<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>You probably have dangling references to the instructions you removed. Before erasing the instruction, you should call replaceAllUsesWith(Value *v) to remove any references in other instructions.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Regards,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Michael Smith<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Arshak Nazaryan [mailto:arshak.info@gmail.com] <br><b>Sent:</b> Thursday, November 03, 2011 3:56 AM<br><b>To:</b> llvmdev@cs.uiuc.edu<br><b>Subject:</b> [LLVMdev] LLVM problem, please do not ignore<o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Dear sir or madam,<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I am a 4-th year student at Yerevan State University, Armenia; and I am studying LLVM in order to write my Bachelor thesis.<o:p></o:p></p></div><div><p class=MsoNormal>I am trying to write an llvm pass that just removes all "Add" commands and gives some statstics. <o:p></o:p></p></div><div><p class=MsoNormal>Nevertheless, I get this segmentation fault:<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>................some rows about functions, that are not changed by my pass. The errors occurs after it has modified a "@_Z3addii" function.<o:p></o:p></p></div><div><div><p class=MsoNormal>store i32 %b.0, i32* %4 and the type is ddddbbm 28<o:p></o:p></p></div><div><p class=MsoNormal> %5 = load i32* %a_addr, align 4 and the type is ddddbbm 27<o:p></o:p></p></div><div><p class=MsoNormal> %6 = load i32* %b_addr, align 4 and the type is ddddbbm 27<o:p></o:p></p></div><div><p class=MsoNormal> %7 = add nsw i32 %5, %6 and the type is ddddbbm 8<o:p></o:p></p></div><div><p class=MsoNormal> store i32 %7, i32* %0, align 4 and the type is ddddbbm 28<o:p></o:p></p></div><div><p class=MsoNormal> %7 = add nsw i32 %5, %6 is erased, ba!<o:p></o:p></p></div><div><p class=MsoNormal> %7 = load i32* %0, align 4 and the type is ddddbbm 27<o:p></o:p></p></div><div><p class=MsoNormal> store i32 %7, i32* %retval, align 4 and the type is ddddbbm 28<o:p></o:p></p></div><div><p class=MsoNormal> br label %return and the type is ddddbbm 2<o:p></o:p></p></div><div><p class=MsoNormal> ret i32 %retval1 and the type is ddddbbm 1<o:p></o:p></p></div><div><p class=MsoNormal>0 opt 0x00000000008ed93f<o:p></o:p></p></div><div><p class=MsoNormal>1 opt 0x00000000008edcea<o:p></o:p></p></div><div><p class=MsoNormal>2 libpthread.so.0 0x00007f9ba1183c60<o:p></o:p></p></div><div><p class=MsoNormal>3 opt 0x00000000004b3615 llvm::PATypeHolder::get() const + 21<o:p></o:p></p></div><div><p class=MsoNormal>4 opt 0x00000000008a4f11<o:p></o:p></p></div><div><p class=MsoNormal>5 opt 0x00000000008a9404<o:p></o:p></p></div><div><p class=MsoNormal>6 opt 0x0000000000882557 llvm::FPPassManager::runOnFunction(llvm::Function&) + 551<o:p></o:p></p></div><div><p class=MsoNormal>7 opt 0x00000000008825db llvm::FPPassManager::runOnModule(llvm::Module&) + 75<o:p></o:p></p></div><div><p class=MsoNormal>8 opt 0x0000000000882197 llvm::MPPassManager::runOnModule(llvm::Module&) + 503<o:p></o:p></p></div><div><p class=MsoNormal>9 opt 0x0000000000882299 llvm::PassManagerImpl::run(llvm::Module&) + 137<o:p></o:p></p></div><div><p class=MsoNormal>10 opt 0x00000000004ac451 main + 4881<o:p></o:p></p></div><div><p class=MsoNormal>11 libc.so.6 0x00007f9ba0459eff __libc_start_main + 255<o:p></o:p></p></div><div><p class=MsoNormal>12 opt 0x000000000049f5f9<o:p></o:p></p></div><div><p class=MsoNormal>Stack dump:<o:p></o:p></p></div><div><p class=MsoNormal>0.<span class=apple-tab-span> </span>Program arguments: opt hello.bc -load ../llvm/llvm-2.9/plugin/BasicBlockStats.so -basic-block-stats -stats -o newhello.bc <o:p></o:p></p></div><div><p class=MsoNormal>1.<span class=apple-tab-span> </span>Running pass 'Function Pass Manager' on module 'hello.bc'.<o:p></o:p></p></div><div><p class=MsoNormal>2.<span class=apple-tab-span> </span>Running pass 'Module Verifier' on function '@_Z3addii'<o:p></o:p></p></div><div><p class=MsoNormal>Segmentation fault<o:p></o:p></p></div></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Please find the source of my pass attached.<o:p></o:p></p></div><div><p class=MsoNormal>Hope to get a reply soon.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Regards,<o:p></o:p></p></div><div><p class=MsoNormal>Arshak Nazaryan<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div></div></body></html>