The block optimizer pass allows the use of sources of the preceding
block if the block is a follower and not a target. This causes issues
when trying to remove FREE instructions: if the source is not in the
block of the FREE, then the FREE and source are still removed. Therefore
the other successor blocks, which must consume or FREE the temporary,
will still contain the FREE opline. This opline will now refer to a
temporary that doesn't exist anymore, which most of the time results in
a crash. For these kind of non-local scenarios, we'll let the SSA
based optimizations handle those cases.
Closes GH-11251.
`zend_uchar` suggests that the value is an ASCII character, but here,
it's about very small integers. This is misleading, so let's use a
C99 integer instead.
On all architectures currently supported by PHP, `zend_uchar` and
`uint8_t` are identical. This change is only about code readability.
We're in the case of ZEND_JMPZ_EX or ZEND_JMPNZ_EX. The opcode gets
overwritten and only after the overwriting gets checked if we're in a
JMPZ or JMPNZ case. This results in a wrong optimization.
Close GH-10329
While JMPZNZ can avoid execution of a separate JMP opcode in some
cases, it also prevents smart branch optimization, so creating
JMPZNZ may actually have a negative effect. It also adds additional
complexity for optimizations.
Drop JMPZNZ in favor of JMPZ+JMP or JMPNZ+JMP.
Closes GH-7857.
This reverts the change from 493c91c742.
Starting a new block means that in the common case where the loop var
free is not unreachable, we'll always merge back the block.
Instead fix the original problem by explicitly removing instructions
apart from the loop var free in block pass.
It's possible for delayed early binding opcodes to get optimized
away if they are "unreachable". However, we still need to attempt
early binding for them. (In some cases we also corrupt the early
binding list outright during optimization, which is how I got here.)
Fix this by storing information about delayed early binding
independently of DECLARE_CLASS_DELAYED opcodes, so early binding is
performed even after the opcode has been dropped.
This results in an assertion failure when running under -e,
because there is an additional EXT_STMT + NOP before the FREE.
I don't think there's a strong reason to handle UNREACHABLE_FREE
specially here (it's only important that we *do* handle it), so
I'm dropping the code rather than adjusting it to scan over
certain opcodes.
1. Update: http://www.php.net/license/3_01.txt to https, as there is anyway server header "Location:" to https.
2. Update few license 3.0 to 3.01 as 3.0 states "php 5.1.1, 4.1.1, and earlier".
3. In some license comments is "at through the world-wide-web" while most is without "at", so deleted.
4. fixed indentation in some files before |
This PR corrects misspellings identified by the check-spelling action.
The misspellings have been reported at jsoref@b6ba3e2#commitcomment-48946465
The action reports that the changes in this PR would make it happy: jsoref@602417c
Closes GH-6822.
This only moves the files, adjusts the build system, exports APIs
and does minor fixups to make sure the code builds.
This does not yet try to make the optimizer usable independently
of opcache.
Closes GH-6642.
2021-01-28 10:38:25 +01:00
Renamed from ext/opcache/Optimizer/block_pass.c (Browse further)
