6g return struct fix:

make t->width of funarg struct be width of struct.

emit MOVSL for 4-byte copy.

R=ken
OCL=24108
CL=24111

src/cmd/6g/align.c

@@ -68,7 +68,12 @@ widstruct(Type *t, uint32 o, int flag)
 	// final width is rounded
 	if(flag)
 		o = rnd(o, maxround);
-	t->width = o;
+
+	// type width only includes back to first field's offset
+	if(t->type == T)
+		t->width = 0;
+	else
+		t->width = o - t->type->width;
 	return o;
 }
 

src/cmd/6g/cgen.c

@@ -906,11 +906,9 @@ sgen(Node *n, Node *ns, int32 w)
 		}
 
 		if(c >= 4) {
-			gconreg(AMOVQ, c, D_CX);
-			gins(AREP, N, N);	// repeat
-			gins(AMOVSB, N, N);	// MOVB *(SI)+,*(DI)+
-
-		} else
+			gins(AMOVSL, N, N);	// MOVL *(SI)+,*(DI)+
+			c -= 4;
+		}
 		while(c > 0) {
 			gins(AMOVSB, N, N);	// MOVB *(SI)+,*(DI)+
 			c--;

src/cmd/6g/gsubr.c

@@ -1887,11 +1887,9 @@ lsort(Sig *l, int(*f)(Sig*, Sig*))
 void
 setmaxarg(Type *t)
 {
-	Type *to;
 	int32 w;
 
-	to = *getoutarg(t);
-	w = to->width;
+	w = t->argwid;
 	if(w > maxarg)
 		maxarg = w;
 }