET;
+	nodreg(n, nn, r);
+	reg[r]++;
+}
+
+void
+regalloc(Node *n, Node *tn, Node *o)
+{
+	int i;
+
+	switch(tn->type->etype) {
+	case TCHAR:
+	case TUCHAR:
+	case TSHORT:
+	case TUSHORT:
+	case TINT:
+	case TUINT:
+	case TLONG:
+	case TULONG:
+	case TVLONG:
+	case TUVLONG:
+	case TIND:
+		if(o != Z && o->op == OREGISTER) {
+			i = o->reg;
+			if(i >= D_AX && i <= D_R15)
+				goto out;
+		}
+		for(i=D_AX; i<=D_R15; i++)
+			if(reg[i] == 0)
+				goto out;
+		diag(tn, "out of fixed registers");
+		goto err;
+
+	case TFLOAT:
+	case TDOUBLE:
+		if(o != Z && o->op == OREGISTER) {
+			i = o->reg;
+			if(i >= D_X0 && i <= D_X7)
+				goto out;
+		}
+		for(i=D_X0; i<=D_X7; i++)
+			if(reg[i] == 0)
+				goto out;
+		diag(tn, "out of float registers");
+		goto out;
+	}
+	diag(tn, "unknown type in regalloc: %T", tn->type);
+err:
+	i = 0;
+out:
+	if(i)
+		reg[i]++;
+	nodreg(n, tn, i);
+}
+
+void
+regialloc(Node *n, Node *tn, Node *o)
+{
+	Node nod;
+
+	nod = *tn;
+	nod.type = types[TIND];
+	regalloc(n, &nod, o);
+}
+
+void
+regfree(Node *n)
+{
+	int i;
+
+	i = 0;
+	if(n->op != OREGISTER && n->op != OINDREG)
+		goto err;
+	i = n->reg;
+	if(i < 0 || i >= sizeof(reg))
+		goto err;
+	if(reg[i] <= 0)
+		goto err;
+	reg[i]--;
+	return;
+err:
+	diag(n, "error in regfree: %R", i);
+}
+
+void
+regsalloc(Node *n, Node *nn)
+{
+	cursafe = align(cursafe, nn->type, Aaut3, nil);
+	maxargsafe = maxround(maxargsafe, cursafe+curarg);
+	*n = *nodsafe;
+	n->xoffset = -(stkoff + cursafe);
+	n->type = nn->type;
+	n->etype = nn->type->etype;
+	n->lineno = nn->lineno;
+}
+
+void
+regaalloc1(Node *n, Node *nn)
+{
+	if(REGARG < 0) {
+		fatal(n, "regaalloc1 and REGARG<0");
+		return;
+	}
+	nodreg(n, nn, REGARG);
+	reg[REGARG]++;
+	curarg = align(curarg, nn->type, Aarg1, nil);
+	curarg = align(curarg, nn->type, Aarg2, nil);
+	maxargsafe = maxround(maxargsafe, cursafe+curarg);
+}
+
+void
+regaalloc(Node *n, Node *nn)
+{
+	curarg = align(curarg, nn->type, Aarg1, nil);
+	*n = *nn;
+	n->op = OINDREG;
+	n->reg = REGSP;
+	n->xoffset = curarg;
+	n->complex = 0;
+	n->addable = 20;
+	curarg = align(curarg, nn->type, Aarg2, nil);
+	maxargsafe = maxround(maxargsafe, cursafe+curarg);
+}
+
+void
+regind(Node *n, Node *nn)
+{
+
+	if(n->op != OREGISTER) {
+		diag(n, "regind not OREGISTER");
+		return;
+	}
+	n->op = OINDREG;
+	n->type = nn->type;
+}
+
+void
+naddr(Node *n, Adr *a)
+{
+	int32 v;
+
+	a->type = D_NONE;
+	if(n == Z)
+		return;
+	switch(n->op) {
+	default:
+	bad:
+		diag(n, "bad in naddr: %O %D", n->op, a);
+		break;
+
+	case OREGISTER:
+		a->type = n->reg;
+		a->sym = S;
+		break;
+
+	case OEXREG:
+		a->type = D_INDIR + D_GS;
+		a->offset = n->reg - 1;
+		break;
+
+	case OIND:
+		naddr(n->left, a);
+		if(a->type >= D_AX && a->type <= D_R15)
+			a->type += D_INDIR;
+		else
+		if(a->type == D_CONST)
+			a->type = D_NONE+D_INDIR;
+		else
+		if(a->type == D_ADDR) {
+			a->type = a->index;
+			a->index = D_NONE;
+		} else
+			goto bad;
+		break;
+
