gc: make static initialization more static

Does as much as possible in data layout instead
of during the init function.

Handles var x = y; var y = z as a special case too,
because it is so prevalent in package unicode
(var Greek = _Greek; var _Greek = []...).

Introduces InitPlan description of initialized data
so that it can be traversed multiple times (for example,
in the copy handler).

Cuts package unicode's init function size by 8x.
All that remains there is map initialization, which
is on the chopping block too.

Fixes sinit.go test case.

Aggregate DATA instructions at end of object file.

Checkpoint.  More to come.

R=ken2
CC=golang-dev
https://golang.org/cl/4969051

src/cmd/5g/gobj.c

@@ -268,54 +268,6 @@ dumpfuncs(void)
 	}
 }
 
-/* deferred DATA output */
-static Prog *strdat;
-static Prog *estrdat;
-static int gflag;
-static Prog *savepc;
-
-void
-data(void)
-{
-	gflag = debug['g'];
-	debug['g'] = 0;
-
-	if(estrdat == nil) {
-		strdat = mal(sizeof(*pc));
-		clearp(strdat);
-		estrdat = strdat;
-	}
-	if(savepc)
-		fatal("data phase error");
-	savepc = pc;
-	pc = estrdat;
-}
-
-void
-text(void)
-{
-	if(!savepc)
-		fatal("text phase error");
-	debug['g'] = gflag;
-	estrdat = pc;
-	pc = savepc;
-	savepc = nil;
-}
-
-void
-dumpdata(void)
-{
-	Prog *p;
-
-	if(estrdat == nil)
-		return;
-	*pc = *strdat;
-	if(gflag)
-		for(p=pc; p!=estrdat; p=p->link)
-			print("%P\n", p);
-	pc = estrdat;
-}
-
 int
 dsname(Sym *sym, int off, char *t, int n)
 {
@@ -381,6 +333,17 @@ gdata(Node *nam, Node *nr, int wid)
 	Prog *p;
 	vlong v;
 
+	if(nr->op == OLITERAL) {
+		switch(nr->val.ctype) {
+		case CTCPLX:
+			gdatacomplex(nam, nr->val.u.cval);
+			return;
+		case CTSTR:
+			gdatastring(nam, nr->val.u.sval);
+			return;
+		}
+	}
+
 	if(wid == 8 && is64(nr->type)) {
 		v = mpgetfix(nr->val.u.xval);
 		p = gins(ADATA, nam, nodintconst(v));

src/cmd/5g/gsubr.c

@@ -52,6 +52,10 @@ clearp(Prog *p)
 	pcloc++;
 }
 
+static int ddumped;
+static Prog *dfirst;
+static Prog *dpc;
+
 /*
  * generate and return proc with p->as = as,
  * linked into program.  pc is next instruction.
@@ -61,10 +65,22 @@ prog(int as)
 {
 	Prog *p;
 
+	if(as == ADATA || as == AGLOBL) {
+		if(ddumped)
+			fatal("already dumped data");
+		if(dpc == nil) {
+			dpc = mal(sizeof(*dpc));
+			dfirst = dpc;
+		}
+		p = dpc;
+		dpc = mal(sizeof(*dpc));
+		p->link = dpc;
+	} else {
 		p = pc;
 		pc = mal(sizeof(*pc));
-
 		clearp(pc);
+		p->link = pc;
+	}
 
 	if(lineno == 0) {
 		if(debug['K'])
@@ -73,10 +89,21 @@ prog(int as)
 
 	p->as = as;
 	p->lineno = lineno;
-	p->link = pc;
 	return p;
 }
 
+void
+dumpdata(void)
+{
+	ddumped = 1;
+	if(dfirst == nil)
+		return;
+	newplist();
+	*pc = *dfirst;
+	pc = dpc;
+	clearp(pc);
+}
+
 /*
  * generate a branch.
  * t is ignored.

src/cmd/6g/gobj.c

@@ -280,54 +280,6 @@ dumpfuncs(void)
 	}
 }
 
-/* deferred DATA output */
-static Prog *strdat;
-static Prog *estrdat;
-static int gflag;
-static Prog *savepc;
-
-void
-data(void)
-{
-	gflag = debug['g'];
-	debug['g'] = 0;
-
-	if(estrdat == nil) {
-		strdat = mal(sizeof(*pc));
-		clearp(strdat);
-		estrdat = strdat;
-	}
-	if(savepc)
-		fatal("data phase error");
-	savepc = pc;
-	pc = estrdat;
-}
-
-void
-text(void)
-{
-	if(!savepc)
-		fatal("text phase error");
-	debug['g'] = gflag;
-	estrdat = pc;
-	pc = savepc;
-	savepc = nil;
-}
-
-void
-dumpdata(void)
-{
-	Prog *p;
-
-	if(estrdat == nil)
-		return;
-	*pc = *strdat;
-	if(gflag)
-		for(p=pc; p!=estrdat; p=p->link)
-			print("%P\n", p);
-	pc = estrdat;
-}
-
 int
 dsname(Sym *s, int off, char *t, int n)
 {
@@ -383,6 +335,16 @@ gdata(Node *nam, Node *nr, int wid)
 {
 	Prog *p;
 
