<html><head><base href="x-msg://46/"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Jun 12, 2011, at 12:50 AM, Shajrawi, Yousef wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: Optima; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div lang="EN-US" link="blue" vlink="purple"><div class="WordSection1" style="page: WordSection1; "><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; ">I’ve reported bug #10125 about debug variables incorrectly deleted by LLVM in the Live Debug Variables pass: <a href="http://llvm.org/bugs/show_bug.cgi?id=10125" style="color: blue; text-decoration: underline; ">http://llvm.org/bugs/show_bug.cgi?id=10125</a></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><o:p> </o:p></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; ">Attached is a patch resolving this bug via adding a check to live ins of a basic block (description is in bugzilla)</div></div></div></span></blockquote><div><br></div><div>Hi Yousef,</div><div><br></div><div>I think you are misunderstanding the purpose of the Live Debug Variables pass. It is supposed to remove all DBG_VALUE instructions. It builds a data structure that is easier to work with for the register allocator passes.</div><div><br></div><div>After register allocation, the DBG_VALUE instructions are written back with references to the correct physical registers and spill slots.</div><div><br></div><div>This is all necessary to keep track of debug variables while the register allocator coalesces and splits and spills live ranges.</div><br><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: Optima; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div lang="EN-US" link="blue" vlink="purple"><div class="WordSection1" style="page: WordSection1; "><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><o:p> </o:p>Please see if this is suitable for adding to LLVM and/or please advise on what to do next, This is my first contribution to LLVM so I don’t know the procedure…</div></div></div></span></blockquote><div><br></div><div>You are on the right track, but please make sure that you describe the actual symptoms when you file a bug report. The behavior you describe sounds correct to me, and when I run your IR through the ARM backend, the result looks fine.</div><div><br></div><div>So what caused you to file a bug in the first place?</div><div><br></div><div>/jakob</div><div><br></div></div></body></html>