diff --git a/src/cmd/6g/cgen.c b/src/cmd/6g/cgen.c
index 1565d32..3661986 100644
--- a/src/cmd/6g/cgen.c
+++ b/src/cmd/6g/cgen.c
@@ -172,17 +172,17 @@
 		break;
 
 	case OCALLMETH:
-		cgen_callmeth(n);
+		cgen_callmeth(n, 0);
 		cgen_callret(n, res);
 		break;
 
 	case OCALLINTER:
-		cgen_callinter(n, res);
+		cgen_callinter(n, res, 0);
 		cgen_callret(n, res);
 		break;
 
 	case OCALL:
-		cgen_call(n);
+		cgen_call(n, 0);
 		cgen_callret(n, res);
 		break;
 
@@ -281,17 +281,17 @@
 //		break;
 
 	case OCALLMETH:
-		cgen_callmeth(n);
+		cgen_callmeth(n, 0);
 		cgen_aret(n, res);
 		break;
 
 	case OCALLINTER:
-		cgen_callinter(n, res);
+		cgen_callinter(n, res, 0);
 		cgen_aret(n, res);
 		break;
 
 	case OCALL:
-		cgen_call(n);
+		cgen_call(n, 0);
 		cgen_aret(n, res);
 		break;
 
diff --git a/src/cmd/6g/gen.c b/src/cmd/6g/gen.c
index 8072b61..9da3dc6 100644
--- a/src/cmd/6g/gen.c
+++ b/src/cmd/6g/gen.c
@@ -14,6 +14,7 @@
 };
 
 static	Node*	curfn;
+static	Node*	newproc;
 
 void
 compile(Node *fn)
@@ -23,6 +24,16 @@
 	Prog *ptxt;
 	long lno;
 
+if(newproc == N) {
+	newproc = nod(ONAME, N, N);
+	memset(newproc, 0, sizeof(*newproc));
+	newproc->op = ONAME;
+	newproc->sym = pkglookup("_newproc", "sys");
+	newproc->class = PEXTERN;
+	newproc->addable = 1;
+	newproc->ullman = 0;
+}
+
 	if(fn->nbody == N)
 		return;
 	lno = setlineno(fn);
@@ -298,15 +309,19 @@
 		break;
 
 	case OCALLMETH:
-		cgen_callmeth(n);
+		cgen_callmeth(n, 0);
 		break;
 
 	case OCALLINTER:
-		cgen_callinter(n, N);
+		cgen_callinter(n, N, 0);
 		break;
 
 	case OCALL:
-		cgen_call(n);
+		cgen_call(n, 0);
+		break;
+
+	case OPROC:
+		cgen_proc(n);
 		break;
 
 	case ORETURN:
@@ -552,7 +567,21 @@
 }
 
 void
-cgen_callinter(Node *n, Node *res)
+ginscall(Node *f, int proc)
+{
+	Node regax;
+
+	if(proc) {
+		nodreg(&regax, types[TINT64], D_AX);
+		gins(ALEAQ, f, &regax);
+		gins(ACALL, N, newproc);
+		return;
+	}
+	gins(ACALL, N, f);
+}
+
+void
+cgen_callinter(Node *n, Node *res, int proc)
 {
 	Node *i, *f;
 	Node tmpi, nodo, nodr, nodsp;
@@ -588,21 +617,19 @@
 	nodo.xoffset -= widthptr;
 	cgen(&nodo, &nodr);	// REG = 0(REG) -- i.m
 
-//print("field = %N\n", f);
-//print("offset = %ld\n", n->left->xoffset);
-
 	nodo.xoffset = n->left->xoffset + 4*widthptr;
 	cgen(&nodo, &nodr);	// REG = 32+offset(REG) -- i.m->fun[f]
 
-	gins(ACALL, N, &nodr);
+	ginscall(&nodr, proc);
+
 	regfree(&nodr);
-	regfree(&nodr);
+	regfree(&nodo);
 
 	setmaxarg(n->left->type);
 }
 
 void
-cgen_callmeth(Node *n)
+cgen_callmeth(Node *n, int proc)
 {
 	Node *l;
 
