<html><head><base href="x-msg://3013/"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi Yin,<div><br></div><div>Comments:</div><div><br></div><div><div>+cl::opt<bool></div><div>+OptimizeGOT("optimize-got", cl::Hidden,</div><div>+ cl::desc("Enable / disable ARM PIC generation using more compact formats"),</div><div>+ cl::init(false));</div><div>+</div></div><div><br></div><div><div>+extern cl::opt<bool> OptimizeGOT;</div><div>+</div><div><br></div><div>This is the wrong way to implement it even if it's temporary. Please have the option sets the value of a member variable instead.</div><div><br></div><div>In ARMBaseInstrInfo.cpp:</div><div><br></div><div><div>+ if (ACPV->isGlobalValue()) {</div></div><div><div>+ if (OptimizeGOT) {</div><div>+ const GlobalValue *GV = cast<ARMConstantPoolConstant>(ACPV)->getGV();</div><div>+ bool UseGOTOFF = GV->hasLocalLinkage() || GV->hasHiddenVisibility();</div><div>+ unsigned PCAdj =</div><div>+ MF.getTarget().getSubtarget<ARMSubtarget>().isThumb() ? 4 : 8;</div><div>+ if (UseGOTOFF) {</div><div>+ NewCPV = ARMConstantPoolConstant::Create(GV,</div><div>+ PCLabelId, ARMCP::CPValue, PCAdj);</div><div>+ } else {</div><div>+ NewCPV = ARMConstantPoolConstant::Create(GV,</div><div>+ PCLabelId, ARMCP::CPValue, PCAdj,</div><div>+ ARMCP::GOTPREL, true);</div><div>+ }</div></div><div><br></div><div>Please add some comments on what's going on because it is not obvious. It seems to me that if duplicateCPV() needs to know that the option OptimizeGOT is set, then this is not designed correctly. That is, what information is missing from the instruction that passes after instruction selection must have implicit knowledge about?</div><div><br></div><div>Evan</div><div><br></div><div><div>On Aug 23, 2012, at 5:33 PM, Yin Ma wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div lang="EN-US" link="blue" vlink="purple"><div class="WordSection1" style="page: WordSection1; "><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">Hi Evan,<o:p></o:p></span></div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "><o:p> </o:p></span></div><div style="margin-right: 0in; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; margin-top: 0in; margin-bottom: 0.0001pt; ">This patch addressed the problem I submitted before. The default<o:p></o:p></div><div style="margin-right: 0in; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; margin-top: 0in; margin-bottom: 0.0001pt; ">Option has been set to off. A segment of redundant elimination code<o:p></o:p></div><div style="margin-right: 0in; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; margin-top: 0in; margin-bottom: 0.0001pt; ">has been removed. I will commit the new redundant elimination later<o:p></o:p></div><div style="margin-right: 0in; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; margin-top: 0in; margin-bottom: 0.0001pt; ">after it becomes available.<o:p></o:p></div><div style="margin-right: 0in; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; margin-top: 0in; margin-bottom: 0.0001pt; "><o:p> </o:p></div><div style="margin-right: 0in; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; margin-top: 0in; margin-bottom: 0.0001pt; ">Thanks,<o:p></o:p></div><div style="margin-right: 0in; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; margin-top: 0in; margin-bottom: 0.0001pt; "><o:p> </o:p></div><div style="margin-right: 0in; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; margin-top: 0in; margin-bottom: 0.0001pt; "> Yin<o:p></o:p></div><div style="margin-right: 0in; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; margin-top: 0in; margin-bottom: 0.0001pt; "><o:p> </o:p></div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "><o:p> </o:p></span></div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "><o:p> </o:p></span></div><div><div style="border-right-style: none; border-bottom-style: none; border-left-style: none; border-width: initial; border-color: initial; border-top-style: solid; border-top-color: rgb(181, 196, 223); border-top-width: 1pt; padding-top: 3pt; padding-right: 0in; padding-bottom: 0in; padding-left: 0in; "><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><b><span style="font-size: 10pt; font-family: Tahoma, sans-serif; ">From:</span></b><span style="font-size: 10pt; font-family: Tahoma, sans-serif; "><span class="Apple-converted-space"> </span>Evan Cheng [mailto:evan.cheng@apple.com]<span class="Apple-converted-space"> </span><br><b>Sent:</b><span class="Apple-converted-space"> </span>Wednesday, August 01, 2012 11:12 AM<br><b>To:</b><span class="Apple-converted-space"> </span>Yin Ma<br><b>Cc:</b><span class="Apple-converted-space"> </span><a href="mailto:llvm-commits@cs.uiuc.edu" style="color: blue; text-decoration: underline; ">llvm-commits@cs.uiuc.edu</a><br><b>Subject:</b><span class="Apple-converted-space"> </span>Re: [llvm-commits] [PATCH][Review Please] Optimize ARM Position Independent Code Generation<o:p></o:p></span></div></div></div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><o:p> </o:p></div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; ">Thanks. This looks like a good change to ELF codegen. I am ok with the isel change.<o:p></o:p></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><o:p> </o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; ">However, I'm not ok with pre-ra load / store optimizer change. It's the wrong place to do it. MachineCSE should be eliminating the unnecessary PIC instructions. You might want to look at Darwin codegen and how it plays with MachineCSE.<o:p></o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><o:p> </o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; ">Evan<o:p></o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><o:p> </o:p></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; ">On Aug 1, 2012, at 10:24 AM, Yin Ma <<a href="mailto:yinma@codeaurora.org" style="color: blue; text-decoration: underline; ">yinma@codeaurora.org</a>> wrote:<o:p></o:p></div></div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><br><br><o:p></o:p></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">Hi Evan,</span><o:p></o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "> </span><o:p></o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; text-indent: 9pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">The attached pdf contains an example of this change. It can result</span><o:p></o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; text-indent: 9pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">In code size reduction for most of PIC enabled programs.