search for: __llvm_profile_raw_version

...ing Peter to comment on the linker resolution issue. >From adding save-temps, it looks like lld and gold are giving different resolutions to the symbols, which is presumably creating this issue: (first file is with lld and second is with gold) $ diff a.out.resolution.txt gold/ 4c4 < -r=a.o,__llvm_profile_raw_version,plx --- > -r=a.o,__llvm_profile_raw_version,l 8,9c8,9 < -r=b.o,__llvm_profile_raw_version,x < -r=b.o,__llvm_profile_filename,x --- > -r=b.o,__llvm_profile_raw_version,l > -r=b.o,__llvm_profile_filename,l I.e. with lld they are all marked as exported. Peter, any ideas? Teresa On...

The duplicate symbol errors are for __llvm_profile_filename and __llvm_profile_raw_version. IIUC, these are supposed to be weak symbols but Thin LTO seems to break this in some way. This does't happen with gold or no LTO or full LTO. $ cat > a.c extern int foo(); int main() { return foo(); } $ cat > b.c int foo() { return 0; } $ clang a.c -fprofile-generate -flto=thin...

The problem is that ThinLTO is not dropping the non-prevailing definitions, and they end up being emitted into the object file for b.o. $ ../ra/bin/llvm-dis -o - b.o0.0.preopt.bc | grep __llvm_prof $__llvm_profile_raw_version = comdat any $__llvm_profile_filename = comdat any @__llvm_profile_raw_version = constant i64 72057594037927940, comdat @__llvm_profile_filename = constant [19 x i8] c"default_%m.profraw\00", comdat lld ignores comdats in LTO object files because it expects all comdats to have already be...

...9, 2018 at 11:26 AM Peter Collingbourne <peter at pcc.me.uk> wrote: > The problem is that ThinLTO is not dropping the non-prevailing > definitions, and they end up being emitted into the object file for b.o. > > $ ../ra/bin/llvm-dis -o - b.o0.0.preopt.bc | grep __llvm_prof > $__llvm_profile_raw_version = comdat any > $__llvm_profile_filename = comdat any > @__llvm_profile_raw_version = constant i64 72057594037927940, comdat > @__llvm_profile_filename = constant [19 x i8] c"default_%m.profraw\00", > comdat > > lld ignores comdats in LTO object files because it expects a...

...gt; >>> >>> Thanks, >>> Teresa >>> >>> On Tue, May 8, 2018 at 7:50 PM Pirama Arumuga Nainar via llvm-dev < >>> llvm-dev at lists.llvm.org> wrote: >>> >>>> The duplicate symbol errors are for __llvm_profile_filename and __llvm_profile_raw_version. >>>> IIUC, these are supposed to be weak symbols but Thin LTO seems to break >>>> this in some way. This does't happen with gold or no LTO or full LTO. >>>> >>>> $ cat > a.c >>>> extern int foo(); >>>> >>>>...

...;> Thanks, >>>> Teresa >>>> >>>> On Tue, May 8, 2018 at 7:50 PM Pirama Arumuga Nainar via llvm-dev < >>>> llvm-dev at lists.llvm.org> wrote: >>>> >>>>> The duplicate symbol errors are for __llvm_profile_filename and __llvm_profile_raw_version. >>>>> IIUC, these are supposed to be weak symbols but Thin LTO seems to break >>>>> this in some way. This does't happen with gold or no LTO or full LTO. >>>>> >>>>> $ cat > a.c >>>>> extern int foo(); >>>&...

...t from > head. What version is your clang? > (and your lld) > > Thanks, > Teresa > > On Tue, May 8, 2018 at 7:50 PM Pirama Arumuga Nainar via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> The duplicate symbol errors are for __llvm_profile_filename and __llvm_profile_raw_version. >> IIUC, these are supposed to be weak symbols but Thin LTO seems to break >> this in some way. This does't happen with gold or no LTO or full LTO. >> >> $ cat > a.c >> extern int foo(); >> >> int main() { >> return foo(); >> } >&g...

...'t reproduce with either lld or gold, using a compiler built from head. What version is your clang? Thanks, Teresa On Tue, May 8, 2018 at 7:50 PM Pirama Arumuga Nainar via llvm-dev < llvm-dev at lists.llvm.org> wrote: > The duplicate symbol errors are for __llvm_profile_filename and __llvm_profile_raw_version. > IIUC, these are supposed to be weak symbols but Thin LTO seems to break > this in some way. This does't happen with gold or no LTO or full LTO. > > $ cat > a.c > extern int foo(); > > int main() { > return foo(); > } > > $ cat > b.c > int foo() {...

...;> > (and your lld) > > >> >> Thanks, >> Teresa >> >> On Tue, May 8, 2018 at 7:50 PM Pirama Arumuga Nainar via llvm-dev < >> llvm-dev at lists.llvm.org> wrote: >> >>> The duplicate symbol errors are for __llvm_profile_filename and __llvm_profile_raw_version. >>> IIUC, these are supposed to be weak symbols but Thin LTO seems to break >>> this in some way. This does't happen with gold or no LTO or full LTO. >>> >>> $ cat > a.c >>> extern int foo(); >>> >>> int main() { >>>...

On Wed, Oct 25, 2017 at 09:13:54AM -0700, Xinliang David Li wrote: > On Wed, Oct 25, 2017 at 12:26 AM, Roger Pau Monné via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > > > Hello, > > > > I've been working on implementing some basic functionality in order to > > use the llvm profiling functionality inside of a kernel (the Xen > > hypervisor).