<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Apr 21, 2013, at 12:05 PM, Evan Cheng <<a href="mailto:evan.cheng@apple.com">evan.cheng@apple.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span style="font-family: monospace; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; display: inline !important; float: none; ">What's preventing early-if-converter from being enabled for x86? I thought the x86 scheduling model is more or less done?</span><br style="font-family: monospace; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "></blockquote></div><br><div>The scheduling models are more or less done.</div><div><br></div><div>The if-converter is still causing some regressions. It looks like the MachineTraceMetrics pass needs a mechanism for estimating how much loop iterations can overlap. The regressions I've been looking at happen when we if-convert in a loop that can execute instructions from more than one iterations at once. This saturates the execution ports, and if-conversion causes more instructions to be executed.</div><div><br></div><div>/jakob</div><div><br></div></body></html>