Hi Mehdi, Thanks for your reply. It seems caused by random rename because I saw %struct.StructTyName.692.475*, which might be twice renaming. Does this collision occur because this type is declared more than once? I encountered this problem when used clang to compile transmission 1.42 (http://download.transmissionbt.com/files/) with configuration: "./configure --disable-gtk". Then in ./third-party/libevent/event.o.ll, you can see the function "event_base_get_method" is an example. Best, Haopeng On 6/2/15 1:48 PM, Mehdi Amini wrote:> Hi, > > I think this is when a collision is found on the name. > I would be interesting to have the full test, it might be that the API is used in a way such that type is constantly re-created even if it already exists, which might be inefficient. > > See in lib/IR/Type.cpp, StructType::setName(StringRef Name): > > ... > // While we have a name collision, try a random rename. > if (Entry->getValue()) { > SmallString<64> TempStr(Name); > TempStr.push_back('.'); > raw_svector_ostream TmpStream(TempStr); > unsigned NameSize = Name.size(); > > do { > TempStr.resize(NameSize + 1); > TmpStream.resync(); > TmpStream << getContext().pImpl->NamedStructTypesUniqueID++; > > Entry = &getContext().pImpl-> > NamedStructTypes.GetOrCreateValue(TmpStream.str()); > } while (Entry->getValue()); > } > > > — > Mehdi > >> On Jun 2, 2015, at 11:23 AM, Haopeng Liu <hyliuhp at gmail.com> wrote: >> >> Hi All, >> >> I generated the following code with "clang -flto" command. >> >> void test(struct StruTyName *a) { >> ... >> } >> >> Then the type of test function is "void (%struct.StruTyName.100*)" by calling function::getFunctionType API. >> >> What's the meaning of number 100? >> >> Best, >> Haopeng >> _______________________________________________ >> LLVM Developers mailing list >> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
Hi Haopeng, One more element, I just noticed you are using LTO, I am not sure how it is implemented but my guess is that there is a shared LLVMContext. If multiple files include this structure declaration, I wouldn’t be surprised if it trigger creating the type over and over in the IR. Why is it a problem for you by the way? Does the compilation fails in some way? — Mehdi> On Jun 2, 2015, at 1:31 PM, Haopeng Liu <hyliuhp at gmail.com> wrote: > > Hi Mehdi, > > Thanks for your reply. > > It seems caused by random rename because I saw %struct.StructTyName.692.475*, which might be twice renaming. > > Does this collision occur because this type is declared more than once? > > I encountered this problem when used clang to compile transmission 1.42 (http://download.transmissionbt.com/files/) with configuration: "./configure --disable-gtk". Then in ./third-party/libevent/event.o.ll, you can see the function "event_base_get_method" is an example. > > Best, > Haopeng > > On 6/2/15 1:48 PM, Mehdi Amini wrote: >> Hi, >> >> I think this is when a collision is found on the name. >> I would be interesting to have the full test, it might be that the API is used in a way such that type is constantly re-created even if it already exists, which might be inefficient. >> >> See in lib/IR/Type.cpp, StructType::setName(StringRef Name): >> >> ... >> // While we have a name collision, try a random rename. >> if (Entry->getValue()) { >> SmallString<64> TempStr(Name); >> TempStr.push_back('.'); >> raw_svector_ostream TmpStream(TempStr); >> unsigned NameSize = Name.size(); >> do { >> TempStr.resize(NameSize + 1); >> TmpStream.resync(); >> TmpStream << getContext().pImpl->NamedStructTypesUniqueID++; >> Entry = &getContext().pImpl-> >> NamedStructTypes.GetOrCreateValue(TmpStream.str()); >> } while (Entry->getValue()); >> } >> >> >> — >> Mehdi >> >>> On Jun 2, 2015, at 11:23 AM, Haopeng Liu <hyliuhp at gmail.com> wrote: >>> >>> Hi All, >>> >>> I generated the following code with "clang -flto" command. >>> >>> void test(struct StruTyName *a) { >>> ... >>> } >>> >>> Then the type of test function is "void (%struct.StruTyName.100*)" by calling function::getFunctionType API. >>> >>> What's the meaning of number 100? >>> >>> Best, >>> Haopeng >>> _______________________________________________ >>> LLVM Developers mailing list >>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >
I tried to compare two types. Because of renaming, the comparison result is not as expected. How to deal with renaming while comparing types? Best, Haopeng On 6/2/15 4:09 PM, Mehdi Amini wrote:> Hi Haopeng, > > One more element, I just noticed you are using LTO, I am not sure how it is implemented but my guess is that there is a shared LLVMContext. If multiple files include this structure declaration, I wouldn’t be surprised if it trigger creating the type over and over in the IR. > > Why is it a problem for you by the way? Does the compilation fails in some way? > > — > Mehdi > >> On Jun 2, 2015, at 1:31 PM, Haopeng Liu <hyliuhp at gmail.com> wrote: >> >> Hi Mehdi, >> >> Thanks for your reply. >> >> It seems caused by random rename because I saw %struct.StructTyName.692.475*, which might be twice renaming. >> >> Does this collision occur because this type is declared more than once? >> >> I encountered this problem when used clang to compile transmission 1.42 (http://download.transmissionbt.com/files/) with configuration: "./configure --disable-gtk". Then in ./third-party/libevent/event.o.ll, you can see the function "event_base_get_method" is an example. >> >> Best, >> Haopeng >> >> On 6/2/15 1:48 PM, Mehdi Amini wrote: >>> Hi, >>> >>> I think this is when a collision is found on the name. >>> I would be interesting to have the full test, it might be that the API is used in a way such that type is constantly re-created even if it already exists, which might be inefficient. >>> >>> See in lib/IR/Type.cpp, StructType::setName(StringRef Name): >>> >>> ... >>> // While we have a name collision, try a random rename. >>> if (Entry->getValue()) { >>> SmallString<64> TempStr(Name); >>> TempStr.push_back('.'); >>> raw_svector_ostream TmpStream(TempStr); >>> unsigned NameSize = Name.size(); >>> do { >>> TempStr.resize(NameSize + 1); >>> TmpStream.resync(); >>> TmpStream << getContext().pImpl->NamedStructTypesUniqueID++; >>> Entry = &getContext().pImpl-> >>> NamedStructTypes.GetOrCreateValue(TmpStream.str()); >>> } while (Entry->getValue()); >>> } >>> >>> >>> — >>> Mehdi >>> >>>> On Jun 2, 2015, at 11:23 AM, Haopeng Liu <hyliuhp at gmail.com> wrote: >>>> >>>> Hi All, >>>> >>>> I generated the following code with "clang -flto" command. >>>> >>>> void test(struct StruTyName *a) { >>>> ... >>>> } >>>> >>>> Then the type of test function is "void (%struct.StruTyName.100*)" by calling function::getFunctionType API. >>>> >>>> What's the meaning of number 100? >>>> >>>> Best, >>>> Haopeng >>>> _______________________________________________ >>>> LLVM Developers mailing list >>>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev