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-rw-r--r--html/subx/apps/crenshaw2-1.subx.html194
-rw-r--r--html/subx/apps/factorial.subx.html258
2 files changed, 390 insertions, 62 deletions
diff --git a/html/subx/apps/crenshaw2-1.subx.html b/html/subx/apps/crenshaw2-1.subx.html
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+<pre id='vimCodeElement'>
+<span id="L1" class="LineNr">  1 </span><span class="SalientComment">## port of <a href="https://github.com/akkartik/crenshaw/blob/master/tutor2.1.pas">https://github.com/akkartik/crenshaw/blob/master/tutor2.1.pas</a></span>
+<span id="L2" class="LineNr">  2 </span><span class="Comment"># corresponds to the section &quot;single digits&quot; in <a href="https://compilers.iecc.com/crenshaw/tutor2.txt">https://compilers.iecc.com/crenshaw/tutor2.txt</a></span>
+<span id="L3" class="LineNr">  3 </span><span class="Comment">#</span>
+<span id="L4" class="LineNr">  4 </span><span class="Comment"># To run:</span>
+<span id="L5" class="LineNr">  5 </span><span class="Comment">#   $ subx translate apps/crenshaw2.1.subx crenshaw 2.1</span>
+<span id="L6" class="LineNr">  6 </span><span class="Comment">#   $ echo '3'  |subx run apps/crenshaw2.1  |xxd -</span>
+<span id="L7" class="LineNr">  7 </span><span class="Comment"># Expected output:</span>
+<span id="L8" class="LineNr">  8 </span><span class="Comment">#   TODO</span>
+<span id="L9" class="LineNr">  9 </span><span class="Comment">#</span>
+<span id="L10" class="LineNr"> 10 </span><span class="Comment"># The output is the code a function would need to include, returning the</span>
+<span id="L11" class="LineNr"> 11 </span><span class="Comment"># result in EAX.</span>
+<span id="L12" class="LineNr"> 12 </span><span class="Comment">#</span>
+<span id="L13" class="LineNr"> 13 </span><span class="Comment"># Major note: byte strings are not null-terminated. Instead they're prefixed</span>
+<span id="L14" class="LineNr"> 14 </span><span class="Comment"># with a 32-bit length.</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"># abort(Error_integer)</span>
+<span id="L23" class="LineNr"> 23 </span>    <span class="Comment"># push args</span>
+<span id="L24" class="LineNr"> 24 </span>  68/push  Error_integer/imm32
+<span id="L25" class="LineNr"> 25 </span>    <span class="Comment"># call</span>
+<span id="L26" class="LineNr"> 26 </span>  e8/call  abort/disp32
+<span id="L27" class="LineNr"> 27 </span>    <span class="Comment"># discard arg</span>
+<span id="L28" class="LineNr"> 28 </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="L29" class="LineNr"> 29 </span>  <span class="Comment"># exit(0)</span>
+<span id="L30" class="LineNr"> 30 </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>              0/imm32           <span class="Comment"># copy 0 to EBX</span>
+<span id="L31" class="LineNr"> 31 </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/exit      <span class="Comment"># copy 1 to EAX</span>
+<span id="L32" class="LineNr"> 32 </span>  cd/syscall  0x80/imm8
+<span id="L33" class="LineNr"> 33 </span>
+<span id="L34" class="LineNr"> 34 </span><span class="Comment"># print error message and exit</span>
+<span id="L35" class="LineNr"> 35 </span><span class="Comment"># really maps to the 'Expected' function in Crenshaw</span>
+<span id="L36" class="LineNr"> 36 </span>abort:  <span class="Comment"># s : (address array byte) -&gt; &lt;void&gt;</span>
+<span id="L37" class="LineNr"> 37 </span>  <span class="Comment"># error(s)</span>
+<span id="L38" class="LineNr"> 38 </span>    <span class="Comment"># push args</span>
+<span id="L39" class="LineNr"> 39 </span>  ff          6/subop/push        1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none <span class="Delimiter"> . </span>         <span class="Delimiter"> . </span>          4/disp8        <span class="Delimiter"> . </span>                <span class="Comment"># push *(ESP+4)</span>
+<span id="L40" class="LineNr"> 40 </span>    <span class="Comment"># call</span>
+<span id="L41" class="LineNr"> 41 </span>  e8/call  error/disp32
+<span id="L42" class="LineNr"> 42 </span>    <span class="Comment"># discard arg</span>
+<span id="L43" class="LineNr"> 43 </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="L44" class="LineNr"> 44 </span>  <span class="Comment"># exit(1)</span>
+<span id="L45" class="LineNr"> 45 </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>              1/imm32           <span class="Comment"># copy 1 to EBX</span>
+<span id="L46" class="LineNr"> 46 </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/exit      <span class="Comment"># copy 1 to EAX</span>