+	if(nr->op == OLITERAL) {
+		switch(nr->val.ctype) {
+		case CTCPLX:
+			gdatacomplex(nam, nr->val.u.cval);
+			return;
+		case CTSTR:
+			gdatastring(nam, nr->val.u.sval);
+			return;
+		}
+	}
 	p = gins(ADATA, nam, nr);
 	p->from.scale = wid;
 }

src/cmd/6g/gsubr.c

@@ -48,6 +48,10 @@ clearp(Prog *p)
 	pcloc++;
 }
 
+static int ddumped;
+static Prog *dfirst;
+static Prog *dpc;
+
 /*
  * generate and return proc with p->as = as,
  * linked into program. pc is next instruction.
@@ -57,10 +61,22 @@ prog(int as)
 {
 	Prog *p;
 
+	if(as == ADATA || as == AGLOBL) {
+		if(ddumped)
+			fatal("already dumped data");
+		if(dpc == nil) {
+			dpc = mal(sizeof(*dpc));
+			dfirst = dpc;
+		}
+		p = dpc;
+		dpc = mal(sizeof(*dpc));
+		p->link = dpc;
+	} else {
 		p = pc;
 		pc = mal(sizeof(*pc));
-
 		clearp(pc);
+		p->link = pc;
+	}
 
 	if(lineno == 0) {
 		if(debug['K'])
@@ -69,10 +85,21 @@ prog(int as)
 
 	p->as = as;
 	p->lineno = lineno;
-	p->link = pc;
 	return p;
 }
 
+void
+dumpdata(void)
+{
+	ddumped = 1;
+	if(dfirst == nil)
+		return;
+	newplist();
+	*pc = *dfirst;
+	pc = dpc;
+	clearp(pc);
+}
+
 /*
  * generate a branch.
  * t is ignored.

src/cmd/8g/gg.h

@@ -161,12 +161,6 @@ void	complexmove(Node*, Node*);
 void	complexgen(Node*, Node*);
 void	complexbool(int, Node*, Node*, int, Prog*);
 
-/*
- * gobj.c
- */
-void	data(void);
-void	text(void);
-
 /*
  * list.c
  */

src/cmd/8g/gobj.c

@@ -278,54 +278,6 @@ dumpfuncs(void)
 	}
 }
 
-/* deferred DATA output */
-static Prog *strdat;
-static Prog *estrdat;
-static int gflag;
-static Prog *savepc;
-
-void
-data(void)
-{
-	gflag = debug['g'];
-	debug['g'] = 0;
-
-	if(estrdat == nil) {
-		strdat = mal(sizeof(*pc));
-		clearp(strdat);
-		estrdat = strdat;
-	}
-	if(savepc)
-		fatal("data phase error");
-	savepc = pc;
-	pc = estrdat;
-}
-
-void
-text(void)
-{
-	if(!savepc)
-		fatal("text phase error");
-	debug['g'] = gflag;
-	estrdat = pc;
-	pc = savepc;
-	savepc = nil;
-}
-
-void
-dumpdata(void)
-{
-	Prog *p;
-
-	if(estrdat == nil)
-		return;
-	*pc = *strdat;
-	if(gflag)
-		for(p=pc; p!=estrdat; p=p->link)
-			print("%P\n", p);
-	pc = estrdat;
-}
-
 int
 dsname(Sym *s, int off, char *t, int n)
 {
@@ -382,6 +334,17 @@ gdata(Node *nam, Node *nr, int wid)
 	Prog *p;
 	vlong v;
 
+	if(nr->op == OLITERAL) {
+		switch(nr->val.ctype) {
+		case CTCPLX:
+			gdatacomplex(nam, nr->val.u.cval);
+			return;
+		case CTSTR:
+			gdatastring(nam, nr->val.u.sval);
+			return;
+		}
+	}
+
 	if(wid == 8 && is64(nr->type)) {
 		v = mpgetfix(nr->val.u.xval);
 		p = gins(ADATA, nam, nodintconst(v));

src/cmd/8g/gsubr.c

@@ -50,6 +50,10 @@ clearp(Prog *p)
 	pcloc++;
 }
 
+static int ddumped;
+static Prog *dfirst;
+static Prog *dpc;
+
 /*
  * generate and return proc with p->as = as,
  * linked into program.  pc is next instruction.
@@ -59,10 +63,22 @@ prog(int as)
 {
 	Prog *p;
 
+	if(as == ADATA || as == AGLOBL) {
+		if(ddumped)
+			fatal("already dumped data");
+		if(dpc == nil) {
+			dpc = mal(sizeof(*dpc));
+			dfirst = dpc;
+		}
+		p = dpc;
+		dpc = mal(sizeof(*dpc));
+		p->link = dpc;
+	} else {
 		p = pc;
 		pc = mal(sizeof(*pc));
-
 		clearp(pc);
+		p->link = pc;
+	}
 
 	if(lineno == 0) {
 		if(debug['K'])
@@ -71,10 +87,21 @@ prog(int as)
 
 	p->as = as;
 	p->lineno = lineno;
-	p->link = pc;
 	return p;
 }
 
+void
+dumpdata(void)
+{
+	ddumped = 1;
+	if(dfirst == nil)
+		return;
+	newplist();
+	*pc = *dfirst;
+	pc = dpc;
+	clearp(pc);
+}
+
 /*
  * generate a branch.
  * t is ignored.

