load binary op arguments into registers

go/test: passes 69% (237/339)

R=rsc
APPROVED=rsc
DELTA=12  (3 added, 9 deleted, 0 changed)
OCL=35178
CL=35180

src/cmd/5g/cgen.c

@@ -364,18 +364,10 @@ sbop:	// symmetric binary
 	}
 
 abop:	// asymmetric binary
+	// TODO(kaib): use fewer registers here.
 	if(nl->ullman >= nr->ullman) {
 		regalloc(&n1, nl->type, res);
 		cgen(nl, &n1);
-
-		if(sudoaddable(a, nr, &addr, &w)) {
-			p1 = gins(a, N, &n1);
-			p1->from = addr;
-			gmove(&n1, res);
-			sudoclean();
-			regfree(&n1);
-			goto ret;
-		}
 		regalloc(&n2, nr->type, N);
 		cgen(nr, &n2);
 	} else {

test/arm-pass.txt

@@ -213,6 +213,7 @@ ken/complit.go
 ken/for.go
 ken/label.go
 ken/mfunc.go
+ken/ptrvar.go
 ken/rob2.go
 ken/robfor.go
 ken/robif.go
@@ -221,6 +222,7 @@ ken/simpfun.go
 ken/simpprint.go
 ken/simpswitch.go
 ken/simpvar.go
+ken/strvar.go
 method1.go
 method2.go
 method3.go