Re: 64-bit performance improvement by reducing zend_op size.

Hey: On Wed, Dec 10, 2014 at 11:27 PM, Dmitry Stogov <dmitry@zend.com> wrote: > Hi, > > Please, review the following patch > https://gist.github.com/dstogov/fba2cc621ef121826efe > > It's huge, but actually, only changes in zend_compile.h are matter. The rest > is obvious renaming. > > 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. > > The patch must affect xdebug and may be other very engine depended > extensions, but it must not be a big problem to fix them (only ext/opcache, > ext/reflection and sapi/phpdbg required minor changes). > > If nobody objects, I'm going to commit this. As I already participated in this patch, I have no problems & objections. thanks > > Thanks. Dmitry. > -- Xinchen Hui @Laruence http://www.laruence.com/