compiler_-_php010.pdf

Transcript

1. 1 Joshua Thijssen jaytaph an introduction into compilers, interpreters and JIT From source to code
2. Computers don't understand: 2 http://blog.ruslans.com/2012_11_01_archive.html
3. 56e9 5200 4641 4c46 5245 0020 0102 0001 e002 4000 f00b 0009 0012 0002 0000 0000 0000 0000 0000 ef29 adbe 52de 4641 4c46 5245 2020 2020 4146 3154 2032 2020 6152 6666 656c 4f72 3a53 0020 414e 454d 2053 2020 4144 0054 4900 fa37 c031 d88e c08e d08e 00bc fb7c 3ebe e87c 0117 00bb b880 0001 12bf e800 00a3 00bb b8a4 0013 0ebf e800 0097 bffc a400 4abe b97c 000b f357 5fa6 0d74 c781 0020 ff81 c000 ea76 fde9 8bff 1c45 55a3 bb7c c000 458b 501a abe8 5800 c381 0200 8953 d1c3 01eb 8bc3 0097 5b80 01a9 7500 8107 ffe2 e90f 0003 eac1 8104 f0fa 890f 72d0 31d4 cdc0 001a 5716 e87c 0088 ff25 8900 bec3 c000 f789 3e03 7c55 0ab4 2588 cbfe 0f74 39ac 7cfe be03 c000 0a3c f074 f1e9 56ff b046 3a0a 7504 c6f9 0004 e85e 006b fde9 50ff 0ae8 5800 c381 0200 4f40 f375 89c3 81e5 08ec be00 0012 d231 f6f7 c2fe 5688 beff 0002 d231 f6f7 5688 89fe fc46 01b0 6e8a 8afc fe76 4e8a b2ff b400 cd02 8913 c3ec 022d 3100 b1c9 f701 05e1 0021 bee8 c3ff 57a1 ba7c 8405 e2f7 063b 7c57 0375 d488 a340 7c57 d089 acc3 003c 0a74 0eb4 07bb cd00 e910 fff1 90c3 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 aa55 3
4. 56e9 5200 4641 4c46 5245 0020 0102 0001 e002 4000 f00b 0009 0012 0002 0000 0000 0000 0000 0000 ef29 adbe 52de 4641 4c46 5245 2020 2020 4146 3154 2032 2020 6152 6666 656c 4f72 3a53 0020 414e 454d 2053 2020 4144 0054 4900 fa37 c031 d88e c08e d08e 00bc fb7c 3ebe e87c 0117 00bb b880 0001 12bf e800 00a3 00bb b8a4 0013 0ebf e800 0097 bffc a400 4abe b97c 000b f357 5fa6 0d74 c781 0020 ff81 c000 ea76 fde9 8bff 1c45 55a3 bb7c c000 458b 501a abe8 5800 c381 0200 8953 d1c3 01eb 8bc3 0097 5b80 01a9 7500 8107 ffe2 e90f 0003 eac1 8104 f0fa 890f 72d0 31d4 cdc0 001a 5716 e87c 0088 ff25 8900 bec3 c000 f789 3e03 7c55 0ab4 2588 cbfe 0f74 39ac 7cfe be03 c000 0a3c f074 f1e9 56ff b046 3a0a 7504 c6f9 0004 e85e 006b fde9 50ff 0ae8 5800 c381 0200 4f40 f375 89c3 81e5 08ec be00 0012 d231 f6f7 c2fe 5688 beff 0002 d231 f6f7 5688 89fe fc46 01b0 6e8a 8afc fe76 4e8a b2ff b400 cd02 8913 c3ec 022d 3100 b1c9 f701 05e1 0021 bee8 c3ff 57a1 ba7c 8405 e2f7 063b 7c57 0375 d488 a340 7c57 d089 acc3 003c 0a74 0eb4 07bb cd00 e910 fff1 90c3 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 9090 aa55 3
5. 4 mov ax, [di + 0x1A] ; Here starts FAT clusters loadClusters: push ax call ReadCluster pop ax add bx, 512 ; Next sector push bx mov bx, ax shr bx, 1 add bx, ax mov dx, [0x8000 + bx] pop bx test ax, 0x01 jnz oddCluster evenCluster: and dx, 0x0FFF jmp testCluster oddCluster: shr dx, 4 testCluster: cmp dx, 0xFF0 mov ax, dx jb loadClusters https://github.com/domcode/rafflers/blob/master/jaytaph-bootsector-asm/raffler.S