+	case OINDEX:
+		a->type = idx.ptr;
+		if(n->left->op == OADDR || n->left->op == OCONST)
+			naddr(n->left, a);
+		if(a->type >= D_AX && a->type <= D_R15)
+			a->type += D_INDIR;
+		else
+		if(a->type == D_CONST)
+			a->type = D_NONE+D_INDIR;
+		else
+		if(a->type == D_ADDR) {
+			a->type = a->index;
+			a->index = D_NONE;
+		} else
+			goto bad;
+		a->index = idx.reg;
+		a->scale = n->scale;
+		a->offset += n->xoffset;
+		break;
+
+	case OINDREG:
+		a->type = n->reg+D_INDIR;
+		a->sym = S;
+		a->offset = n->xoffset;
+		break;
+
+	case ONAME:
+		a->etype = n->etype;
+		a->type = D_STATIC;
+		a->sym = n->sym;
+		a->offset = n->xoffset;
+		if(n->class == CSTATIC)
+			break;
+		if(n->class == CEXTERN || n->class == CGLOBL) {
+			a->type = D_EXTERN;
+			break;
+		}
+		if(n->class == CAUTO) {
+			a->type = D_AUTO;
+			break;
+		}
+		if(n->class == CPARAM) {
+			a->type = D_PARAM;
+			break;
+		}
+		goto bad;
+
+	case OCONST:
+		if(typefd[n->type->etype]) {
+			a->type = D_FCONST;
+			a->dval = n->fconst;
+			break;
+		}
+		a->sym = S;
+		a->type = D_CONST;
+		if(typev[n->type->etype] || n->type->etype == TIND)
+			a->offset = n->vconst;
+		else
+			a->offset = convvtox(n->vconst, typeu[n->type->etype]? TULONG: TLONG);
+		break;
+
+	case OADDR:
+		naddr(n->left, a);
+		if(a->type >= D_INDIR) {
+			a->type -= D_INDIR;
+			break;
+		}
+		if(a->type == D_EXTERN || a->type == D_STATIC ||
+		   a->type == D_AUTO || a->type == D_PARAM)
+			if(a->index == D_NONE) {
+				a->index = a->type;
+				a->type = D_ADDR;
+				break;
+			}
+		goto bad;
+
+	case OADD:
+		if(n->right->op == OCONST) {
+			v = n->right->vconst;
+			naddr(n->left, a);
+		} else
+		if(n->left->op == OCONST) {
+			v = n->left->vconst;
+			naddr(n->right, a);
+		} else
+			goto bad;
+		a->offset += v;
+		break;
+
+	}
+}
+
+void
+gcmp(int op, Node *n, vlong val)
+{
+	Node *cn, nod;
+
+	cn = nodgconst(val, n->type);
+	if(!immconst(cn)){
+		regalloc(&nod, n, Z);
+		gmove(cn, &nod);
+		gopcode(op, n->type, n, &nod);
+		regfree(&nod);
+	}else
+		gopcode(op, n->type, n, cn);
+}
+
+#define	CASE(a,b)	((a<<8)|(b<<0))
+
+void
+gmove(Node *f, Node *t)
+{
+	int ft, tt, t64, a;
+	Node nod, nod1, nod2, nod3;
+	Prog *p1, *p2;
+
+	ft = f->type->etype;
+	tt = t->type->etype;
+	t64 = tt == TVLONG || tt == TUVLONG || tt == TIND;
+	if(debug['M'])
+		print("gop: %O %O[%s],%O[%s]\n", OAS,
+			f->op, tnames[ft], t->op, tnames[tt]);
+	if(typefd[ft] && f->op == OCONST) {
+		/* TO DO: pick up special constants, possibly preloaded */
+		if(f->fconst == 0.0){
+			regalloc(&nod, t, t);
+			gins(AXORPD, &nod, &nod);
+			gmove(&nod, t);
+			regfree(&nod);
+			return;
+		}
+	}
+/*
+ * load
+ */
+	if(ft == TVLONG || ft == TUVLONG)
+	if(f->op == OCONST)
+	if(f->vconst > 0x7fffffffLL || f->vconst < -0x7fffffffLL)
+	if(t->op != OREGISTER) {
+		regalloc(&nod, f, Z);
+		gmove(f, &nod);
+		gmove(&nod, t);
+		regfree(&nod);
+		return;
+	}
+
+	if(f->op == ONAME || f->op == OINDREG ||
