4082

subx: correct a 'copy' ('mov') instruction as well to get its operand
right from the opcode.

4 files changed, 67 insertions, 55 deletions

diff --git a/html/subx/011direct_addressing.cc.html b/html/subx/011direct_addressing.cc.html
index a08f0e3f..f9508be6 100644
--- a/html/subx/011direct_addressing.cc.html
+++ b/html/subx/011direct_addressing.cc.html
@@ -300,7 +300,7 @@ if ('onhashchange' in window) {
 <span id="L235" class="LineNr">235 </span><span class="Normal">case</span> <span class="Constant">0x54</span>:
 <span id="L236" class="LineNr">236 </span><span class="Normal">case</span> <span class="Constant">0x55</span>:
 <span id="L237" class="LineNr">237 </span><span class="Normal">case</span> <span class="Constant">0x56</span>:
-<span id="L238" class="LineNr">238 </span><span class="Normal">case</span> <span class="Constant">0x57</span>: <span class="Delimiter">{</span>
+<span id="L238" class="LineNr">238 </span><span class="Normal">case</span> <span class="Constant">0x57</span>: <span class="Delimiter">{</span>  <span class="Comment">// push r32 to stack</span>
 <span id="L239" class="LineNr">239 </span>  <span class="Normal">uint8_t</span> <a href='010core.cc.html#L17'>reg</a> = op &amp; <span class="Constant">0x7</span><span class="Delimiter">;</span>
 <span id="L240" class="LineNr">240 </span>  <a href='003trace.cc.html#L160'>trace</a><span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;push <a href='010core.cc.html#L17'>reg</a> &quot;</span> &lt;&lt; <a href='010core.cc.html#L232'>NUM</a><span class="Delimiter">(</span><a href='010core.cc.html#L17'>reg</a><span class="Delimiter">)</span> &lt;&lt; <a href='003trace.cc.html#L184'>end</a><span class="Delimiter">();</span>
 <span id="L241" class="LineNr">241 </span>  <span class="Normal">const</span> <span class="Normal">int32_t</span> val = Reg[reg]<span class="Delimiter">.</span>u<span class="Delimiter">;</span>
diff --git a/html/subx/013immediate_addressing.cc.html b/html/subx/013immediate_addressing.cc.html
index 6215b01c..80939a21 100644
--- a/html/subx/013immediate_addressing.cc.html
+++ b/html/subx/013immediate_addressing.cc.html
@@ -396,58 +396,64 @@ if ('onhashchange' in window) {
 <span id="L332" class="LineNr">332 </span>
 <span id="L333" class="LineNr">333 </span><span class="Delimiter">:(scenario copy_imm32_to_r32)</span>
 <span id="L334" class="LineNr">334 </span><span class="Comment"># op  ModRM   SIB   displacement  immediate</span>
-<span id="L335" class="LineNr">335 </span>  b8  <span class="PreProc">0</span><span class="Constant">3</span>                          0a 0b 0c 0d  <span class="Comment"># copy 0x0d0c0b0a to EBX (reg 3)</span>
+<span id="L335" class="LineNr">335 </span>  bb                              0a 0b 0c 0d  <span class="Comment"># copy 0x0d0c0b0a to EBX (reg 3)</span>
 <span id="L336" class="LineNr">336 </span><span class="traceContains">+run: copy <a href='010core.cc.html#L219'>imm32</a> 0x0d0c0b0a to <a href='010core.cc.html#L17'>reg</a> 3</span>
 <span id="L337" class="LineNr">337 </span>
 <span id="L338" class="LineNr">338 </span><span class="Delimiter">:(before &quot;End Single-Byte Opcodes&quot;)</span>
-<span id="L339" class="LineNr">339 </span><span class="Normal">case</span> <span class="Constant">0xb8</span>: <span class="Delimiter">{</span>  <span class="Comment">// copy imm32 to r32</span>
-<span id="L340" class="LineNr">340 </span>  <span class="Normal">uint8_t</span> modrm = <a href='010core.cc.html#L214'>next</a><span class="Delimiter">();</span>