@@ -619,14 +646,14 @@
 
 	if(n->left->op == ONAME)
 		n->left->class = PEXTERN;
-	cgen_call(n);
+	cgen_call(n, proc);
 }
 
 void
-cgen_call(Node *n)
+cgen_call(Node *n, int proc)
 {
 	Type *t;
-	Node nod, afun;
+	Node nod, afun, regax;
 
 	if(n == N)
 		return;
@@ -652,7 +679,7 @@
 	if(n->left->ullman >= UINF) {
 		regalloc(&nod, types[tptr], N);
 		cgen_as(&nod, &afun, 0);
-		gins(ACALL, N, &nod);
+		ginscall(&nod, proc);
 		regfree(&nod);
 		goto ret;
 	}
@@ -661,20 +688,42 @@
 	if(isptr[n->left->type->etype]) {
 		regalloc(&nod, types[tptr], N);
 		cgen_as(&nod, n->left, 0);
-		gins(ACALL, N, &nod);
+		ginscall(&nod, proc);
 		regfree(&nod);
 		goto ret;
 	}
 
 	// call direct
 	n->left->method = 1;
-	gins(ACALL, N, n->left);
+	ginscall(n->left, proc);
 
 ret:
 	;
 }
 
 void
+cgen_proc(Node *n)
+{
+	switch(n->left->op) {
+	default:
+		fatal("cgen_proc: unknown call %O", n->left->op);
+
+	case OCALLMETH:
+		cgen_callmeth(n->left, 1);
+		break;
+
+	case OCALLINTER:
+		cgen_callinter(n->left, N, 1);
+		break;
+
+	case OCALL:
+		cgen_call(n->left, 1);
+		break;
+	}
+		
+}
+
+void
 cgen_callret(Node *n, Node *res)
 {
 	Node nod;
diff --git a/src/cmd/6g/gg.h b/src/cmd/6g/gg.h
index 195788b..c6ee3ab 100644
--- a/src/cmd/6g/gg.h
+++ b/src/cmd/6g/gg.h
@@ -113,9 +113,10 @@
 void	cgen_as(Node*, Node*, int);
 void	cgen_asop(Node*);
 void	cgen_ret(Node*);
-void	cgen_call(Node*);
-void	cgen_callmeth(Node*);
-void	cgen_callinter(Node*, Node*);
+void	cgen_call(Node*, int);
+void	cgen_callmeth(Node*, int);
+void	cgen_callinter(Node*, Node*, int);
+void	cgen_proc(Node*);
 void	cgen_callret(Node*, Node*);
 void	cgen_div(int, Node*, Node*, Node*);
 void	cgen_shift(int, Node*, Node*, Node*);
diff --git a/src/cmd/6g/gsubr.c b/src/cmd/6g/gsubr.c
index 7b53446..c56a338 100644
--- a/src/cmd/6g/gsubr.c
+++ b/src/cmd/6g/gsubr.c
@@ -1673,7 +1673,6 @@
 	n->op = ONAME;
 	n->sym = s;
 	n->type = t;
-	n->sym = s;
 	n->etype = t->etype;
 	n->class = PAUTO;
 	n->addable = 1;
diff --git a/src/cmd/gc/go.h b/src/cmd/gc/go.h
index 9efbb39..7f5b382 100644
--- a/src/cmd/gc/go.h
+++ b/src/cmd/gc/go.h
@@ -581,7 +581,6 @@
 Node*	newcompat(Node*);
 Node*	stringop(Node*, int);
 Node*	mapop(Node*, int);
-Node*	procop(Node*);
 Node*	convas(Node*);
 void	arrayconv(Type*, Node*);
 Node*	colas(Node*, Node*);
diff --git a/src/cmd/gc/sys.go b/src/cmd/gc/sys.go
index 8bac583..be6cf73 100644
--- a/src/cmd/gc/sys.go
+++ b/src/cmd/gc/sys.go
@@ -44,8 +44,6 @@
 func	mapassign1(hmap *map[any]any, key any, val any);
 func	mapassign2(hmap *map[any]any, key any, val any, pres bool);
 