+	   f->op == OIND || f->op == OINDEX)
+	switch(ft) {
+	case TCHAR:
+		a = AMOVBLSX;
+		if(t64)
+			a = AMOVBQSX;
+		goto ld;
+	case TUCHAR:
+		a = AMOVBLZX;
+		if(t64)
+			a = AMOVBQZX;
+		goto ld;
+	case TSHORT:
+		a = AMOVWLSX;
+		if(t64)
+			a = AMOVWQSX;
+		goto ld;
+	case TUSHORT:
+		a = AMOVWLZX;
+		if(t64)
+			a = AMOVWQZX;
+		goto ld;
+	case TINT:
+	case TLONG:
+		if(typefd[tt]) {
+			regalloc(&nod, t, t);
+			if(tt == TDOUBLE)
+				a = ACVTSL2SD;
+			else
+				a = ACVTSL2SS;
+			gins(a, f, &nod);
+			gmove(&nod, t);
+			regfree(&nod);
+			return;
+		}
+		a = AMOVL;
+		if(t64)
+			a = AMOVLQSX;
+		goto ld;
+	case TUINT:
+	case TULONG:
+		a = AMOVL;
+		if(t64)
+			a = AMOVLQZX;	/* could probably use plain MOVL */
+		goto ld;
+	case TVLONG:
+		if(typefd[tt]) {
+			regalloc(&nod, t, t);
+			if(tt == TDOUBLE)
+				a = ACVTSQ2SD;
+			else
+				a = ACVTSQ2SS;
+			gins(a, f, &nod);
+			gmove(&nod, t);
+			regfree(&nod);
+			return;
+		}
+	case TUVLONG:
+		a = AMOVQ;
+		goto ld;
+	case TIND:
+		a = AMOVQ;
+
+	ld:
+		regalloc(&nod, f, t);
+		nod.type = t64? types[TVLONG]: types[TINT];
+		gins(a, f, &nod);
+		gmove(&nod, t);
+		regfree(&nod);
+		return;
+
+	case TFLOAT:
+		a = AMOVSS;
+		goto fld;
+	case TDOUBLE:
+		a = AMOVSD;
+	fld:
+		regalloc(&nod, f, t);
+		if(tt != TDOUBLE && tt != TFLOAT){	/* TO DO: why is this here */
+			prtree(f, "odd tree");
+			nod.type = t64? types[TVLONG]: types[TINT];
+		}
+		gins(a, f, &nod);
+		gmove(&nod, t);
+		regfree(&nod);
+		return;
+	}
+
+/*
+ * store
+ */
+	if(t->op == ONAME || t->op == OINDREG ||
+	   t->op == OIND || t->op == OINDEX)
+	switch(tt) {
+	case TCHAR:
+	case TUCHAR:
+		a = AMOVB;	goto st;
+	case TSHORT:
+	case TUSHORT:
+		a = AMOVW;	goto st;
+	case TINT:
+	case TUINT:
+	case TLONG:
+	case TULONG:
+		a = AMOVL;	goto st;
+	case TVLONG:
+	case TUVLONG:
+	case TIND:
+		a = AMOVQ;	goto st;
+
+	st:
+		if(f->op == OCONST) {
+			gins(a, f, t);
+			return;
+		}
+	fst:
+		regalloc(&nod, t, f);
+		gmove(f, &nod);
+		gins(a, &nod, t);
+		regfree(&nod);
+		return;
+
+	case TFLOAT:
+		a = AMOVSS;
+		goto fst;
+	case TDOUBLE:
+		a = AMOVSD;
+		goto fst;
+	}
+
+/*
+ * convert
+ */
+	switch(CASE(ft,tt)) {
+	default:
+/*
+ * integer to integer
+ ********
+		a = AGOK;	break;
+
+	case CASE(	TCHAR,	TCHAR):
+	case CASE(	TUCHAR,	TCHAR):
+	case CASE(	TSHORT,	TCHAR):
+	case CASE(	TUSHORT,TCHAR):
+	case CASE(	TINT,	TCHAR):
+	case CASE(	TUINT,	TCHAR):
+	case CASE(	TLONG,	TCHAR):
+	case CASE(	TULONG,	TCHAR):
+	case CASE(	TIND,	TCHAR):
+
+	case CASE(	TCHAR,	TUCHAR):
+	case CASE(	TUCHAR,	TUCHAR):
+	case CASE(	TSHORT,	TUCHAR):
+	case CASE(	TUSHORT,TUCHAR):
+	case CASE(	TINT,	TUCHAR):
+	case CASE(	TUINT,	TUCHAR):
+	case CASE(	TLONG,	TUCHAR):
+	case CASE(	TULONG,	TUCHAR):
+	case CASE(	TIND,	TUCHAR):
+
+	case CASE(	TSHORT,	TSHORT):
+	case CASE(	TUSHORT,TSHORT):
+	case CASE(	TINT,	TSHORT):
+	case CASE(	TUINT,	TSHORT):
+	case CASE(	TLONG,	TSHORT):
+	case CASE(	TULONG,	TSHORT):