src/cmd/gc/const.c

@@ -1101,7 +1101,7 @@ cmpslit(Node *l, Node *r)
 int
 smallintconst(Node *n)
 {
-	if(n->op == OLITERAL && n->type != T)
+	if(n->op == OLITERAL && n->val.ctype == CTINT && n->type != T)
 	switch(simtype[n->type->etype]) {
 	case TINT8:
 	case TUINT8:
@@ -1112,6 +1112,7 @@ smallintconst(Node *n)
 	case TBOOL:
 	case TPTR32:
 		return 1;
+	case TIDEAL:
 	case TINT64:
 	case TUINT64:
 		if(mpcmpfixfix(n->val.u.xval, minintval[TINT32]) < 0

src/cmd/gc/go.h

@@ -200,6 +200,27 @@ struct	Type
 };
 #define	T	((Type*)0)
 
+typedef struct InitEntry InitEntry;
+typedef struct InitPlan InitPlan;
+
+struct InitEntry
+{
+	vlong xoffset;  // struct, array only
+	Node *key;  // map only
+	Node *expr;
+};
+
+struct InitPlan
+{
+	vlong lit;  // bytes of initialized non-zero literals
+	vlong zero;  // bytes of zeros
+	vlong expr;  // bytes of run-time computed expressions
+
+	InitEntry *e;
+	int len;
+	int cap;
+};
+
 enum
 {
 	EscUnknown,
@@ -239,8 +260,8 @@ struct	Node
 	uchar	walkdef;
 	uchar	typecheck;
 	uchar	local;
+	uchar	dodata;
 	uchar	initorder;
-	uchar	dodata;		// compile literal assignment as data statement
 	uchar	used;
 	uchar	isddd;
 	uchar	pun;		// don't registerize variable ONAME
@@ -282,6 +303,9 @@ struct	Node
 	// OPACK
 	Pkg*	pkg;
 	
+	// OARRAYLIT, OMAPLIT, OSTRUCTLIT.
+	InitPlan*	initplan;
+
 	// Escape analysis.
 	NodeList* escflowsrc;	// flow(this, src)
 	int	escloopdepth;	// -1: global, 0: not set, function top level:1, increased inside function for every loop or label to mark scopes
@@ -1306,8 +1330,6 @@ Prog*	unpatch(Prog*);
 void	zfile(Biobuf *b, char *p, int n);
 void	zhist(Biobuf *b, int line, vlong offset);
 void	zname(Biobuf *b, Sym *s, int t);
-void	data(void);
-void	text(void);
 
 #pragma	varargck	type	"A"	int
 #pragma	varargck	type	"B"	Mpint*

src/cmd/gc/obj.c

@@ -31,10 +31,6 @@ dumpobj(void)
 
 	outhist(bout);
 
-	// add nil plist w AEND to catch
-	// auto-generated trampolines, data
-	newplist();
-
 	dumpglobls();
 	dumptypestructs();
 	dumpdata();
@@ -280,7 +276,6 @@ stringsym(char *s, int len)
 		return sym;
 	sym->flags |= SymUniq;
 
-	data();
 	off = 0;
 	
 	// string header
@@ -297,7 +292,6 @@ stringsym(char *s, int len)
 	off = duint8(sym, off, 0);  // terminating NUL for runtime
 	off = (off+widthptr-1)&~(widthptr-1);  // round to pointer alignment
 	ggloblsym(sym, off, 1);
-	text();
 
 	return sym;	
 }

src/cmd/gc/reflect.c

@@ -142,7 +142,6 @@ methods(Type *t)
 	Type *f, *mt, *it, *this;
 	Sig *a, *b;
 	Sym *method;
-	Prog *oldlist;
 
 	// named method type
 	mt = methtype(t);
@@ -158,7 +157,6 @@ methods(Type *t)
 	// make list of methods for t,
 	// generating code if necessary.
 	a = nil;
-	oldlist = nil;
 	for(f=mt->xmethod; f; f=f->down) {
 		if(f->type->etype != TFUNC)
 			continue;
@@ -197,8 +195,6 @@ methods(Type *t)
 		if(!(a->isym->flags & SymSiggen)) {
 			a->isym->flags |= SymSiggen;
 			if(!eqtype(this, it) || this->width < types[tptr]->width) {
-				if(oldlist == nil)
-					oldlist = pc;
 				// Is okay to call genwrapper here always,
 				// but we can generate more efficient code
 				// using genembedtramp if all that is necessary
@@ -214,8 +210,6 @@ methods(Type *t)
 		if(!(a->tsym->flags & SymSiggen)) {
 			a->tsym->flags |= SymSiggen;
 			if(!eqtype(this, t)) {
-				if(oldlist == nil)
-					oldlist = pc;
 				if(isptr[t->etype] && isptr[this->etype]
 				&& f->embedded && !isifacemethod(f->type))
 					genembedtramp(t, f, a->tsym, 0);
@@ -225,16 +219,6 @@ methods(Type *t)
 		}
 	}
 
