Author: tstellar Date: Mon Oct 14 20:50:26 2019 New Revision: 374858 URL: http://llvm.org/viewvc/llvm-project?rev=374858&view=rev Log: Merging r372020 and r372182:
------------------------------------------------------------------------ r372020 | rnk | 2019-09-16 11:49:09 -0700 (Mon, 16 Sep 2019) | 30 lines [PGO] Use linkonce_odr linkage for __profd_ variables in comdat groups This fixes relocations against __profd_ symbols in discarded sections, which is PR41380. In general, instrumentation happens very early, and optimization and inlining happens afterwards. The counters for a function are calculated early, and after inlining, counters for an inlined function may be widely referenced by other functions. For C++ inline functions of all kinds (linkonce_odr & available_externally mainly), instr profiling wants to deduplicate these __profc_ and __profd_ globals. Otherwise the binary would be quite large. I made __profd_ and __profc_ comdat in r355044, but I chose to make __profd_ internal. At the time, I was only dealing with coverage, and in that case, none of the instrumentation needs to reference __profd_. However, if you use PGO, then instrumentation passes add calls to __llvm_profile_instrument_range which reference __profd_ globals. The solution is to make these globals externally visible by using linkonce_odr linkage for data as was done for counters. This is safe because PGO adds a CFG hash to the names of the data and counter globals, so if different TUs have different globals, they will get different data and counter arrays. Reviewers: xur, hans Differential Revision: https://reviews.llvm.org/D67579 ------------------------------------------------------------------------ ------------------------------------------------------------------------ r372182 | rnk | 2019-09-17 14:10:49 -0700 (Tue, 17 Sep 2019) | 12 lines [PGO] Don't use comdat groups for counters & data on COFF For COFF, a comdat group is really a symbol marked IMAGE_COMDAT_SELECT_ANY and zero or more other symbols marked IMAGE_COMDAT_SELECT_ASSOCIATIVE. Typically the associative symbols in the group are not external and are not referenced by other TUs, they are things like debug info, C++ dynamic initializers, or other section registration schemes. The Visual C++ linker reports a duplicate symbol error for symbols marked IMAGE_COMDAT_SELECT_ASSOCIATIVE even if they would be discarded after handling the leader symbol. Fixes coverage-inline.cpp in check-profile after r372020. ------------------------------------------------------------------------ Modified: llvm/branches/release_90/lib/Transforms/Instrumentation/InstrProfiling.cpp llvm/branches/release_90/test/Instrumentation/InstrProfiling/PR23499.ll llvm/branches/release_90/test/Instrumentation/InstrProfiling/comdat.ll llvm/branches/release_90/test/Instrumentation/InstrProfiling/linkage.ll Modified: llvm/branches/release_90/lib/Transforms/Instrumentation/InstrProfiling.cpp URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_90/lib/Transforms/Instrumentation/InstrProfiling.cpp?rev=374858&r1=374857&r2=374858&view=diff ============================================================================== --- llvm/branches/release_90/lib/Transforms/Instrumentation/InstrProfiling.cpp (original) +++ llvm/branches/release_90/lib/Transforms/Instrumentation/InstrProfiling.cpp Mon Oct 14 20:50:26 2019 @@ -731,9 +731,8 @@ InstrProfiling::getOrCreateRegionCounter PD = It->second; } - // Match the linkage and visibility of the name global, except on COFF, where - // the linkage must be local and consequentially the visibility must be - // default. + // Match the linkage and visibility of the name global. COFF supports using + // comdats with internal symbols, so do that if we can. Function *Fn = Inc->getParent()->getParent(); GlobalValue::LinkageTypes Linkage = NamePtr->getLinkage(); GlobalValue::VisibilityTypes Visibility = NamePtr->getVisibility(); @@ -749,19 +748,25 @@ InstrProfiling::getOrCreateRegionCounter // new