6. 1 static void out_string(conn *c, const char *str) { 2 size_t len; 3 4 assert(c != NULL); 5 6 if (c->noreply) { 7 if (settings.verbose > 1) 8 fprintf(stderr, ">%d NOREPLY %s\n", c->sfd, str); 9 c->noreply = false; 10 conn_set_state(c, conn_new_cmd); 11 return; 12 } 13 14 if (settings.verbose > 1) 15 fprintf(stderr, ">%d %s\n", c->sfd, str); 16 17 /* Nuke a partial output... */ 18 c->msgcurr = 0; 19 c->msgused = 0; 20 c->iovused = 0; 21 add_msghdr(c); 22 23 len = strlen(str); 24 if ((len + 2) > c->wsize) { 25 /* ought to be always enough. just fail for simplicity */ 26 str = "SERVER_ERROR output line too long"; 27 len = strlen(str); 28 } 29 30 memcpy(c->wbuf, str, len); 31 memcpy(c->wbuf + len, "\r\n", 2); 5 https://github.com/memcached/memcached/blob/master/memcached.c
7. 1 <?php 2 3 if (! isset($_POST['email'])) { 4 die("Need mail"); 5 } 6 7 $email_to = "johndoe@example.org"; 8 $email_subject = "subject line"; 9 10 // What could possibly go wrong here... 11 $email_message = $_POST['email']; 12 13 @mail($email_to, $email_subject, $email_message); 6
8. Let's write a language (in 5 minutes or less) 7
9. 8 set a 1 set b 2 add a b c print c
10. 8 set a 1 set b 2 add a b c print c operator
11. 8 set a 1 set b 2 add a b c print c operator operands
12. 8 set a 1 set b 2 add a b c print c 1 <?php 2 3 $vars = array(); 4 5 $lines = file("example.010"); 6 7 foreach ($lines as $line) { 8 $line = explode(" ", trim($line)); 9 switch ($line[0]) { 10 case "set" : 11 $vars[$line[1]] = $line[2]; 12 break; 13 case "add" : 14 $vars[$line[3]] = $vars[$line[1]] + $vars[$line[2]]; 15 break; 16 case "print" : 17 echo $vars[$line[1]]; 18 break; 19 } 20 } operator operands
13. 9 Interpreter
15. 10 ➡ Runs directly from the source.
16. 10 ➡ Runs directly from the source. ➡ Platform agnostic.
17. 10 ➡ Runs directly from the source. ➡ Platform agnostic. ➡ Runtime checks.
18. 10 ➡ Runs directly from the source. ➡ Platform agnostic. ➡ Runtime checks. ➡ Slow.
19. 10 ➡ Runs directly from the source. ➡ Platform agnostic. ➡ Runtime checks. ➡ Slow. ➡ Every instruction interpreted over and over again.
20. 11 PHP is an interpreted language (for now)
21. What if: we could convert our source code into machine code? 12
22. Compiler 13
23. Pro 14
24. Pro 14 ➡ Compiles source into machine code.
25. Pro 14 ➡ Compiles source into machine code. ➡ Runs very fast (no "layers" in between).
26. Pro 14 ➡ Compiles source into machine code. ➡ Runs very fast (no "layers" in between). ➡ No need for the source code.
27. Pro 14 ➡ Compiles source into machine code. ➡ Runs very fast (no "layers" in between). ➡ No need for the source code. ➡ Optimized for the running platform.
28. Cons 15
29. Cons ➡ Can ONLY run on the compiled architecture (x64, arm, sparc etc). 15
30. Cons ➡ Can ONLY run on the compiled architecture (x64, arm, sparc etc). ➡ A change in the source code means a recompilation is needed. 15
31. Cons ➡ Can ONLY run on the compiled architecture (x64, arm, sparc etc). ➡ A change in the source code means a recompilation is needed. ➡ 15
33. 17 http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-manual-325462.pdf
34. This is why sane people do not write compilers* 18 * I'm currently writing a compiler.
36. Hybrid system 20
38. 21 ➡ We compile source code to an intermediate code.
