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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Hi Chris,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;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…<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Thanks,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Nicolas<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
llvmdev-bounces@cs.uiuc.edu [mailto:llvmdev-bounces@cs.uiuc.edu] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Chris Lattner<br>
<b><span style='font-weight:bold'>Sent:</span></b> Friday, 18 July, 2008 20:06<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">LLVM
Developers Mailing List</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [LLVMdev] Changing
target features from C++</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>On Jul 18, 2008, at 8:42 AM, Nicolas Capens wrote:<o:p></o:p></span></font></p>
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<br>
<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
11.0pt;font-family:Arial;color:black'>Hi all,<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
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<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
11.0pt;font-family:Arial;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
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<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
11.0pt;font-family:Arial;color:black'>How do I properly/conveniently change ISA
features of the code to be generated? For instance I have a Core 2 Duo with
SSSE3 but I’d also like to test whether everything would JIT compile correctly
on something with just SSE2 (a Pentium 4) or even older. In other words, how do
I prevent LLVM from using certain target features?<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
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<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
11.0pt;font-family:Arial;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>The JIT defaults to using whatever it can. You can
hack X86Subtarget::AutoDetectSubtargetFeatures() to disable specific
features.<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>-Chris<o:p></o:p></span></font></p>
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