Add a specialized opcode handler to use for `===`/`!==` when:
1. At least one side is a $cv, and the other is a $cv or CONST
(avoids the need to free operands)
2. Neither operand can be undefined or a reference
(avoids the need for error handling and dereferencing)
```
// Elapsed time decreased from 0.275 seconds to 0.243 seconds in combination
// with PR #4982
function count_same(array $values) {
$same = 0;
foreach ($values as $x) {
foreach ($values as $y) {
if ($y === $x) {
$same++;
}
}
}
return $same;
}
$values = range(0, 5000);
$values[] = new stdClass();
$values[] = null;
$values[] = 3;
$start = microtime(true);
$total = count_same($values);
```
Make sure we deref the OBJ_IS result, because we store it in a TMP
var, which is not allowed to contain references and will cause
assertion failures in the unspecialized VM.
This also partially reverts fd463a9a60,
which merged the TMP and VAR specializations of COALESCE to work
around this bug.
An alternative would be to change the result type of OBJ_IS back
to VAR.
RFC: https://wiki.php.net/rfc/null_coalesce_equal_operator
$a ??= $b is $a ?? ($a = $b), with the difference that $a is only
evaluated once, to the degree that this is possible. In particular
in $a[foo()] ?? $b function foo() is only ever called once.
However, the variable access themselves will be reevaluated.
RFC: https://wiki.php.net/rfc/typed_properties_v2
This is a squash of PR #3734, which is a squash of PR #3313.
Co-authored-by: Bob Weinand <bobwei9@hotmail.com>
Co-authored-by: Joe Watkins <krakjoe@php.net>
Co-authored-by: Dmitry Stogov <dmitry@zend.com>
determine whether pass by ref is possible or pass by value is needed.
# This is usefull when functions take array or string parameters as
# expressions. In such a case force by ref is not applicable and the
# executor would copy the variable unnecessarily as soon as it is at least
# once referenced.
- Extensions which delete global variables need to use new special function
- delete_global_variable() (I'm about to rename it) to remove them.
- Will post to internals@ or via commit messages if there's anything else.
a) We specialize opcodes according to op_type fields. Each opcode has to
be marked with which op_type's it uses.
b) We support different execution methods. Function handlers, switch()
and goto dispatching. goto seems to be the fastest but it really
depends on the compiler and how well it optimizes. I suggest playing
around with optimization flags.
- Warning: Things might break so keep us posted on how things are going.
(Dmitry, Andi)
