interface equality

R=r
OCL=17116
CL=17118

src/cmd/gc/lex.c

@@ -1063,6 +1063,7 @@ lexinit(void)
 
 		case TPTR32:
 		case TPTR64:
+		case TINTER:
 			okforeq[i] = 1;
 			break;
 		}

src/cmd/gc/sys.go

@@ -31,6 +31,7 @@ export func	arraystring(*[]byte) string;
 export func	ifaceT2I(sigi *byte, sigt *byte, elem any) (ret any);
 export func	ifaceI2T(sigt *byte, iface any) (ret any);
 export func	ifaceI2I(sigi *byte, iface any) (ret any);
+export func	ifaceeq(i1 any, i2 any) (ret bool);
 
 export func	argc() int32;
 export func	envc() int32;

src/cmd/gc/sysimport.c

@@ -31,6 +31,7 @@ char *sysimport =
 	"export func sys.ifaceT2I (sigi *sys.uint8, sigt *sys.uint8, elem sys.any) (ret sys.any)\n"
 	"export func sys.ifaceI2T (sigt *sys.uint8, iface sys.any) (ret sys.any)\n"
 	"export func sys.ifaceI2I (sigi *sys.uint8, iface sys.any) (ret sys.any)\n"
+	"export func sys.ifaceeq (i1 sys.any, i2 sys.any) (ret sys.bool)\n"
 	"export func sys.argc () (? sys.int32)\n"
 	"export func sys.envc () (? sys.int32)\n"
 	"export func sys.argv (? sys.int32) (? sys.string)\n"

src/cmd/gc/walk.c

@@ -681,7 +681,7 @@ loop:
 		convlit(n->right, n->left->type);
 		if(n->left->type == T || n->right->type == T)
 			goto ret;
-		if(!ascompat(n->left->type, n->right->type))
+		if(!eqtype(n->left->type, n->right->type, 0))
 			goto badt;
 
 		switch(n->op) {
@@ -952,6 +952,10 @@ loop:
 		et = n->left->type->etype;
 		if(!okforeq[et])
 			goto badt;
+		if(isinter(n->left->type)) {
+			indir(n, ifaceop(T, n, n->op));
+			goto ret;
+		}
 		t = types[TBOOL];
 		break;
 
@@ -2550,6 +2554,28 @@ ifaceop(Type *tl, Node *n, int op)
 		argtype(on, tr);
 		argtype(on, tl);
 		break;
+
+	case OEQ:
+	case ONE:
+		// ifaceeq(i1 any-1, i2 any-2) (ret bool);
+		a = n->right;				// i2
+		r = a;
+
+		a = n->left;				// i1
+		r = list(a, r);
+
+		on = syslook("ifaceeq", 1);
+		argtype(on, n->right->type);
+		argtype(on, n->left->type);
+
+		r = nod(OCALL, on, r);
+		if(op == ONE)
+			r = nod(ONOT, r, N);
+
+		dump("bef", r);
+		walktype(r, Erv);
+		dump("aft", r);
+		return r;
 	}
 
 	r = nod(OCALL, on, r);

src/runtime/iface.c

@@ -261,6 +261,53 @@ sys·ifaceI2I(Sigi *si, Map *im, void *it, Map *retim, void *retit)
 	FLUSH(&retit);
 }
 
+// ifaceeq(i1 any, i2 any) (ret bool);
+void
+sys·ifaceeq(Map *im1, void *it1, Map *im2, void *it2, byte ret)
+{
+	if(debug) {
+		prints("Ieq i1=");
+		printiface(im1, it1);
+		prints(" i2=");
+		printiface(im2, it2);
+		prints("\n");
+	}
+
+	ret = false;
+
+	// are they both nil
+	if(im1 == nil) {
+		if(im2 == nil)
+			goto yes;
+		goto no;
+	}
+	if(im2 == nil)
+		goto no;
+
+	// values
+	if(it1 != it2)
+		goto no;
+
+	// types
+	if(im1 == im2)
+		goto yes;
+	if(im1->sigt == im2->sigt)
+		goto yes;
+	if(im1->sigt->hash != im2->sigt->hash)
+		goto no;
+
+
+yes:
+	ret = true;
+no:
+	if(debug) {
+		prints("Ieq ret=");
+		sys·printbool(ret);
+		prints("\n");
+	}
+	FLUSH(&ret);
+}
+
 void
 sys·printinter(Map *im, void *it)
 {