-<span id="L341" class="LineNr">341 </span>  <span class="Normal">int32_t</span> arg2 = <a href='010core.cc.html#L219'>imm32</a><span class="Delimiter">();</span>
-<span id="L342" class="LineNr">342 </span>  <span class="Normal">uint8_t</span> reg1 = modrm&amp;<span class="Constant">0x7</span><span class="Delimiter">;</span>  <span class="Comment">// ignore mod bits</span>
-<span id="L343" class="LineNr">343 </span>  <a href='003trace.cc.html#L160'>trace</a><span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;copy <a href='010core.cc.html#L219'>imm32</a> 0x&quot;</span> &lt;&lt; <a href='010core.cc.html#L230'>HEXWORD</a> &lt;&lt; arg2 &lt;&lt; <span class="Constant">&quot; to <a href='010core.cc.html#L17'>reg</a> &quot;</span> &lt;&lt; <a href='010core.cc.html#L232'>NUM</a><span class="Delimiter">(</span>reg1<span class="Delimiter">)</span> &lt;&lt; <a href='003trace.cc.html#L184'>end</a><span class="Delimiter">();</span>
-<span id="L344" class="LineNr">344 </span>  Reg[reg1]<span class="Delimiter">.</span>i = arg2<span class="Delimiter">;</span>
-<span id="L345" class="LineNr">345 </span>  <span class="Identifier">break</span><span class="Delimiter">;</span>
-<span id="L346" class="LineNr">346 </span><span class="Delimiter">}</span>
-<span id="L347" class="LineNr">347 </span>
-<span id="L348" class="LineNr">348 </span><span class="Comment">//:</span>
-<span id="L349" class="LineNr">349 </span>
-<span id="L350" class="LineNr">350 </span><span class="Delimiter">:(scenario copy_imm32_to_mem_at_r32)</span>
-<span id="L351" class="LineNr">351 </span><span class="Special">% Reg[3].i = 0x60;</span>
-<span id="L352" class="LineNr">352 </span><span class="Comment"># op  ModRM   SIB   displacement  immediate</span>
-<span id="L353" class="LineNr">353 </span>  c7  <span class="PreProc">0</span><span class="Constant">3</span>                          0a 0b 0c 0d  <span class="Comment"># copy 0x0d0c0b0a to *EBX (reg 3)</span>
-<span id="L354" class="LineNr">354 </span><span class="traceContains">+run: copy <a href='010core.cc.html#L219'>imm32</a> 0x0d0c0b0a to effective address</span>
-<span id="L355" class="LineNr">355 </span><span class="traceContains">+run: effective address is mem at address 0x60 (reg 3)</span>
-<span id="L356" class="LineNr">356 </span>
-<span id="L357" class="LineNr">357 </span><span class="Delimiter">:(before &quot;End Single-Byte Opcodes&quot;)</span>
-<span id="L358" class="LineNr">358 </span><span class="Normal">case</span> <span class="Constant">0xc7</span>: <span class="Delimiter">{</span>  <span class="Comment">// copy imm32 to r32</span>
-<span id="L359" class="LineNr">359 </span>  <span class="Normal">uint8_t</span> modrm = <a href='010core.cc.html#L214'>next</a><span class="Delimiter">();</span>
-<span id="L360" class="LineNr">360 </span>  <span class="Normal">int32_t</span> arg2 = <a href='010core.cc.html#L219'>imm32</a><span class="Delimiter">();</span>
-<span id="L361" class="LineNr">361 </span>  <a href='003trace.cc.html#L160'>trace</a><span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;copy <a href='010core.cc.html#L219'>imm32</a> 0x&quot;</span> &lt;&lt; <a href='010core.cc.html#L230'>HEXWORD</a> &lt;&lt; arg2 &lt;&lt; <span class="Constant">&quot; to effective address&quot;</span> &lt;&lt; <a href='003trace.cc.html#L184'>end</a><span class="Delimiter">();</span>