-	// restore data output
-	if(oldlist) {
-		// old list ended with AEND; change to ANOP
-		// so that the trampolines that follow can be found.
-		nopout(oldlist);
-
-		// start new data list
-		newplist();
-	}
-
 	return lsort(a, sigcmp);
 }
 
@@ -247,11 +231,9 @@ imethods(Type *t)
 	Sig *a, *all, *last;
 	Type *f;
 	Sym *method, *isym;
-	Prog *oldlist;
 
 	all = nil;
 	last = nil;
-	oldlist = nil;
 	for(f=t->type; f; f=f->down) {
 		if(f->etype != TFIELD)
 			fatal("imethods: not field");
@@ -289,21 +271,9 @@ imethods(Type *t)
 		isym = methodsym(method, t, 0);
 		if(!(isym->flags & SymSiggen)) {
 			isym->flags |= SymSiggen;
-			if(oldlist == nil)
-				oldlist = pc;
 			genwrapper(t, f, isym, 0);
 		}
 	}
-
-	if(oldlist) {
-		// old list ended with AEND; change to ANOP
-		// so that the trampolines that follow can be found.
-		nopout(oldlist);
-
-		// start new data list
-		newplist();
-	}
-
 	return all;
 }
 

src/cmd/gc/sinit.c

@@ -10,9 +10,20 @@
 #include	<libc.h>
 #include	"go.h"
 
+enum
+{
+	InitNotStarted = 0,
+	InitDone = 1,
+	InitPending = 2,
+};
+
+static int iszero(Node*);
+static void initplan(Node*);
 static NodeList *initlist;
 static void init2(Node*, NodeList**);
 static void init2list(NodeList*, NodeList**);
+static int staticinit(Node*, NodeList**);
+static Node *staticname(Type*, int);
 
 static void
 init1(Node *n, NodeList **out)
@@ -33,16 +44,16 @@ init1(Node *n, NodeList **out)
 	case PFUNC:
 		break;
 	default:
-		if(isblank(n) && n->defn != N && !n->defn->initorder) {
+		if(isblank(n) && n->defn != N && n->defn->initorder == InitNotStarted) {
-			n->defn->initorder = 1;
+			n->defn->initorder = InitDone;
 			*out = list(*out, n->defn);
 		}
 		return;
 	}
 
-	if(n->initorder == 1)
+	if(n->initorder == InitDone)
 		return;
-	if(n->initorder == 2) {
+	if(n->initorder == InitPending) {
 		if(n->class == PFUNC)
 			return;
 		
@@ -65,7 +76,7 @@ init1(Node *n, NodeList **out)
 		print("\t%L %S\n", n->lineno, n->sym);
 		errorexit();
 	}
-	n->initorder = 2;
+	n->initorder = InitPending;
 	l = malloc(sizeof *l);
 	l->next = initlist;
 	l->n = n;
@@ -86,20 +97,38 @@ init1(Node *n, NodeList **out)
 		case OAS:
 			if(n->defn->left != n)
 				goto bad;
+		/*
 			n->defn->dodata = 1;
 			init1(n->defn->right, out);
 			if(debug['j'])
 				print("%S\n", n->sym);
 			*out = list(*out, n->defn);
 			break;
+		*/
+			if(1) {
+				init1(n->defn->right, out);
+				if(debug['j'])
+					print("%S\n", n->sym);
+				if(!staticinit(n, out)) {
+if(debug['%']) dump("nonstatic", n->defn);
+					*out = list(*out, n->defn);
+				}
+			} else if(0) {
+				n->defn->dodata = 1;
+				init1(n->defn->right, out);
+				if(debug['j'])
+					print("%S\n", n->sym);
+				*out = list(*out, n->defn);
+			}
+			break;
 		
 		case OAS2FUNC:
 		case OAS2MAPR:
 		case OAS2DOTTYPE:
 		case OAS2RECV:
-			if(n->defn->initorder)
+			if(n->defn->initorder != InitNotStarted)
 				break;
-			n->defn->initorder = 1;
+			n->defn->initorder = InitDone;
 			for(l=n->defn->rlist; l; l=l->next)
 				init1(l->n, out);
 			*out = list(*out, n->defn);
@@ -111,7 +140,7 @@ init1(Node *n, NodeList **out)
 	if(l->n != n)
 		fatal("bad initlist");
 	free(l);
-	n->initorder = 1;
+	n->initorder = InitDone;
 	return;
 
 bad:
@@ -123,7 +152,7 @@ bad:
 static void
 init2(Node *n, NodeList **out)
 {
-	if(n == N || n->initorder == 1)
+	if(n == N || n->initorder == InitDone)
 		return;
 	init1(n, out);
 	init2(n->left, out);
@@ -143,7 +172,6 @@ init2list(NodeList *l, NodeList **out)
 		init2(l->n, out);
 }
 
-
 static void
 initreorder(NodeList *l, NodeList **out)
 {
@@ -167,12 +195,220 @@ NodeList*
 initfix(NodeList *l)
 {
 	NodeList *lout;
+	int lno;
 
 	lout = nil;
+	lno = lineno;
 	initreorder(l, &lout);
+	lineno = lno;
 	return lout;
 }
 
