<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, 2014, at 10:19 AM, Hal Finkel <<a href="mailto:hfinkel@anl.gov">hfinkel@anl.gov</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;">To be honest, I don't understand why you're seeing this problem. I know this was a problem pre-SSE, but I think that once SSE became available, the cost of forcing IEEE strict math became reasonable. IEEE arithmetic (although not the transcendental functions) should be strictly deterministic across platforms, and I don't see any reason we should support building LLVM in any other mode.</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;"></blockquote></div><br><div>Even pre-SSE, you can change the default excess precision mode for x87 to force 32/64-bit rounding. The default is different on different platforms, and I thought I saw somewhere in LLVM the wrappers around all the different wrappers for fldcw before.</div></body></html>