Imported Upstream version 60upstream/60

1 files changed, 1155 insertions, 0 deletions

diff --git a/src/cmd/8g/ggen.c b/src/cmd/8g/ggen.c
new file mode 100644
index 000000000..108c493aa
--- /dev/null
+++ b/src/cmd/8g/ggen.c
@@ -0,0 +1,1155 @@
+// 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.
+
+#undef	EXTERN
+#define	EXTERN
+#include "gg.h"
+#include "opt.h"
+
+void
+defframe(Prog *ptxt)
+{
+	// fill in argument size
+	ptxt->to.offset2 = rnd(curfn->type->argwid, widthptr);
+
+	// fill in final stack size
+	if(stksize > maxstksize)
+		maxstksize = stksize;
+	ptxt->to.offset = rnd(maxstksize+maxarg, widthptr);
+	maxstksize = 0;
+}
+
+// Sweep the prog list to mark any used nodes.
+void
+markautoused(Prog* p)
+{
+	for (; p; p = p->link) {
+		if (p->from.type == D_AUTO && p->from.node)
+			p->from.node->used++;
+
+		if (p->to.type == D_AUTO && p->to.node)
+			p->to.node->used++;
+	}
+}
+
+// Fixup instructions after compactframe has moved all autos around.
+void
+fixautoused(Prog* p)
+{
+	for (; p; p = p->link) {
+		if (p->from.type == D_AUTO && p->from.node)
+			p->from.offset += p->from.node->stkdelta;
+
+		if (p->to.type == D_AUTO && p->to.node)
+			p->to.offset += p->to.node->stkdelta;
+	}
+}
+
+void
+clearfat(Node *nl)
+{
+	uint32 w, c, q;
+	Node n1;
+
+	/* clear a fat object */
+	if(debug['g'])
+		dump("\nclearfat", nl);
+
+	w = nl->type->width;
+	c = w % 4;	// bytes
+	q = w / 4;	// quads
+
+	gconreg(AMOVL, 0, D_AX);
+	nodreg(&n1, types[tptr], D_DI);
+	agen(nl, &n1);
+
+	if(q >= 4) {
+		gconreg(AMOVL, q, D_CX);
+		gins(AREP, N, N);	// repeat
+		gins(ASTOSL, N, N);	// STOL AL,*(DI)+
+	} else
+	while(q > 0) {
+		gins(ASTOSL, N, N);	// STOL AL,*(DI)+
+		q--;
+	}
+
+	if(c >= 4) {
+		gconreg(AMOVL, c, D_CX);
+		gins(AREP, N, N);	// repeat
+		gins(ASTOSB, N, N);	// STOB AL,*(DI)+
+	} else
+	while(c > 0) {
+		gins(ASTOSB, N, N);	// STOB AL,*(DI)+
+		c--;
+	}
+}
+
+/*
+ * generate:
+ *	call f
+ *	proc=0	normal call
+ *	proc=1	goroutine run in new proc
+ *	proc=2	defer call save away stack
+ */
+void
+ginscall(Node *f, int proc)
+{
+	Prog *p;
+	Node reg, con;
+
+	switch(proc) {
+	default:
+		fatal("ginscall: bad proc %d", proc);
+		break;
+
+	case 0:	// normal call
+		p = gins(ACALL, N, f);
+		afunclit(&p->to);
+		break;
+
+	case 1:	// call in new proc (go)
+	case 2:	// deferred call (defer)
+		nodreg(&reg, types[TINT32], D_CX);
+		gins(APUSHL, f, N);
+		nodconst(&con, types[TINT32], argsize(f->type));
+		gins(APUSHL, &con, N);
+		if(proc == 1)
+			ginscall(newproc, 0);
+		else
+			ginscall(deferproc, 0);
+		gins(APOPL, N, &reg);
+		gins(APOPL, N, &reg);
+		if(proc == 2) {
+			nodreg(&reg, types[TINT64], D_AX);
+			gins(ATESTL, &reg, &reg);
+			patch(gbranch(AJNE, T), retpc);
+		}
+		break;
+	}
+}
+
+/*
+ * n is call to interface method.
+ * generate res = n.
+ */
+void
+cgen_callinter(Node *n, Node *res, int proc)
+{
+	Node *i, *f;
+	Node tmpi, nodo, nodr, nodsp;
+
+	i = n->left;
+	if(i->op != ODOTINTER)
+		fatal("cgen_callinter: not ODOTINTER %O", i->op);
+
+	f = i->right;		// field
+	if(f->op != ONAME)
+		fatal("cgen_callinter: not ONAME %O", f->op);
+
+	i = i->left;		// interface
+
+	if(!i->addable) {
+		tempname(&tmpi, i->type);
+		cgen(i, &tmpi);
+		i = &tmpi;
+	}
+
+	genlist(n->list);		// assign the args
+
+	// Can regalloc now; i is known to be addable,
+	// so the agen will be easy.
