PHP 7 provides major performance improvements over previous versions through a refactored engine. It focuses on optimizing core functions and data structures like ZVAL and HashTable to reduce CPU and memory overhead. Some key optimizations include using an Abstract Syntax Tree, improving integer handling, making function calls more efficient, and enhancing the memory manager. Benchmark tests show PHP 7 can be over 5 times faster than PHP 5 for simple tests and around 2 times faster for real-world applications like WordPress. The goal is to achieve a new level of PHP performance while maintaining 100% compatibility.

1. PHP 7
- New Engine For The Good Old Train
@laruence

2. About Me
• Author of Yaf, Yar, Yac, Taint, Lua, etc
• Maintainer of APC, Zend Opcache, Msgpack, etc
• Chief software architect At Weibo since 2012
• PHP core developer since 2011
• Zend consultant since 2013
• Core author of PHP7

3. About PHP
• 20 years history
• Most popular Web service program language
• Over 82% sites are use PHP as server program language

4. PHP 7 New Features

5. PHP 7?
• PHP NG – Engine Refactor - performance improvements
• Abstarct Syntanx Tree
• Int64 Improvement
• Uniform variable syntax
• Native TLS
• Consistently foreach behaviors
• New <=>, **, ?? operaters
• Return Type Declarations
• Scalar Type Declarations
• Exceptions in Engine
• And Dozens features…

6. Abstract Syntax Tree
PHP
Parser
AST
Opcodes
Execution
PHP
Parser
Opcodes
Execution
• PHP5
• PHP7

7. Int64 Improvement
• >2GB string
• >2GB file uploading
• Fully 64bits intgers cross platforms

8. Uniform Variables Syntanx
• $foo()['bar']()
• $foo['bar']::$baz
• foo()() – (foo())()
• $foo->bar()::baz()
• (function() { ... })()
• $this->{$name}()
• [$obj, 'method']()
• Foo::$bar['baz']()
PHP5: Foo::{$bar['baz']}()
PHP7: (Foo::$bar)['baz']()

9. Return Type Declarations
• function foo(): array {
return [];
}
• interface A {
static function make(): A;
}
• function foo(): DateTime {
return null;
}
PHP Fatal error: Return value of foo() must be an instance of DateTime, null returned

10. Scalar Type Declarations
• function foo(int num)
• function bar (string name)
• function foobar() : float {}
• function add(int l, int r) : int {}
• class A {
public function start (bool start) {}
}

11. Exceptions in Engine
• Use of exceptions in Engine
try {
non_exists_func();
} catch (EngineException $e) {
echo "Exception: {$e->getMessage()}n";
}
Exception: Call to undefined function non_exists_func()
• Uncaught Exception result to FATAL ERROR
non_exists_func();
PHP Fatal error: Call to undefined function non_exists()

12. PHP NG (Next Generation)

13. PHP Performance Evaluation
2.991
3.045
3.102
3.762
5.318
6.527
13.424
0 2 4 6 8 10 12 14 16
PHP-5.6
PHP-5.5
PHP-5.4
PHP-5.3
PHP-5.2
PHP-5.1
PHP-5.0
bench.php(sec)

14. PHP Performance Evaluation
112
110
107
82
75
0
0
0 20 40 60 80 100 120
PHP-5.6
PHP-5.5
PHP-5.4
PHP-5.3
PHP-5.2
PHP-5.1
PHP-5.0
Wordpress 3.6 home page qps

15. PHP Performance Evaluation
• ~5 times faster from 5.0 to 5.6 in bench
• ~2 times faster from 5.0 to 5.6 in real-life apps
• No big performance improvement after 5.4
• Zend VM is already highly optimized

16. • Generate optimized codes based on run-time types inference
PHP Just In Time Compiler?
PHP
Parser
Opcodes
TypeInf
JIT
Bytecodes
Execution

17. PHP Just In Time Compiler?
• We created a POC of JIT compiler based on LLVM for PHP-5.5 in 2013
• ~8 times speedup on bench.php
• Negligible speedup on real-life apps (1% on Wordpress)
• https://github.com/zendtech/php-src/tree/zend-jit

18. Wordpress profile

19. • 21% CPU time in meory manager
• 12% CPU time in hash tables operations
• 30% CPU time in internal functions
• 25% CPU time in VM
Wordpress profile