</span><o:p></o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "> </span><o:p></o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">Thanks,</span><o:p></o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "> </span><o:p></o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "> Yin</span><o:p></o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "> </span><o:p></o:p></div></div><div><div style="border-right-style: none; border-bottom-style: none; border-left-style: none; border-width: initial; border-color: initial; border-top-style: solid; border-top-color: rgb(181, 196, 223); border-top-width: 1pt; padding-top: 3pt; padding-right: 0in; padding-bottom: 0in; padding-left: 0in; "><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><b><span style="font-size: 10pt; font-family: Tahoma, sans-serif; ">From:</span></b><span class="apple-converted-space"><span style="font-size: 10pt; font-family: Tahoma, sans-serif; "> </span></span><span style="font-size: 10pt; font-family: Tahoma, sans-serif; ">Evan Cheng [mailto:evan.cheng@<a href="http://apple.com" style="color: blue; text-decoration: underline; "><span style="color: purple; ">apple.com</span></a>]<span class="apple-converted-space"> </span><br><b>Sent:</b><span class="apple-converted-space"> </span>Tuesday, July 31, 2012 5:48 PM<br><b>To:</b><span class="apple-converted-space"> </span>Yin Ma<br><b>Cc:</b><span class="apple-converted-space"> </span><a href="mailto:llvm-commits@cs.uiuc.edu" style="color: blue; text-decoration: underline; "><span style="color: purple; ">llvm-commits@cs.uiuc.edu</span></a><br><b>Subject:</b><span class="apple-converted-space"> </span>Re: [llvm-commits] [PATCH][Review Please] Optimize ARM Position Independent Code Generation</span><o:p></o:p></div></div></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "> <o:p></o:p></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; ">Hi Yin,<o:p></o:p></div></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "> <o:p></o:p></div></div></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; ">Can you provide some assembly code so we can understand what you are trying to do?<o:p></o:p></div></div></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "> <o:p></o:p></div></div></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; ">Thanks,<o:p></o:p></div></div></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "> <o:p></o:p></div></div></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; ">Evan<o:p></o:p></div></div></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "> <o:p></o:p></div></div><div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; ">On Jul 30, 2012, at 10:55 AM, Yin Ma <<a href="mailto:yinma@codeaurora.org" style="color: blue; text-decoration: underline; "><span style="color: purple; ">yinma@codeaurora.org</span></a>> wrote:<o:p></o:p></div></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><br><br><br><o:p></o:p></div></div><div><p style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-bottom: 12pt; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: white; background-position: initial initial; background-repeat: initial initial; "><span style="font-size: 10.5pt; font-family: Arial, sans-serif; ">Hi</span><o:p></o:p></p><p style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-bottom: 12pt; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: white; background-position: initial initial; background-repeat: initial initial; "><span style="font-size: 10.5pt; font-family: Arial, sans-serif; ">Currently LLVM ARM backend is still using the x86 way to generate position independent code. The algorithm retrieves the pointer of global offset table at first. However, GCC has been using the label relative offset to computer position independent code. The GCC way results smaller code size in ARM architecture. This patch is to implement GCC way to generate position independent code.</span><o:p></o:p></p><p style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-bottom: 12pt; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: white; background-position: initial initial; background-repeat: initial initial; "><span style="font-size: 10.5pt; font-family: Arial, sans-serif; ">In the attachment.<br>pic.diff is the code patch<br>the rest of four files are the test validation results before and after code changed</span><o:p></o:p></p><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; ">Please give a review</span><o:p></o:p></div></div></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; "> </span><o:p></o:p></div></div></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; ">Thanks,</span><o:p></o:p></div></div></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; "> </span><o:p></o:p></div></div></div><div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; "> Yin</span><o:p></o:p></div></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 13.5pt; font-family: Helvetica, sans-serif; "><report.simple.new.txt><report.simple.org.txt><cross.new><<a href="http://cross.org" style="color: blue; text-decoration: underline; "><span style="color: purple; ">cross.org</span></a>><pic.diff>_______________________________________________<br>llvm-commits mailing list<br><a href="mailto:llvm-commits@cs.uiuc.edu" style="color: blue; text-decoration: underline; "><span style="color: purple; ">llvm-commits@cs.uiuc.edu</span></a><br><a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits" style="color: blue; text-decoration: underline; "><span style="color: purple; ">http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits</span></a></span><o:p></o:p></div></div></div></div><div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "> <o:p></o:p></div></div></div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><span style="font-size: 13.5pt; font-family: Helvetica, sans-serif; "><pic.pdf><o:p></o:p></span></div></div></div><div style="margin-right: 0in; margin-left: 0in; font-size: 12pt; font-family: 'Times New Roman', serif; margin-top: 0in; margin-bottom: 0.0001pt; "><o:p> </o:p></div></div></div><span><report.simple.new.txt></span><span><report.simple.org.txt></span><span><cross.new></span><span><<a href="http://cross.org">cross.org</a>></span><span><pic2.diff></span></div></blockquote></div><br></div></body></html>