<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Jan 16, 2018, at 11:31 PM, Martin J. O'Riordan <<a href="mailto:MartinO@theheart.ie" class="">MartinO@theheart.ie</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="WordSection1" style="page: WordSection1; font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;"><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman", serif;" class=""><span style="font-family: "Book Antiqua", serif; color: rgb(148, 54, 52);" class="">Thanks Matthias,<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman", serif;" class=""><span style="font-family: "Book Antiqua", serif; color: rgb(148, 54, 52);" class=""><o:p class=""> </o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman", serif;" class=""><span style="font-family: "Book Antiqua", serif; color: rgb(148, 54, 52);" class="">I have both a pre-RA and a post-RA scheduler, and I had thought that I could track “has RA happened?” by setting a flag in my pre-RA scheduler as it completes - my suspicion (which you have confirmed) was that “#vregs == 0” was not a safe assumption. What I cannot be sure of, is what passes execute after my pre-RA scheduler but before RA, and what passes execute after RA but before my post-RA scheduler since this is largely target-independent. If any of those passes trigger a custom lowering action (frame setup for example), and it requires additional scratch registers, then my code generation strategy needs to change. As it happens, I know that frame lowering always occurs post-RA so that is not a real example, but is it possible that another pass between pre-RA and post-RA scheduling could trigger lowering actions? If not, then setting a flag in my pre-RA scheduler will solve the problem perfectly.</span></div></div></div></blockquote><div>Do you have a specific callback in TargetInstrInfo or similar in mind? I would expect them to either be used pre-ra or post-ra but not both...</div><div><br class=""></div><div>- Matthias</div><div><br class=""></div></div></body></html>