-func	newproc() bool;				// create a new coroutine; true is child
-
 func	readfile(string) (string, bool);	// read file into string; boolean status
 
 func	exit(int32);
@@ -93,9 +91,6 @@
 	mapassign1
 	mapassign2
 
-	// threads/coroutines
-	newproc
-
 	// files
 	readfile
 
diff --git a/src/cmd/gc/sysimport.c b/src/cmd/gc/sysimport.c
index 6ff9b4f..8c6d3f0 100644
--- a/src/cmd/gc/sysimport.c
+++ b/src/cmd/gc/sysimport.c
@@ -3,10 +3,10 @@
 	"type sys._e002 {}\n"
 	"type sys.any 24\n"
 	"type sys._e003 *sys.any\n"
-	"type sys._o254 {_e252 sys._e003}\n"
+	"type sys._o257 {_e255 sys._e003}\n"
 	"type sys.uint32 6\n"
-	"type sys._i256 {_e253 sys.uint32}\n"
-	"type sys._e001 (sys._e002 sys._o254 sys._i256)\n"
+	"type sys._i259 {_e256 sys.uint32}\n"
+	"type sys._e001 (sys._e002 sys._o257 sys._i259)\n"
 	"var !sys.mal sys._e001\n"
 	"type sys._e005 {}\n"
 	"type sys._e006 {}\n"
@@ -16,186 +16,181 @@
 	"type sys._e009 {}\n"
 	"type sys._e010 {}\n"
 	"type sys.int32 5\n"
-	"type sys._i262 {_e261 sys.int32}\n"
-	"type sys._e008 (sys._e009 sys._e010 sys._i262)\n"
+	"type sys._i265 {_e264 sys.int32}\n"
+	"type sys._e008 (sys._e009 sys._e010 sys._i265)\n"
 	"var !sys.panicl sys._e008\n"
 	"type sys._e012 {}\n"
 	"type sys._e013 {}\n"
 	"type sys.bool 12\n"
-	"type sys._i267 {_e266 sys.bool}\n"
-	"type sys._e011 (sys._e012 sys._e013 sys._i267)\n"
+	"type sys._i270 {_e269 sys.bool}\n"
+	"type sys._e011 (sys._e012 sys._e013 sys._i270)\n"
 	"var !sys.printbool sys._e011\n"
 	"type sys._e015 {}\n"
 	"type sys._e016 {}\n"
 	"type sys.float64 10\n"
-	"type sys._i272 {_e271 sys.float64}\n"
-	"type sys._e014 (sys._e015 sys._e016 sys._i272)\n"
+	"type sys._i275 {_e274 sys.float64}\n"
+	"type sys._e014 (sys._e015 sys._e016 sys._i275)\n"
 	"var !sys.printfloat sys._e014\n"
 	"type sys._e018 {}\n"
 	"type sys._e019 {}\n"
 	"type sys.int64 7\n"
-	"type sys._i277 {_e276 sys.int64}\n"
-	"type sys._e017 (sys._e018 sys._e019 sys._i277)\n"
+	"type sys._i280 {_e279 sys.int64}\n"
+	"type sys._e017 (sys._e018 sys._e019 sys._i280)\n"
 	"var !sys.printint sys._e017\n"
 	"type sys._e021 {}\n"
 	"type sys._e022 {}\n"
 	"type sys._e023 25\n"
 	"type sys.string *sys._e023\n"
-	"type sys._i282 {_e281 sys.string}\n"
-	"type sys._e020 (sys._e021 sys._e022 sys._i282)\n"
+	"type sys._i285 {_e284 sys.string}\n"
+	"type sys._e020 (sys._e021 sys._e022 sys._i285)\n"
 	"var !sys.printstring sys._e020\n"
 	"type sys._e025 {}\n"
 	"type sys._e026 {}\n"
 	"type sys.uint8 2\n"
 	"type sys._e027 *sys.uint8\n"
-	"type sys._i287 {_e286 sys._e027}\n"
-	"type sys._e024 (sys._e025 sys._e026 sys._i287)\n"
+	"type sys._i290 {_e289 sys._e027}\n"
+	"type sys._e024 (sys._e025 sys._e026 sys._i290)\n"
 	"var !sys.printpointer sys._e024\n"
 	"type sys._e029 {}\n"
-	"type sys._o294 {_e291 sys.string}\n"
-	"type sys._i296 {_e292 sys.string _e293 sys.string}\n"
-	"type sys._e028 (sys._e029 sys._o294 sys._i296)\n"
+	"type sys._o297 {_e294 sys.string}\n"
+	"type sys._i299 {_e295 sys.string _e296 sys.string}\n"
+	"type sys._e028 (sys._e029 sys._o297 sys._i299)\n"
 	"var !sys.catstring sys._e028\n"
