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Diffstat (limited to 'Zend/README.ZEND_VM')
| -rw-r--r-- | Zend/README.ZEND_VM | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/Zend/README.ZEND_VM b/Zend/README.ZEND_VM new file mode 100644 index 0000000..15ff6fd --- /dev/null +++ b/Zend/README.ZEND_VM @@ -0,0 +1,108 @@ +ZEND_VM +======= + +ZEND_VM architecture allows specializing opcode handlers according to op_type +fields and using different execution methods (call threading, switch threading +and direct threading). As a result ZE2 got more than 20% speedup on raw PHP +code execution (with specialized executor and direct threading execution +method). As in most PHP applications raw execution speed isn't the limiting +factor but system calls and database callls are, your mileage with this patch +will vary. + +Most parts of the old zend_execute.c go into zend_vm_def.h. Here you can +find opcode handlers and helpers. The typical opcode handler template looks +like this: + +ZEND_VM_HANDLER(<OPCODE-NUMBER>, <OPCODE>, <OP1_TYPES>, <OP2_TYPES>) +{ + <HANDLER'S CODE> +} + +<OPCODE-NUMBER> is a opcode number (0, 1, ...) +<OPCODE> is an opcode name (ZEN_NOP, ZEND_ADD, :) +<OP1_TYPES> & <OP2_TYPES> are masks for allowed operand op_types. Specializer +will generate code only for defined combination of types. You can use any +combination of the following op_types UNUSED, CONST, VAR, TMP and CV also +you can use ANY mask to disable specialization according operand's op_type. +<HANDLER'S CODE> is a handler's code itself. For most handlers it stills the +same as in old zend_execute.c, but now it uses macros to access opcode operands +and some internal executor data. + +You can see the conformity of new macros to old code in the following list: + +EXECUTE_DATA + execute_data +ZEND_VM_DISPATCH_TO_HANDLER(<OP>) + return <OP>_helper(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU) +ZEND_VM_DISPATCH_TO_HELPER(<NAME>) + return <NAME>(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU) +ZEND_VM_DISPATCH_TO_HELPER_EX(<NAME>,<PARAM>,<VAL>) + return <NAME>(<VAL>, ZEND_OPCODE_HANDLER_ARGS_PASSTHRU) +ZEND_VM_CONTINUE() + return 0 +ZEND_VM_NEXT_OPCODE() + NEXT_OPCODE() +ZEND_VM_SET_OPCODE(<TARGET> + SET_OPCODE(<TARGET> +ZEND_VM_INC_OPCODE() + INC_OPCOD() +ZEND_VM_RETURN_FROM_EXECUTE_LOOP() + RETURN_FROM_EXECUTE_LOOP() +ZEND_VM_C_LABEL(<LABEL>): + <LABEL>: +ZEND_VM_C_GOTO(<LABEL>) + goto <LABEL> +OP<X>_TYPE + opline->op<X>.op_type +GET_OP<X>_ZVAL_PTR(<TYPE>) + get_zval_ptr(&opline->op<X>, EX(Ts), &free_op<X>, <TYPE>) +GET_OP<X>_ZVAL_PTR_PTR(<TYPE>) + get_zval_ptr_ptr(&opline->op<X>, EX(Ts), &free_op<X>, <TYPE>) +GET_OP<X>_OBJ_ZVAL_PTR(<TYPE>) + get_obj_zval_ptr(&opline->op<X>, EX(Ts), &free_op<X>, <TYPE>) +GET_OP<X>_OBJ_ZVAL_PTR_PTR(<TYPE>) + get_obj_zval_ptr_ptr(&opline->op<X>, EX(Ts), &free_op<X>, <TYPE>) +IS_OP<X>_TMP_FREE() + IS_TMP_FREE(free_op<X>) +FREE_OP<X>() + FREE_OP(free_op<X>) +FREE_OP<X>_IF_VAR() + FREE_VAR(free_op<X>) +FREE_OP<X>_VAR_PTR() + FREE_VAR_PTR(free_op<X>) + + +Executor's helpers can be defined without parameters or with one parameter. +This is done with the following constructs: + +ZEND_VM_HELPER(<HELPER-NAME>, <OP1_TYPES>, <OP2_TYPES>) +{ + <HELPER'S CODE> +} + +ZEND_VM_HELPER_EX(<HELPER-NAME>, <OP1_TYPES>, <OP2_TYPES>, <PARAM_SPEC>) +{ + <HELPER'S CODE> +} + +Executor's code is generated by PHP script zend_vm_gen.php it uses zend_vm_def.h +and zend_vm_execute.skl as input and produces zend_vm_opcodes.h and +zend_vm_execute.h. The first file is a list of opcode definitions. It is +included from zend_compile.h. The second one is an executor code itself. It is +included from zend_execute.c. + +zend_vm_gen.php can produce different kind of executors. You can select +different opcode threading model using --with-vm-kind=CALL|SWITCH|GOTO. You can +disable opcode specialization using --without-specializer. You can include or +exclude old executor together with specialized one using --without-old-executor. +At last you can debug executor using original zend_vm_def.h or generated file +zend_vm_execute.h. Debugging with original file requires --with-lines +option. By default ZE2 uses the following command to generate executor: + +$ php zend_vm_gen.php --with-vm-kind=CALL + +Zend Engine II currently includes two executors during the build process, one +is the specialized version and the other is the old one non-specialized with +function handlers. By default Zend Engine II uses the specialized one but you +can switch to the old executor at runtime by calling zend_vm_use_old_executor(). + |