+	regalloc(&nodr, types[tptr], res);
+	regalloc(&nodo, types[tptr], &nodr);
+	nodo.op = OINDREG;
+
+	agen(i, &nodr);		// REG = &inter
+
+	nodindreg(&nodsp, types[tptr], D_SP);
+	nodo.xoffset += widthptr;
+	cgen(&nodo, &nodsp);	// 0(SP) = 4(REG) -- i.data
+
+	nodo.xoffset -= widthptr;
+	cgen(&nodo, &nodr);	// REG = 0(REG) -- i.tab
+
+	if(n->left->xoffset == BADWIDTH)
+		fatal("cgen_callinter: badwidth");
+	nodo.xoffset = n->left->xoffset + 3*widthptr + 8;
+	cgen(&nodo, &nodr);	// REG = 20+offset(REG) -- i.tab->fun[f]
+
+	// BOTCH nodr.type = fntype;
+	nodr.type = n->left->type;
+	ginscall(&nodr, proc);
+
+	regfree(&nodr);
+	regfree(&nodo);
+
+	setmaxarg(n->left->type);
+}
+
+/*
+ * generate function call;
+ *	proc=0	normal call
+ *	proc=1	goroutine run in new proc
+ *	proc=2	defer call save away stack
+ */
+void
+cgen_call(Node *n, int proc)
+{
+	Type *t;
+	Node nod, afun;
+
+	if(n == N)
+		return;
+
+	if(n->left->ullman >= UINF) {
+		// if name involves a fn call
+		// precompute the address of the fn
+		tempname(&afun, types[tptr]);
+		cgen(n->left, &afun);
+	}
+
+	genlist(n->list);		// assign the args
+	t = n->left->type;
+
+	setmaxarg(t);
+
+	// call tempname pointer
+	if(n->left->ullman >= UINF) {
+		regalloc(&nod, types[tptr], N);
+		cgen_as(&nod, &afun);
+		nod.type = t;
+		ginscall(&nod, proc);
+		regfree(&nod);
+		return;
+	}
+
+	// call pointer
+	if(n->left->op != ONAME || n->left->class != PFUNC) {
+		regalloc(&nod, types[tptr], N);
+		cgen_as(&nod, n->left);
+		nod.type = t;
+		ginscall(&nod, proc);
+		regfree(&nod);
+		return;
+	}
+
+	// call direct
+	n->left->method = 1;
+	ginscall(n->left, proc);
+}
+
+/*
+ * call to n has already been generated.
+ * generate:
+ *	res = return value from call.
+ */
+void
+cgen_callret(Node *n, Node *res)
+{
+	Node nod;
+	Type *fp, *t;
+	Iter flist;
+
+	t = n->left->type;
+	if(t->etype == TPTR32 || t->etype == TPTR64)
+		t = t->type;
+
+	fp = structfirst(&flist, getoutarg(t));
+	if(fp == T)
+		fatal("cgen_callret: nil");
+
+	memset(&nod, 0, sizeof(nod));
+	nod.op = OINDREG;
+	nod.val.u.reg = D_SP;
+	nod.addable = 1;
+
+	nod.xoffset = fp->width;
+	nod.type = fp->type;
+	cgen_as(res, &nod);
+}
+
+/*
+ * call to n has already been generated.
+ * generate:
+ *	res = &return value from call.
+ */
+void
+cgen_aret(Node *n, Node *res)
+{
+	Node nod1, nod2;
+	Type *fp, *t;
+	Iter flist;
+
+	t = n->left->type;
+	if(isptr[t->etype])
+		t = t->type;
+
+	fp = structfirst(&flist, getoutarg(t));
+	if(fp == T)
+		fatal("cgen_aret: nil");
+
+	memset(&nod1, 0, sizeof(nod1));
+	nod1.op = OINDREG;
+	nod1.val.u.reg = D_SP;
+	nod1.addable = 1;
+
+	nod1.xoffset = fp->width;
+	nod1.type = fp->type;
+
+	if(res->op != OREGISTER) {
+		regalloc(&nod2, types[tptr], res);
+		gins(ALEAL, &nod1, &nod2);
+		gins(AMOVL, &nod2, res);
+		regfree(&nod2);
+	} else
+		gins(ALEAL, &nod1, res);
+}
+
+/*
+ * generate return.
+ * n->left is assignments to return values.