-<span id="L362" class="LineNr">362 </span>  <span class="Normal">int32_t</span>* arg1 = <a href='011direct_addressing.cc.html#L26'>effective_address</a><span class="Delimiter">(</span>modrm<span class="Delimiter">);</span>
-<span id="L363" class="LineNr">363 </span>  *arg1 = arg2<span class="Delimiter">;</span>
-<span id="L364" class="LineNr">364 </span>  <span class="Identifier">break</span><span class="Delimiter">;</span>
-<span id="L365" class="LineNr">365 </span><span class="Delimiter">}</span>
-<span id="L366" class="LineNr">366 </span>
-<span id="L367" class="LineNr">367 </span><span class="SalientComment">//:: push</span>
-<span id="L368" class="LineNr">368 </span>
-<span id="L369" class="LineNr">369 </span><span class="Delimiter">:(scenario push_imm32)</span>
-<span id="L370" class="LineNr">370 </span><span class="Special">% Reg[ESP].u = 0x14;</span>
-<span id="L371" class="LineNr">371 </span><span class="Comment"># op  ModRM   SIB   displacement  immediate</span>
-<span id="L372" class="LineNr">372 </span>  <span class="Constant">68</span>                              af <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span>  <span class="Comment"># push *EAX (reg 0) to stack</span>
-<span id="L373" class="LineNr">373 </span><span class="traceContains">+run: push <a href='010core.cc.html#L219'>imm32</a> 0x000000af</span>
-<span id="L374" class="LineNr">374 </span><span class="traceContains">+run: <a href='010core.cc.html#L11'>ESP</a> is now 0x00000010</span>
-<span id="L375" class="LineNr">375 </span><span class="traceContains">+run: <a href='003trace.cc.html#L74'>contents</a> at <a href='010core.cc.html#L11'>ESP</a>: 0x000000af</span>
-<span id="L376" class="LineNr">376 </span>
-<span id="L377" class="LineNr">377 </span><span class="Delimiter">:(before &quot;End Single-Byte Opcodes&quot;)</span>
-<span id="L378" class="LineNr">378 </span><span class="Normal">case</span> <span class="Constant">0x68</span>: <span class="Delimiter">{</span>
-<span id="L379" class="LineNr">379 </span>  <span class="Normal">int32_t</span> val = <a href='010core.cc.html#L219'>imm32</a><span class="Delimiter">();</span>
-<span id="L380" class="LineNr">380 </span>  <a href='003trace.cc.html#L160'>trace</a><span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;push <a href='010core.cc.html#L219'>imm32</a> 0x&quot;</span> &lt;&lt; <a href='010core.cc.html#L230'>HEXWORD</a> &lt;&lt; val &lt;&lt; <a href='003trace.cc.html#L184'>end</a><span class="Delimiter">();</span>
-<span id="L381" class="LineNr">381 </span>  Reg[ESP]<span class="Delimiter">.</span>u -= <span class="Constant">4</span><span class="Delimiter">;</span>
-<span id="L382" class="LineNr">382 </span>  *<span class="Normal">reinterpret_cast</span>&lt;<span class="Normal">uint32_t</span>*&gt;<span class="Delimiter">(</span>&amp;Mem<span class="Delimiter">.</span>at<span class="Delimiter">(</span>Reg[ESP]<span class="Delimiter">.</span>u<span class="Delimiter">))</span> = val<span class="Delimiter">;</span>
-<span id="L383" class="LineNr">383 </span>  <a href='003trace.cc.html#L160'>trace</a><span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;ESP is now 0x&quot;</span> &lt;&lt; <a href='010core.cc.html#L230'>HEXWORD</a> &lt;&lt; Reg[ESP]<span class="Delimiter">.</span>u &lt;&lt; <a href='003trace.cc.html#L184'>end</a><span class="Delimiter">();</span>