+/*
+ * compilation of top-level (static) assignments
+ * into DATA statements if at all possible.
+ */
+
+static int staticassign(Node*, Node*, NodeList**);
+
+static int
+staticinit(Node *n, NodeList **out)
+{
+	Node *l, *r;
+
+	if(n->op != ONAME || n->class != PEXTERN || n->defn == N || n->defn->op != OAS)
+		fatal("staticinit");
+
+	lineno = n->lineno;
+	l = n->defn->left;
+	r = n->defn->right;
+	return staticassign(l, r, out);
+}
+
+// like staticassign but we are copying an already
+// initialized value r.
+static int
+staticcopy(Node *l, Node *r, NodeList **out)
+{
+	int i;
+	InitEntry *e;
+	InitPlan *p;
+	Node *a, *ll, *rr, *orig, n1;
+
+	if(r->op != ONAME || r->class != PEXTERN || r->sym->pkg != localpkg)
+		return 0;
+	if(r->defn == N)	// zeroed
+		return 1;
+	if(r->defn->op != OAS)
+		return 0;
+	orig = r;
+	r = r->defn->right;
+	
+	switch(r->op) {
+	case ONAME:
+		if(staticcopy(l, r, out))
+			return 1;
+		*out = list(*out, nod(OAS, l, r));
+		return 1;
+	
+	case OLITERAL:
+		if(iszero(r))
+			return 1;
+		gdata(l, r, l->type->width);
+		return 1;
+
+	case OADDR:
+		switch(r->left->op) {
+		case ONAME:
+			gdata(l, r, l->type->width);
+			return 1;
+		case OARRAYLIT:
+		case OSTRUCTLIT:
+		case OMAPLIT:
+			// copy pointer
+			gdata(l, nod(OADDR, r->nname, N), l->type->width);
+			return 1;
+		}
+		break;
+
+	case OARRAYLIT:
+		if(isslice(r->type)) {
+			// copy slice
+			a = r->nname;
+			n1 = *l;
+			n1.xoffset = l->xoffset + Array_array;
+			gdata(&n1, nod(OADDR, a, N), widthptr);
+			n1.xoffset = l->xoffset + Array_nel;
+			gdata(&n1, r->right, 4);
+			n1.xoffset = l->xoffset + Array_cap;
+			gdata(&n1, r->right, 4);
+			return 1;
+		}
+		// fall through
+	case OSTRUCTLIT:
+		p = r->initplan;
+		n1 = *l;
+		for(i=0; i<p->len; i++) {
+			e = &p->e[i];
+			n1.xoffset = l->xoffset + e->xoffset;
+			n1.type = e->expr->type;
+			if(e->expr->op == OLITERAL)
+				gdata(&n1, e->expr, n1.type->width);
+			else if(staticassign(&n1, e->expr, out)) {
+				// Done
+			} else {
+				// Requires computation, but we're
+				// copying someone else's computation.
+				ll = nod(OXXX, N, N);
+				*ll = n1;
+				rr = nod(OXXX, N, N);
+				*rr = *orig;
+				rr->type = ll->type;
+				rr->xoffset += e->xoffset;
+				*out = list(*out, nod(OAS, ll, rr));
+			}
+		}
+		return 1;
+	}
+	return 0;
+}
+
+static int
+staticassign(Node *l, Node *r, NodeList **out)
+{
+	Node *a, n1;
+	Type *ta;
+	InitPlan *p;
+	InitEntry *e;
+	int i;
+	
+	switch(r->op) {
+	default:
+		//dump("not static", r);
+		break;
+	
+	case ONAME:
+		if(r->class == PEXTERN && r->sym->pkg == localpkg)
+			return staticcopy(l, r, out);
+		break;
+
+	case OLITERAL:
+		if(iszero(r))
+			return 1;
+		gdata(l, r, l->type->width);
+		return 1;
+
+	case OADDR:
+		switch(r->left->op) {
+		default:
+			//dump("not static addr", r);
+			break;
+
+		case ONAME:
+			gdata(l, r, l->type->width);
+			return 1;
+		
+		case OARRAYLIT:
+		case OMAPLIT:
+		case OSTRUCTLIT:
+			// Init pointer.
+			a = staticname(r->left->type, 1);
+			r->nname = a;
+			gdata(l, nod(OADDR, a, N), l->type->width);
+			// Init underlying literal.
+			if(!staticassign(a, r->left, out))
+				*out = list(*out, nod(OAS, a, r->left));
+			return 1;
+		}
+		break;
+
+	case OARRAYLIT:
+		initplan(r);
+		if(isslice(r->type)) {
+			// Init slice.
+			ta = typ(TARRAY);
+			ta->type = r->type->type;
+			ta->bound = mpgetfix(r->right->val.u.xval);
+			a = staticname(ta, 1);
+			r->nname = a;
+			n1 = *l;
+			n1.xoffset = l->xoffset + Array_array;
+			gdata(&n1, nod(OADDR, a, N), widthptr);
+			n1.xoffset = l->xoffset + Array_nel;
+			gdata(&n1, r->right, 4);
+			n1.xoffset = l->xoffset + Array_cap;
+			gdata(&n1, r->right, 4);
+			// Fall through to init underlying array.
+			l = a;
+		}
+		// fall through
+	case OSTRUCTLIT:
+		initplan(r);
+		p = r->initplan;
+		n1 = *l;
+		for(i=0; i<p->len; i++) {
+			e = &p->e[i];
+			n1.xoffset = l->xoffset + e->xoffset;
+			n1.type = e->expr->type;
+			if(e->expr->op == OLITERAL)
+				gdata(&n1, e->expr, n1.type->width);
+			else if(staticassign(&n1, e->expr, out)) {
+				// done
+			} else {
+				a = nod(OXXX, N, N);
+				*a = n1;
+				*out = list(*out, nod(OAS, a, e->expr));
+			}
+		}
+		return 1;
+
+	case OMAPLIT:
+		// TODO: Table-driven map insert.
+		break;
+	}
+	return 0;
+}
+
 /*
  * from here down is the walk analysis
  * of composite literals.
@@ -924,18 +1160,15 @@ gen_as_init(Node *n)
 	case TPTR64:
 	case TFLOAT32:
 	case TFLOAT64:
-		gused(N); // in case the data is the dest of a goto
 		gdata(&nam, nr, nr->type->width);
 		break;
 
