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<pre id='vimCodeElement'>
<span id="L1" class="LineNr"> 1 </span><span class="SalientComment">## add the first 10 numbers, 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 ex3.subx ex3</span>
<span id="L5" class="LineNr"> 5 </span><span class="Comment"># $ subx run ex3</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"># 55</span>
<span id="L9" class="LineNr"> 9 </span>
<span id="L10" class="LineNr">10 </span>== 0x08048054 <span class="Comment"># code segment, after leaving room for ELF header</span>
<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 class="Comment"># result: EBX = 0</span>
<span id="L15" class="LineNr">15 </span> bb/copy 0/imm32 <span class="Comment"># copy 0 to EBX</span>
<span id="L16" class="LineNr">16 </span> <span class="Comment"># counter: ECX = 1</span>
<span id="L17" class="LineNr">17 </span> b9/copy 1/imm32 <span class="Comment"># copy 1 to ECX</span>
<span id="L18" class="LineNr">18 </span>
<span id="L19" class="LineNr">19 </span>loop:
<span id="L20" class="LineNr">20 </span> <span class="Comment"># while (counter <= 10)</span>
<span id="L21" class="LineNr">21 </span> 81 7/subop/compare 3/mod/direct 1/rm32/ecx 0xa/imm32 <span class="Comment"># compare ECX, 10/imm</span>
<span id="L22" class="LineNr">22 </span> 7f/jump-if exit/disp8 <span class="Comment"># jump-if-greater exit</span>
<span id="L23" class="LineNr">23 </span> <span class="Comment"># result += counter</span>
<span id="L24" class="LineNr">24 </span> 01/add 3/mod/direct 3/rm32/ebx 1/r32/ecx <span class="Comment"># add ECX to EBX</span>
<span id="L25" class="LineNr">25 </span> <span class="Comment"># ++counter</span>
<span id="L26" class="LineNr">26 </span> 81 0/subop/add 3/mod/direct 1/rm32/ecx 1/imm32 <span class="Comment"># add 1 to ECX</span>
<span id="L27" class="LineNr">27 </span> <span class="Comment"># loop</span>
<span id="L28" class="LineNr">28 </span> eb/jump loop/disp8 <span class="Comment"># jump loop</span>
<span id="L29" class="LineNr">29 </span>
<span id="L30" class="LineNr">30 </span>exit:
<span id="L31" class="LineNr">31 </span> <span class="Comment"># exit(EBX)</span>
<span id="L32" class="LineNr">32 </span> b8/copy 1/imm32 <span class="Comment"># copy 1 to EAX</span>
<span id="L33" class="LineNr">33 </span> cd/syscall 0x80/imm8 <span class="Comment"># int 80h</span>
<span id="L34" class="LineNr">34 </span>
<span id="L35" class="LineNr">35 </span><span class="Comment"># vim:ft=subx:nowrap</span>
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