 	"type sys._e031 {}\n"
-	"type sys._o304 {_e301 sys.int32}\n"
-	"type sys._i306 {_e302 sys.string _e303 sys.string}\n"
-	"type sys._e030 (sys._e031 sys._o304 sys._i306)\n"
+	"type sys._o307 {_e304 sys.int32}\n"
+	"type sys._i309 {_e305 sys.string _e306 sys.string}\n"
+	"type sys._e030 (sys._e031 sys._o307 sys._i309)\n"
 	"var !sys.cmpstring sys._e030\n"
 	"type sys._e033 {}\n"
-	"type sys._o315 {_e311 sys.string}\n"
-	"type sys._i317 {_e312 sys.string _e313 sys.int32 _e314 sys.int32}\n"
-	"type sys._e032 (sys._e033 sys._o315 sys._i317)\n"
+	"type sys._o318 {_e314 sys.string}\n"
+	"type sys._i320 {_e315 sys.string _e316 sys.int32 _e317 sys.int32}\n"
+	"type sys._e032 (sys._e033 sys._o318 sys._i320)\n"
 	"var !sys.slicestring sys._e032\n"
 	"type sys._e035 {}\n"
-	"type sys._o326 {_e323 sys.uint8}\n"
-	"type sys._i328 {_e324 sys.string _e325 sys.int32}\n"
-	"type sys._e034 (sys._e035 sys._o326 sys._i328)\n"
+	"type sys._o329 {_e326 sys.uint8}\n"
+	"type sys._i331 {_e327 sys.string _e328 sys.int32}\n"
+	"type sys._e034 (sys._e035 sys._o329 sys._i331)\n"
 	"var !sys.indexstring sys._e034\n"
 	"type sys._e037 {}\n"
-	"type sys._o335 {_e333 sys.string}\n"
-	"type sys._i337 {_e334 sys.int64}\n"
-	"type sys._e036 (sys._e037 sys._o335 sys._i337)\n"
+	"type sys._o338 {_e336 sys.string}\n"
+	"type sys._i340 {_e337 sys.int64}\n"
+	"type sys._e036 (sys._e037 sys._o338 sys._i340)\n"
 	"var !sys.intstring sys._e036\n"
 	"type sys._e039 {}\n"
-	"type sys._o344 {_e341 sys.string}\n"
+	"type sys._o347 {_e344 sys.string}\n"
 	"type sys._e040 *sys.uint8\n"
-	"type sys._i346 {_e342 sys._e040 _e343 sys.int32}\n"
-	"type sys._e038 (sys._e039 sys._o344 sys._i346)\n"
+	"type sys._i349 {_e345 sys._e040 _e346 sys.int32}\n"
+	"type sys._e038 (sys._e039 sys._o347 sys._i349)\n"
 	"var !sys.byteastring sys._e038\n"
 	"type sys._e042 {}\n"
 	"type sys._e043 <>\n"
-	"type sys._o355 {_e351 sys._e043}\n"
+	"type sys._o358 {_e354 sys._e043}\n"
 	"type sys._e044 *sys.uint8\n"
 	"type sys._e045 *sys.uint8\n"
-	"type sys._s362 {}\n"
-	"type sys._e046 *sys._s362\n"
-	"type sys._i357 {_e352 sys._e044 _e353 sys._e045 _e354 sys._e046}\n"
-	"type sys._e041 (sys._e042 sys._o355 sys._i357)\n"
+	"type sys._s365 {}\n"
+	"type sys._e046 *sys._s365\n"
+	"type sys._i360 {_e355 sys._e044 _e356 sys._e045 _e357 sys._e046}\n"
+	"type sys._e041 (sys._e042 sys._o358 sys._i360)\n"
 	"var !sys.mkiface sys._e041\n"
 	"type sys._e048 {}\n"
-	"type sys._o366 {_e365 sys.int32}\n"
+	"type sys._o369 {_e368 sys.int32}\n"
 	"type sys._e049 {}\n"
-	"type sys._e047 (sys._e048 sys._o366 sys._e049)\n"
+	"type sys._e047 (sys._e048 sys._o369 sys._e049)\n"
 	"var !sys.argc sys._e047\n"
 	"type sys._e051 {}\n"
-	"type sys._o370 {_e369 sys.int32}\n"
+	"type sys._o373 {_e372 sys.int32}\n"
 	"type sys._e052 {}\n"
-	"type sys._e050 (sys._e051 sys._o370 sys._e052)\n"
+	"type sys._e050 (sys._e051 sys._o373 sys._e052)\n"
 	"var !sys.envc sys._e050\n"
 	"type sys._e054 {}\n"
-	"type sys._o375 {_e373 sys.string}\n"
-	"type sys._i377 {_e374 sys.int32}\n"
-	"type sys._e053 (sys._e054 sys._o375 sys._i377)\n"
