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<p class="MsoNormal">> I’m not sure whether this restriction should be relaxed to allow operands with different size or it’s the<o:p></o:p></p>
<p class="MsoNormal">> source program that has to be fixed. I couldn’t find anything in gcc’s documentation that says whether<o:p></o:p></p>
<p class="MsoNormal">> or not this is legal.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">I'm not sure either.
</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">I have some candidate patches to the source program and changing the source is my preference because there's only a single instance of this construct as far as I know. However it also
makes sense to be able to do something like:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> int result;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> short operand;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> asm ("seh %0, %1" : "=r"(result) : "0"(operand)) // seh is a sign-extend instruction<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">as long as an int and a short can be stored in the same register.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Akira Hatanaka [mailto:ahatanaka@apple.com]
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<b>Sent:</b> 04 February 2015 19:15<br>
<b>To:</b> Reid Kleckner<br>
<b>Cc:</b> Daniel Sanders; cfe-dev@cs.uiuc.edu<br>
<b>Subject:</b> Re: [cfe-dev] Clang rejects inline assembly that has tied operands with different types<o:p></o:p></span></p>
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<p class="MsoNormal">I changed this function recently (yesterday), but I think this error message is unrelated to the change I made. The piece of code that emits this error was committed originally in r70142.<o:p></o:p></p>
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<p class="MsoNormal"><a href="http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20090420/016312.html">http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20090420/016312.html</a><o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I’m not sure whether this restriction should be relaxed to allow operands with different size or it’s the source program that has to be fixed. I couldn’t find anything in gcc’s documentation that says whether or not this is legal.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><a href="https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended-Asm">https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended-Asm</a><o:p></o:p></p>
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<p class="MsoNormal">On Feb 4, 2015, at 10:25 AM, Reid Kleckner <<a href="mailto:rnk@google.com">rnk@google.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Courier New"">csum_ipv6_magic</span><o:p></o:p></p>
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