 	case TCOMPLEX64:
 	case TCOMPLEX128:
-		gused(N); // in case the data is the dest of a goto
 		gdatacomplex(&nam, nr->val.u.cval);
 		break;
 
 	case TSTRING:
-		gused(N); // in case the data is the dest of a goto
 		gdatastring(&nam, nr->val.u.sval);
 		break;
 	}
@@ -976,3 +1209,149 @@ no:
 	return 0;
 }
 
+static int iszero(Node*);
+static int isvaluelit(Node*);
+static InitEntry* entry(InitPlan*);
+static void addvalue(InitPlan*, vlong, Node*, Node*);
+
+static void
+initplan(Node *n)
+{
+	InitPlan *p;
+	Node *a;
+	NodeList *l;
+
+	if(n->initplan != nil)
+		return;
+	p = mal(sizeof *p);
+	n->initplan = p;
+	switch(n->op) {
+	default:
+		fatal("initplan");
+	case OARRAYLIT:
+		for(l=n->list; l; l=l->next) {
+			a = l->n;
+			if(a->op != OKEY || !smallintconst(a->left))
+				fatal("initplan arraylit");
+			addvalue(p, n->type->type->width*mpgetfix(a->left->val.u.xval), N, a->right);
+		}
+		break;
+	case OSTRUCTLIT:
+		for(l=n->list; l; l=l->next) {
+			a = l->n;
+			if(a->op != OKEY || a->left->type == T)
+				fatal("initplan structlit");
+			addvalue(p, a->left->type->width, N, a->right);
+		}
+		break;
+	case OMAPLIT:
+		for(l=n->list; l; l=l->next) {
+			a = l->n;
+			if(a->op != OKEY)
+				fatal("initplan maplit");
+			addvalue(p, -1, a->left, a->right);
+		}
+		break;
+	}
+}
+
+static void
+addvalue(InitPlan *p, vlong xoffset, Node *key, Node *n)
+{
+	int i;
+	InitPlan *q;
+	InitEntry *e;
+
+	// special case: zero can be dropped entirely
+	if(iszero(n)) {
+		p->zero += n->type->width;
+		return;
+	}
+	
+	// special case: inline struct and array (not slice) literals
+	if(isvaluelit(n)) {
+		initplan(n);
+		q = n->initplan;
+		for(i=0; i<q->len; i++) {
+			e = entry(p);
+			*e = q->e[i];
+			e->xoffset += xoffset;
+		}
+		return;
+	}
+	
+	// add to plan
+	if(n->op == OLITERAL)
+		p->lit += n->type->width;
+	else
+		p->expr += n->type->width;
+
+	e = entry(p);
+	e->xoffset = xoffset;
+	e->expr = n;
+}
+
+static int
+iszero(Node *n)
+{
+	NodeList *l;
+
+	switch(n->op) {
+	case OLITERAL:
+		switch(n->val.ctype) {
+		default:
+			dump("unexpected literal", n);
+			fatal("iszero");
+	
+		case CTNIL:
+			return 1;
+		
+		case CTSTR:
+			return n->val.u.sval == nil || n->val.u.sval->len == 0;
+	
+		case CTBOOL:
+			return n->val.u.bval == 0;
+			
+		case CTINT:
+			return mpcmpfixc(n->val.u.xval, 0) == 0;
+	
+		case CTFLT:
+			return mpcmpfltc(n->val.u.fval, 0) == 0;
+	
+		case CTCPLX:
+			return mpcmpfltc(&n->val.u.cval->real, 0) == 0 && mpcmpfltc(&n->val.u.cval->imag, 0) == 0;
+		}
+		break;
+	case OARRAYLIT:
+		if(isslice(n->type))
+			break;
+		// fall through
+	case OSTRUCTLIT:
+		for(l=n->list; l; l=l->next)
+			if(!iszero(l->n->right))
+				return 0;
+		return 1;
+	}
+	return 0;
+}
+
+static int
+isvaluelit(Node *n)
+{
+	return (n->op == OARRAYLIT && isfixedarray(n->type)) || n->op == OSTRUCTLIT;
+}
+
+static InitEntry*
+entry(InitPlan *p)
+{
+	if(p->len >= p->cap) {
+		if(p->cap == 0)
+			p->cap = 4;
+		else
+			p->cap *= 2;
+		p->e = realloc(p->e, p->cap*sizeof p->e[0]);
+		if(p->e == nil)
+			fatal("out of memory");
+	}
+	return &p->e[p->len++];
+}