-<span id="L384" class="LineNr">384 </span>  <a href='003trace.cc.html#L160'>trace</a><span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;contents at <a href='010core.cc.html#L11'>ESP</a>: 0x&quot;</span> &lt;&lt; <a href='010core.cc.html#L230'>HEXWORD</a> &lt;&lt; *<span class="Normal">reinterpret_cast</span>&lt;<span class="Normal">uint32_t</span>*&gt;<span class="Delimiter">(</span>&amp;Mem<span class="Delimiter">.</span>at<span class="Delimiter">(</span>Reg[ESP]<span class="Delimiter">.</span>u<span class="Delimiter">))</span> &lt;&lt; <a href='003trace.cc.html#L184'>end</a><span class="Delimiter">();</span>
-<span id="L385" class="LineNr">385 </span>  <span class="Identifier">break</span><span class="Delimiter">;</span>
-<span id="L386" class="LineNr">386 </span><span class="Delimiter">}</span>
+<span id="L339" class="LineNr">339 </span><span class="Normal">case</span> <span class="Constant">0xb8</span>:
+<span id="L340" class="LineNr">340 </span><span class="Normal">case</span> <span class="Constant">0xb9</span>:
+<span id="L341" class="LineNr">341 </span><span class="Normal">case</span> <span class="Constant">0xba</span>:
+<span id="L342" class="LineNr">342 </span><span class="Normal">case</span> <span class="Constant">0xbb</span>:
+<span id="L343" class="LineNr">343 </span><span class="Normal">case</span> <span class="Constant">0xbc</span>:
+<span id="L344" class="LineNr">344 </span><span class="Normal">case</span> <span class="Constant">0xbd</span>:
+<span id="L345" class="LineNr">345 </span><span class="Normal">case</span> <span class="Constant">0xbe</span>:
+<span id="L346" class="LineNr">346 </span><span class="Normal">case</span> <span class="Constant">0xbf</span>: <span class="Delimiter">{</span>  <span class="Comment">// copy imm32 to r32</span>
+<span id="L347" class="LineNr">347 </span>  <span class="Normal">uint8_t</span> reg1 = op &amp; <span class="Constant">0x7</span><span class="Delimiter">;</span>
+<span id="L348" class="LineNr">348 </span>  <span class="Normal">int32_t</span> arg2 = <a href='010core.cc.html#L219'>imm32</a><span class="Delimiter">();</span>
+<span id="L349" class="LineNr">349 </span>  <a href='003trace.cc.html#L160'>trace</a><span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;copy <a href='010core.cc.html#L219'>imm32</a> 0x&quot;</span> &lt;&lt; <a href='010core.cc.html#L230'>HEXWORD</a> &lt;&lt; arg2 &lt;&lt; <span class="Constant">&quot; to <a href='010core.cc.html#L17'>reg</a> &quot;</span> &lt;&lt; <a href='010core.cc.html#L232'>NUM</a><span class="Delimiter">(</span>reg1<span class="Delimiter">)</span> &lt;&lt; <a href='003trace.cc.html#L184'>end</a><span class="Delimiter">();</span>
+<span id="L350" class="LineNr">350 </span>  Reg[reg1]<span class="Delimiter">.</span>i = arg2<span class="Delimiter">;</span>
+<span id="L351" class="LineNr">351 </span>  <span class="Identifier">break</span><span class="Delimiter">;</span>
+<span id="L352" class="LineNr">352 </span><span class="Delimiter">}</span>
+<span id="L353" class="LineNr">353 </span>
+<span id="L354" class="LineNr">354 </span><span class="Comment">//:</span>
+<span id="L355" class="LineNr">355 </span>
+<span id="L356" class="LineNr">356 </span><span class="Delimiter">:(scenario copy_imm32_to_mem_at_r32)</span>
+<span id="L357" class="LineNr">357 </span><span class="Special">% Reg[3].i = 0x60;</span>
+<span id="L358" class="LineNr">358 </span><span class="Comment"># op  ModRM   SIB   displacement  immediate</span>
+<span id="L359" class="LineNr">359 </span>  c7  <span class="PreProc">0</span><span class="Constant">3</span>                          0a 0b 0c 0d  <span class="Comment"># copy 0x0d0c0b0a to *EBX (reg 3)</span>