comdat group for the counters and profiling data. If we use the comdat // of the parent function, that will result in relocations against discarded // sections. - Comdat *Cmdt = nullptr; - GlobalValue::LinkageTypes CounterLinkage = Linkage; - if (needsComdatForCounter(*Fn, *M)) { - StringRef CmdtPrefix = getInstrProfComdatPrefix(); + bool NeedComdat = needsComdatForCounter(*Fn, *M); + Comdat *Cmdt = nullptr; // Comdat group. + if (NeedComdat) { if (TT.isOSBinFormatCOFF()) { - // For COFF, the comdat group name must be the name of a symbol in the - // group. Use the counter variable name, and upgrade its linkage to - // something externally visible, like linkonce_odr. - CmdtPrefix = getInstrProfCountersVarPrefix(); - CounterLinkage = GlobalValue::LinkOnceODRLinkage; + // For COFF, put the counters, data, and values each into their own + // comdats. We can't use a group because the Visual C++ linker will + // report duplicate symbol errors if there are multiple external symbols + // with the same name marked IMAGE_COMDAT_SELECT_ASSOCIATIVE. + Linkage = GlobalValue::LinkOnceODRLinkage; + Visibility = GlobalValue::HiddenVisibility; + } else { + // Otherwise, create one comdat group for everything. + Cmdt = M->getOrInsertComdat(getVarName(Inc, getInstrProfComdatPrefix())); } - Cmdt = M->getOrInsertComdat(getVarName(Inc, CmdtPrefix)); } + auto MaybeSetComdat = [=](GlobalVariable *GV) { + if (NeedComdat) + GV->setComdat(Cmdt ? Cmdt : M->getOrInsertComdat(GV->getName())); + }; uint64_t NumCounters = Inc->getNumCounters()->getZExtValue(); LLVMContext &Ctx = M->getContext(); @@ -776,8 +781,8 @@ InstrProfiling::getOrCreateRegionCounter CounterPtr->setSection( getInstrProfSectionName(IPSK_cnts, TT.getObjectFormat())); CounterPtr->setAlignment(8); - CounterPtr->setComdat(Cmdt); - CounterPtr->setLinkage(CounterLinkage); + MaybeSetComdat(CounterPtr); + CounterPtr->setLinkage(Linkage); auto *Int8PtrTy = Type::getInt8PtrTy(Ctx); // Allocate statically the array of pointers to value profile nodes for @@ -798,7 +803,7 @@ InstrProfiling::getOrCreateRegionCounter ValuesVar->setSection( getInstrProfSectionName(IPSK_vals, TT.getObjectFormat())); ValuesVar->setAlignment(8); - ValuesVar->setComdat(Cmdt); + MaybeSetComdat(ValuesVar); ValuesPtrExpr = ConstantExpr::getBitCast(ValuesVar, Type::getInt8PtrTy(Ctx)); } @@ -831,7 +836,8 @@ InstrProfiling::getOrCreateRegionCounter Data->setVisibility(Visibility); Data->setSection(getInstrProfSectionName(IPSK_data, TT.getObjectFormat())); Data->setAlignment(INSTR_PROF_DATA_ALIGNMENT); - Data->setComdat(Cmdt); + MaybeSetComdat(Data); + Data->setLinkage(Linkage); PD.RegionCounters = CounterPtr; PD.DataVar = Data; Modified: llvm/branches/release_90/test/Instrumentation/InstrProfiling/PR23499.ll URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_90/test/Instrumentation/InstrProfiling/PR23499.ll?rev=374858&r1=374857&r2=374858&view=diff ============================================================================== --- llvm/branches/release_90/test/Instrumentation/InstrProfiling/PR23499.ll (original) +++ llvm/branches/release_90/test/Instrumentation/InstrProfiling/PR23499.ll Mon Oct 14 20:50:26 2019 @@ -20,8 +20,8 @@ $_Z3barIvEvv = comdat any ; COFF-NOT: __profn__Z3barIvEvv -; COFF: @__profc__Z3barIvEvv = linkonce_odr dso_local global [1 x i64] zeroinitializer, section "{{.*}}prfc$M", comdat, align 8 -; COFF: @__profd__Z3barIvEvv = internal global { i64, i64, i64*, i8*, i8*, i32, [2 x i16] } { i64 4947693190065689389, i64 0, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc__Z3barIvEvv, i32 0, i32 0), i8*{{.*}}, i8* null, i32 1, [2 x i16] zeroinitializer }, section "{{.*}}prfd{{.*}}", comdat($__profc__Z3barIvEvv), align 8 +; COFF: @__profc__Z3barIvEvv = linkonce_odr hidden global [1 x i64] zeroinitializer, section "{{.*}}prfc$M", comdat, align 8 +; COFF: @__profd__Z3barIvEvv = linkonce_odr hidden global { i64, i64, i64*, i8*, i8*, i32, [2 x i16] } { i64 4947693190065689389, i64 0, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc__Z3barIvEvv, i32 0, i32 0), i8*{{.