39. 21 ➡ We compile source code to an intermediate code. ➡ Run this intermediate code in a specialized interpreter.
40. 21 ➡ We compile source code to an intermediate code. ➡ Run this intermediate code in a specialized interpreter. ➡ Faster interpretation.
42. 22 <?php function foo() { $i = 1; $i = $i + 1; return $i; } line #* E I O op ext return operands --------------------------------------------------- 4 0 E > ASSIGN !0, 1 5 1 ADD ~2 !0, 1 2 ASSIGN !0, ~2 6 3 > RETURN !0 7 4* > RETURN null PHP
43. 22 <?php function foo() { $i = 1; $i = $i + 1; return $i; } line #* E I O op ext return operands --------------------------------------------------- 4 0 E > ASSIGN !0, 1 5 1 ADD ~2 !0, 1 2 ASSIGN !0, ~2 6 3 > RETURN !0 7 4* > RETURN null PHP def foo(): i = 1 i = i + 1 return i 4 0 LOAD_CONST 1 (1) 3 STORE_FAST 0 (i) 5 6 LOAD_FAST 0 (i) 9 LOAD_CONST 1 (1) 12 BINARY_ADD 13 STORE_FAST 0 (i) 6 16 LOAD_FAST 0 (i) 19 RETURN_VALUE PYTHON
44. 23 compile PHP to bytecode Run PHP bytecode read PHP file into memory
45. 24 compile PHP to bytecode Run PHP bytecode read PHP file into memory
46. 24 compile PHP to bytecode Run PHP bytecode read PHP file into memory OPCache
47. 25 compile PHP to bytecode read PHP file into memory OPCache Run PHP bytecode
48. JIT ( just in time ) 26
50. ➡ Compiles to native machine code at runtime. 27
51. ➡ Compiles to native machine code at runtime. ➡ Compiles per function /method 27
52. ➡ Compiles to native machine code at runtime. ➡ Compiles per function /method ➡ Or, compiles code block. 27
53. ➡ Compiles to native machine code at runtime. ➡ Compiles per function /method ➡ Or, compiles code block. ➡ Or, only compiles on multiple calls. 27
54. ➡ Compiles to native machine code at runtime. ➡ Compiles per function /method ➡ Or, compiles code block. ➡ Or, only compiles on multiple calls. ➡ Or, interprets, compiles in the background, and switches to compiled code when compilation is finished. 27
55. init(); $a = 1; for ($i=0; $i!=1000; $i++) { // very CPU consuming functions $a = $i / 100 * sqrt($i / 163.21) + foobar($i)); echo $a; } 28
57. 29 ➡ We don't have to "wait" for compilation.
58. 29 ➡ We don't have to "wait" for compilation. ➡ Still runs fast (as in binary code).
59. 29 ➡ We don't have to "wait" for compilation. ➡ Still runs fast (as in binary code). ➡ Can optimize even better than pre- compilation (it has more context).
60. PHP7 30
61. 31 Lexing & Parsing Bytecode Compilation Execution
62. 32 AST Generation Bytecode Compiliation Execution Lexing & Parsing
63. 33 AST Generation Bytecode Compiliation Execution Lexing & parsing Whatever you want to do
64. 34 Abstract Syntax Tree https://upload.wikimedia.org/wikipedia/commons/thumb/c/c7/Abstract_syntax_tree_for_Euclidean_algorithm.svg/400px-Abstract_syntax_tree_for_Euclidean_algorithm.svg.png while ($b != 0) { if ($a > $b) { $a = $a - $b; } else { $b = $b - $a; } } return $a;
65. 35 ➡ Make changes to the tree (eg: remove all else-statements) ➡ Convert code back to older versions or other language (transpiling) ➡ Analyze code ➡ Optimize code
66. 36 ➡ JIT system (other than HHVM) ➡ LLVM ? ➡ Bytecode interchange ? ➡ PhpPhp (php interpreter written in php?) The future
67. http://farm1.static.flickr.com/73/163450213_18478d3aa6_d.jpg 37
68. 38 Find me on twitter: @jaytaph Find me for development and training: www.noxlogic.nl / www.techademy.nl Find me on email: jthijssen@noxlogic.nl Find me for blogs: www.adayinthelifeof.nl