Only check for undef in RECV(_INIT)

As we initialize CVs to undef, we don't need to check for both
argument count and undef here, the latter is enough.

Author: nikic

Zend/zend_vm_def.h

@@ -5322,11 +5322,9 @@ ZEND_VM_COLD_HELPER(zend_verify_recv_arg_type_helper, ANY, ANY, zval *op_1)
 ZEND_VM_HOT_HANDLER(63, ZEND_RECV, NUM, UNUSED, CACHE_SLOT)
 {
 	USE_OPLINE
-	uint32_t arg_num = opline->op1.num;
-	zval *param;
-
-	param = EX_VAR(opline->result.var);
-	if (UNEXPECTED(arg_num > EX_NUM_ARGS() || Z_ISUNDEF_P(param))) {
+	zval *param = EX_VAR(opline->result.var);
+	if (UNEXPECTED(Z_ISUNDEF_P(param))) {
+		uint32_t arg_num = opline->op1.num;
 		ZEND_VM_DISPATCH_TO_HELPER(zend_missing_arg_helper, arg_num, arg_num);
 	}
 
@@ -5340,9 +5338,9 @@ ZEND_VM_HOT_HANDLER(63, ZEND_RECV, NUM, UNUSED, CACHE_SLOT)
 ZEND_VM_HOT_TYPE_SPEC_HANDLER(ZEND_RECV, op->op2.num == MAY_BE_ANY, ZEND_RECV_NOTYPE, NUM, NUM, CACHE_SLOT)
 {
 	USE_OPLINE
-	uint32_t arg_num = opline->op1.num;
 
-	if (UNEXPECTED(arg_num > EX_NUM_ARGS()) || Z_ISUNDEF_P(EX_VAR(opline->result.var))) {
+	if (UNEXPECTED(Z_ISUNDEF_P(EX_VAR(opline->result.var)))) {
+		uint32_t arg_num = opline->op1.num;
 		ZEND_VM_DISPATCH_TO_HELPER(zend_missing_arg_helper, arg_num, arg_num);
 	}
 

Zend/zend_vm_execute.h

@@ -2221,9 +2221,9 @@ static zend_never_inline ZEND_COLD ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL zend_ve
 static ZEND_VM_HOT ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_RECV_NOTYPE_SPEC_HANDLER(ZEND_OPCODE_HANDLER_ARGS)
 {
 	USE_OPLINE
-	uint32_t arg_num = opline->op1.num;
 
-	if (UNEXPECTED(arg_num > EX_NUM_ARGS()) || Z_ISUNDEF_P(EX_VAR(opline->result.var))) {
+	if (UNEXPECTED(Z_ISUNDEF_P(EX_VAR(opline->result.var)))) {
+		uint32_t arg_num = opline->op1.num;
 		ZEND_VM_TAIL_CALL(zend_missing_arg_helper_SPEC(arg_num ZEND_OPCODE_HANDLER_ARGS_PASSTHRU_CC));
 	}
 
@@ -3237,11 +3237,9 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_INIT_DYNAMIC_CALL_SPEC_TMPVAR_
 static ZEND_VM_HOT ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_RECV_SPEC_UNUSED_HANDLER(ZEND_OPCODE_HANDLER_ARGS)
 {
 	USE_OPLINE
-	uint32_t arg_num = opline->op1.num;
-	zval *param;
-
-	param = EX_VAR(opline->result.var);
-	if (UNEXPECTED(arg_num > EX_NUM_ARGS() || Z_ISUNDEF_P(param))) {
+	zval *param = EX_VAR(opline->result.var);
+	if (UNEXPECTED(Z_ISUNDEF_P(param))) {
+		uint32_t arg_num = opline->op1.num;
 		ZEND_VM_TAIL_CALL(zend_missing_arg_helper_SPEC(arg_num ZEND_OPCODE_HANDLER_ARGS_PASSTHRU_CC));
 	}