src/cmd/gc/typecheck.c

@@ -153,7 +153,7 @@ typecheck(Node **np, int top)
 	}
 
 	if(n->typecheck == 2) {
-		yyerror("typechecking loop");
+		yyerror("typechecking loop involving %#N", n);
 		lineno = lno;
 		return n;
 	}
@@ -2103,6 +2103,7 @@ typecheckcomplit(Node **np)
 					yyerror("implicit assignment of unexported field '%s' in %T literal", s->name, t);
 				ll->n = assignconv(ll->n, f->type, "field value");
 				ll->n = nod(OKEY, newname(f->sym), ll->n);
+				ll->n->left->type = f;
 				ll->n->left->typecheck = 1;
 				f = f->down;
 			}
@@ -2132,14 +2133,15 @@ typecheckcomplit(Node **np)
 				// before we do the lookup.
 				if(s->pkg != localpkg)
 					s = lookup(s->name);
-				l->left = newname(s);
-				l->left->typecheck = 1;
 				f = lookdot1(s, t, t->type, 0);
 				typecheck(&l->right, Erv);
 				if(f == nil) {
 					yyerror("unknown %T field '%s' in struct literal", t, s->name);
 					continue;
 				}
+				l->left = newname(s);
+				l->left->typecheck = 1;
+				l->left->type = f;
 				s = f->sym;
 				fielddup(newname(s), hash, nhash);
 				l->right = assignconv(l->right, f->type, "field value");

test/golden.out

@@ -42,9 +42,6 @@ hello, world
 =========== ./sigchld.go
 survived SIGCHLD
 
-=========== ./sinit.go
-FAIL
-
 =========== ./turing.go
 Hello World!
 

test/sinit.go

@@ -1,4 +1,4 @@
-// $G -S $D/$F.go | egrep initdone >/dev/null && echo FAIL || true
+// $G -S $D/$F.go | egrep initdone >/dev/null && echo BUG sinit || true
 
 // Copyright 2010 The Go Authors.  All rights reserved.
 // Use of this source code is governed by a BSD-style
@@ -9,17 +9,17 @@ package p
 // Should be no init func in the assembly.
 // All these initializations should be done at link time.
 
-type	S	struct{ a,b,c int }
+type S struct{ a, b, c int }
-type	SS	struct{ aa,bb,cc S }
+type SS struct{ aa, bb, cc S }
-type	SA	struct{ a,b,c [3]int }
+type SA struct{ a, b, c [3]int }
-type	SC	struct{ a,b,c []int }
+type SC struct{ a, b, c []int }
 
 var (
 	zero                      = 2
 	one                       = 1
 	pi                        = 3.14
-	slice = []byte{1,2,3}
+	slice                     = []byte{1, 2, 3}
-	sliceInt = []int{1,2,3}
+	sliceInt                  = []int{1, 2, 3}
 	hello                     = "hello, world"
 	bytes                     = []byte("hello, world")
 	four, five                = 4, 5
@@ -35,19 +35,19 @@ var	a	= [3]int{1001, 1002, 1003}
 var s = S{1101, 1102, 1103}
 var c = []int{1201, 1202, 1203}
 
-var	aa	= [3][3]int{[3]int{2001,2002,2003}, [3]int{2004,2005,2006}, [3]int{2007,2008,2009}}
+var aa = [3][3]int{[3]int{2001, 2002, 2003}, [3]int{2004, 2005, 2006}, [3]int{2007, 2008, 2009}}
-var	as	= [3]S{S{2101,2102,2103},S{2104,2105,2106},S{2107,2108,2109}}
+var as = [3]S{S{2101, 2102, 2103}, S{2104, 2105, 2106}, S{2107, 2108, 2109}}
-var	ac	= [3][]int{[]int{2201,2202,2203}, []int{2204,2205,2206}, []int{2207,2208,2209}}
+var ac = [3][]int{[]int{2201, 2202, 2203}, []int{2204, 2205, 2206}, []int{2207, 2208, 2209}}
 
-var	sa	= SA{[3]int{3001,3002,3003},[3]int{3004,3005,3006},[3]int{3007,3008,3009}}
+var sa = SA{[3]int{3001, 3002, 3003}, [3]int{3004, 3005, 3006}, [3]int{3007, 3008, 3009}}
-var	ss	= SS{S{3101,3102,3103},S{3104,3105,3106},S{3107,3108,3109}}
+var ss = SS{S{3101, 3102, 3103}, S{3104, 3105, 3106}, S{3107, 3108, 3109}}
-var	sc	= SC{[]int{3201,3202,3203},[]int{3204,3205,3206},[]int{3207,3208,3209}}
+var sc = SC{[]int{3201, 3202, 3203}, []int{3204, 3205, 3206}, []int{3207, 3208, 3209}}
 