20. New Generation
• It’s a refactoring
• Main goal — achieve new performance level and make base for future
improvements
• No new features for users (only internals)
• Keep 100% compatibility in PHP behavior
• May 2014 we opened the project

21. ZVAL
• Zval is changed

22. ZVAL
• No refcount for scalar types
• zvals are always pre-allcocated or allocated in stack(nomore
MAKE_STD_ZVAL and ALLOC_ZVAL)
• String using refcout instead of copy (zend_string)
• gc_info, temporary_variables, should_free_var, cache_slot all in zval
• New types: IS_TRUE, IS_FALSE, IS_REFERENCE, IS_INDIRECT
Zend VM
execute data
Internal Functions
zval zval zval zval zval
Uesr land
zend array
zval zval zval zval zval
stack zvals
zval zval zval zval zval

23. • IS_UNDEF
• IS_NULL
• IS_FALSE
• IS_TRUE
• IS_LONG
• IS_DOUBLE
• IS_STRING
• IS_ARRAY
• IS_OBJECT
• IS_RESOURCE
• IS_REFERENCE
ZVAL
v28u4
tAp4 u2f826s
0 8 32 63
IS_S.RING/IS_ARRA0/IS_OBJEC./IS_RESRO/CE/...
r4f3ount 63_infotAp4
0 32 63
f826s
48

24. • IS_NULL
• IS_FALSE
• IS_TRUE
• IS_LONG
• IS_DOUBLE
ZVAL NON REFCOUNED
value
type u2flags
0 8 32 63

25. • IS_STRING
• IS_ARRAY
• IS_OBJECT
• IS_RESOURCE
• IS_REFERENCE
ZVAL REFCOUNED
IS_S.RING/IS_ARRA0/IS_OBJEC./IS_RESRO/CE/...
r4f3ount 63_infotyp4
0 32 63
f826s
48

26. • New Internal Type: Zend String
IS_STRING
• IS_STRING_PERSISTENT
• IS_STR_INTERNED
• IS_STR_PERMANENT
• IS_STR_CONSTANT
un3igned l0ng ha3h_6alue
2efc0un4 gc_inf04y1e
0 32 63
flag3
48
3i8e_4 342ing_len
cha2[  ] 6al

27. • New Internal Type: Zend Array
IS_ARRAY
• IS_ARRAY_IMMUTABLE
refcount gc_infotype
0 32 63
flags
48
nTableMasku
Bucket *arData
nNumUsed nNumOfElements
.....

28. IS_OBJECT
• Zend Object
• IS_OBJ_APPLY_COUNT
• IS_OBJ_DESTRUCTOR_CALLED
• IS_OBJ_FREE_CALLED
zend_class_entry *ce
refcount gc_infotype
0 32 63
flags
48
zend_object_handlers *handlers
zend_array *properties
zend_array *guarders
zval *properties_table[1]

29. • New Internal Type: Zend Reference
• Reference is type
IS_REFERENCE
refco0nt gc_infot2pe
0 3  63
flags
48
3val val0e

30. HashTable – PHP 5
HashTable
nTableMasknTableSize
0 8 32 63
pInternalPointer
nNumOfElem
nNextFreeElement
Bucket *
pListHead
pListTail
arBuckets
pDestructor
Bucket *
Bucket *
.......
Bucket
hashval
nKeyLength
pDataPtr
pData
pListNext
pListPrev
pNext
pLast
arKey
Bucket
hashval
nKeyLength
pDataPtr
pData
pListNext
pListPrev
pNext
pLast
arKey
Zval
value
type

31. Zend Array – PHP 7
zend_array
refcounted
0 8 32 63
u
arData
idx
idx
Bucket 0
nTableMask
nNumUsed nNumOfElem
nTableSize InternalPointer
pNextFreeElement
pDestructor
.......
hashval
key
zval
Bucket 1
hashval
key
zval
Bucket 2 ......

