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Diffstat (limited to 'html/subx/apps/factorial.subx.html')
| -rw-r--r-- | html/subx/apps/factorial.subx.html | 258 |
1 files changed, 196 insertions, 62 deletions
diff --git a/html/subx/apps/factorial.subx.html b/html/subx/apps/factorial.subx.html index 1fa6a4e3..3b03150d 100644 --- a/html/subx/apps/factorial.subx.html +++ b/html/subx/apps/factorial.subx.html @@ -54,68 +54,202 @@ if ('onhashchange' in window) { </head> <body onload='JumpToLine();'> <pre id='vimCodeElement'> -<span id="L1" class="LineNr"> 1 </span><span class="SalientComment">## compute the factorial of 5, and return the result in the exit code</span> -<span id="L2" class="LineNr"> 2 </span><span class="Comment">#</span> -<span id="L3" class="LineNr"> 3 </span><span class="Comment"># To run:</span> -<span id="L4" class="LineNr"> 4 </span><span class="Comment"># $ subx translate apps/factorial.subx apps/factorial</span> -<span id="L5" class="LineNr"> 5 </span><span class="Comment"># $ subx run apps/factorial</span> -<span id="L6" class="LineNr"> 6 </span><span class="Comment"># Expected result:</span> -<span id="L7" class="LineNr"> 7 </span><span class="Comment"># $ echo $?</span> -<span id="L8" class="LineNr"> 8 </span><span class="Comment"># 120</span> -<span id="L9" class="LineNr"> 9 </span> -<span id="L10" class="LineNr">10 </span>== code -<span id="L11" class="LineNr">11 </span><span class="Comment"># instruction effective address operand displacement immediate</span> -<span id="L12" class="LineNr">12 </span><span class="Comment"># op subop mod rm32 base index scale r32</span> -<span id="L13" class="LineNr">13 </span><span class="Comment"># 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</span> -<span id="L14" class="LineNr">14 </span> -<span id="L15" class="LineNr">15 </span><span class="Comment"># main:</span> -<span id="L16" class="LineNr">16 </span> <span class="Comment"># prepare to make a call</span> -<span id="L17" class="LineNr">17 </span> 55/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># push EBP</span> -<span id="L18" class="LineNr">18 </span> 89/copy 3/mod/direct 5/rm32/EBP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 4/r32/ESP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># copy ESP to EBP</span> -<span id="L19" class="LineNr">19 </span> <span class="Comment"># factorial(5)</span> -<span id="L20" class="LineNr">20 </span> 68/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 5/imm32 <span class="Comment"># push 5</span> -<span id="L21" class="LineNr">21 </span> e8/call <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> factorial/disp32 -<span id="L22" class="LineNr">22 </span> <span class="Comment"># discard arg</span> -<span id="L23" class="LineNr">23 </span> 5a/pop <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># pop into EDX</span> -<span id="L24" class="LineNr">24 </span> <span class="Comment"># clean up after call</span> -<span id="L25" class="LineNr">25 </span> 89/copy 3/mod/direct 4/rm32/ESP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 5/r32/EBP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># copy EBP to ESP</span> -<span id="L26" class="LineNr">26 </span> 5d/pop <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># pop to EBP</span> -<span id="L27" class="LineNr">27 </span> -<span id="L28" class="LineNr">28 </span> <span class="Comment"># exit(EAX)</span> -<span id="L29" class="LineNr">29 </span> 89/copy 3/mod/direct 3/rm32/EBX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 0/r32/EAX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># copy EAX to EBX</span> -<span id="L30" class="LineNr">30 </span> b8/copy <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 1/imm32 <span class="Comment"># copy 1 to EAX</span> -<span id="L31" class="LineNr">31 </span> cd/syscall <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 0x80/imm8 <span class="Comment"># int 80h</span> -<span id="L32" class="LineNr">32 </span> -<span id="L33" class="LineNr">33 </span><span class="Comment"># factorial(n)</span> -<span id="L34" class="LineNr">34 </span>factorial: -<span