+ */
+void
+cgen_ret(Node *n)
+{
+	genlist(n->list);		// copy out args
+	if(retpc)
+		gjmp(retpc);
+	else
+		gins(ARET, N, N);
+}
+
+/*
+ * generate += *= etc.
+ */
+void
+cgen_asop(Node *n)
+{
+	Node n1, n2, n3, n4;
+	Node *nl, *nr;
+	Prog *p1;
+	Addr addr;
+	int a;
+
+	nl = n->left;
+	nr = n->right;
+
+	if(nr->ullman >= UINF && nl->ullman >= UINF) {
+		tempname(&n1, nr->type);
+		cgen(nr, &n1);
+		n2 = *n;
+		n2.right = &n1;
+		cgen_asop(&n2);
+		goto ret;
+	}
+
+	if(!isint[nl->type->etype])
+		goto hard;
+	if(!isint[nr->type->etype])
+		goto hard;
+	if(is64(nl->type) || is64(nr->type))
+		goto hard;
+
+	switch(n->etype) {
+	case OADD:
+		if(smallintconst(nr))
+		if(mpgetfix(nr->val.u.xval) == 1) {
+			a = optoas(OINC, nl->type);
+			if(nl->addable) {
+				gins(a, N, nl);
+				goto ret;
+			}
+			if(sudoaddable(a, nl, &addr)) {
+				p1 = gins(a, N, N);
+				p1->to = addr;
+				sudoclean();
+				goto ret;
+			}
+		}
+		break;
+
+	case OSUB:
+		if(smallintconst(nr))
+		if(mpgetfix(nr->val.u.xval) == 1) {
+			a = optoas(ODEC, nl->type);
+			if(nl->addable) {
+				gins(a, N, nl);
+				goto ret;
+			}
+			if(sudoaddable(a, nl, &addr)) {
+				p1 = gins(a, N, N);
+				p1->to = addr;
+				sudoclean();
+				goto ret;
+			}
+		}
+		break;
+	}
+
+	switch(n->etype) {
+	case OADD:
+	case OSUB:
+	case OXOR:
+	case OAND:
+	case OOR:
+		a = optoas(n->etype, nl->type);
+		if(nl->addable) {
+			if(smallintconst(nr)) {
+				gins(a, nr, nl);
+				goto ret;
+			}
+			regalloc(&n2, nr->type, N);
+			cgen(nr, &n2);
+			gins(a, &n2, nl);
+			regfree(&n2);
+			goto ret;
+		}
+		if(nr->ullman < UINF)
+		if(sudoaddable(a, nl, &addr)) {
+			if(smallintconst(nr)) {
+				p1 = gins(a, nr, N);
+				p1->to = addr;
+				sudoclean();
+				goto ret;
+			}
+			regalloc(&n2, nr->type, N);
+			cgen(nr, &n2);
+			p1 = gins(a, &n2, N);
+			p1->to = addr;
+			regfree(&n2);
+			sudoclean();
+			goto ret;
+		}
+	}
+
+hard:
+	n2.op = 0;
+	n1.op = 0;
+	if(nr->ullman >= nl->ullman || nl->addable) {
+		mgen(nr, &n2, N);
+		nr = &n2;
+		nr = &n2;
+	} else {
+		tempname(&n2, nr->type);
+		cgen(nr, &n2);
+		nr = &n2;
+	}
+	if(!nl->addable) {
+		igen(nl, &n1, N);
+		nl = &n1;
+	}
+
+	n3 = *n;
+	n3.left = nl;
+	n3.right = nr;
+	n3.op = n->etype;
+
+	mgen(&n3, &n4, N);
+	gmove(&n4, nl);
+
+	if(n1.op)
+		regfree(&n1);
+	mfree(&n2);
+	mfree(&n4);
+
+ret:
+	;
+}
+
+int
+samereg(Node *a, Node *b)
+{
+	if(a->op != OREGISTER)
+		return 0;
+	if(b->op != OREGISTER)
+		return 0;
+	if(a->val.u.reg != b->val.u.reg)
+		return 0;
+	return 1;
+}
+
+/*
+ * generate division.
+ * caller must set:
+ *	ax = allocated AX register
+ *	dx = allocated DX register
+ * generates one of:
+ *	res = nl / nr
+ *	res = nl % nr
+ * according to op.
+ */
+void
+dodiv(int op, Node *nl, Node *nr, Node *res, Node *ax, Node *dx)
+{
+	int check;
+	Node n1, t1, t2, n4, nz;
+	Type *t;
+	Prog *p1, *p2, *p3;
+
+	// Have to be careful about handling
+	// most negative int divided by -1 correctly.
+	// The hardware will trap.
+	// Also the byte divide instruction needs AH,
+	// which we otherwise don't have to deal with.
+	// Easiest way to avoid for int8, int16: use int32.
+	// For int32 and int64, use explicit test.
+	// Could use int64 hw for int32.
+	t = nl->type;
+	check = 0;
+	if(issigned[t->etype]) {
+		check = 1;
+		if(isconst(nl, CTINT) && mpgetfix(nl->val.u.xval) != -1LL<<(t->width*8-1))
+			check = 0;
+		else if(isconst(nr, CTINT) && mpgetfix(nr->val.u.xval) != -1)
+			check = 0;
+	}
+	if(t->width < 4) {
+		if(issigned[t->etype])
+			t = types[TINT32];
+		else
+			t = types[TUINT32];
+		check = 0;
+	}
+
+	tempname(&t1, t);
+	tempname(&t2, t);
+	cgen(nl, &t1);
+	cgen(nr, &t2);
+
+	if(!samereg(ax, res) && !samereg(dx, res))
+		regalloc(&n1, t, res);
+	else
+		regalloc(&n1, t, N);
+	gmove(&t2, &n1);
+	gmove(&t1, ax);
+	p3 = P;
+	if(check) {
+		nodconst(&n4, t, -1);
+		gins(optoas(OCMP, t), &n1, &n4);
+		p1 = gbranch(optoas(ONE, t), T);
+		nodconst(&n4, t, -1LL<<(t->width*8-1));
+		gins(optoas(OCMP, t), ax, &n4);
+		p2 = gbranch(optoas(ONE, t), T);
+		if(op == ODIV)
+			gmove(&n4, res);
+		if(op == OMOD) {
+			nodconst(&n4, t, 0);
+			gmove(&n4, res);
+		}
+		p3 = gbranch(AJMP, T);
+		patch(p1, pc);
+		patch(p2, pc);
+	}
+	if(!issigned[t->etype]) {
+		nodconst(&nz, t, 0);
+		gmove(&nz, dx);
+	} else
+		gins(optoas(OEXTEND, t), N, N);
+	gins(optoas(op, t), &n1, N);
+	regfree(&n1);
+
+	if(op == ODIV)
+		gmove(ax, res);
+	else
+		gmove(dx, res);
+	if(check)
+		patch(p3, pc);
+}
+
+static void
+savex(int dr, Node *x, Node *oldx, Node *res, Type *t)
+{
+	int r;
+
+	r = reg[dr];
+	nodreg(x, types[TINT32], dr);
+
+	// save current ax and dx if they are live
+	// and not the destination
+	memset(oldx, 0, sizeof *oldx);
+	if(r > 0 && !samereg(x, res)) {
+		tempname(oldx, types[TINT32]);
+		gmove(x, oldx);
+	}
+
+	regalloc(x, t, x);
+}
+
+static void
+restx(Node *x, Node *oldx)
+{
+	regfree(x);
+
+	if(oldx->op != 0) {
+		x->type = types[TINT32];
+		gmove(oldx, x);
+	}
+}
+
+/*
+ * generate division according to op, one of:
+ *	res = nl / nr
+ *	res = nl % nr
+ */
+void
+cgen_div(int op, Node *nl, Node *nr, Node *res)
+{
+	Node ax, dx, oldax, olddx;
+	Type *t;
+
+	if(is64(nl->type))
+		fatal("cgen_div %T", nl->type);
+
+	if(issigned[nl->type->etype])
+		t = types[TINT32];
+	else
+		t = types[TUINT32];
+	savex(D_AX, &ax, &oldax, res, t);
+	savex(D_DX, &dx, &olddx, res, t);
+	dodiv(op, nl, nr, res, &ax, &dx);
+	restx(&dx, &olddx);
+	restx(&ax, &oldax);
+}
+
+/*
+ * generate shift according to op, one of:
+ *	res = nl << nr
+ *	res = nl >> nr
+ */
+void
+cgen_shift(int op, Node *nl, Node *nr, Node *res)
+{
+	Node n1, n2, nt, cx, oldcx, hi, lo;
+	int a, w;
+	Prog *p1, *p2;
+	uvlong sc;
+
+	if(nl->type->width > 4)
+		fatal("cgen_shift %T", nl->type);
+
+	w = nl->type->width * 8;
+
+	a = optoas(op, nl->type);
+
+	if(nr->op == OLITERAL) {
+		tempname(&n2, nl->type);
+		cgen(nl, &n2);
+		regalloc(&n1, nl->type, res);
+		gmove(&n2, &n1);
+		sc = mpgetfix(nr->val.u.xval);
+		if(sc >= nl->type->width*8) {
+			// large shift gets 2 shifts by width
+			gins(a, ncon(w-1), &n1);
+			gins(a, ncon(w-1), &n1);
+		} else
+			gins(a, nr, &n1);
+		gmove(&n1, res);
+		regfree(&n1);
+		return;
+	}
+
+	memset(&oldcx, 0, sizeof oldcx);
+	nodreg(&cx, types[TUINT32], D_CX);
+	if(reg[D_CX] > 1 && !samereg(&cx, res)) {
+		tempname(&oldcx, types[TUINT32]);
+		gmove(&cx, &oldcx);
+	}
+
+	if(nr->type->width > 4) {
+		tempname(&nt, nr->type);
+		n1 = nt;
+	} else {
+		nodreg(&n1, types[TUINT32], D_CX);
+		regalloc(&n1, nr->type, &n1);		// to hold the shift type in CX
+	}
+
+	if(samereg(&cx, res))
+		regalloc(&n2, nl->type, N);
+	else
+		regalloc(&n2, nl->type, res);
+	if(nl->ullman >= nr->ullman) {
+		cgen(nl, &n2);
+		cgen(nr, &n1);
+	} else {
+		cgen(nr, &n1);
+		cgen(nl, &n2);
+	}
+
+	// test and fix up large shifts
+	if(nr->type->width > 4) {
+		// delayed reg alloc
+		nodreg(&n1, types[TUINT32], D_CX);
+		regalloc(&n1, types[TUINT32], &n1);		// to hold the shift type in CX
+		split64(&nt, &lo, &hi);
+		gmove(&lo, &n1);
+		gins(optoas(OCMP, types[TUINT32]), &hi, ncon(0));
+		p2 = gbranch(optoas(ONE, types[TUINT32]), T);
+		gins(optoas(OCMP, types[TUINT32]), &n1, ncon(w));
+		p1 = gbranch(optoas(OLT, types[TUINT32]), T);
+		patch(p2, pc);
+	} else {
+		gins(optoas(OCMP, nr->type), &n1, ncon(w));
+		p1 = gbranch(optoas(OLT, types[TUINT32]), T);
+	}
+	if(op == ORSH && issigned[nl->type->etype]) {
+		gins(a, ncon(w-1), &n2);
+	} else {
+		gmove(ncon(0), &n2);
+	}
+	patch(p1, pc);
+	gins(a, &n1, &n2);
+
+	if(oldcx.op != 0)
+		gmove(&oldcx, &cx);
+
+	gmove(&n2, res);
+
+	regfree(&n1);
+	regfree(&n2);
+}
+
+/*
+ * generate byte multiply:
+ *	res = nl * nr
+ * no byte multiply instruction so have to do
+ * 16-bit multiply and take bottom half.
+ */
+void
+cgen_bmul(int op, Node *nl, Node *nr, Node *res)
+{
+	Node n1b, n2b, n1w, n2w;
+	Type *t;
+	int a;
+
+	if(nl->ullman >= nr->ullman) {
+		regalloc(&n1b, nl->type, res);
+		cgen(nl, &n1b);
+		regalloc(&n2b, nr->type, N);
+		cgen(nr, &n2b);
+	} else {
+		regalloc(&n2b, nr->type, N);
+		cgen(nr, &n2b);
+		regalloc(&n1b, nl->type, res);
+		cgen(nl, &n1b);
+	}
+
+	// copy from byte to short registers
+	t = types[TUINT16];
+	if(issigned[nl->type->etype])
+		t = types[TINT16];
+
+	regalloc(&n2w, t, &n2b);
+	cgen(&n2b, &n2w);
+
+	regalloc(&n1w, t, &n1b);
+	cgen(&n1b, &n1w);
+
+	a = optoas(op, t);
+	gins(a, &n2w, &n1w);
+	cgen(&n1w, &n1b);
+	cgen(&n1b, res);
+
+	regfree(&n1w);
+	regfree(&n2w);
+	regfree(&n1b);
+	regfree(&n2b);
+}
+
+static int
+regcmp(const void *va, const void *vb)
+{
+	Node *ra, *rb;
+
+	ra = (Node*)va;
+	rb = (Node*)vb;
+	return ra->local - rb->local;
+}
+
+static	Prog*	throwpc;
+
+// We're only going to bother inlining if we can
+// convert all the arguments to 32 bits safely.  Can we?
+static int
+fix64(NodeList *nn, int n)
+{
+	NodeList *l;
+	Node *r;
+	int i;
+	
+	l = nn;
+	for(i=0; i<n; i++) {
+		r = l->n->right;
+		if(is64(r->type) && !smallintconst(r)) {
+			if(r->op == OCONV)
+				r = r->left;
+			if(is64(r->type))
+				return 0;
+		}
+		l = l->next;
+	}
+	return 1;
+}
+
+void
+getargs(NodeList *nn, Node *reg, int n)
+{
+	NodeList *l;
+	Node *r;
+	int i;
+
+	throwpc = nil;
+
+	l = nn;
+	for(i=0; i<n; i++) {
+		r = l->n->right;
+		if(is64(r->type)) {
+			if(r->op == OCONV)
+				r = r->left;
+			else if(smallintconst(r))
+				r->type = types[TUINT32];
+			if(is64(r->type))
+				fatal("getargs");
+		}
+		if(!smallintconst(r) && !isslice(r->type)) {
+			if(i < 3)	// AX CX DX
+				nodreg(reg+i, r->type, D_AX+i);
+			else
+				reg[i].op = OXXX;
+			regalloc(reg+i, r->type, reg+i);
+			cgen(r, reg+i);
+		} else
+			reg[i] = *r;
+		if(reg[i].local != 0)
+			yyerror("local used");
+		reg[i].local = l->n->left->xoffset;
+		l = l->next;
+	}
+	qsort((void*)reg, n, sizeof(*reg), regcmp);
+	for(i=0; i<n; i++)
+		reg[i].local = 0;
+}
+
+void
+cmpandthrow(Node *nl, Node *nr)
+{
+	vlong cl;
+	Prog *p1;
+	int op;
+	Node *c, n1;
+	Type *t;
+
+	op = OLE;
+	if(smallintconst(nl)) {
+		cl = mpgetfix(nl->val.u.xval);
+		if(cl == 0)
+			return;
+		if(smallintconst(nr))
+			return;
+		// put the constant on the right
+		op = brrev(op);
+		c = nl;
+		nl = nr;
+		nr = c;
+	}
+	
+	// Arguments are known not to be 64-bit,
+	// but they might be smaller than 32 bits.
+	// Check if we need to use a temporary.
+	// At least one of the arguments is 32 bits
+	// (the len or cap) so one temporary suffices.
+	n1.op = OXXX;
+	t = types[TUINT32];
+	if(nl->type->width != t->width) {
+		regalloc(&n1, t, nl);
+		gmove(nl, &n1);
+		nl = &n1;
+	} else if(nr->type->width != t->width) {
+		regalloc(&n1, t, nr);
+		gmove(nr, &n1);
+		nr = &n1;
+	}
+	gins(optoas(OCMP, t), nl, nr);
+	if(n1.op != OXXX)
+		regfree(&n1);
+	if(throwpc == nil) {
+		p1 = gbranch(optoas(op, t), T);
+		throwpc = pc;
+		ginscall(panicslice, 0);
+		patch(p1, pc);
+	} else {
+		op = brcom(op);
+		p1 = gbranch(optoas(op, t), T);
+		patch(p1, throwpc);
+	}
+}
+
+int
+sleasy(Node *n)
+{
+	if(n->op != ONAME)
+		return 0;
+	if(!n->addable)
+		return 0;
+	return 1;
+}
+
+// generate inline code for
+//	slicearray
+//	sliceslice
+//	arraytoslice
+int
+cgen_inline(Node *n, Node *res)
+{
+	Node nodes[5];
+	Node n1, n2, nres, ntemp;
+	vlong v;
+	int i, narg, nochk;
+
+	if(n->op != OCALLFUNC)
+		goto no;
+	if(!n->left->addable)
+		goto no;
+	if(n->left->sym == S)
+		goto no;
+	if(n->left->sym->pkg != runtimepkg)
+		goto no;
+	if(strcmp(n->left->sym->name, "slicearray") == 0)
+		goto slicearray;
+	if(strcmp(n->left->sym->name, "sliceslice") == 0) {
+		narg = 4;
+		goto sliceslice;
+	}
+	if(strcmp(n->left->sym->name, "sliceslice1") == 0) {
+		narg = 3;
+		goto sliceslice;
+	}
+	goto no;
+
+slicearray:
+	if(!sleasy(res))
+		goto no;
+	if(!fix64(n->list, 5))
+		goto no;
+	getargs(n->list, nodes, 5);
+
+	// if(hb[3] > nel[1]) goto throw
+	cmpandthrow(&nodes[3], &nodes[1]);
+
+	// if(lb[2] > hb[3]) goto throw
+	cmpandthrow(&nodes[2], &nodes[3]);
+
+	// len = hb[3] - lb[2] (destroys hb)
+	n2 = *res;
+	n2.xoffset += Array_nel;
+	n2.type = types[TUINT32];
+
+	if(smallintconst(&nodes[3]) && smallintconst(&nodes[2])) {
+		v = mpgetfix(nodes[3].val.u.xval) -
+			mpgetfix(nodes[2].val.u.xval);
+		nodconst(&n1, types[TUINT32], v);
+		gins(optoas(OAS, types[TUINT32]), &n1, &n2);
+	} else {
+		regalloc(&n1, types[TUINT32], &nodes[3]);
+		gmove(&nodes[3], &n1);
+		if(!smallintconst(&nodes[2]) || mpgetfix(nodes[2].val.u.xval) != 0)
+			gins(optoas(OSUB, types[TUINT32]), &nodes[2], &n1);
+		gins(optoas(OAS, types[TUINT32]), &n1, &n2);
+		regfree(&n1);
+	}
+
+	// cap = nel[1] - lb[2] (destroys nel)
+	n2 = *res;
+	n2.xoffset += Array_cap;
+	n2.type = types[TUINT32];
+
+	if(smallintconst(&nodes[1]) && smallintconst(&nodes[2])) {
+		v = mpgetfix(nodes[1].val.u.xval) -
+			mpgetfix(nodes[2].val.u.xval);
+		nodconst(&n1, types[TUINT32], v);
+		gins(optoas(OAS, types[TUINT32]), &n1, &n2);
+	} else {
+		regalloc(&n1, types[TUINT32], &nodes[1]);
+		gmove(&nodes[1], &n1);
+		if(!smallintconst(&nodes[2]) || mpgetfix(nodes[2].val.u.xval) != 0)
+			gins(optoas(OSUB, types[TUINT32]), &nodes[2], &n1);
+		gins(optoas(OAS, types[TUINT32]), &n1, &n2);
+		regfree(&n1);
+	}
+
+	// if slice could be too big, dereference to
+	// catch nil array pointer.
+	if(nodes[0].op == OREGISTER && nodes[0].type->type->width >= unmappedzero) {
+		n2 = nodes[0];
+		n2.xoffset = 0;
+		n2.op = OINDREG;
+		n2.type = types[TUINT8];
+		gins(ATESTB, nodintconst(0), &n2);
+	}
+
+	// ary = old[0] + (lb[2] * width[4]) (destroys old)
+	n2 = *res;
+	n2.xoffset += Array_array;
+	n2.type = types[tptr];
+
+	if(smallintconst(&nodes[2]) && smallintconst(&nodes[4])) {
+		v = mpgetfix(nodes[2].val.u.xval) *
+			mpgetfix(nodes[4].val.u.xval);
+		if(v != 0) {
+			nodconst(&n1, types[tptr], v);
+			gins(optoas(OADD, types[tptr]), &n1, &nodes[0]);
+		}
+	} else {
+		regalloc(&n1, types[tptr], &nodes[2]);
+		gmove(&nodes[2], &n1);
+		if(!smallintconst(&nodes[4]) || mpgetfix(nodes[4].val.u.xval) != 1)
+			gins(optoas(OMUL, types[tptr]), &nodes[4], &n1);
+		gins(optoas(OADD, types[tptr]), &n1, &nodes[0]);
+		regfree(&n1);
+	}
+	gins(optoas(OAS, types[tptr]), &nodes[0], &n2);
+
+	for(i=0; i<5; i++) {
+		if(nodes[i].op == OREGISTER)
+			regfree(&nodes[i]);
+	}
+	return 1;
+
+sliceslice:
+	if(!fix64(n->list, narg))
+		goto no;
+	nochk = n->etype;  // skip bounds checking
+	ntemp.op = OXXX;
+	if(!sleasy(n->list->n->right)) {
+		Node *n0;
+		
+		n0 = n->list->n->right;
+		tempname(&ntemp, res->type);
+		cgen(n0, &ntemp);
+		n->list->n->right = &ntemp;
+		getargs(n->list, nodes, narg);
+		n->list->n->right = n0;
+	} else
+		getargs(n->list, nodes, narg);
+
+	nres = *res;		// result
+	if(!sleasy(res)) {
+		if(ntemp.op == OXXX)
+			tempname(&ntemp, res->type);
+		nres = ntemp;
+	}
+
+	if(narg == 3) {	// old[lb:]
+		// move width to where it would be for old[lb:hb]
