<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Apr 29, 2015, at 3:00 PM, Stephen Canon <<a href="mailto:scanon@apple.com" class="">scanon@apple.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=windows-1252" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><blockquote type="cite" class="">On Apr 29, 2015, at 2:33 PM, Matt Arsenault <<a href="mailto:arsenm2@gmail.com" class="">arsenm2@gmail.com</a>> wrote:<br class=""></blockquote><div class=""><blockquote type="cite" class=""><div class=""><meta http-equiv="Content-Type" content="text/html charset=windows-1252" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Apr 29, 2015, at 10:06 AM, Silviu Baranga <<a href="mailto:Silviu.Baranga@arm.com" class="">Silviu.Baranga@arm.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif; 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;" class="">Note that dividing by an integer constant should be a cheap operation<o:p class=""></o:p></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif; 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;" class="">compared to FP multiplication and comparison as this would get lowered to a<o:p class=""></o:p></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif; 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;" class="">multiply+subtract+shift sequence (and should certainly be true on cores with no<o:p class=""></o:p></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif; 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;" class="">FP unit)<o:p class=""></o:p></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif; 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;" class=""><o:p class=""> </o:p></div></div></blockquote></div><br class=""><div class="">This is not true on the targets I care about. The integer division (which, even with the division by constant expansion to multiplies with magic constants) would be significantly more expensive.</div></div></div></blockquote><br class=""></div><div class="">What targets *does* this benefit? Soft-float targets and Cortex-A8?</div><div class=""><br class=""></div><div class="">Anyway, both integer and floating-point multiplication and division are monotonic, so it suffices to check the two values of x that bracket y/f.</div></div></div></blockquote><br class=""></div><div>Ah, I see now that y is not a constant. Slightly more subtle. =)</div><div><br class=""></div><div>I’ll respond later.</div></body></html>