id="L35" class="LineNr">35 </span> <span class="Comment"># initialize EAX to 1 (base case)</span> -<span id="L36" class="LineNr">36 </span> b8/copy <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 1/imm32 <span class="Comment"># copy 1 to EAX</span> -<span id="L37" class="LineNr">37 </span> <span class="Comment"># if (n <= 1) jump exit</span> -<span id="L38" class="LineNr">38 </span> 81 7/subop/compare 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 4/disp8 1/imm32 <span class="Comment"># compare *(ESP+4) with 1</span> -<span id="L39" class="LineNr">39 </span> 7e/jump-if-<= <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> $factorial:exit/disp8 <span class="Comment"># jump if <= to $factorial:exit</span> -<span id="L40" class="LineNr">40 </span> <span class="Comment"># EBX: n-1</span> -<span id="L41" class="LineNr">41 </span> 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none 3/r32/EBX 4/disp8 <span class="Delimiter"> . </span> <span class="Comment"># copy *(ESP+4) to EBX</span> -<span id="L42" class="LineNr">42 </span> 81 5/subop/subtract 3/mod/direct 3/rm32/EBX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 1/imm32 <span class="Comment"># subtract 1 from EBX</span> -<span id="L43" class="LineNr">43 </span> <span class="Comment"># prepare call</span> -<span id="L44" class="LineNr">44 </span> 55/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># push EBP</span> -<span id="L45" class="LineNr">45 </span> 89/copy 3/mod/direct 5/rm32/EBP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 4/r32/ESP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># copy ESP to EBP</span> -<span id="L46" class="LineNr">46 </span> <span class="Comment"># EAX: factorial(n-1)</span> -<span id="L47" class="LineNr">47 </span> 53/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># push EBX</span> -<span id="L48" class="LineNr">48 </span> e8/call <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> factorial/disp32 -<span id="L49" class="LineNr">49 </span> <span class="Comment"># discard arg</span> -<span id="L50" class="LineNr">50 </span> 5e/pop <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># pop into ESI</span> -<span id="L51" class="LineNr">51 </span> <span class="Comment"># clean up after call</span> -<span id="L52" class="LineNr">52 </span> 89/copy 3/mod/direct 4/rm32/ESP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 5/r32/EBP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># copy EBP to ESP</span> -<span id="L53" class="LineNr">53 </span> 5d/pop <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># pop to EBP</span> -<span id="L54" class="LineNr">54 </span> <span class="Comment"># refresh n</span> -<span id="L55" class="LineNr">55 </span> 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none 2/r32/EDX 4/disp8 <span class="Delimiter"> . </span> <span class="Comment"># copy *(ESP+4) to EDX</span> -<span id="L56" class="LineNr">56 </span> <span class="Comment"># return n * factorial(n-1)</span> -<span id="L57" class="LineNr">57 </span> f7 4/subop/multiply 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none 4/disp8 <span class="Delimiter"> . </span> <span class="Comment"># multiply *(ESP+4) (n) into EAX (factorial(n-1))</span> -<span id="L58" class="LineNr">58 </span> <span class="Comment"># TODO: check for overflow</span> -<span id="L59" class="LineNr">59 </span>$factorial:exit: -<span id="L60" class="LineNr">60 </span> c3/return -<span id="L61" class="LineNr">61 </span> -<span id="L62" class="LineNr">62 </span><span class="Comment"># vim:ft=subx:nowrap:so=0</span> +<span id="L1" class="LineNr"> 1 </span><span class="SalientComment">## compute the factorial of 5, and return the result in the exit code</span> +<span id="L2" class="LineNr"> 2 </span><span class="Comment">#</span> +<span id="L3" class="LineNr"> 3 </span><span class="Comment"># To run:</span> +<span id="L4" class="LineNr"> 4 </span><span class="Comment"># $ subx translate apps/factorial.subx apps/factorial</span> +<span id="L5" class="LineNr"> 5 </span><span class="Comment"># $ subx run apps/factorial</span> +<span id="L6" class="LineNr"> 6 </span><span class="Comment"># Expected result:</span> +<span id="L7" class="LineNr"> 7 </span><span class="Comment"># $ echo $?