+		nodes[3] = nodes[2];
+		nodes[2].op = OXXX;
+		
+		// if(lb[1] > old.nel[0]) goto throw;
+		n2 = nodes[0];
+		n2.xoffset += Array_nel;
+		n2.type = types[TUINT32];
+		if(!nochk)
+			cmpandthrow(&nodes[1], &n2);
+
+		// ret.nel = old.nel[0]-lb[1];
+		n2 = nodes[0];
+		n2.xoffset += Array_nel;
+		n2.type = types[TUINT32];
+	
+		regalloc(&n1, types[TUINT32], N);
+		gins(optoas(OAS, types[TUINT32]), &n2, &n1);
+		if(!smallintconst(&nodes[1]) || mpgetfix(nodes[1].val.u.xval) != 0)
+			gins(optoas(OSUB, types[TUINT32]), &nodes[1], &n1);
+	
+		n2 = nres;
+		n2.xoffset += Array_nel;
+		n2.type = types[TUINT32];
+		gins(optoas(OAS, types[TUINT32]), &n1, &n2);
+		regfree(&n1);
+	} else {	// old[lb:hb]
+		n2 = nodes[0];
+		n2.xoffset += Array_cap;
+		n2.type = types[TUINT32];
+		if (!nochk) {
+			// if(hb[2] > old.cap[0]) goto throw;
+			cmpandthrow(&nodes[2], &n2);
+			// if(lb[1] > hb[2]) goto throw;
+			cmpandthrow(&nodes[1], &nodes[2]);
+		}
+
+		// ret.len = hb[2]-lb[1]; (destroys hb[2])
+		n2 = nres;
+		n2.xoffset += Array_nel;
+		n2.type = types[TUINT32];
+
+		if(smallintconst(&nodes[2]) && smallintconst(&nodes[1])) {
+			v = mpgetfix(nodes[2].val.u.xval) -
+				mpgetfix(nodes[1].val.u.xval);
+			nodconst(&n1, types[TUINT32], v);
+			gins(optoas(OAS, types[TUINT32]), &n1, &n2);
+		} else {
+			regalloc(&n1, types[TUINT32], &nodes[2]);
+			gmove(&nodes[2], &n1);
+			if(!smallintconst(&nodes[1]) || mpgetfix(nodes[1].val.u.xval) != 0)
+				gins(optoas(OSUB, types[TUINT32]), &nodes[1], &n1);
+			gins(optoas(OAS, types[TUINT32]), &n1, &n2);
+			regfree(&n1);
+		}
+	}
+
+	// ret.cap = old.cap[0]-lb[1]; (uses hb[2])
+	n2 = nodes[0];
+	n2.xoffset += Array_cap;
+	n2.type = types[TUINT32];
+
+	regalloc(&n1, types[TUINT32], &nodes[2]);
+	gins(optoas(OAS, types[TUINT32]), &n2, &n1);
+	if(!smallintconst(&nodes[1]) || mpgetfix(nodes[1].val.u.xval) != 0)
+		gins(optoas(OSUB, types[TUINT32]), &nodes[1], &n1);
+
+	n2 = nres;
+	n2.xoffset += Array_cap;
+	n2.type = types[TUINT32];
+	gins(optoas(OAS, types[TUINT32]), &n1, &n2);
+	regfree(&n1);
+
+	// ret.array = old.array[0]+lb[1]*width[3]; (uses lb[1])
+	n2 = nodes[0];
+	n2.xoffset += Array_array;
+	n2.type = types[tptr];
+
+	regalloc(&n1, types[tptr], &nodes[1]);
+	if(smallintconst(&nodes[1]) && smallintconst(&nodes[3])) {
+		gins(optoas(OAS, types[tptr]), &n2, &n1);
+		v = mpgetfix(nodes[1].val.u.xval) *
+			mpgetfix(nodes[3].val.u.xval);
+		if(v != 0) {
+			nodconst(&n2, types[tptr], v);
+			gins(optoas(OADD, types[tptr]), &n2, &n1);
+		}
+	} else {
+		gmove(&nodes[1], &n1);
+		if(!smallintconst(&nodes[3]) || mpgetfix(nodes[3].val.u.xval) != 1)
+			gins(optoas(OMUL, types[tptr]), &nodes[3], &n1);
+		gins(optoas(OADD, types[tptr]), &n2, &n1);
+	}
+
+	n2 = nres;
+	n2.xoffset += Array_array;
+	n2.type = types[tptr];
+	gins(optoas(OAS, types[tptr]), &n1, &n2);
+	regfree(&n1);
+
+	for(i=0; i<4; i++) {
+		if(nodes[i].op == OREGISTER)
+			regfree(&nodes[i]);
+	}
+
+	if(!sleasy(res)) {
+		cgen(&nres, res);
+	}
+	return 1;
+
+no:
+	return 0;
+}