+	case CASE(	TIND,	TSHORT):
+
+	case CASE(	TSHORT,	TUSHORT):
+	case CASE(	TUSHORT,TUSHORT):
+	case CASE(	TINT,	TUSHORT):
+	case CASE(	TUINT,	TUSHORT):
+	case CASE(	TLONG,	TUSHORT):
+	case CASE(	TULONG,	TUSHORT):
+	case CASE(	TIND,	TUSHORT):
+
+	case CASE(	TINT,	TINT):
+	case CASE(	TUINT,	TINT):
+	case CASE(	TLONG,	TINT):
+	case CASE(	TULONG,	TINT):
+	case CASE(	TIND,	TINT):
+
+	case CASE(	TINT,	TUINT):
+	case CASE(	TUINT,	TUINT):
+	case CASE(	TLONG,	TUINT):
+	case CASE(	TULONG,	TUINT):
+	case CASE(	TIND,	TUINT):
+
+	case CASE(	TUINT,	TIND):
+	case CASE(	TVLONG,	TUINT):
+	case CASE(	TVLONG,	TULONG):
+	case CASE(	TUVLONG, TUINT):
+	case CASE(	TUVLONG, TULONG):
+ *****/
+		a = AMOVL;
+		break;
+
+	case CASE(	TVLONG,	TCHAR):
+	case	CASE(	TVLONG,	TSHORT):
+	case CASE(	TVLONG,	TINT):
+	case CASE(	TVLONG,	TLONG):
+	case CASE(	TUVLONG, TCHAR):
+	case	CASE(	TUVLONG, TSHORT):
+	case CASE(	TUVLONG, TINT):
+	case CASE(	TUVLONG, TLONG):
+	case CASE(	TINT,	TVLONG):
+	case CASE(	TINT,	TUVLONG):
+	case CASE(	TLONG,	TVLONG):
+	case CASE(	TINT,	TIND):
+	case CASE(	TLONG,	TIND):
+		a = AMOVLQSX;
+		if(f->op == OCONST) {
+			f->vconst &= (uvlong)0xffffffffU;
+			if(f->vconst & 0x80000000)
+				f->vconst |= (vlong)0xffffffff << 32;
+			a = AMOVQ;
+		}
+		break;
+
+	case CASE(	TUINT,	TIND):
+	case CASE(	TUINT,	TVLONG):
+	case CASE(	TUINT,	TUVLONG):
+	case CASE(	TULONG,	TVLONG):
+	case CASE(	TULONG,	TUVLONG):
+	case CASE(	TULONG,	TIND):
+		a = AMOVL;	/* same effect as AMOVLQZX */
+		if(f->op == OCONST) {
+			f->vconst &= (uvlong)0xffffffffU;
+			a = AMOVQ;
+		}
+		break;
+
+	case CASE(	TIND,	TVLONG):
+	case CASE(	TVLONG,	TVLONG):
+	case CASE(	TUVLONG,	TVLONG):
+	case CASE(	TVLONG,	TUVLONG):
+	case CASE(	TUVLONG,	TUVLONG):
+	case CASE(	TIND,	TUVLONG):
+	case CASE(	TVLONG,	TIND):
+	case CASE(	TUVLONG,	TIND):
+	case CASE(	TIND,	TIND):
+		a = AMOVQ;
+		break;
+
+	case CASE(	TSHORT,	TINT):
+	case CASE(	TSHORT,	TUINT):
+	case CASE(	TSHORT,	TLONG):
+	case CASE(	TSHORT,	TULONG):
+		a = AMOVWLSX;
+		if(f->op == OCONST) {
+			f->vconst &= 0xffff;
+			if(f->vconst & 0x8000)
+				f->vconst |= 0xffff0000;
+			a = AMOVL;
+		}
+		break;
+
+	case CASE(	TSHORT,	TVLONG):
+	case CASE(	TSHORT,	TUVLONG):
+	case CASE(	TSHORT,	TIND):
+		a = AMOVWQSX;
+		if(f->op == OCONST) {
+			f->vconst &= 0xffff;
+			if(f->vconst & 0x8000){
+				f->vconst |= 0xffff0000;
+				f->vconst |= (vlong)~0 << 32;
+			}
+			a = AMOVL;
+		}
+		break;
+
+	case CASE(	TUSHORT,TINT):
+	case CASE(	TUSHORT,TUINT):
+	case CASE(	TUSHORT,TLONG):
+	case CASE(	TUSHORT,TULONG):
+		a = AMOVWLZX;
+		if(f->op == OCONST) {
+			f->vconst &= 0xffff;
+			a = AMOVL;
+		}
+		break;
+
+	case CASE(	TUSHORT,TVLONG):
+	case CASE(	TUSHORT,TUVLONG):
+	case CASE(	TUSHORT,TIND):
+		a = AMOVWQZX;
+		if(f->op == OCONST) {
+			f->vconst &= 0xffff;
+			a = AMOVL;	/* MOVL also zero-extends to 64 bits */
+		}
+		break;
+
+	case CASE(	TCHAR,	TSHORT):
+	case CASE(	TCHAR,	TUSHORT):
+	case CASE(	TCHAR,	TINT):