</span> +<span id="L8" class="LineNr"> 8 </span><span class="Comment"># 120</span> +<span id="L9" class="LineNr"> 9 </span><span class="Comment">#</span> +<span id="L10" class="LineNr"> 10 </span><span class="Comment"># You can also run an automated test (that does the exact same thing):</span> +<span id="L11" class="LineNr"> 11 </span><span class="Comment"># $ subx run apps/factorial test</span> +<span id="L12" class="LineNr"> 12 </span><span class="Comment"># Expected output:</span> +<span id="L13" class="LineNr"> 13 </span><span class="Comment"># .</span> +<span id="L14" class="LineNr"> 14 </span><span class="Comment"># Every '.' indicates a passing test. Failing tests get a 'F'.</span> +<span id="L15" class="LineNr"> 15 </span> +<span id="L16" class="LineNr"> 16 </span>== code +<span id="L17" class="LineNr"> 17 </span><span class="Comment"># instruction effective address operand displacement immediate</span> +<span id="L18" class="LineNr"> 18 </span><span class="Comment"># op subop mod rm32 base index scale r32</span> +<span id="L19" class="LineNr"> 19 </span><span class="Comment"># 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</span> +<span id="L20" class="LineNr"> 20 </span> +<span id="L21" class="LineNr"> 21 </span><span class="Comment"># main:</span> +<span id="L22" class="LineNr"> 22 </span> <span class="Comment"># if (argc > 1)</span> +<span id="L23" class="LineNr"> 23 </span> 8b/copy 0/mod/indirect 4/rm32/sib 4/base/ESP 4/index/none <span class="Delimiter"> . </span> 0/r32/EAX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># copy *ESP to EAX</span> +<span id="L24" class="LineNr"> 24 </span> 3d/compare <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 1/imm32 <span class="Comment"># compare EAX with 1</span> +<span id="L25" class="LineNr"> 25 </span> 7e/jump-if-lesser-or-equal $run_main/disp8 +<span id="L26" class="LineNr"> 26 </span> <span class="Comment"># and if (argv[1] == "test")</span> +<span id="L27" class="LineNr"> 27 </span> 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none <span class="Delimiter"> . </span> 0/r32/EAX 8/disp8 <span class="Delimiter"> . </span> <span class="Comment"># copy *(ESP+8) to EAX</span> +<span id="L28" class="LineNr"> 28 </span> <span class="Comment"># push args</span> +<span id="L29" class="LineNr"> 29 </span> 68/push Test_argv/imm32 +<span id="L30" class="LineNr"> 30 </span> 50/push-EAX +<span id="L31" class="LineNr"> 31 </span> <span class="Comment"># call</span> +<span id="L32" class="LineNr"> 32 </span> e8/call argv_equal/disp32 +<span id="L33" class="LineNr"> 33 </span> <span class="Comment"># discard args</span> +<span id="L34" class="LineNr"> 34 </span> 81 0/subop/add 3/mod/direct 4/rm32/ESP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 8/imm32 <span class="Comment"># add 8 to ESP</span> +<span id="L35" class="LineNr"> 35 </span> <span class="Comment"># check result</span> +<span id="L36" class="LineNr"> 36 </span> 3d/compare <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 1/imm32 <span class="Comment"># compare EAX with 1</span> +<span id="L37" class="LineNr"> 37 </span> 75/jump-if-not-equal $run_main/disp8 +<span id="L38" class="LineNr"> 38 </span> <span class="Comment"># then</span> +<span id="L39" class="LineNr"> 39 </span> e8/call run_tests/disp32 +<span id="L40" class="LineNr"> 40 </span> eb/jump $main_exit/disp8 +<span id="L41" class="LineNr"> 41 </span> <span class="Comment"># else EAX <- factorial(5)</span> +<span id="L42" class="LineNr"> 42 </span>$run_main: +<span id="L43" class="LineNr"> 43 </span> <span class="Comment"># push arg</span> +<span id="L44" class="LineNr"> 44 </span> 68/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 5/imm32 <span class="Comment"># push 5</span> +<span id="L45" class="LineNr"> 45 </span> <span class="Comment"># EAX <- call</span> +<span id="L46" class="LineNr"> 46 </span> e8/call <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> factorial/disp32 +<span id="L47" class="LineNr"> 47 </span> <span class="Comment"># discard arg</span> +<span id="L48" class="LineNr"> 48 </span> 81 0/subop/add 3/mod/direct 4/rm32/ESP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 4/imm32 <span class="Comment"># add 4 to ESP</span> +<span id="L49" class="LineNr"> 49 </span>$main_exit: +<span id="L50" class="LineNr"> 50 </span> <span class="Comment"># exit(EAX)</span> +<span id="L51" class="LineNr"> 51 </span> 89/copy 3/mod/direct 3/rm32/EBX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 0/r32/EAX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># copy EAX to EBX</span> +<span id="L52" class="LineNr"> 52 </span> b8/copy <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 1/imm32 <span class="Comment"># copy 1 to EAX</span> +<span id="L53" class="LineNr"> 53 </span> cd/syscall 0x80/imm8 +<span id="L54" class="LineNr"> 54 </span> +<span id="L55" class="LineNr"> 55 </span><span class="Comment"># factorial(n)</span> +<span id="L56" class="LineNr"> 56 </span>factorial: +<span id="L57" class="LineNr"> 57 </span> <span class="Comment"># initialize EAX to 1 (base case)</span> +<span id="L58" class="LineNr"> 58 </span> b8/copy <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 1/imm32 <span class="Comment"># copy 1 to EAX</span> +<span id="L59" class="LineNr"> 59 </span> <span class="Comment"># if (n <= 1) jump exit</span> +<span id="L60" class="LineNr"> 60 </span> 81 7/subop/compare 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 4/disp8 1/imm32 <span class="Comment"># compare *(ESP+4) with 1</span> +<span id="L61" class="LineNr"> 61 </span> 7e/jump-if-<= <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> $factorial:exit/disp8 <span class="Comment"># jump if <= to $factorial:exit</span> +<span id="L62" class="LineNr"> 62 </span> <span class="Comment"># EBX: n-1</span> +<span id="L63" class="LineNr"> 63 </span> 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none 3/r32/EBX 4/disp8 <span class="Delimiter"> . </span> <span class="Comment"># copy *(ESP+4) to EBX</span> +<span id="L64" class="LineNr"> 64 </span> 81 5/subop/subtract 3/mod/direct 3/rm32/EBX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 1/imm32 <span class="Comment"># subtract 1 from EBX</span> +<span id="L65" class="LineNr"> 65 </span> <span class="Comment"># prepare call</span> +<span id="L66" class="LineNr"> 66 </span> 55/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># push EBP</span> +<span id="L67" class="LineNr"> 67 </span> 89/copy 3/mod/direct 5/rm32/EBP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 4/r32/ESP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># copy ESP to EBP</span> +<span id="L68" class="LineNr"> 68 </span> <span class="Comment"># EAX: factorial(n-1)</span> +<span id="L69" class="LineNr"> 69 </span> 53/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># push EBX</span> +<span id="L70" class="LineNr"> 70 </span> e8/call <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> factorial/disp32 +<span id="L71" class="LineNr"> 71 </span> <span class="Comment"># discard arg</span> +<span id="L72" class="LineNr"> 72 </span> 81 0/subop/add 3/mod/direct 4/rm32/ESP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 4/imm32 <span class="Comment"># add 4 to ESP</span> +<span id="L73" class="LineNr"> 73 </span> <span class="Comment"># clean up after call</span> +<span id="L74" class="LineNr"> 74 </span> 89/copy 3/mod/direct 4/rm32/ESP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 5/r32/EBP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># copy EBP to ESP</span> +<span id="L75" class="LineNr"> 75 </span> 5d/pop <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># pop to EBP</span> +<span id="L76" class="LineNr"> 76 </span> <span class="Comment"># refresh n</span> +<span id="L77" class="LineNr"> 77 </span> 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none 2/r32/EDX 4/disp8 <span class="Delimiter"> . </span> <span class="Comment"># copy *(ESP+4) to EDX</span> +<span id="L78" class="LineNr"> 78 </span> <span class="Comment"># return n * factorial(n-1)</span> +<span id="L79" class="LineNr"> 79 </span> f7 4/subop/multiply 