76d7c616bb
This changes the signature of opcode handlers in the CALL VM so that the opline
is passed directly via arguments. This reduces the number of memory operations
on EX(opline), and makes the CALL VM considerably faster.
Additionally, this unifies the CALL and HYBRID VMs a bit, as EX(opline) is now
handled in the same way in both VMs.
This is a part of GH-17849.
Currently we have two VMs:
* HYBRID: Used when compiling with GCC. execute_data and opline are global
register variables
* CALL: Used when compiling with something else. execute_data is passed as
opcode handler arg, but opline is passed via execute_data->opline
(EX(opline)).
The Call VM looks like this:
while (1) {
ret = execute_data->opline->handler(execute_data);
if (UNEXPECTED(ret != 0)) {
if (ret > 0) { // returned by ZEND_VM_ENTER() / ZEND_VM_LEAVE()
execute_data = EG(current_execute_data);
} else { // returned by ZEND_VM_RETURN()
return;
}
}
}
// example op handler
int ZEND_INIT_FCALL_SPEC_CONST_HANDLER(zend_execute_data *execute_data) {
// load opline
const zend_op *opline = execute_data->opline;
// instruction execution
// dispatch
// ZEND_VM_NEXT_OPCODE():
execute_data->opline++;
return 0; // ZEND_VM_CONTINUE()
}
Opcode handlers return a positive value to signal that the loop must load a
new execute_data from EG(current_execute_data), typically when entering
or leaving a function.
Here I make the following changes:
* Pass opline as opcode handler argument
* Return next opline from opcode handlers
* ZEND_VM_ENTER / ZEND_VM_LEAVE return opline|(1<<0) to signal that
execute_data must be reloaded from EG(current_execute_data)
This gives us:
while (1) {
opline = opline->handler(execute_data, opline);
if (UNEXPECTED((uintptr_t) opline & ZEND_VM_ENTER_BIT) {
opline = opline & ~ZEND_VM_ENTER_BIT;
if (opline != 0) { // ZEND_VM_ENTER() / ZEND_VM_LEAVE()
execute_data = EG(current_execute_data);
} else { // ZEND_VM_RETURN()
return;
}
}
}
// example op handler
const zend_op * ZEND_INIT_FCALL_SPEC_CONST_HANDLER(zend_execute_data *execute_data, const zend_op *opline) {
// opline already loaded
// instruction execution
// dispatch
// ZEND_VM_NEXT_OPCODE():
return ++opline;
}
bench.php is 23% faster on Linux / x86_64, 18% faster on MacOS / M1.
Symfony Demo is 2.8% faster.
When using the HYBRID VM, JIT'ed code stores execute_data/opline in two fixed
callee-saved registers and rarely touches EX(opline), just like the VM.
Since the registers are callee-saved, the JIT'ed code doesn't have to
save them before calling other functions, and can assume they always
contain execute_data/opline. The code also avoids saving/restoring them in
prologue/epilogue, as execute_ex takes care of that (JIT'ed code is called
exclusively from there).
The CALL VM can now use a fixed register for execute_data/opline as well, but
we can't rely on execute_ex to save the registers for us as it may use these
registers itself. So we have to save/restore the two registers in JIT'ed code
prologue/epilogue.
Closes GH-17952
The PHP Interpreter
PHP is a popular general-purpose scripting language that is especially suited to web development. Fast, flexible and pragmatic, PHP powers everything from your blog to the most popular websites in the world. PHP is distributed under the PHP License v3.01.
Documentation
The PHP manual is available at php.net/docs.
Installation
Prebuilt packages and binaries
Prebuilt packages and binaries can be used to get up and running fast with PHP.
For Windows, the PHP binaries can be obtained from
windows.php.net. After extracting the archive the
*.exe files are ready to use.
For other systems, see the installation chapter.
Building PHP source code
For Windows, see Build your own PHP on Windows.
For a minimal PHP build from Git, you will need autoconf, bison, and re2c. For a default build, you will additionally need libxml2 and libsqlite3.
On Ubuntu, you can install these using:
sudo apt install -y pkg-config build-essential autoconf bison re2c \
libxml2-dev libsqlite3-dev
On Fedora, you can install these using:
sudo dnf install re2c bison autoconf make libtool ccache libxml2-devel sqlite-devel
Generate configure:
./buildconf
Configure your build. --enable-debug is recommended for development, see
./configure --help for a full list of options.
# For development
./configure --enable-debug
# For production
./configure
Build PHP. To speed up the build, specify the maximum number of jobs using -j:
make -j4
The number of jobs should usually match the number of available cores, which
can be determined using nproc.
Testing PHP source code
PHP ships with an extensive test suite, the command make test is used after
successful compilation of the sources to run this test suite.
It is possible to run tests using multiple cores by setting -jN in
TEST_PHP_ARGS:
make TEST_PHP_ARGS=-j4 test
Shall run make test with a maximum of 4 concurrent jobs: Generally the maximum
number of jobs should not exceed the number of cores available.
The qa.php.net site provides more detailed info about testing and quality assurance.
Installing PHP built from source
After a successful build (and test), PHP may be installed with:
make install
Depending on your permissions and prefix, make install may need super user
permissions.
PHP extensions
Extensions provide additional functionality on top of PHP. PHP consists of many essential bundled extensions. Additional extensions can be found in the PHP Extension Community Library - PECL.
Contributing
The PHP source code is located in the Git repository at github.com/php/php-src. Contributions are most welcome by forking the repository and sending a pull request.
Discussions are done on GitHub, but depending on the topic can also be relayed to the official PHP developer mailing list internals@lists.php.net.
New features require an RFC and must be accepted by the developers. See Request for comments - RFC and Voting on PHP features for more information on the process.
Bug fixes don't require an RFC. If the bug has a GitHub issue, reference it in
the commit message using GH-NNNNNN. Use #NNNNNN for tickets in the old
bugs.php.net bug tracker.
Fix GH-7815: php_uname doesn't recognise latest Windows versions
Fix #55371: get_magic_quotes_gpc() throws deprecation warning
See Git workflow for details on how pull requests are merged.
Guidelines for contributors
See further documents in the repository for more information on how to contribute:
- Contributing to PHP
- PHP coding standards
- Internal documentation
- Mailing list rules
- PHP release process
Credits
For the list of people who've put work into PHP, please see the PHP credits page.