the main idea - the smaller the zend_op structure, the lees memory traffic is required to load VM instructions during execution. The patch reduces the size of each opcode from 48 to 32 bytes (saves 16 bytes for each opcode, and applications use thousands of opoceds). This reduced the number of CPU cache misses by 12% and improved performance of real-life apps by 1-2%.
The patch affects how constants and jump targets are represented in VM during execution. Previously they were implemented as absolute 64-bit pointers. Now they are relative 32-bit offsets.
In run-time constant now should be accessed as:
RT_CONSTANT(op_array, opine->op1) instead of opline->op1.zv
EX_CONSTANT(opline->op1) instead of opline->op1.zv
Jump targets:
OP_JMP_ADDR(opline, opline->op2) instead of opline->op2.jmp_addr
The patch doesn't change zend_op representation for 32-bit systems. They still use absolute addresses. The compile-time representation is also kept the same.
* FE_RESET_VARIABLE and FE_RESET_REFERENCE were always set
together.
* In some places the code checked FE_FETCH_BYREF instead of
FE_RESET_REFERENCE and relied on them having the same value.
* Now the FE_RESET_* flags are dropped and everything uses
FE_FETCH_BYREF
This moves handling of inheritance and interface implementation
from zend_compile.c into a separate zend_inheritance.c file, as
this is not really related to compilation.
* PHP-5.6:
update NEWS
Only destruct if EG(active) in zend_shutdown(). (bug #65463, #66036)
Fix typo from commit 32314f6b6
Fix destruction order in zend_shutdown (bug #65463, #66036)
Conflicts:
Zend/zend_compile.h
Zend/zend_execute_API.c
* PHP-5.5:
update NEWS
Only destruct if EG(active) in zend_shutdown(). (bug #65463, #66036)
Fix typo from commit 32314f6b6
Fix destruction order in zend_shutdown (bug #65463, #66036)
* PHP-5.4:
update NEWS
Only destruct if EG(active) in zend_shutdown(). (bug #65463, #66036)
Fix typo from commit 32314f6b6
Fix destruction order in zend_shutdown (bug #65463, #66036)
* pull-request/770:
Only destruct if EG(active) in zend_shutdown(). (bug #65463, #66036)
Fix typo from commit 32314f6b6
Fix destruction order in zend_shutdown (bug #65463, #66036)
Now one common stack to handle both, which stores znodes instead of
full oplines (foreach copy stack) or switch entries (switch cond
stack).
Also removed EG(start_op) while at it.
This removes the need to use $<ast>{n} or $<list>$ casts in the
reduction actions.
Keeping the distinction in the parser doesn't really give us any
benefit and only makes changing the grammar harder.
As far as I can discern these are leftovers of the interactive
shell implementation that was used before PHP 5.4. Now the readline
ext makes use of normal eval calls for this.
So, dropping these until there is evidence to the contrary, as they
currently wouldn't work anyway.