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none 4/disp8 <span class="Delimiter"> . </span> <span class="Comment"># multiply *(ESP+4) (n) into EAX (factorial(n-1))</span> +<span id="L80" class="LineNr"> 80 </span> <span class="Comment"># TODO: check for overflow</span> +<span id="L81" class="LineNr"> 81 </span>$factorial:exit: +<span id="L82" class="LineNr"> 82 </span> c3/return +<span id="L83" class="LineNr"> 83 </span> +<span id="L84" class="LineNr"> 84 </span>test_factorial: +<span id="L85" class="LineNr"> 85 </span> <span class="Comment"># factorial(5)</span> +<span id="L86" class="LineNr"> 86 </span> <span class="Comment"># push arg</span> +<span id="L87" class="LineNr"> 87 </span> 68/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 5/imm32 <span class="Comment"># push 5</span> +<span id="L88" class="LineNr"> 88 </span> <span class="Comment"># call</span> +<span id="L89" class="LineNr"> 89 </span> e8/call <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> factorial/disp32 +<span id="L90" class="LineNr"> 90 </span> <span class="Comment"># discard arg</span> +<span id="L91" class="LineNr"> 91 </span> 81 0/subop/add 3/mod/direct 4/rm32/ESP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 4/imm32 <span class="Comment"># add 4 to ESP</span> +<span id="L92" class="LineNr"> 92 </span> <span class="Comment"># if EAX == 120</span> +<span id="L93" class="LineNr"> 93 </span> 3d/compare <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 0x78/imm32/120 <span class="Comment"># compare EAX with 120</span> +<span id="L94" class="LineNr"> 94 </span> 75/jump-if-unequal <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> $test_factorial:else/disp8 +<span id="L95" class="LineNr"> 95 </span> <span class="Comment"># print('.')</span> +<span id="L96" class="LineNr"> 96 </span> <span class="Comment"># push args</span> +<span id="L97" class="LineNr"> 97 </span> 68/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> Test_passed/imm32 +<span id="L98" class="LineNr"> 98 </span> <span class="Comment"># call</span> +<span id="L99" class="LineNr"> 99 </span> e8/call <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> write_stderr/disp32 +<span id="L100" class="LineNr">100 </span> <span class="Comment"># discard arg</span> +<span id="L101" class="LineNr">101 </span> 81 0/subop/add 3/mod/direct 4/rm32/ESP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 4/imm32 <span class="Comment"># add 4 to ESP</span> +<span id="L102" class="LineNr">102 </span> <span class="Comment"># return</span> +<span id="L103" class="LineNr">103 </span> c3/return +<span id="L104" class="LineNr">104 </span> <span class="Comment"># else:</span> +<span id="L105" class="LineNr">105 </span>$test_factorial:else: +<span id="L106" class="LineNr">106 </span> <span class="Comment"># print('F')</span> +<span id="L107" class="LineNr">107 </span> <span class="Comment"># push args</span> +<span id="L108" class="LineNr">108 </span> 68/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> Test_failed/imm32 +<span id="L109" class="LineNr">109 </span> <span class="Comment"># call</span> +<span id="L110" class="LineNr">110 </span> e8/call <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> write_stderr/disp32 +<span id="L111" class="LineNr">111 </span> <span class="Comment"># discard arg</span> +<span id="L112" class="LineNr">112 </span> 81 0/subop/add 3/mod/direct 4/rm32/ESP <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 4/imm32 <span class="Comment"># add 4 to ESP</span> +<span id="L113" class="LineNr">113 </span> <span class="Comment"># end</span> +<span id="L114" class="LineNr">114 </span> c3/return +<span id="L115" class="LineNr">115 </span> +<span id="L116" class="LineNr">116 </span><span class="SalientComment">## helpers</span> +<span id="L117" class="LineNr">117 </span> +<span id="L118" class="LineNr">118 </span><span class="Comment"># compare two null-terminated ascii strings</span> +<span id="L119" class="LineNr">119 </span><span class="Comment"># reason for the name: the only place we should have null-terminated ascii strings is from commandline args</span> +<span