+	"type sys._o378 {_e376 sys.string}\n"
+	"type sys._i380 {_e377 sys.int32}\n"
+	"type sys._e053 (sys._e054 sys._o378 sys._i380)\n"
 	"var !sys.argv sys._e053\n"
 	"type sys._e056 {}\n"
-	"type sys._o383 {_e381 sys.string}\n"
-	"type sys._i385 {_e382 sys.int32}\n"
-	"type sys._e055 (sys._e056 sys._o383 sys._i385)\n"
+	"type sys._o386 {_e384 sys.string}\n"
+	"type sys._i388 {_e385 sys.int32}\n"
+	"type sys._e055 (sys._e056 sys._o386 sys._i388)\n"
 	"var !sys.envv sys._e055\n"
 	"type sys._e058 {}\n"
-	"type sys._o392 {_e389 sys.int32 _e390 sys.float64}\n"
-	"type sys._i394 {_e391 sys.float64}\n"
-	"type sys._e057 (sys._e058 sys._o392 sys._i394)\n"
+	"type sys._o395 {_e392 sys.int32 _e393 sys.float64}\n"
+	"type sys._i397 {_e394 sys.float64}\n"
+	"type sys._e057 (sys._e058 sys._o395 sys._i397)\n"
 	"var !sys.frexp sys._e057\n"
 	"type sys._e060 {}\n"
-	"type sys._o401 {_e398 sys.float64}\n"
-	"type sys._i403 {_e399 sys.int32 _e400 sys.float64}\n"
-	"type sys._e059 (sys._e060 sys._o401 sys._i403)\n"
+	"type sys._o404 {_e401 sys.float64}\n"
+	"type sys._i406 {_e402 sys.int32 _e403 sys.float64}\n"
+	"type sys._e059 (sys._e060 sys._o404 sys._i406)\n"
 	"var !sys.ldexp sys._e059\n"
 	"type sys._e062 {}\n"
-	"type sys._o411 {_e408 sys.float64 _e409 sys.float64}\n"
-	"type sys._i413 {_e410 sys.float64}\n"
-	"type sys._e061 (sys._e062 sys._o411 sys._i413)\n"
+	"type sys._o414 {_e411 sys.float64 _e412 sys.float64}\n"
+	"type sys._i416 {_e413 sys.float64}\n"
+	"type sys._e061 (sys._e062 sys._o414 sys._i416)\n"
 	"var !sys.modf sys._e061\n"
 	"type sys._e064 {}\n"
-	"type sys._o420 {_e417 sys.bool}\n"
-	"type sys._i422 {_e418 sys.float64 _e419 sys.int32}\n"
-	"type sys._e063 (sys._e064 sys._o420 sys._i422)\n"
+	"type sys._o423 {_e420 sys.bool}\n"
+	"type sys._i425 {_e421 sys.float64 _e422 sys.int32}\n"
+	"type sys._e063 (sys._e064 sys._o423 sys._i425)\n"
 	"var !sys.isInf sys._e063\n"
 	"type sys._e066 {}\n"
-	"type sys._o429 {_e427 sys.bool}\n"
-	"type sys._i431 {_e428 sys.float64}\n"
-	"type sys._e065 (sys._e066 sys._o429 sys._i431)\n"
+	"type sys._o432 {_e430 sys.bool}\n"
+	"type sys._i434 {_e431 sys.float64}\n"
+	"type sys._e065 (sys._e066 sys._o432 sys._i434)\n"
 	"var !sys.isNaN sys._e065\n"
 	"type sys._e068 {}\n"
-	"type sys._o437 {_e435 sys.float64}\n"
-	"type sys._i439 {_e436 sys.int32}\n"
-	"type sys._e067 (sys._e068 sys._o437 sys._i439)\n"
+	"type sys._o440 {_e438 sys.float64}\n"
+	"type sys._i442 {_e439 sys.int32}\n"
+	"type sys._e067 (sys._e068 sys._o440 sys._i442)\n"
 	"var !sys.Inf sys._e067\n"
 	"type sys._e070 {}\n"
-	"type sys._o444 {_e443 sys.float64}\n"
+	"type sys._o447 {_e446 sys.float64}\n"
 	"type sys._e071 {}\n"
-	"type sys._e069 (sys._e070 sys._o444 sys._e071)\n"
+	"type sys._e069 (sys._e070 sys._o447 sys._e071)\n"
 	"var !sys.NaN sys._e069\n"
 	"type sys._e073 {}\n"
 	"type sys._e075 [sys.any] sys.any\n"
 	"type sys._e074 *sys._e075\n"
-	"type sys._o447 {hmap sys._e074}\n"
-	"type sys._i449 {keysize sys.uint32 valsize sys.uint32 keyalg sys.uint32 valalg sys.uint32 hint sys.uint32}\n"
