<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;"><br><div><div>On Sep 5, 2014, at 10:35 AM, Quentin Colombet <<a href="mailto:qcolombet@apple.com">qcolombet@apple.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div 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;"><div><br class="Apple-interchange-newline">On Sep 5, 2014, at 10:21 AM, Juergen Ributzka <<a href="mailto:juergen@apple.com">juergen@apple.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">clearKillFlags seems a little "overkill" to me. In this case you could just simply transfer the value of the kill flag from the SrcReg to the DstReg.</blockquote><div><br></div><div>We are extending the live-range of SrcReg. I do not see how you could relate that to the kill flag of DstReg.</div></div></blockquote><div><br></div><div>I mean, we *may* extend, but we do not really know.</div><br><blockquote type="cite"><div 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;"><div><br></div><div>Therefore, I still think, this is the right fix.</div><div><br></div><div>-Quentin</div><br><blockquote type="cite"><div><br></div><div>-Juergen<br><br><span>On 09/05/14,<span class="Apple-converted-space"> </span><b class="name">Quentin Colombet<span class="Apple-converted-space"> </span></b><<a href="mailto:qcolombet@apple.com">qcolombet@apple.com</a>> wrote:</span><blockquote cite="mid:25C90F09-8351-42FE-8761-4F890DB09A05@apple.com" class="iwcQuote" type="cite" style="border-left-width: 1px; border-left-style: solid; border-left-color: rgb(0, 0, 255); padding-left: 13px; margin-left: 0px;"><div class="mimepart text html"><span><p><table><tbody><tr><td style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><p>Hi Patrik,</p><div><br></div><div>LGTM.</div><div><br></div><div>Thanks,</div><div>-Quentin<br><div><div>On Sep 5, 2014, at 1:03 AM, Patrik Hägglund H <<a href="mailto:patrik.h.hagglund@ericsson.com">patrik.h.hagglund@ericsson.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div lang="EN-US" link="blue" vlink="purple" 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;"><div class="WordSection1" style="page: WordSection1;"><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">Hi Quentin,<o:p></o:p></span></div><div><br></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">Jonas looked further into the problem below, and asked me to submit his patch. Note the we have our own out-of-tree target, and we have not been able to reproduce this problem on an in-tree target. /Patrik<span class="SpellE">Hägglund</span><o:p></o:p></span></div><div><br></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">[<span class="SpellE">MachineSinking</span>] Conservatively clear kill flags after coalescing.<o:p></o:p></span></div><div><br></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">This solves the problem of having a kill flag inside a loop<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">with a definition of the register prior to the loop:<o:p></o:p></span></div><div><br></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">%vreg368<<span class="SpellE">def</span>> ...<o:p></o:p></span></div><div><br></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">Inside loop:<o:p></o:p></span></div><div><br></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);"><span> </span>%vreg520<<span class="SpellE">def</span>> = COPY %vreg368<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);"><span> </span>%vreg568<def,tied1> = add %vreg341<tied0>, %vreg520<kill><o:p></o:p></span></div><div><br></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">=> was coalesced into =><o:p></o:p></span></div><div><br></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);"> </span><span lang="SV" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">%vreg568<def,tied1> =<span class="SpellE">add</span>%vreg341<tied0>, %vreg368<kill><o:p></o:p></span></div><div><br></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span class="SpellE"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">MachineVerifier</span></span><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">then complained:<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">*** Bad machine code: Virtual register killed in block, but needed live out. ***<o:p></o:p></span></div><div><br></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">The kill flag for %vreg368 is incorrect, and is cleared by this patch.<o:p></o:p></span></div><div><br></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">This is similar to the clearing done at the end of<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span class="SpellE"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">MachineSinking</span></span><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">::<span class="SpellE">SinkInstruction</span>().<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">---<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">lib/<span class="SpellE">CodeGen</span>/MachineSink.cpp | 5 +++++<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">1 file changed, 5 insertions(+)<o:p></o:p></span></div><div><br></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">diff --<span class="SpellE">git</span>a/lib/<span class="SpellE">CodeGen</span>/MachineSink.cpp b/lib/<span class="SpellE">CodeGen</span>/MachineSink.cpp<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">index 7782001..261af54 100644<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">--- a/lib/<span class="SpellE">CodeGen</span>/MachineSink.cpp<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">+++ b/lib/<span class="SpellE">CodeGen</span>/MachineSink.cpp<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">@@ -157,6 +157,11 @@<span class="SpellE">bool</span><span class="SpellE">MachineSinking</span>::<span class="SpellE">PerformTrivialForwardCoalescing</span>(<span class="SpellE">MachineInstr</span>*MI,<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);"><span> </span>DEBUG(<span class="SpellE">dbgs</span>() << "*** to: " << *MI);<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);"><span> </span>MRI-><span class="SpellE">replaceRegWith</span>(<span class="SpellE">DstReg</span>,<span class="SpellE">SrcReg</span>);<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);"><span> </span>MI-><span class="SpellE">eraseFromParent</span>();<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">+<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">+<span> </span>// Conservatively, clear any kill flags, since it's possible that they are no<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">+<span> </span>// longer correct.<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">+<span> </span>MRI-><span class="SpellE">clearKillFlags</span>(<span class="SpellE">SrcReg</span>);<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">+<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);"><span> </span>++<span class="SpellE">NumCoalesces</span>;<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);"><span> </span>return true;<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">}<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">--<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">2.1.0<o:p></o:p></span></div><div><br></div><div><div style="border-style: solid none none; border-top-color: rgb(181, 196, 223); border-top-width: 1pt; padding: 3pt 0cm 0cm;"><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><b><span style="font-size: 10pt; font-family: Tahoma, sans-serif;">From:</span></b><span style="font-size: 10pt; font-family: Tahoma, sans-serif;"><a href="mailto:llvmdev-bounces@cs.uiuc.edu" style="color: purple; text-decoration: underline;">llvmdev-bounces@cs.uiuc.edu</a>[<a href="mailto:llvmdev-bounces@cs.uiuc.edu" style="color: purple; text-decoration: underline;">mailto:llvmdev-bounces@cs.uiuc.edu</a>]<b>On Behalf Of</b>Quentin Colombet<br><b>Sent:</b>den 2 september 2014 18:37<br><b>To:</b>Jonas Paulsson<br><b>Cc:</b><a href="mailto:llvmdev@cs.uiuc.edu" style="color: purple; text-decoration: underline;">llvmdev@cs.uiuc.edu</a><br><b>Subject:</b>Re: [LLVMdev] Machine code sinking pass<o:p></o:p></span></div></div></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><o:p> </o:p></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span>Hi Jonas,<o:p></o:p></span></div><div><br></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span>This looks like a bug in Machine code sinking pass.