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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Hi Chandler,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>That’s fine, it was a pedantic nitpick anyway </span><span
style='font-size:11.0pt;font-family:Wingdings;color:#1F497D'>J</span><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Cheers,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>James<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><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"'> Chris Lattner [mailto:clattner@apple.com] <br>
<b>Sent:</b> 31 January 2012 04:56<br>
<b>To:</b> Chandler Carruth<br>
<b>Cc:</b> James Molloy; llvm-commits@cs.uiuc.edu; Anton Korobeynikov<br>
<b>Subject:</b> Re: [llvm-commits] PATCH: Add 64-bit architecture predicate to
llvm::Triple<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>On Jan 30, 2012, at 8:51 PM, Chandler Carruth wrote:<o:p></o:p></p>
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<br>
<o:p></o:p></p>
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<p class=MsoNormal>On Mon, Jan 30, 2012 at 10:08 AM, James Molloy <<a
href="mailto:james.molloy@arm.com">james.molloy@arm.com</a>> wrote:<o:p></o:p></p>
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<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
style='color:#1F497D'>Hi Chandler,</span><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
style='color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
style='color:#1F497D'>One point:</span><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
style='color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
style='color:#1F497D'>+ /// Note that this tests for 16-bit pointer
width, and nothing else.</span><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
style='color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
style='color:#1F497D'>I’m not sure this comment is accurate. For example, real
mode x86 would be 16-bit but has 24-bit pointers (seg:offset).</span><o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>As far as I can tell, there is no support for x86-16 or real
mode or any of the other segmented addressing modes on x86. If such modes are
added, I would be quite happy for them to return false on all three of these
queries. ;] I still think "pointer size" is the most descriptive
term, but I'm open to more suggestions.<o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>FWIW, the reason I don't particularly like "native
width of the register file" is that i find it much less clear and
unambiguous given the diversity of register widths on even modern architectures.
However, addresses generally have a fixed size on modern architectures, and so
that seems a good classification scheme.<o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>Just my contribution to the bikeshed: I don't think that it
makes sense for llvm::Triple to know the "native width of the register
file", since that is such an amorphous statement. The best that
llvm::Triple can know is sizeof(void*) in the default address space.<o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>-Chris<o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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