*}}, i8* null, i32 1, [2 x i16] zeroinitializer }, section "{{.*}}prfd{{.*}}", comdat, align 8 declare void @llvm.instrprof.increment(i8*, i64, i32, i32) #1 Modified: llvm/branches/release_90/test/Instrumentation/InstrProfiling/comdat.ll URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_90/test/Instrumentation/InstrProfiling/comdat.ll?rev=374858&r1=374857&r2=374858&view=diff ============================================================================== --- llvm/branches/release_90/test/Instrumentation/InstrProfiling/comdat.ll (original) +++ llvm/branches/release_90/test/Instrumentation/InstrProfiling/comdat.ll Mon Oct 14 20:50:26 2019 @@ -17,8 +17,8 @@ $foo_inline = comdat any ; ELF: @__profc_foo_inline = linkonce_odr hidden global{{.*}}, section "__llvm_prf_cnts", comdat($__profv_foo_inline), align 8 ; ELF: @__profd_foo_inline = linkonce_odr hidden global{{.*}}, section "__llvm_prf_data", comdat($__profv_foo_inline), align 8 -; COFF: @__profc_foo_inline = linkonce_odr dso_local global{{.*}}, section ".lprfc$M", comdat, align 8 -; COFF: @__profd_foo_inline = internal global{{.*}}, section ".lprfd$M", comdat($__profc_foo_inline), align 8 +; COFF: @__profc_foo_inline = linkonce_odr hidden global{{.*}}, section ".lprfc$M", comdat, align 8 +; COFF: @__profd_foo_inline = linkonce_odr hidden global{{.*}}, section ".lprfd$M", comdat, align 8 define weak_odr void @foo_inline() comdat { call void @llvm.instrprof.increment(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @__profn_foo_inline, i32 0, i32 0), i64 0, i32 1, i32 0) ret void @@ -30,8 +30,8 @@ $foo_extern = comdat any ; ELF: @__profc_foo_extern = linkonce_odr hidden global{{.*}}, section "__llvm_prf_cnts", comdat($__profv_foo_extern) ; ELF: @__profd_foo_extern = linkonce_odr hidden global{{.*}}, section "__llvm_prf_data", comdat($__profv_foo_extern) -; COFF: @__profc_foo_extern = linkonce_odr dso_local global{{.*}}, section ".lprfc$M", comdat, align 8 -; COFF: @__profd_foo_extern = internal global{{.*}}, section ".lprfd$M", comdat($__profc_foo_extern), align 8 +; COFF: @__profc_foo_extern = linkonce_odr hidden global{{.*}}, section ".lprfc$M", comdat, align 8 +; COFF: @__profd_foo_extern = linkonce_odr hidden global{{.*}}, section ".lprfd$M", comdat, align 8 define available_externally void @foo_extern() { call void @llvm.instrprof.increment(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @__profn_foo_extern, i32 0, i32 0), i64 0, i32 1, i32 0) ret void Modified: llvm/branches/release_90/test/Instrumentation/InstrProfiling/linkage.ll URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_90/test/Instrumentation/InstrProfiling/linkage.ll?rev=374858&r1=374857&r2=374858&view=diff ============================================================================== --- llvm/branches/release_90/test/Instrumentation/InstrProfiling/linkage.ll (original) +++ llvm/branches/release_90/test/Instrumentation/InstrProfiling/linkage.ll Mon Oct 14 20:50:26 2019 @@ -57,8 +57,8 @@ define linkonce_odr void @foo_inline() { ; LINUX: @__profd_foo_extern = linkonce_odr hidden global {{.*}}section "__llvm_prf_data", comdat($__profv_foo_extern), align 8 ; MACHO: @__profc_foo_extern = linkonce_odr hidden global ; MACHO: @__profd_foo_extern = linkonce_odr hidden global -; COFF: @__profc_foo_extern = linkonce_odr dso_local global {{.*}}section ".lprfc$M", comdat, align 8 -; COFF: @__profd_foo_extern = internal global {{.*}}section ".lprfd$M", comdat($__profc_foo_extern), align 8 +; COFF: @__profc_foo_extern = linkonce_odr hidden global {{.*}}section ".lprfc$M", comdat, align 8 +; COFF: @__profd_foo_extern = linkonce_odr hidden global {{.*}}section ".lprfd$M", comdat, align 8 define available_externally void @foo_extern() { call void @llvm.instrprof.increment(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @__profn_foo_extern, i32 0, i32 0), i64 0, i32 1, i32 0) ret void _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