+	case CASE(	TCHAR,	TUINT):
+	case CASE(	TCHAR,	TLONG):
+	case CASE(	TCHAR,	TULONG):
+		a = AMOVBLSX;
+		if(f->op == OCONST) {
+			f->vconst &= 0xff;
+			if(f->vconst & 0x80)
+				f->vconst |= 0xffffff00;
+			a = AMOVL;
+		}
+		break;
+
+	case CASE(	TCHAR,	TVLONG):
+	case CASE(	TCHAR,	TUVLONG):
+	case CASE(	TCHAR,	TIND):
+		a = AMOVBQSX;
+		if(f->op == OCONST) {
+			f->vconst &= 0xff;
+			if(f->vconst & 0x80){
+				f->vconst |= 0xffffff00;
+				f->vconst |= (vlong)~0 << 32;
+			}
+			a = AMOVQ;
+		}
+		break;
+
+	case CASE(	TUCHAR,	TSHORT):
+	case CASE(	TUCHAR,	TUSHORT):
+	case CASE(	TUCHAR,	TINT):
+	case CASE(	TUCHAR,	TUINT):
+	case CASE(	TUCHAR,	TLONG):
+	case CASE(	TUCHAR,	TULONG):
+		a = AMOVBLZX;
+		if(f->op == OCONST) {
+			f->vconst &= 0xff;
+			a = AMOVL;
+		}
+		break;
+
+	case CASE(	TUCHAR,	TVLONG):
+	case CASE(	TUCHAR,	TUVLONG):
+	case CASE(	TUCHAR,	TIND):
+		a = AMOVBQZX;
+		if(f->op == OCONST) {
+			f->vconst &= 0xff;
+			a = AMOVL;	/* zero-extends to 64-bits */
+		}
+		break;
+
+/*
+ * float to fix
+ */
+	case CASE(	TFLOAT,	TCHAR):
+	case CASE(	TFLOAT,	TUCHAR):
+	case CASE(	TFLOAT,	TSHORT):
+	case CASE(	TFLOAT,	TUSHORT):
+	case CASE(	TFLOAT,	TINT):
+	case CASE(	TFLOAT,	TUINT):
+	case CASE(	TFLOAT,	TLONG):
+	case CASE(	TFLOAT,	TULONG):
+	case CASE(	TFLOAT,	TVLONG):
+	case CASE(	TFLOAT,	TUVLONG):
+	case CASE(	TFLOAT,	TIND):
+
+	case CASE(	TDOUBLE,TCHAR):
+	case CASE(	TDOUBLE,TUCHAR):
+	case CASE(	TDOUBLE,TSHORT):
+	case CASE(	TDOUBLE,TUSHORT):
+	case CASE(	TDOUBLE,TINT):
+	case CASE(	TDOUBLE,TUINT):
+	case CASE(	TDOUBLE,TLONG):
+	case CASE(	TDOUBLE,TULONG):
+	case CASE(	TDOUBLE,TVLONG):
+	case CASE(	TDOUBLE,TUVLONG):
+	case CASE(	TDOUBLE,TIND):
+		regalloc(&nod, t, Z);
+		if(ewidth[tt] == SZ_VLONG || typeu[tt] && ewidth[tt] == SZ_INT){
+			if(ft == TFLOAT)
+				a = ACVTTSS2SQ;
+			else
+				a = ACVTTSD2SQ;
+		}else{
+			if(ft == TFLOAT)
+				a = ACVTTSS2SL;
+			else
+				a = ACVTTSD2SL;
+		}
+		gins(a, f, &nod);
+		gmove(&nod, t);
+		regfree(&nod);
+		return;
+
+/*
+ * uvlong to float
+ */
+	case CASE(	TUVLONG,	TDOUBLE):
+	case CASE(	TUVLONG,	TFLOAT):
+		a = ACVTSQ2SS;
+		if(tt == TDOUBLE)
+			a = ACVTSQ2SD;
+		regalloc(&nod, f, f);
+		gmove(f, &nod);
+		regalloc(&nod1, t, t);
+		gins(ACMPQ, &nod, nodconst(0));
+		gins(AJLT, Z, Z);
+		p1 = p;
+		gins(a, &nod, &nod1);
+		gins(AJMP, Z, Z);
+		p2 = p;
+		patch(p1, pc);
+		regalloc(&nod2, f, Z);
+		regalloc(&nod3, f, Z);
+		gmove(&nod, &nod2);
+		gins(ASHRQ, nodconst(1), &nod2);
+		gmove(&nod, &nod3);
+		gins(AANDL, nodconst(1), &nod3);
+		gins(AORQ, &nod3, &nod2);
+		gins(a, &nod2, &nod1);
+		gins(tt == TDOUBLE? AADDSD: AADDSS, &nod1, &nod1);
+		regfree(&nod2);
+		regfree(&nod3);
+		patch(p2, pc);
+		regfree(&nod);
+		regfree(&nod1);
+		return;
+
+	case CASE(	TULONG,	TDOUBLE):
+	case CASE(	TUINT,	TDOUBLE):
+	case CASE(	TULONG,	TFLOAT):
+	case CASE(	TUINT,	TFLOAT):
+		a = ACVTSQ2SS;
+		if(tt == TDOUBLE)
+			a = ACVTSQ2SD;
+		regalloc(&nod, f, f);
+		gins(AMOVLQZX, f, &nod);
+		regalloc(&nod1, t, t);
+		gins(a, &nod, &nod1);
+		gmove(&nod1, t);
+		regfree(&nod);
+		regfree(&nod1);
+		return;
+
+/*
+ * fix to float
+ */
+	case CASE(	TCHAR,	TFLOAT):
+	case CASE(	TUCHAR,	TFLOAT):
+	case CASE(	TSHORT,	TFLOAT):
+	case CASE(	TUSHORT,TFLOAT):
+	case CASE(	TINT,	TFLOAT):
+	case CASE(	TLONG,	TFLOAT):
+	case	CASE(	TVLONG,	TFLOAT):
+	case CASE(	TIND,	TFLOAT):
+
+	case CASE(	TCHAR,	TDOUBLE):
+	case CASE(	TUCHAR,	TDOUBLE):
+	case CASE(	TSHORT,	TDOUBLE):
+	case CASE(	TUSHORT,TDOUBLE):
+	case CASE(	TINT,	TDOUBLE):
+	case CASE(	TLONG,	TDOUBLE):
+	case CASE(	TVLONG,	TDOUBLE):
+	case CASE(	TIND,	TDOUBLE):
+		regalloc(&nod, t, t);
+		if(ewidth[ft] == SZ_VLONG){
+			if(tt == TFLOAT)
+				a = ACVTSQ2SS;
+			else
+				a = ACVTSQ2SD;
+		}else{
+			if(tt == TFLOAT)
+				a = ACVTSL2SS;
+			else
+				a = ACVTSL2SD;
+		}
+		gins(a, f, &nod);
+		gmove(&nod, t);
+		regfree(&nod);
+		return;
+
+/*
+ * float to float
+ */
+	case CASE(	TFLOAT,	TFLOAT):
+		a = AMOVSS;
+		break;
+	case CASE(	TDOUBLE,TFLOAT):
+		a = ACVTSD2SS;
+		break;
+	case CASE(	TFLOAT,	TDOUBLE):
+		a = ACVTSS2SD;
+		break;
+	case CASE(	TDOUBLE,TDOUBLE):
+		a = AMOVSD;
+		break;
+	}
+	if(a == AMOVQ || a == AMOVSD || a == AMOVSS || a == AMOVL && ewidth[ft] == ewidth[tt])	/* TO DO: check AMOVL */
+	if(samaddr(f, t))
+		return;
+	gins(a, f, t);
+}
+
+void
+doindex(Node *n)
+{
+	Node nod, nod1;
+	int32 v;
+
+if(debug['Y'])
+prtree(n, "index");
+
+if(n->left->complex >= FNX)
+print("botch in doindex\n");
+
+	regalloc(&nod, &qregnode, Z);
+	v = constnode.vconst;
+	cgen(n->right, &nod);
+	idx.ptr = D_NONE;
+	if(n->left->op == OCONST)
+		idx.ptr = D_CONST;
+	else if(n->left->op == OREGISTER)
+		idx.ptr = n->left->reg;
+	else if(n->left->op != OADDR) {
+		reg[D_BP]++;	// cant be used as a base
+		regalloc(&nod1, &qregnode, Z);
+		cgen(n->left, &nod1);
+		idx.ptr = nod1.reg;
+		regfree(&nod1);
+		reg[D_BP]--;
+	}
+	idx.reg = nod.reg;
+	regfree(&nod);
+	constnode.vconst = v;
+}
+
+void
+gins(int a, Node *f, Node *t)
+{
+
+	if(f != Z && f->op == OINDEX)
+		doindex(f);
+	if(t != Z && t->op == OINDEX)
+		doindex(t);
+	nextpc();
+	p->as = a;
+	if(f != Z)
+		naddr(f, &p->from);
+	if(t != Z)
+		naddr(t, &p->to);
+	if(debug['g'])
+		print("%P\n", p);
+}
+
+void
+gopcode(int o, Type *ty, Node *f, Node *t)
+{
+	int a, et;
+
+	et = TLONG;
+	if(ty != T)
+		et = ty->etype;
+	if(debug['M']) {
+		if(f != Z && f->type != T)
+			print("gop: %O %O[%s],", o, f->op, tnames[et]);
+		else
+			print("gop: %O Z,", o);
+		if(t != Z && t->type != T)
+			print("%O[%s]\n", t->op, tnames[t->type->etype]);
+		else
+			print("Z\n");
+	}
+	a = AGOK;
+	switch(o) {
+	case OCOM:
+		a = ANOTL;
+		if(et == TCHAR || et == TUCHAR)
+			a = ANOTB;
+		if(et == TSHORT || et == TUSHORT)
+			a = ANOTW;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = ANOTQ;
+		break;
+
+	case ONEG:
+		a = ANEGL;
+		if(et == TCHAR || et == TUCHAR)
+			a = ANEGB;
+		if(et == TSHORT || et == TUSHORT)
