While we avoid emitting labels for handlers that are not referenced
from anywhere else, we do not perform a fine-grained analysis on
used specializations, so some of the specialization labels may not
be used. Use ATTRIBUTE_UNUSED_LABEL to suppress the warning. Drop
"cold" from the definition of this attribute, as it is completely
unrelated.
From an engine perspective, named parameters mainly add three
concepts:
* The SEND_* opcodes now accept a CONST op2, which is the
argument name. For now, it is looked up by linear scan and
runtime cached.
* This may leave UNDEF arguments on the stack. To avoid having
to deal with them in other places, a CHECK_UNDEF_ARGS opcode
is used to either replace them with defaults, or error.
* For variadic functions, EX(extra_named_params) are collected
and need to be freed based on ZEND_CALL_HAS_EXTRA_NAMED_PARAMS.
RFC: https://wiki.php.net/rfc/named_params
Closes GH-5357.
Some code paths were checking this manually, but we can turn this
into a general assertion to avoid surprises (functions returning
failure without throwing).
Do this by reusing the implementation used for `==`
when both arguments are ints (IS_LONG) or both are floats (IS_DOUBLE)
```php
// Before: nestedloop_ni took 0.442 seconds
// After: nestedloop_ni takes 0.401 seconds (same as nestedloop_ne)
function nestedloop_ni(int $k) {
$x = 0;
for ($i=0; $i < 50000000; $i++) {
if ($i === $k) {
$x++;
}
}
print "$x\n";
}
function nestedloop_ne(int $k) {
$x = 0;
for ($i=0; $i < 50000000; $i++) {
if ($i == $k) {
$x++;
}
}
print "$x\n";
}
```
Avoid need of insertion NOP opcoes between unrelated SMART BRANCH instruction and following JMPZ/JMPNZ.
Now instead of checking the opcode of following instruction, the same information is encoded into SMART BRANH result_type.
This removes object auto-vivification support.
This also means that we can remove the corresponding special
handling for typed properites: We no longer need to check that a
property is convertible to stdClass if such a conversion might
take place indirectly due to a nested property write.
Additionally OBJ_W style operations now no longer modify the
object operand, and as such we no longer need to treat op1 as a
def in SSA form.
The next step would be to actually compile the whole LHS of OBJ_W
operations in R rather than W mode, but that causes issues with
SimpleXML, whose object handlers depend on the current compilation
structure.
Part of https://wiki.php.net/rfc/engine_warnings.
* PHP-7.4:
Remove HOT attribute from some VM handlers. Comparisons almost always followed by JMPZ/JMPNZ; JMPZNZ is rare used.
Remove --with-zlib-dir option from mysqlnd config
By avoiding unused variable opline warnings. Also clean up the
replacement of ZEND_VM_SPEC -- we were sometimes treating it as
an always-defined constant with a value (what it actually is) and
sometimes as a conditionally defined constant (which it isn't, but
which still worked thanks to the specializer). Switch to only
treating it as a constant with a value.