<o:p></o:p></span></div></div><div><br></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span>Please file a PR on<a href="http://llvm.org/bugs" target="1" style="color: purple; text-decoration: underline;">llvm.org/bugs</a>with a reduced test case to keep track of the issue.<o:p></o:p></span></div></div><div><br></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span>Thanks,<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span>-Quentin<o:p></o:p></span></div></div><div><div><br></div><div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span>On Sep 2, 2014, at 5:57 AM, Jonas Paulsson <<a href="mailto:jonas.paulsson@ericsson.com" style="color: purple; text-decoration: underline;">jonas.paulsson@ericsson.com</a>> wrote:<o:p></o:p></span></div></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span><br><br><o:p></o:p></span></div><div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span lang="SV" style="font-size: 11pt; font-family: Calibri, sans-serif;">Hi,</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;">I ran into MachineVerifier ”Virtual register killed in block, but needed live out.”<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"> <o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;">It was MachineSinking:PerformTrivialForwardCoalescing() that coalesced a COPY inside a single-block loop, but left the<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;">kill-flag and then MachineVerifier complains that a register in vregsRequired is killed in MBB.<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"> <o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;">In the example, %vreg520 is replaced by %vreg368 by PerformTrivialForwardCoalescing(), without clearing the kill flag:<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"> <o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: 'Courier New';">BB#13: derived from LLVM BB %CF250</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: 'Courier New';"> Predecessors according to CFG: BB#12 BB#13 BB#14</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span lang="SV" style="font-size: 11pt; font-family: 'Courier New';"> …</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span lang="SV" style="font-size: 11pt; font-family: 'Courier New';"> %vreg520<def> = COPY %vreg368</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span lang="SV" style="font-size: 11pt; font-family: 'Courier New';"> %vreg568<def,tied1> = cmp %vreg341<tied0>, %vreg520<kill></span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span lang="SV" style="font-size: 11pt; font-family: 'Courier New';"> </span><span style="font-size: 11pt; font-family: 'Courier New';">brr_cond <BB#13></span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: 'Courier New';"> brr_uncond <BB#14></span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: 'Courier New';"> Successors according to CFG: BB#13, BB#14</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"> <o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;">Into<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"> <o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: 'Courier New';">BB#13: derived from LLVM BB %CF250</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: 'Courier New';"> Predecessors according to CFG: BB#12 BB#13 BB#14</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span lang="SV" style="font-size: 11pt; font-family: 'Courier New';"> …</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span lang="SV" style="font-size: 11pt; font-family: 'Courier New';"> %vreg568<def,tied1> = cmp %vreg341<tied0>, %vreg368<kill></span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span lang="SV" style="font-size: 11pt; font-family: 'Courier New';"> </span><span style="font-size: 11pt; font-family: 'Courier New';">brr_cond <BB#13></span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: 'Courier New';"> brr_uncond <BB#14></span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: 'Courier New';">=></span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: 'Courier New';">*** Bad machine code: Virtual register killed in block, but needed live out. ***</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: 'Courier New';">- function: autogen_SD15028</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: 'Courier New';">- basic block: BB#13 CF250 (0x1c75890)</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: 'Courier New';">Virtual register %vreg368 is used after the block.</span><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;">There is only one use of %vreg368 in the function.<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"> <o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;">One thing that strikes me is that one might want to clear the kill flag for a use inside a loop of a register defined prior to<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;">the loop?<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"> <o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;">Best regards,<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"> <o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;">Jonas Paulsson<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"> <o:p></o:p></span></div></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-size: 9pt; font-family: Helvetica, sans-serif;">_______________________________________________<br>LLVM Developers mailing list<br><a href="mailto:LLVMdev@cs.uiuc.edu" style="color: purple; text-decoration: underline;"><span style="color: purple;">LLVMdev@cs.uiuc.edu</span></a> <a href="http://llvm.cs.uiuc.edu/" target="1" style="color: purple; text-decoration: underline;"><span style="color: purple;">http://llvm.cs.uiuc.edu</span></a><br><a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev" target="1" style="color: purple; text-decoration: underline;"><span style="color: purple;">http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev</span></a><o:p></o:p></span></div></div></div><div><br></div></div></div><span><0001-MachineSinking-Conservatively-clear-kill-flags-after.patch></span></div></blockquote></div><br></div></td></tr></tbody></table></p></span></div></blockquote></div></blockquote></div><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;"><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;">_______________________________________________</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;"><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;">llvm-commits mailing list</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;"><a href="mailto:llvm-commits@cs.uiuc.edu" 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;">llvm-commits@cs.uiuc.edu</a><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;"><a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits" 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;">http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits</a></blockquote></div><br></body></html>