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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Hi Chris,<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'>I need it to test correct code generation on a wide variety of
CPUs. I’m not entirely confident that if it runs fine on my Core 2 it
will run fine on a Pentium 4 or an Athlon 64, etc. (especially since I use lots
of vector operations). And since I don’t have ten different systems to
test on I need to make sure LLVM can be forced not to use certain CPU features.<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'>Nicolas<o:p></o:p></span></p>
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color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
llvmdev-bounces@cs.uiuc.edu [mailto:llvmdev-bounces@cs.uiuc.edu] <b>On Behalf
Of </b>Chris Lattner<br>
<b>Sent:</b> Sunday, 20 July, 2008 19:32<br>
<b>To:</b> LLVM Developers Mailing List<br>
<b>Subject:</b> Re: [LLVMdev] Changing target features from C++<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 Jul 20, 2008, at 2:59 AM, Nicolas Capens wrote:<o:p></o:p></p>
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<br>
<o:p></o:p></p>
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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>Hi Chris,</span><span style='color:black'><o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'> </span><span style='color:black'><o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>I see. While hacking AutoDetectSubtargetFeatures() works for me for
now, would it be useful to define an interface for X86Subtarget to change the
features in a cleaner way? Would methods like disableSSEn()/enableSSEn() work
or do you have another suggestion? I certainly want to avoid a situation where
one module uses other settings than another module…</span><span
style='color:black'><o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'> </span><span style='color:black'><o:p></o:p></span></p>
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<p class=MsoNormal>Why would this be useful for other users? It seems
best to always take advantage of features the cpu has if possible, and the JIT
has perfect knowledge of what the host cpu has.<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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