<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></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 Jun 16, 2017, at 2:43 PM, 陳韋任 via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" class="">llvm-dev@lists.llvm.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br class=""></div><div class="gmail_extra"><br class=""><div class="gmail_quote">2017-06-17 4:36 GMT+08:00 upcfrost <span dir="ltr" class=""><<a href="mailto:upcfrost@gmail.com" target="_blank" class="">upcfrost@gmail.com</a>></span>:<br class=""><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class=""><div class="">Hi,</div><div class=""><br class=""></div><div class="">Same here, my backend only has 64bit load/store. But i still use 64bit virt regs and expand/declare missing instructions by myself. </div><div class=""><br class=""></div><div class="">I'll try looking into sparc backend, thanks. Also, only after writing this post I found a bunch of built-in transforms. Still trying to understand how to use those.</div><div class=""><br class=""></div><div class="">By the way, constraint-wise (alignment), is there any difference between virt regclass and regtuple?</div></div></blockquote></div></div></div></div></blockquote><div><br class=""></div></div>That question makes no sense.<div class="">- Every virtual register has a register class assigned.</div><div class="">- You can construct special register classes that represent register tuples so that when the allocator chooses an entry from that register class it really has choosen a tuple of machine registers (even though it looks like a single register with funny aliasing as far as llvm codegen is concerned).<div class=""><br class=""></div><div class="">- Matthias</div></div></body></html>