+			a = ANEGW;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = ANEGQ;
+		break;
+
+	case OADDR:
+		a = ALEAQ;
+		break;
+
+	case OASADD:
+	case OADD:
+		a = AADDL;
+		if(et == TCHAR || et == TUCHAR)
+			a = AADDB;
+		if(et == TSHORT || et == TUSHORT)
+			a = AADDW;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = AADDQ;
+		if(et == TFLOAT)
+			a = AADDSS;
+		if(et == TDOUBLE)
+			a = AADDSD;
+		break;
+
+	case OASSUB:
+	case OSUB:
+		a = ASUBL;
+		if(et == TCHAR || et == TUCHAR)
+			a = ASUBB;
+		if(et == TSHORT || et == TUSHORT)
+			a = ASUBW;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = ASUBQ;
+		if(et == TFLOAT)
+			a = ASUBSS;
+		if(et == TDOUBLE)
+			a = ASUBSD;
+		break;
+
+	case OASOR:
+	case OOR:
+		a = AORL;
+		if(et == TCHAR || et == TUCHAR)
+			a = AORB;
+		if(et == TSHORT || et == TUSHORT)
+			a = AORW;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = AORQ;
+		break;
+
+	case OASAND:
+	case OAND:
+		a = AANDL;
+		if(et == TCHAR || et == TUCHAR)
+			a = AANDB;
+		if(et == TSHORT || et == TUSHORT)
+			a = AANDW;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = AANDQ;
+		break;
+
+	case OASXOR:
+	case OXOR:
+		a = AXORL;
+		if(et == TCHAR || et == TUCHAR)
+			a = AXORB;
+		if(et == TSHORT || et == TUSHORT)
+			a = AXORW;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = AXORQ;
+		break;
+
+	case OASLSHR:
+	case OLSHR:
+		a = ASHRL;
+		if(et == TCHAR || et == TUCHAR)
+			a = ASHRB;
+		if(et == TSHORT || et == TUSHORT)
+			a = ASHRW;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = ASHRQ;
+		break;
+
+	case OASASHR:
+	case OASHR:
+		a = ASARL;
+		if(et == TCHAR || et == TUCHAR)
+			a = ASARB;
+		if(et == TSHORT || et == TUSHORT)
+			a = ASARW;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = ASARQ;
+		break;
+
+	case OASASHL:
+	case OASHL:
+		a = ASALL;
+		if(et == TCHAR || et == TUCHAR)
+			a = ASALB;
+		if(et == TSHORT || et == TUSHORT)
+			a = ASALW;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = ASALQ;
+		break;
+
+	case OFUNC:
+		a = ACALL;
+		break;
+
+	case OASMUL:
+	case OMUL:
+		if(f->op == OREGISTER && t != Z && isreg(t, D_AX) && reg[D_DX] == 0)
+			t = Z;
+		a = AIMULL;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = AIMULQ;
+		if(et == TFLOAT)
+			a = AMULSS;
+		if(et == TDOUBLE)
+			a = AMULSD;
+		break;
+
+	case OASMOD:
+	case OMOD:
+	case OASDIV:
+	case ODIV:
+		a = AIDIVL;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = AIDIVQ;
+		if(et == TFLOAT)
+			a = ADIVSS;
+		if(et == TDOUBLE)
+			a = ADIVSD;
+		break;
+
+	case OASLMUL:
+	case OLMUL:
+		a = AMULL;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = AMULQ;
+		break;
+
+	case OASLMOD:
+	case OLMOD:
+	case OASLDIV:
+	case OLDIV:
+		a = ADIVL;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = ADIVQ;
+		break;
+
+	case OEQ:
+	case ONE:
+	case OLT:
+	case OLE:
+	case OGE:
+	case OGT:
+	case OLO:
+	case OLS:
+	case OHS:
+	case OHI:
+		a = ACMPL;