+<span id="L360" class="LineNr">360 </span><span class="traceContains">+run: copy <a href='010core.cc.html#L219'>imm32</a> 0x0d0c0b0a to effective address</span>
+<span id="L361" class="LineNr">361 </span><span class="traceContains">+run: effective address is mem at address 0x60 (reg 3)</span>
+<span id="L362" class="LineNr">362 </span>
+<span id="L363" class="LineNr">363 </span><span class="Delimiter">:(before &quot;End Single-Byte Opcodes&quot;)</span>
+<span id="L364" class="LineNr">364 </span><span class="Normal">case</span> <span class="Constant">0xc7</span>: <span class="Delimiter">{</span>  <span class="Comment">// copy imm32 to r32</span>
+<span id="L365" class="LineNr">365 </span>  <span class="Normal">uint8_t</span> modrm = <a href='010core.cc.html#L214'>next</a><span class="Delimiter">();</span>
+<span id="L366" class="LineNr">366 </span>  <span class="Normal">int32_t</span> arg2 = <a href='010core.cc.html#L219'>imm32</a><span class="Delimiter">();</span>
+<span id="L367" class="LineNr">367 </span>  <a href='003trace.cc.html#L160'>trace</a><span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;copy <a href='010core.cc.html#L219'>imm32</a> 0x&quot;</span> &lt;&lt; <a href='010core.cc.html#L230'>HEXWORD</a> &lt;&lt; arg2 &lt;&lt; <span class="Constant">&quot; to effective address&quot;</span> &lt;&lt; <a href='003trace.cc.html#L184'>end</a><span class="Delimiter">();</span>
+<span id="L368" class="LineNr">368 </span>  <span class="Normal">int32_t</span>* arg1 = <a href='011direct_addressing.cc.html#L26'>effective_address</a><span class="Delimiter">(</span>modrm<span class="Delimiter">);</span>
+<span id="L369" class="LineNr">369 </span>  *arg1 = arg2<span class="Delimiter">;</span>
+<span id="L370" class="LineNr">370 </span>  <span class="Identifier">break</span><span class="Delimiter">;</span>
+<span id="L371" class="LineNr">371 </span><span class="Delimiter">}</span>
+<span id="L372" class="LineNr">372 </span>
+<span id="L373" class="LineNr">373 </span><span class="SalientComment">//:: push</span>
+<span id="L374" class="LineNr">374 </span>
+<span id="L375" class="LineNr">375 </span><span class="Delimiter">:(scenario push_imm32)</span>
+<span id="L376" class="LineNr">376 </span><span class="Special">% Reg[ESP].u = 0x14;</span>
+<span id="L377" class="LineNr">377 </span><span class="Comment"># op  ModRM   SIB   displacement  immediate</span>
+<span id="L378" class="LineNr">378 </span>  <span class="Constant">68</span>                              af <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span> <span class="PreProc">0</span><span class="Constant">0</span>  <span class="Comment"># push *EAX (reg 0) to stack</span>
+<span id="L379" class="LineNr">379 </span><span class="traceContains">+run: push <a href='010core.cc.html#L219'>imm32</a> 0x000000af</span>
+<span id="L380" class="LineNr">380 </span><span class="traceContains">+run: <a href='010core.cc.html#L11'>ESP</a> is now 0x00000010</span>
+<span id="L381" class="LineNr">381 </span><span class="traceContains">+run: <a href='003trace.cc.html#L74'>contents</a> at <a href='010core.cc.html#L11'>ESP</a>: 0x000000af</span>
+<span id="L382" class="LineNr">382 </span>
+<span id="L383" class="LineNr">383 </span><span class="Delimiter">:(before &quot;End Single-Byte Opcodes&quot;)</span>
+<span id="L384" class="LineNr">384 </span><span class="Normal">case</span> <span class="Constant">0x68</span>: <span class="Delimiter">{</span>
+<span id="L385" class="LineNr">385 </span>  <span class="Normal">int32_t</span> val = <a href='010core.cc.html#L219'>imm32</a><span class="Delimiter">();</span>