-var	ca	= [][3]int{[3]int{4001,4002,4003}, [3]int{4004,4005,4006}, [3]int{4007,4008,4009}}
+var ca = [][3]int{[3]int{4001, 4002, 4003}, [3]int{4004, 4005, 4006}, [3]int{4007, 4008, 4009}}
-var	cs	= []S{S{4101,4102,4103},S{4104,4105,4106},S{4107,4108,4109}}
+var cs = []S{S{4101, 4102, 4103}, S{4104, 4105, 4106}, S{4107, 4108, 4109}}
-var	cc	= [][]int{[]int{4201,4202,4203}, []int{4204,4205,4206}, []int{4207,4208,4209}}
+var cc = [][]int{[]int{4201, 4202, 4203}, []int{4204, 4205, 4206}, []int{4207, 4208, 4209}}
 
-var	answers	= [...]int {
+var answers = [...]int{
 	// s
 	1101, 1102, 1103,
 
@@ -98,3 +98,158 @@ var	answers	= [...]int {
 	2008, 2208, 2308, 4008, 4208, 4308, 5008, 5208, 5308,
 	2009, 2209, 2309, 4009, 4209, 4309, 5009, 5209, 5309,
 }
+
+var (
+	copy_zero = zero
+	copy_one = one
+	copy_pi = pi
+	copy_slice = slice
+	copy_sliceInt = sliceInt
+	copy_hello = hello
+	copy_bytes = bytes
+	copy_four, copy_five = four, five
+	copy_x, copy_y = x, y
+	copy_nilslice = nilslice
+	copy_nilmap = nilmap
+	copy_nilfunc = nilfunc
+	copy_nilchan = nilchan
+	copy_nilptr = nilptr
+)
+
+var copy_a = a
+var copy_s = s
+var copy_c = c
+
+var copy_aa = aa
+var copy_as = as
+var copy_ac = ac
+
+var copy_sa = sa
+var copy_ss = ss
+var copy_sc = sc
+
+var copy_ca = ca
+var copy_cs = cs
+var copy_cc = cc
+
+var copy_answers = answers
+
+var bx bool
+var b0 = false
+var b1 = true
+
+var fx float32
+var f0 = float32(0)
+var f1 = float32(1)
+
+var gx float64
+var g0 = float64(0)
+var g1 = float64(1)
+
+var ix int
+var i0 = 0
+var i1 = 1
+
+var jx uint
+var j0 = uint(0)
+var j1 = uint(1)
+
+var cx complex64
+var c0 = complex64(0)
+var c1 = complex64(1)
+
+var dx complex128
+var d0 = complex128(0)
+var d1 = complex128(1)
+
+var sx []int
+var s0 = []int{0, 0, 0}
+var s1 = []int{1, 2, 3}
+
+func fi() int
+
+var ax [10]int
+var a0 = [10]int{0, 0, 0}
+var a1 = [10]int{1, 2, 3, 4}
+
+type T struct{ X, Y int }
+
+var tx T
+var t0 = T{}
+var t0a = T{0, 0}
+var t0b = T{X: 0}
+var t1 = T{X: 1, Y: 2}
+var t1a = T{3, 4}
+
+var psx *[]int
+var ps0 = &[]int{0, 0, 0}
+var ps1 = &[]int{1, 2, 3}
+
+var pax *[10]int
+var pa0 = &[10]int{0, 0, 0}
+var pa1 = &[10]int{1, 2, 3}
+
+var ptx *T
+var pt0 = &T{}
+var pt0a = &T{0, 0}
+var pt0b = &T{X: 0}
+var pt1 = &T{X: 1, Y: 2}
+var pt1a = &T{3, 4}
+
+var copy_bx = bx
+var copy_b0 = b0
+var copy_b1 = b1
+
+var copy_fx = fx
+var copy_f0 = f0
+var copy_f1 = f1
+
+var copy_gx = gx
+var copy_g0 = g0
+var copy_g1 = g1
+
+var copy_ix = ix
+var copy_i0 = i0
+var copy_i1 = i1
+
+var copy_jx = jx
+var copy_j0 = j0
+var copy_j1 = j1
+
+var copy_cx = cx
+var copy_c0 = c0
+var copy_c1 = c1
+
+var copy_dx = dx
+var copy_d0 = d0
+var copy_d1 = d1
+
+var copy_sx = sx
+var copy_s0 = s0
+var copy_s1 = s1
+
+var copy_ax = ax
+var copy_a0 = a0
+var copy_a1 = a1
+
+var copy_tx = tx
+var copy_t0 = t0
+var copy_t0a = t0a
+var copy_t0b = t0b
+var copy_t1 = t1
+var copy_t1a = t1a
+
+var copy_psx = psx
+var copy_ps0 = ps0
+var copy_ps1 = ps1
+
+var copy_pax = pax
+var copy_pa0 = pa0
+var copy_pa1 = pa1
+
+var copy_ptx = ptx
+var copy_pt0 = pt0
+var copy_pt0a = pt0a
+var copy_pt0b = pt0b
+var copy_pt1 = pt1
+var copy_pt1a = pt1a