<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="">Thanks!<div class=""><br class=""></div><div class="">Q.</div><div class=""><br class=""><div style=""><blockquote type="cite" class=""><div class="">On Jul 16, 2015, at 11:56 AM, Matthias Braun <<a href="mailto:matze@braunis.de" class="">matze@braunis.de</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">I improved things in r242431.</div><div class=""><br class=""></div><div class="">- Matthias</div><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Jul 16, 2015, at 10:37 AM, Quentin Colombet <<a href="mailto:qcolombet@apple.com" class="">qcolombet@apple.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Ping!<div class=""><br class=""></div><div class="">On the highlighted points, look for ##</div><div class=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Jul 1, 2015, at 4:04 PM, Quentin Colombet <<a href="mailto:qcolombet@apple.com" class="">qcolombet@apple.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><blockquote type="cite" 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;" class=""><br class="Apple-interchange-newline">On Jul 1, 2015, at 3:36 PM, Matthias Braun <<a href="mailto:matze@braunis.de" class="">matze@braunis.de</a>> wrote:<br class=""><br class=""><br class=""><blockquote type="cite" class="">On Jul 1, 2015, at 3:12 PM, Quentin Colombet <<a href="mailto:qcolombet@apple.com" class="">qcolombet@apple.com</a>> wrote:<br class=""><br class="">Hi Matthias,<br class=""><br class="">Is there a way we can do that as part of shrinkToUses?<br class="">My concern is that future users of that API may have similar problems and would need a similar fix.<br class=""></blockquote>The problem is that these shrinkToUses variants work on a single SubRange, but in the context of a subrange you can't just remove yourself from the list (or you'll very likely invalidate the iterators of people calling the function).<br class=""></blockquote><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;" class=""><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;" class="">That’s right. I was thinking that we could return a boolean in that case, but that would be inconsistent with the meaning of the boolean for the non-specialized version of shrinkToUses.</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;" class=""><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;" class=""><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;" class="">I am wondering if we should return via an output parameter (like the dead definition) the empty subrange.</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;" class=""></div></blockquote><div class=""><br class=""></div>## Anyway, we could add a comment on the method to point out that it might generate empty subranges and that those must be cleaned up.<br class=""><br class=""><blockquote type="cite" class=""><div class=""><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;" class=""><blockquote type="cite" 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;" class="">I can change some verifiers/check functions to catch those cases earlier though.<br class=""></blockquote><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;" class=""></div></blockquote><div class=""><br class=""></div>## A check in the verifier would be nice indeed!</div><div class=""><br class=""></div><div class="">Thanks,</div><div class="">-Quentin<br class=""><blockquote type="cite" class=""><div class=""><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;" class=""><blockquote type="cite" 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;" class="">It's probably also possible to loosen the requirements and allow empty subranges but that needs a careful code review.<br class=""><br class=""><blockquote type="cite" class=""><br class="">Also, could you check that we generate something meaningful, not just don’t crash (I know we already have this discussion, I still don’t like test case with FileCheck :)).<br class=""></blockquote>I'm pretty sure you meant "without" here :)<br class=""></blockquote><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;" class=""><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;" class="">Indeed :).</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;" class=""><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;" class=""><blockquote type="cite" 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;" class="">I've added some FileCheck there now, but I can't help you with the "meaningful" part because I don't know enough about AMDGPU to judge that, it's just testing for a fixed output now.<br class=""></blockquote><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;" class=""><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;" class="">That’s good enough for me.