+<span id="L386" class="LineNr">386 </span>  <a href='003trace.cc.html#L160'>trace</a><span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;push <a href='010core.cc.html#L219'>imm32</a> 0x&quot;</span> &lt;&lt; <a href='010core.cc.html#L230'>HEXWORD</a> &lt;&lt; val &lt;&lt; <a href='003trace.cc.html#L184'>end</a><span class="Delimiter">();</span>
+<span id="L387" class="LineNr">387 </span>  Reg[ESP]<span class="Delimiter">.</span>u -= <span class="Constant">4</span><span class="Delimiter">;</span>
+<span id="L388" class="LineNr">388 </span>  *<span class="Normal">reinterpret_cast</span>&lt;<span class="Normal">uint32_t</span>*&gt;<span class="Delimiter">(</span>&amp;Mem<span class="Delimiter">.</span>at<span class="Delimiter">(</span>Reg[ESP]<span class="Delimiter">.</span>u<span class="Delimiter">))</span> = val<span class="Delimiter">;</span>
+<span id="L389" class="LineNr">389 </span>  <a href='003trace.cc.html#L160'>trace</a><span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;ESP is now 0x&quot;</span> &lt;&lt; <a href='010core.cc.html#L230'>HEXWORD</a> &lt;&lt; Reg[ESP]<span class="Delimiter">.</span>u &lt;&lt; <a href='003trace.cc.html#L184'>end</a><span class="Delimiter">();</span>
+<span id="L390" class="LineNr">390 </span>  <a href='003trace.cc.html#L160'>trace</a><span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;contents at <a href='010core.cc.html#L11'>ESP</a>: 0x&quot;</span> &lt;&lt; <a href='010core.cc.html#L230'>HEXWORD</a> &lt;&lt; *<span class="Normal">reinterpret_cast</span>&lt;<span class="Normal">uint32_t</span>*&gt;<span class="Delimiter">(</span>&amp;Mem<span class="Delimiter">.</span>at<span class="Delimiter">(</span>Reg[ESP]<span class="Delimiter">.</span>u<span class="Delimiter">))</span> &lt;&lt; <a href='003trace.cc.html#L184'>end</a><span class="Delimiter">();</span>
+<span id="L391" class="LineNr">391 </span>  <span class="Identifier">break</span><span class="Delimiter">;</span>
+<span id="L392" class="LineNr">392 </span><span class="Delimiter">}</span>
 </pre>
 </body>
 </html>
diff --git a/subx/011direct_addressing.cc b/subx/011direct_addressing.cc
index 827ce41e..a8f3fe7e 100644
--- a/subx/011direct_addressing.cc
+++ b/subx/011direct_addressing.cc
@@ -235,7 +235,7 @@ case 0x53:
 case 0x54:
 case 0x55:
 case 0x56:
-case 0x57: {
+case 0x57: {  // push r32 to stack
   uint8_t reg = op & 0x7;
   trace(2, "run") << "push reg " << NUM(reg) << end();
   const int32_t val = Reg[reg].u;
diff --git a/subx/013immediate_addressing.cc b/subx/013immediate_addressing.cc
index 14121d42..4773e75f 100644
--- a/subx/013immediate_addressing.cc
+++ b/subx/013immediate_addressing.cc
@@ -332,14 +332,20 @@ case 7: {
 
 :(scenario copy_imm32_to_r32)
 # op  ModRM   SIB   displacement  immediate
-  b8  03                          0a 0b 0c 0d  # copy 0x0d0c0b0a to EBX (reg 3)
+  bb                              0a 0b 0c 0d  # copy 0x0d0c0b0a to EBX (reg 3)
 +run: copy imm32 0x0d0c0b0a to reg 3
 
 :(before "End Single-Byte Opcodes")
-case 0xb8: {  // copy imm32 to r32
-  uint8_t modrm = next();
+case 0xb8:
+case 0xb9:
+case 0xba:
+case 0xbb:
+case 0xbc:
+case 0xbd:
+case 0xbe:
+case 0xbf: {  // copy imm32 to r32
+  uint8_t reg1 = op & 0x7;
   int32_t arg2 = imm32();
-  uint8_t reg1 = modrm&0x7;  // ignore mod bits
   trace(2, "run") << "copy imm32 0x" << HEXWORD << arg2 << " to reg " << NUM(reg1) << end();
   Reg[reg1].i = arg2;
   break;