+<span id="L47" class="LineNr"> 47 </span>  cd/syscall  0x80/imm8
+<span id="L48" class="LineNr"> 48 </span>
+<span id="L49" class="LineNr"> 49 </span><span class="Comment"># print out &quot;Error: #{s} expected\n&quot; to stderr</span>
+<span id="L50" class="LineNr"> 50 </span>error:  <span class="Comment"># s : (address array byte) -&gt; &lt;void&gt;</span>
+<span id="L51" class="LineNr"> 51 </span>  <span class="Comment"># write_stderr(&quot;Error: &quot;)</span>
+<span id="L52" class="LineNr"> 52 </span>    <span class="Comment"># push args</span>
+<span id="L53" class="LineNr"> 53 </span>  68/push  Error/imm32
+<span id="L54" class="LineNr"> 54 </span>    <span class="Comment"># call</span>
+<span id="L55" class="LineNr"> 55 </span>  e8/call  write_stderr/disp32
+<span id="L56" class="LineNr"> 56 </span>    <span class="Comment"># discard arg</span>
+<span id="L57" class="LineNr"> 57 </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="L58" class="LineNr"> 58 </span>  <span class="Comment"># write_stderr(s)</span>
+<span id="L59" class="LineNr"> 59 </span>    <span class="Comment"># push args</span>
+<span id="L60" class="LineNr"> 60 </span>  ff          6/subop/push        1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none <span class="Delimiter"> . </span>         <span class="Delimiter"> . </span>          4/disp8        <span class="Delimiter"> . </span>                <span class="Comment"># push *(ESP+4)</span>
+<span id="L61" class="LineNr"> 61 </span>    <span class="Comment"># call</span>
+<span id="L62" class="LineNr"> 62 </span>  e8/call  write_stderr/disp32
+<span id="L63" class="LineNr"> 63 </span>    <span class="Comment"># discard arg</span>
+<span id="L64" class="LineNr"> 64 </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="L65" class="LineNr"> 65 </span>  <span class="Comment"># write_stderr(&quot; expected&quot;)</span>
+<span id="L66" class="LineNr"> 66 </span>    <span class="Comment"># push args</span>
+<span id="L67" class="LineNr"> 67 </span>  68/push  Expected_suffix/imm32
+<span id="L68" class="LineNr"> 68 </span>    <span class="Comment"># call</span>
+<span id="L69" class="LineNr"> 69 </span>  e8/call  write_stderr/disp32
+<span id="L70" class="LineNr"> 70 </span>    <span class="Comment"># discard arg</span>
+<span id="L71" class="LineNr"> 71 </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="L72" class="LineNr"> 72 </span>  <span class="Comment"># write_stderr(&quot;\n&quot;)</span>
+<span id="L73" class="LineNr"> 73 </span>    <span class="Comment"># push args</span>
+<span id="L74" class="LineNr"> 74 </span>  68/push  Newline/imm32
+<span id="L75" class="LineNr"> 75 </span>    <span class="Comment"># call</span>
+<span id="L76" class="LineNr"> 76 </span>  e8/call  write_stderr/disp32
+<span id="L77" class="LineNr"> 77 </span>    <span class="Comment"># discard arg</span>
+<span id="L78" class="LineNr"> 78 </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="L79" class="LineNr"> 79 </span>  <span class="Comment"># end</span>
+<span id="L80" class="LineNr"> 80 </span>  c3/return
+<span id="L81" class="LineNr"> 81 </span>
+<span id="L82" class="LineNr"> 82 </span>write_stderr:  <span class="Comment"># s : (address array byte) -&gt; &lt;void&gt;</span>
+<span id="L83" class="LineNr"> 83 </span>  <span class="Comment"># write(2/stderr, (data) s+4, (size) *s)</span>
+<span id="L84" class="LineNr"> 84 </span>    <span class="Comment"># fd = 2 (stderr)</span>
+<span id="L85" class="LineNr"> 85 </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="L86" class="LineNr"> 86 </span>    <span class="Comment"># x = s+4</span>
+<span id="L87" class="LineNr"> 87 </span>  8b/copy                         1/mod/*+disp8   4/rm32/SIB    4/base/ESP  4/index/none <span class="Delimiter"> . </span>          1/r32/ECX   4/disp8        <span class="Delimiter"> . </span>                <span class="Comment"># copy *(ESP+4) to ECX</span>
+<span id="L88" class="LineNr"> 88 </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="L89" class="LineNr"> 89 </span>    <span class="Comment"># size = *s</span>
+<span id="L90" class="LineNr"> 90 </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="L91" class="LineNr"> 91 </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="L92" class="LineNr"> 92 </span>    <span class="Comment"># call write()</span>
+<span id="L93" class="LineNr"> 93 </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="L94" class="LineNr"> 94 </span>  cd/syscall  0x80/imm8
+<span id="L95" class="LineNr"> 95 </span>  <span class="Comment"># end</span>