</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;" class=""><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;" class=""><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;" class="">Thanks,</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;" class=""><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;" class="">-Quentin</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;" class=""><blockquote type="cite" 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;" class=""><br class="">- Matthias<br class=""><br class=""><blockquote type="cite" class=""><br class="">Thanks,<br class="">-Quentin<br class=""><br class=""><blockquote type="cite" class="">On Jun 29, 2015, at 5:33 PM, Matthias Braun <<a href="mailto:matze@braunis.de" class="">matze@braunis.de</a>> wrote:<br class=""><br class="">Author: matze<br class="">Date: Mon Jun 29 19:33:44 2015<br class="">New Revision: 241027<br class=""><br class="">URL: <a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_viewvc_llvm-2Dproject-3Frev-3D241027-26view-3Drev&d=AwMFaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=mQ4LZ2PUj9hpadE3cDHZnIdEwhEBrbAstXeMaFoB9tg&m=pCcxCKfF2PXt8TiSX5s8Ta-Wnhb2pKT_sldhGZ9NGD4&s=bdHrjCMa5HP0Il4M8ZeICCb7FggLodM0dWuFB16JN1g&e=" class="">http://llvm.org/viewvc/llvm-project?rev=241027&view=rev</a><br class="">Log:<br class="">RegisterCoalescer: Cleanup empty subranges after shrinkToUses()<br class=""><br class="">A call to removeEmptySubranges() is necessary after every operation that<br class="">potentially removes all segments from a subregister range; this case in<br class="">the register coalescer was missing.<br class=""><br class="">Added:<br class="">llvm/trunk/test/CodeGen/AMDGPU/subreg-coalescer-undef-use.ll<br class="">Modified:<br class="">llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp<br class=""><br class="">Modified: llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp<br class="">URL: <a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_lib_CodeGen_RegisterCoalescer.cpp-3Frev-3D241027-26r1-3D241026-26r2-3D241027-26view-3Ddiff&d=AwMFaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=mQ4LZ2PUj9hpadE3cDHZnIdEwhEBrbAstXeMaFoB9tg&m=pCcxCKfF2PXt8TiSX5s8Ta-Wnhb2pKT_sldhGZ9NGD4&s=DfXdw403uIKq4O24cYCW9eoorJXzmyzqlvSEtv0uL3k&e=" class="">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp?rev=241027&r1=241026&r2=241027&view=diff</a><br class="">==============================================================================<br class="">--- llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp (original)<br class="">+++ llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp Mon Jun 29 19:33:44 2015<br class="">@@ -1449,6 +1449,7 @@ bool RegisterCoalescer::joinCopy(Machine<br class=""> << format("%04X", S.LaneMask) << ")\n");<br class=""> LIS->shrinkToUses(S, LI.reg);<br class=""> }<br class="">+ LI.removeEmptySubRanges();<br class="">}<br class="">if (ShrinkMainRange) {<br class=""> LiveInterval &LI = LIS->getInterval(CP.getDstReg());<br class=""><br class="">Added: llvm/trunk/test/CodeGen/AMDGPU/subreg-coalescer-undef-use.ll<br class="">URL: <a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_test_CodeGen_AMDGPU_subreg-2Dcoalescer-2Dundef-2Duse.ll-3Frev-3D241027-26view-3Dauto&d=AwMFaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=mQ4LZ2PUj9hpadE3cDHZnIdEwhEBrbAstXeMaFoB9tg&m=pCcxCKfF2PXt8TiSX5s8Ta-Wnhb2pKT_sldhGZ9NGD4&s=AaVYqE4fF_EZFC5XsYzkpZ6gbqPhRaWV6L9bq1FjSyM&e=" class="">http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/subreg-coalescer-undef-use.ll?rev=241027&view=auto</a><br class="">==============================================================================<br class="">--- llvm/trunk/test/CodeGen/AMDGPU/subreg-coalescer-undef-use.ll (added)<br class="">+++ llvm/trunk/test/CodeGen/AMDGPU/subreg-coalescer-undef-use.ll Mon Jun 29 19:33:44 2015<br class="">@@ -0,0 +1,20 @@<br class="">+; RUN: llc -march=amdgcn -mcpu=SI -o /dev/null %s<br class="">+; Don't crash when the use of an undefined value is only detected by the<br class="">+; register coalescer because it is hidden with subregister insert/extract.<br class="">+target triple="amdgcn--"<br class="">+<br class="">+define void @foobar(float %a0, float %a1, float addrspace(1)* %out) nounwind {<br class="">+entry:<br class="">+ %v0 = insertelement <4 x float> undef, float %a0, i32 0<br class="">+ br i1 undef, label %ift, label %ife<br class="">+<br class="">+ift:<br class="">+ %v1 = insertelement <4 x float> undef, float %a1, i32 0<br class="">+ br label %ife<br class="">+<br class="">+ife:<br class="">+ %val = phi <4 x float> [ %v1, %ift ], [ %v0, %entry ]<br class="">+ %v2 = extractelement <4 x float> %val, i32 1<br class="">+ store float %v2, float addrspace(1)* %out, align 4<br class="">+ ret void<br class="">+}<br class=""><br class=""><br class="">_______________________________________________<br class="">llvm-commits mailing list<br class=""><a href="mailto:llvm-commits@cs.uiuc.edu" class="">llvm-commits@cs.uiuc.edu</a><br class=""><a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits" class="">http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits</a><br class=""></blockquote><br class=""><br class="">_______________________________________________<br class="">llvm-commits mailing list<br class=""><a href="mailto:llvm-commits@cs.uiuc.edu" class="">llvm-commits@cs.uiuc.edu</a><br class=""><a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits" class="">http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits</a><br class=""></blockquote><br class=""></blockquote><br style="font-family: Helvetica; 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