-	"type sys._e072 (sys._e073 sys._o447 sys._i449)\n"
+	"type sys._o450 {hmap sys._e074}\n"
+	"type sys._i452 {keysize sys.uint32 valsize sys.uint32 keyalg sys.uint32 valalg sys.uint32 hint sys.uint32}\n"
+	"type sys._e072 (sys._e073 sys._o450 sys._i452)\n"
 	"var !sys.newmap sys._e072\n"
 	"type sys._e077 {}\n"
-	"type sys._o458 {val sys.any}\n"
+	"type sys._o461 {val sys.any}\n"
 	"type sys._e079 [sys.any] sys.any\n"
 	"type sys._e078 *sys._e079\n"
-	"type sys._i460 {hmap sys._e078 key sys.any}\n"
-	"type sys._e076 (sys._e077 sys._o458 sys._i460)\n"
+	"type sys._i463 {hmap sys._e078 key sys.any}\n"
+	"type sys._e076 (sys._e077 sys._o461 sys._i463)\n"
 	"var !sys.mapaccess1 sys._e076\n"
 	"type sys._e081 {}\n"
-	"type sys._o466 {val sys.any pres sys.bool}\n"
+	"type sys._o469 {val sys.any pres sys.bool}\n"
 	"type sys._e083 [sys.any] sys.any\n"
 	"type sys._e082 *sys._e083\n"
-	"type sys._i468 {hmap sys._e082 key sys.any}\n"
-	"type sys._e080 (sys._e081 sys._o466 sys._i468)\n"
+	"type sys._i471 {hmap sys._e082 key sys.any}\n"
+	"type sys._e080 (sys._e081 sys._o469 sys._i471)\n"
 	"var !sys.mapaccess2 sys._e080\n"
 	"type sys._e085 {}\n"
 	"type sys._e086 {}\n"
 	"type sys._e088 [sys.any] sys.any\n"
 	"type sys._e087 *sys._e088\n"
-	"type sys._i475 {hmap sys._e087 key sys.any val sys.any}\n"
-	"type sys._e084 (sys._e085 sys._e086 sys._i475)\n"
+	"type sys._i478 {hmap sys._e087 key sys.any val sys.any}\n"
+	"type sys._e084 (sys._e085 sys._e086 sys._i478)\n"
 	"var !sys.mapassign1 sys._e084\n"
 	"type sys._e090 {}\n"
 	"type sys._e091 {}\n"
 	"type sys._e093 [sys.any] sys.any\n"
 	"type sys._e092 *sys._e093\n"
-	"type sys._i481 {hmap sys._e092 key sys.any val sys.any pres sys.bool}\n"
-	"type sys._e089 (sys._e090 sys._e091 sys._i481)\n"
+	"type sys._i484 {hmap sys._e092 key sys.any val sys.any pres sys.bool}\n"
+	"type sys._e089 (sys._e090 sys._e091 sys._i484)\n"
 	"var !sys.mapassign2 sys._e089\n"
 	"type sys._e095 {}\n"
-	"type sys._o489 {_e488 sys.bool}\n"
-	"type sys._e096 {}\n"
-	"type sys._e094 (sys._e095 sys._o489 sys._e096)\n"
-	"var !sys.newproc sys._e094\n"
+	"type sys._o494 {_e491 sys.string _e492 sys.bool}\n"
+	"type sys._i496 {_e493 sys.string}\n"
+	"type sys._e094 (sys._e095 sys._o494 sys._i496)\n"
+	"var !sys.readfile sys._e094\n"
+	"type sys._e097 {}\n"
 	"type sys._e098 {}\n"
-	"type sys._o495 {_e492 sys.string _e493 sys.bool}\n"
-	"type sys._i497 {_e494 sys.string}\n"
-	"type sys._e097 (sys._e098 sys._o495 sys._i497)\n"
-	"var !sys.readfile sys._e097\n"
-	"type sys._e100 {}\n"
-	"type sys._e101 {}\n"
-	"type sys._i502 {_e501 sys.int32}\n"
-	"type sys._e099 (sys._e100 sys._e101 sys._i502)\n"
-	"var !sys.exit sys._e099\n"
+	"type sys._i501 {_e500 sys.int32}\n"
+	"type sys._e096 (sys._e097 sys._e098 sys._i501)\n"
+	"var !sys.exit sys._e096\n"
 	"))\n"
 ;
diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index cc3431e..a92358c 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -159,7 +159,7 @@
 	case OPROC:
 		if(top != Etop)
 			goto nottop;
-		*n = *procop(n);
+		walktype(n->left, Etop);
 		goto ret;
 