+		if(et == TCHAR || et == TUCHAR)
+			a = ACMPB;
+		if(et == TSHORT || et == TUSHORT)
+			a = ACMPW;
+		if(et == TVLONG || et == TUVLONG || et == TIND)
+			a = ACMPQ;
+		if(et == TFLOAT)
+			a = AUCOMISS;
+		if(et == TDOUBLE)
+			a = AUCOMISD;
+		gins(a, f, t);
+		switch(o) {
+		case OEQ:	a = AJEQ; break;
+		case ONE:	a = AJNE; break;
+		case OLT:	a = AJLT; break;
+		case OLE:	a = AJLE; break;
+		case OGE:	a = AJGE; break;
+		case OGT:	a = AJGT; break;
+		case OLO:	a = AJCS; break;
+		case OLS:	a = AJLS; break;
+		case OHS:	a = AJCC; break;
+		case OHI:	a = AJHI; break;
+		}
+		gins(a, Z, Z);
+		return;
+	}
+	if(a == AGOK)
+		diag(Z, "bad in gopcode %O", o);
+	gins(a, f, t);
+}
+
+int
+samaddr(Node *f, Node *t)
+{
+	return f->op == OREGISTER && t->op == OREGISTER && f->reg == t->reg;
+}
+
+void
+gbranch(int o)
+{
+	int a;
+
+	a = AGOK;
+	switch(o) {
+	case ORETURN:
+		a = ARET;
+		break;
+	case OGOTO:
+		a = AJMP;
+		break;
+	}
+	nextpc();
+	if(a == AGOK) {
+		diag(Z, "bad in gbranch %O",  o);
+		nextpc();
+	}
+	p->as = a;
+}
+
+void
+patch(Prog *op, int32 pc)
+{
+
+	op->to.offset = pc;
+	op->to.type = D_BRANCH;
+}
+
+void
+gpseudo(int a, Sym *s, Node *n)
+{
+
+	nextpc();
+	p->as = a;
+	p->from.type = D_EXTERN;
+	p->from.sym = s;
+	p->from.scale = textflag;
+	textflag = 0;
+
+	if(s->class == CSTATIC)
+		p->from.type = D_STATIC;
+	naddr(n, &p->to);
+	if(a == ADATA || a == AGLOBL)
+		pc--;
+}
+
+int
+sconst(Node *n)
+{
+	int32 v;
+
+	if(n->op == OCONST && !typefd[n->type->etype]) {
+		v = n->vconst;
+		if(v >= -32766L && v < 32766L)
+			return 1;
+	}
+	return 0;
+}
+
+int32
+exreg(Type *t)
+{
+	int32 o;
+
+	if(typechlpv[t->etype]) {
+		if(exregoffset >= 64)
+			return 0;
+		o = exregoffset;
+		exregoffset += 8;
+		return o+1;	// +1 to avoid 0 == failure; naddr's case OEXREG will subtract 1.
+	}
+	return 0;
+}
+
+schar	ewidth[NTYPE] =
+{
+	-1,		/*[TXXX]*/
+	SZ_CHAR,	/*[TCHAR]*/
+	SZ_CHAR,	/*[TUCHAR]*/
+	SZ_SHORT,	/*[TSHORT]*/
+	SZ_SHORT,	/*[TUSHORT]*/
+	SZ_INT,		/*[TINT]*/
+	SZ_INT,		/*[TUINT]*/
+	SZ_LONG,	/*[TLONG]*/
+	SZ_LONG,	/*[TULONG]*/
+	SZ_VLONG,	/*[TVLONG]*/
+	SZ_VLONG,	/*[TUVLONG]*/
+	SZ_FLOAT,	/*[TFLOAT]*/
+	SZ_DOUBLE,	/*[TDOUBLE]*/
+	SZ_IND,		/*[TIND]*/
+	0,		/*[TFUNC]*/
+	-1,		/*[TARRAY]*/
+	0,		/*[TVOID]*/
+	-1,		/*[TSTRUCT]*/
+	-1,		/*[TUNION]*/
+	SZ_INT,		/*[TENUM]*/
+};
+int32	ncast[NTYPE] =
+{
+	0,				/*[TXXX]*/
+	BCHAR|BUCHAR,			/*[TCHAR]*/
+	BCHAR|BUCHAR,			/*[TUCHAR]*/
+	BSHORT|BUSHORT,			/*[TSHORT]*/
+	BSHORT|BUSHORT,			/*[TUSHORT]*/
+	BINT|BUINT|BLONG|BULONG,	/*[TINT]*/
+	BINT|BUINT|BLONG|BULONG,	/*[TUINT]*/
+	BINT|BUINT|BLONG|BULONG,	/*[TLONG]*/
+	BINT|BUINT|BLONG|BULONG,	/*[TULONG]*/
+	BVLONG|BUVLONG|BIND,			/*[TVLONG]*/
+	BVLONG|BUVLONG|BIND,			/*[TUVLONG]*/
+	BFLOAT,				/*[TFLOAT]*/
+	BDOUBLE,			/*[TDOUBLE]*/
+	BVLONG|BUVLONG|BIND,		/*[TIND]*/
+	0,				/*[TFUNC]*/
+	0,				/*[TARRAY]*/
+	0,				/*[TVOID]*/
+	BSTRUCT,			/*[TSTRUCT]*/
+	BUNION,				/*[TUNION]*/
+	0,				/*[TENUM]*/
+};