mu - Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.

	Commit message (Collapse)	Author	Age	Files	Lines
*	5629	Kartik Agaram	2019-09-06	1	-3/+3
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*	5592 - switch register names to lowercase	Kartik Agaram	2019-08-26	1	-81/+81
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*	5582	Kartik Agaram	2019-08-25	1	-6/+93
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*	5490	Kartik Agaram	2019-07-27	1	-2/+2
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*	5485 - promote SubX to top-level	Kartik Agaram	2019-07-27	1	-0/+353

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Mu - apps/factorial.subx</title> <meta name="Generator" content="Vim/8.1"> <meta name="plugin-version" content="vim8.1_v1"> <meta name="syntax" content="none"> <meta name="settings" content="number_lines,use_css,no_foldcolumn,expand_tabs,line_ids,prevent_copy="> <meta name="colorscheme" content="minimal-light"> <style type="text/css">  </style> <script type='text/javascript'>  </script> </head> <body onload='JumpToLine();'> <a href='https://github.com/akkartik/mu/blob/master/apps/factorial.subx'>https://github.com/akkartik/mu/blob/master/apps/factorial.subx</a> <pre id='vimCodeElement'> 1 ## compute the factorial of 5, and return the result in the exit code 2 # 3 # To run: 4 # $ ./subx translate init.linux 0*.subx apps/factorial.subx -o apps/factorial 5 # $ ./subx run apps/factorial 6 # Expected result: 7 # $ echo $? 8 # 120 9 # 10 # You can also run the automated test suite: 11 # $ ./subx run apps/factorial test 12 # Expected output: 13 # ........ 14 # Every '.' indicates a passing test. Failing tests get a 'F'. 15 16 == code 17 # instruction effective address register displacement immediate 18 # . op subop mod rm32 base index scale r32 19 # . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes 20 21 Entry: # run tests if necessary, compute `factorial(5)` if not 22 # . prolog 23 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp 24 25 # initialize heap 26 # . Heap = new-segment(Heap-size) 27 # . . push args 28 68/push <a href='../069allocate.subx.html#L22'>Heap</a>/imm32 29 68/push <a href='../069allocate.subx.html#L29'>Heap-size</a>/imm32 30 # . . call 31 e8/call <a href='../053new-segment.subx.html#L41'>new-segment</a>/disp32 32 # . . discard args 33 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp 34 35 # - if argc > 1 and argv[1] == "test", then return run_tests() 36 # if (argc <= 1) goto run-main 37 81 7/subop/compare 1/mod/*+disp8 5/rm32/ebp . . . . 0/disp8 1/imm32 # compare *ebp 38 7e/jump-if-lesser-or-equal $run-main/disp8 39 # if (!kernel-string-equal?(argv[1], "test")) goto run-main 40 # . eax = kernel-string-equal?(argv[1], "test") 41 # . . push args 42 68/push "test"/imm32 43 ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8) 44 # . . call 45 e8/call <a href='../052kernel-string-equal.subx.html#L31'>kernel-string-equal?</a>/disp32 46 # . . discard args 47 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp 48 # . if (eax == 0) goto run-main 49 3d/compare-eax-and 0/imm32 50 74/jump-if-equal $run-main/disp8 51 # run-tests() 52 e8/call run-tests/disp32 53 # syscall(exit, *Num-test-failures) 54 8b/copy 0/mod/indirect 5/rm32/.disp32 . . 3/r32/ebx <a href='../051test.subx.html#L90'>Num-test-failures</a>/disp32 # copy *Num-test-failures to ebx 55 eb/jump $main:end/disp8 56 $run-main: 57 # - otherwise return factorial(5) 58 # eax = factorial(5) 59 # . . push args 60 68/push 5/imm32 61 # . . call 62 e8/call <a href='factorial.subx.html#L71'>factorial</a>/disp32 63 # . . discard args 64 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp 65 # syscall(exit, eax) 66 89/copy 3/mod/direct 3/rm32/ebx . . . 0/r32/eax . . # copy eax to ebx 67 $main:end: 68 b8/copy-to-eax 1/imm32/exit 69 cd/syscall 0x80/imm8 70 71 factorial: # n : int -> int/eax 72 # . prolog 73 55/push-ebp 74 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp 75 53/push-ebx 76 # if (n <= 1) return 1 77 b8/copy-to-eax 1/imm32 78 81 7/subop/compare 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 1/imm32 # compare *(ebp+8) 79 7e/jump-if-<= $factorial:end/disp8 80 # ebx = n-1 81 8b/copy 1/mod/*+disp8 5/rm32/ebp . . 3/r32/ebx 8/disp8 . # copy *(ebp+8) to ebx 82 81 5/subop/subtract 3/mod/direct 3/rm32/ebx . . . . . 1/imm32 # subtract from ebx 83 # eax = factorial(n-1) 84 # . . push args 85 53/push-ebx 86 # . . call 87 e8/call <a href='factorial.subx.html#L71'>factorial</a>/disp32 88 # . . discard args 89 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp 90 # return n * factorial(n-1) 91 f7 4/subop/multiply 1/mod/*+disp8 5/rm32/ebp . . 8/disp8 . # multiply *(ebp+8) into eax 92 # TODO: check for overflow 93 $factorial:end: 94 # . epilog 95 5b/pop-to-ebx 96 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 97 5d/pop-to-ebp 98 c3/return 99 100 test-factorial: 101 # factorial(5) 102 # . . push args 103 68/push 5/imm32 104 # . . call 105 e8/call <a href='factorial.subx.html#L71'>factorial</a>/disp32 106 # . . discard args 107 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp 108 # check-ints-equal(eax, 120, msg) 109 # . . push args 110 68/push "F - test-factorial"/imm32 111 68/push 0x78/imm32/expected-120 112 50/push-eax 113 # . . call 114 e8/call <a href='../051test.subx.html#L24'>check-ints-equal</a>/disp32 115 # . . discard args 116 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp 117 # end 118 c3/return 119 120 # . . vim:nowrap:textwidth=0 </pre> </body> </html>