<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Jul 18, 2008, at 8:42 AM, Nicolas Capens wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div lang="EN-US" link="blue" vlink="purple"><div class="Section1"><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif; ">Hi all,<o:p></o:p></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif; "><o:p> </o:p></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif; ">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></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif; "><o:p> </o:p></div></div></div></span></blockquote><br></div><div>The JIT defaults to using whatever it can. You can hack X86Subtarget::AutoDetectSubtargetFeatures() to disable specific features.</div><div><br></div><div>-Chris</div></body></html>