id="L120" class="LineNr">120 </span>argv_equal: <span class="Comment"># (s1, s2) : null-terminated ascii strings -> EAX : boolean</span> +<span id="L121" class="LineNr">121 </span> <span class="Comment"># initialize s1 (ECX) and s2 (EDX)</span> +<span id="L122" class="LineNr">122 </span> 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none <span class="Delimiter"> . </span> 1/r32/ECX 8/disp8 <span class="Delimiter"> . </span> <span class="Comment"># copy *(ESP+8) to ECX</span> +<span id="L123" class="LineNr">123 </span> 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none <span class="Delimiter"> . </span> 2/r32/EDX 4/disp8 <span class="Delimiter"> . </span> <span class="Comment"># copy *(ESP+4) to EDX</span> +<span id="L124" class="LineNr">124 </span> <span class="Comment"># while (true)</span> +<span id="L125" class="LineNr">125 </span>$argv_loop: +<span id="L126" class="LineNr">126 </span> <span class="Comment"># c1/EAX, c2/EBX = *s1, *s2</span> +<span id="L127" class="LineNr">127 </span> b8/copy 0/imm32 <span class="Comment"># clear EAX</span> +<span id="L128" class="LineNr">128 </span> 8a/copy 0/mod/indirect 1/rm32/ECX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 0/r32/EAX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># copy byte at *ECX to lower byte of EAX</span> +<span id="L129" class="LineNr">129 </span> bb/copy 0/imm32 <span class="Comment"># clear EBX</span> +<span id="L130" class="LineNr">130 </span> 8a/copy 0/mod/indirect 2/rm32/EDX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 3/r32/EBX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># copy byte at *EDX to lower byte of EBX</span> +<span id="L131" class="LineNr">131 </span> <span class="Comment"># if (c1 == 0) break</span> +<span id="L132" class="LineNr">132 </span> 3d/compare <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 0/imm32 <span class="Comment"># compare EAX with 0</span> +<span id="L133" class="LineNr">133 </span> 74/jump-if-equal $argv_break/disp8 +<span id="L134" class="LineNr">134 </span> <span class="Comment"># if (c1 != c2) return false</span> +<span id="L135" class="LineNr">135 </span> 39/compare 3/mod/direct 0/rm32/EAX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 3/r32/EBX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># compare EAX with EBX</span> +<span id="L136" class="LineNr">136 </span> 75/jump-if-not-equal $argv_fail/disp8 +<span id="L137" class="LineNr">137 </span> <span class="Comment"># ++s1, ++s2</span> +<span id="L138" class="LineNr">138 </span> 41/inc-ECX +<span id="L139" class="LineNr">139 </span> 42/inc-EDX +<span id="L140" class="LineNr">140 </span> <span class="Comment"># end while</span> +<span id="L141" class="LineNr">141 </span> eb/jump $argv_loop/disp8 +<span id="L142" class="LineNr">142 </span>$argv_break: +<span id="L143" class="LineNr">143 </span> <span class="Comment"># if (c2 == 0) return true</span> +<span id="L144" class="LineNr">144 </span> 81 7/subop/compare 3/mod/direct 3/rm32/EBX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 0/imm32 <span class="Comment"># compare EBX with 0</span> +<span id="L145" class="LineNr">145 </span> 75/jump-if-not-equal $argv_fail/disp8 +<span id="L146" class="LineNr">146 </span> b8/copy <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 1/imm32 <span class="Comment"># copy 1 to EAX</span> +<span id="L147" class="LineNr">147 </span> c3/return +<span id="L148" class="LineNr">148 </span> <span class="Comment"># return false</span> +<span id="L149" class="LineNr">149 </span>$argv_fail: +<span id="L150" class="LineNr">150 </span> b8/copy <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 0/imm32 <span class="Comment"># copy 0 to EAX</span> +<span id="L151" class="LineNr">151 </span> c3/return +<span id="L152" class="LineNr">152 </span> +<span id="L153" class="LineNr">153 </span>write_stderr: <span class="Comment"># s : (address array byte) -> <void></span> +<span id="L154" class="LineNr">154 </span> <span class="Comment"># save registers</span> +<span id="L155" class="LineNr">155 </span> 50/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># push