+<span id="L96" class="LineNr"> 96 </span>  c3/return
+<span id="L97" class="LineNr"> 97 </span>
+<span id="L98" class="LineNr"> 98 </span>write_stdout:  <span class="Comment"># s : (address array byte) -&gt; &lt;void&gt;</span>
+<span id="L99" class="LineNr"> 99 </span>  <span class="Comment"># write(1/stdout, (data) s+4, (size) *s)</span>
+<span id="L100" class="LineNr">100 </span>    <span class="Comment"># fd = 1 (stdout)</span>
+<span id="L101" class="LineNr">101 </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>              1/imm32           <span class="Comment"># copy 1 to EBX</span>
+<span id="L102" class="LineNr">102 </span>    <span class="Comment"># x = s+4</span>
+<span id="L103" class="LineNr">103 </span>  8b/copy                         1/mod/*+disp8   4/rm32/SIB    4/base/ESP  4/index/none <span class="Delimiter"> . </span>          1/r32/ECX   4/disp8        <span class="Delimiter"> . </span>                <span class="Comment"># copy *(ESP+4) to ECX</span>
+<span id="L104" class="LineNr">104 </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="L105" class="LineNr">105 </span>    <span class="Comment"># size = *s</span>
+<span id="L106" class="LineNr">106 </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="L107" class="LineNr">107 </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="L108" class="LineNr">108 </span>    <span class="Comment"># call write()</span>
+<span id="L109" class="LineNr">109 </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="L110" class="LineNr">110 </span>  cd/syscall  0x80/imm8
+<span id="L111" class="LineNr">111 </span>  <span class="Comment"># end</span>
+<span id="L112" class="LineNr">112 </span>  c3/return
+<span id="L113" class="LineNr">113 </span>
+<span id="L114" class="LineNr">114 </span>== data
+<span id="L115" class="LineNr">115 </span>Newline:
+<span id="L116" class="LineNr">116 </span>  <span class="Comment"># size</span>
+<span id="L117" class="LineNr">117 </span>  01 00 00 00
+<span id="L118" class="LineNr">118 </span>  <span class="Comment"># data</span>
+<span id="L119" class="LineNr">119 </span>  0a/newline
+<span id="L120" class="LineNr">120 </span>Error:  <span class="Comment"># &quot;Error: &quot; : (array byte)</span>
+<span id="L121" class="LineNr">121 </span>  <span class="Comment"># size</span>
+<span id="L122" class="LineNr">122 </span>  07 00 00 00
+<span id="L123" class="LineNr">123 </span>  <span class="Comment"># data</span>
+<span id="L124" class="LineNr">124 </span>  45/E 72/r 72/r 6f/o 72/r 3a/: 20/space
+<span id="L125" class="LineNr">125 </span>Expected_suffix:  <span class="Comment"># &quot; expected&quot; : (array byte)</span>
+<span id="L126" class="LineNr">126 </span>  <span class="Comment"># size</span>
+<span id="L127" class="LineNr">127 </span>  09 00 00 00
+<span id="L128" class="LineNr">128 </span>  <span class="Comment"># data</span>
+<span id="L129" class="LineNr">129 </span>  20/space 65/e 78/x 70/p 65/e 63/c 74/t 65/e 64/d
+<span id="L130" class="LineNr">130 </span>Error_integer:  <span class="Comment"># &quot;Integer&quot; : (array byte)</span>
+<span id="L131" class="LineNr">131 </span>  <span class="Comment"># size</span>
+<span id="L132" class="LineNr">132 </span>  07 00 00 00
+<span id="L133" class="LineNr">133 </span>  <span class="Comment"># data</span>
+<span id="L134" class="LineNr">134 </span>  49/I 6e/n 74/t 65/e 67/g 65/e 72/r
+</pre>
+</body>
+</html>
+<!-- vim: set foldmethod=manual : -->
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 &lt;= 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-&lt;=                  <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 &lt;= 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&#0058;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 &gt; 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] == &quot;test&quot;)</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  $main_exit/disp8
+<span id="L41" class="LineNr"> 41 </span>  <span class="Comment"># else EAX &lt;- factorial(5)</span>
+<span id="L42" class="LineNr"> 42 </span>$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 &lt;- 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 &lt;= 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-&lt;=                  <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 &lt;= 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 -&gt; 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) -&gt; &lt;void&gt;</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&#0058;ft=subx:nowrap:so=0</span>
 </pre>
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