 	case OCALLMETH:
@@ -1594,27 +1594,6 @@
 	return N;
 }
 
-Node*
-procop(Node *n)
-{
-	Node *r, *on;
-
-	switch(n->op) {
-	default:
-		fatal("mapop: unknown op %E", n->op);
-
-	case OPROC:	// rewrite if(sys.newproc()) (n->left)
-		on = syslook("newproc", 0);
-		r = nod(OIF, N, N);
-		r->ntest = nod(OCALL, on, N);
-		r->nbody = n->left;
-dump("newproc", r);
-		walktype(r, Etop);
-		break;
-	}
-	return r;
-}
-
 void
 diagnamed(Type *t)
 {
@@ -1772,6 +1751,7 @@
 		l = listnext(&savel);
 		r = listnext(&saver);
 	}
+	n = rev(n);
 	return n;
 
 multi:
@@ -1827,6 +1807,7 @@
 		n = nod(OLIST, n, a);
 		break;
 	}
+	n = rev(n);
 	return n;
 
 badt:
diff --git a/src/runtime/rt0_amd64.s b/src/runtime/rt0_amd64.s
index 21c1aa9..edc40df 100644
--- a/src/runtime/rt0_amd64.s
+++ b/src/runtime/rt0_amd64.s
@@ -179,6 +179,12 @@
 TEXT _endmorestack(SB), 7, $-8
 	RET
 
+// call a subroutine in a new coroutine
+// argument list is on the stack addr of fn is in AX
+TEXT	sys·_newproc(SB), 7, $0
+	JMP	AX
+	RET
+
 TEXT	FLUSH(SB),7,$-8
 	RET
 
@@ -186,5 +192,4 @@
 	MOVQ	R15, AX
 	RET
 
-
 GLOBL	peruser<>(SB),$64