Implement single "last matched CE" cache slot for RECV and VERIFY_RETURN_TYPE

[nielsdos]

No description provided.

[nielsdos]

TODO: remove this accident

[arnaud-lb]

Thank you for trying this!

I get -0.14% wall time on symfony demo:

base:        mean:  1.0295;  stddev:  0.0012;  diff:  -0.00%
cache-slot:  mean:  1.0281;  stddev:  0.0012;  diff:  -0.14%

(Average of 5 runs -T10,100 runs)

We may avoid allocating a cache slot for simple types, as we use it only for complex ones.

[nielsdos]

We may avoid allocating a cache slot for simple types, as we use it only for complex ones.

Good point.

I get -0.14% wall time on symfony demo:

For me it's a bit of a hit or miss on my older CPU. I can try again on some more recent machine a bit later.

I also see only now that Ilija also tried something like this (before I removed the original cache slot implementation): iluuu1994#155
Maybe I can also check it earlier, however I don't want to cache it later as that can slow down the path that doesn't use objects.

[nielsdos]

I just committed this to run in CI and get a CI Valgrind bench going:

diff --git a/Zend/zend_execute.c b/Zend/zend_execute.c
index 7d2e4112797..563e12d3af2 100644
--- a/Zend/zend_execute.c
+++ b/Zend/zend_execute.c
@@ -1145,9 +1145,9 @@ static zend_always_inline bool zend_check_type_slow(
 		bool is_return_type, bool is_internal)
 {
 	if (ZEND_TYPE_IS_COMPLEX(*type) && EXPECTED(Z_TYPE_P(arg) == IS_OBJECT)) {
-		if (*cache_slot == Z_OBJCE_P(arg)) {
-			return true;
-		}
+		// if (*cache_slot == Z_OBJCE_P(arg)) {
+			// return true;
+		// }
 		zend_class_entry *ce;
 		if (UNEXPECTED(ZEND_TYPE_HAS_LIST(*type))) {
 			if (ZEND_TYPE_IS_INTERSECTION(*type)) {
@@ -1242,6 +1242,10 @@ static zend_always_inline bool zend_verify_recv_arg_type(const zend_function *zf
 	ZEND_ASSERT(arg_num <= zf->common.num_args);
 	cur_arg_info = &zf->common.arg_info[arg_num-1];
 
+	if (Z_TYPE_P(arg) == IS_OBJECT && *cache_slot == Z_OBJCE_P(arg)) {
+		return 1;
+	}
+
 	if (ZEND_TYPE_IS_SET(cur_arg_info->type)
 			&& UNEXPECTED(!zend_check_type(&cur_arg_info->type, arg, cache_slot, zf->common.scope, 0, 0))) {
 		zend_verify_arg_error(zf, cur_arg_info, arg_num, arg);

I'm afraid this may degrade scalar checks though.