EAX</span> +<span id="L156" class="LineNr">156 </span> 51/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># push ECX</span> +<span id="L157" class="LineNr">157 </span> 52/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># push EDX</span> +<span id="L158" class="LineNr">158 </span> 53/push <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># push EBX</span> +<span id="L159" class="LineNr">159 </span> <span class="Comment"># write(2/stderr, (data) s+4, (size) *s)</span> +<span id="L160" class="LineNr">160 </span> <span class="Comment"># fd = 2 (stderr)</span> +<span id="L161" class="LineNr">161 </span> bb/copy <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 2/imm32 <span class="Comment"># copy 2 to EBX</span> +<span id="L162" class="LineNr">162 </span> <span class="Comment"># x = s+4</span> +<span id="L163" class="LineNr">163 </span> 8b/copy 1/mod/*+disp8 4/rm32/SIB 4/base/ESP 4/index/none <span class="Delimiter"> . </span> 1/r32/ECX 0x14/disp8 <span class="Delimiter"> . </span> <span class="Comment"># copy *(ESP+20) to ECX</span> +<span id="L164" class="LineNr">164 </span> 81 0/subop/add 3/mod/direct 1/rm32/ECX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 4/imm32 <span class="Comment"># add 4 to ECX</span> +<span id="L165" class="LineNr">165 </span> <span class="Comment"># size = *s</span> +<span id="L166" class="LineNr">166 </span> 8b/copy 1/mod/*+disp8 4/rm32/SIB 4/base/ESP 4/index/none <span class="Delimiter"> . </span> 2/r32/EDX 0x14/disp8 <span class="Delimiter"> . </span> <span class="Comment"># copy *(ESP+20) to EDX</span> +<span id="L167" class="LineNr">167 </span> 8b/copy 0/mod/indirect 2/rm32/EDX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 2/r32/EDX <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># copy *EDX to EDX</span> +<span id="L168" class="LineNr">168 </span> <span class="Comment"># call write()</span> +<span id="L169" class="LineNr">169 </span> b8/copy <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> 4/imm32/write <span class="Comment"># copy 1 to EAX</span> +<span id="L170" class="LineNr">170 </span> cd/syscall 0x80/imm8 +<span id="L171" class="LineNr">171 </span> <span class="Comment"># restore registers</span> +<span id="L172" class="LineNr">172 </span> 5b/pop <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># pop EBX</span> +<span id="L173" class="LineNr">173 </span> 5a/pop <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># pop EDX</span> +<span id="L174" class="LineNr">174 </span> 59/pop <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># pop ECX</span> +<span id="L175" class="LineNr">175 </span> 58/pop <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Delimiter"> . </span> <span class="Comment"># pop EAX</span> +<span id="L176" class="LineNr">176 </span> <span class="Comment"># end</span> +<span id="L177" class="LineNr">177 </span> c3/return +<span id="L178" class="LineNr">178 </span> +<span id="L179" class="LineNr">179 </span>== data +<span id="L180" class="LineNr">180 </span>Test_argv: <span class="Comment"># null-terminated</span> +<span id="L181" class="LineNr">181 </span> <span class="Comment"># data</span> +<span id="L182" class="LineNr">182 </span> 74/t 65/e 73/s 74/t 00/null +<span id="L183" class="LineNr">183 </span> +<span id="L184" class="LineNr">184 </span>Test_passed: +<span id="L185" class="LineNr">185 </span> <span class="Comment"># size</span> +<span id="L186" class="LineNr">186 </span> 01 00 00 00 +<span id="L187" class="LineNr">187 </span> <span class="Comment"># data</span> +<span id="L188" class="LineNr">188 </span> 2e/dot +<span id="L189" class="LineNr">189 </span> +<span id="L190" class="LineNr">190 </span>Test_failed: +<span id="L191" class="LineNr">191 </span> <span class="Comment"># size</span> +<span id="L192" class="LineNr">192 </span> 01 00 00 00 +<span id="L193" class="LineNr">193 </span> <span class="Comment"># data</span> +<span id="L194" class="LineNr">194 </span> 46/F +<span id="L195" class="LineNr">195 </span> +<span id="L196" class="LineNr">196 </span><span class="Comment"># vim:ft=subx:nowrap:so=0</span> </pre> </body> </html> |