32. Zend Array(HashTable)
• Values of arrays are zval by default
• HashTable size reduced from 72 to 56 bytes
• Bucket size reduced from 72 to 32 bytes
• Memory for all Buckets is allocated at once
• Bucket.key now is a pointer to zend_string
• Values of array elements are embedded into the Buckets
• Improved data locality => less CPU cache misses

33. Function calling convention – PHP5
• function add ($a, $b) {
return $a + $b;
}
add(1, 2);
send_val 1
send_val 2
do_fcall add (2)
1
2
call frame(add)
opcodes(main):
call frame(main)
recv 1 $a
recv 2 $b
zend_add $a, $b ~0
opcodes(add):
zend_return ~0
1
2
3
vm stack

34. Function calling convention – PHP7
• function add ($a, $b) {
return $a + $b;
}
add(1, 2);
send_val 1
send_val 2
do_fcall 2
call frame(add)
init_fcall add
call frame(main)
recv 1 $a
recv 2 $b
zend_add $a, $b ~0
opcodes(add):
zend_return ~0
1
2
3
vm stack

35. Fast Parameters Parsing APIs
• ~5% of the CPU time is spent in zend_parse_parameters()
• For some simple functions the overhead of zend_parse_parameters() is
over 90%

36. Inline Frequently used simple functions
• call_user_function(_array) => ZEND_INIT_USER_CALL
• is_int/string/array/* etc => ZEND_TYPE_CHECK
• strlen => ZEND_STRLEN
• defined => ZEND+DEFINED
• …

37. Faster zend_qsort
• Refactor zend_qsort for better performance
• Hybrid Sorting Algo(Quick Sort and Selection Sort)
• <16 elements do stable sorting
• $array = array(0 => 0, 1=>0); asort($array);
• PHP5: array(1=>0, 0=>0);
• PHP7: array(0=>1, 1=>0);

38. New Memory Manager
• Friendly to moder CPU cache
• less CPU cache misses
• Faster builtin types allocating
• ~5% CPU time reduce in wordpress homepage

39. Dozens of other improvements
• Fast HashTable iteration APIs
• Immutable array
• Array duplication optimization
• PCRE with JIT
• BIND_GLOBAL instead of FETCH and ASSIGN_REF
• More specifical DO_UCALL and DO_ICALL
• Global registers for execute_data and opline(GCC-4.8+)
• ZEND_ROPE_* for faster string concating
• ZEND_CALL_TRAMPOLINE for faster__call/__callstatic
• Dozens logic optimizations
• ….

40. Wordpress profile (2015-04-14)

41. Wordpress profiled (2015-04-14)
• >50% CPU IRs reduced
• 5% CPU time in meory manager
• 12% CPU time in hash tables operations

42. PHP7 Performance – Benchmark (2014-04-14)
1.186
2.991
3.045
3.102
3.762
5.318
6.527
13.424
0 2 4 6 8 10 12 14 16
PHP-7
PHP-5.6
PHP-5.5
PHP-5.4
PHP-5.3
PHP-5.2
PHP-5.1
PHP-5.0
bench.php(sec)

43. PHP7 Performance – Reallife App (2015-04-14)
311
112
110
107
82
75
0
0
0 50 100 150 200 250 300 350
PHP-7
PHP-5.6
PHP-5.5
PHP-5.4
PHP-5.3
PHP-5.2
PHP-5.1
PHP-5.0
wordpress 3.0.1 home page qps

44. PHP7 Performance (By Rasmus 2015-04-21)

45. PHP7 Performance (2015-04-21)

46. PHP7 Performance (2015-04-21)

47. PHP7 Performance (2015-03-15)

48. Always Do Your Own Benchmark

49. PHP 7 Next
• Keep 99.99% compatible with PHP5
• Keep Improving performance
• Port common used PECL extensions (memcached, redis etc)
• Release PHP 7 (oct 2015)
• Restart JIT (Sep 2014)

50. Links
• phpng:_Refactored_PHP_Engine_with_Big_Performance_Improveme
nt: http://news.php.net/php.internals/73888
• PHPNG RFC: https://wiki.php.net/phpng
• PHPNG Implementation details: https://wiki.php.net/phpng-int
• Upgrading PHP extensions from PHP5 to PHPNG:
https://wiki.php.net/phpng-upgrading
• Zeev <Benchmarking PHPNG>:
http://zsuraski.blogspot.co.il/2014/07/benchmarking-phpng.html
• Rasmus <SPEEDING UP THE WEB WITH PHP 7>:
http://talks.php.net/fluent15#/

51. Questions?
Thanks