compiler_-_php010.pdf

Transcript

1. 1
   Joshua Thijssen
   jaytaph
   an introduction into compilers, interpreters and JIT
   From source to code
   

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2. Computers don't understand:
   2
   http://blog.ruslans.com/2012_11_01_archive.html
   

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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
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   3
   

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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
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   9090 9090 9090 9090 9090 9090 9090 9090
   9090 9090 9090 9090 9090 9090 9090 aa55
   3
   

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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
   

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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
   

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7. 1 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
   

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8. Let's write a language
   (in 5 minutes or less)
   7
   

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9. 8
   set a 1
   set b 2
   add a b c
   print c
   

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10. 8
    set a 1
    set b 2
    add a b c
    print c
    operator
    

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11. 8
    set a 1
    set b 2
    add a b c
    print c
    operator operands
    

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12. 8
    set a 1
    set b 2
    add a b c
    print c
    1 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
    

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13. 9
    Interpreter
    

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15. 10
    ➡ Runs directly from the source.
    

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16. 10
    ➡ Runs directly from the source.
    ➡ Platform agnostic.
    

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17. 10
    ➡ Runs directly from the source.
    ➡ Platform agnostic.
    ➡ Runtime checks.
    

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18. 10
    ➡ Runs directly from the source.
    ➡ Platform agnostic.
    ➡ Runtime checks.
    ➡ Slow.
    

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19. 10
    ➡ Runs directly from the source.
    ➡ Platform agnostic.
    ➡ Runtime checks.
    ➡ Slow.
    ➡ Every instruction interpreted over and over
    again.
    

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20. 11
    PHP is an
    interpreted language
    (for now)
    

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21. What if:
    we could convert our
    source code into
    machine code?
    12
    

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22. Compiler
    13
    

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23. Pro
    14
    

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24. Pro
    14
    ➡ Compiles source into machine code.
    

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25. Pro
    14
    ➡ Compiles source into machine code.
    ➡ Runs very fast (no "layers" in between).
    

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26. Pro
    14
    ➡ Compiles source into machine code.
    ➡ Runs very fast (no "layers" in between).
    ➡ No need for the source code.
    

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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.
    

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28. Cons
    15
    

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29. Cons
    ➡ Can ONLY run on the compiled
    architecture (x64, arm, sparc etc).
    15
    

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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
    

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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
    

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32. View Slide

33. 17
    http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-manual-325462.pdf
    

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34. This is why sane people do
    not write compilers*
    18
    * I'm currently writing a compiler.
    

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35. View Slide

36. Hybrid system
    20
    

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37. View Slide

38. 21
    ➡ We compile source code to an
    intermediate code.
    

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39. 21
    ➡ We compile source code to an
    intermediate code.
    ➡ Run this intermediate code in a specialized
    interpreter.
    

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40. 21
    ➡ We compile source code to an
    intermediate code.
    ➡ Run this intermediate code in a specialized
    interpreter.
    ➡ Faster interpretation.
    

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41. View Slide

42. 22
    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
    

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43. 22
    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
    

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44. 23
    compile PHP to
    bytecode
    Run PHP bytecode
    read PHP file into
    memory
    

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45. 24
    compile PHP to
    bytecode
    Run PHP bytecode
    read PHP file into
    memory
    

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46. 24
    compile PHP to
    bytecode
    Run PHP bytecode
    read PHP file into
    memory
    OPCache
    

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47. 25
    compile PHP to
    bytecode
    read PHP file into
    memory
    OPCache
    Run PHP bytecode
    

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48. JIT
    ( just in time )
    26
    

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49. View Slide

50. ➡ Compiles to native machine code at
    runtime.
    27
    

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51. ➡ Compiles to native machine code at
    runtime.
    ➡ Compiles per function /method
    27
    

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52. ➡ Compiles to native machine code at
    runtime.
    ➡ Compiles per function /method
    ➡ Or, compiles code block.
    27
    

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53. ➡ Compiles to native machine code at
    runtime.
    ➡ Compiles per function /method
    ➡ Or, compiles code block.
    ➡ Or, only compiles on multiple calls.
    27
    

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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
    

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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
    

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56. View Slide

57. 29
    ➡ We don't have to "wait" for compilation.
    

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58. 29
    ➡ We don't have to "wait" for compilation.
    ➡ Still runs fast (as in binary code).
    

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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).
    

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60. PHP7
    30
    

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61. 31
    Lexing &
    Parsing
    Bytecode
    Compilation
    Execution
    

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62. 32
    AST Generation
    Bytecode
    Compiliation
    Execution
    Lexing &
    Parsing
    

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63. 33
    AST Generation
    Bytecode
    Compiliation
    Execution
    Lexing &
    parsing
    Whatever
    you want to do
    

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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;
    

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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
    

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66. 36
    ➡ JIT system (other than HHVM)
    ➡ LLVM ?
    ➡ Bytecode interchange ?
    ➡ PhpPhp (php interpreter written in php?)
    The future
    

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67. http://farm1.static.flickr.com/73/163450213_18478d3aa6_d.jpg 37
    

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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
    

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