https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95264
Bug ID: 95264 Summary: Infinite Loop When Compiling Templated C++ code at -O1 and above Product: gcc Version: 10.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: freddie at witherden dot org Target Milestone: --- Created attachment 48578 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48578&action=edit Preprocessed source. When attempting to compile the header-only C++ application Polyquad (https://github.com/PyFR/Polyquad) with any recent version of GCC at any optimization level, the compiler gets stuck. (And either dies with c++: fatal error: Killed signal terminated program cc1plus or an out of memory error depending on the platform.) This is believed to be an interaction between the Boost bfloat type (an arbitrary precision numerical type) and the Eigen library (a heavily templated matrix library). By comparison, Clang is able to compile the application in a few minutes at any optimization level with memory never peaking above 3-4 GiB. GCC with -O3 -g will happily malloc in excess of 30 GiB before dying (although this can be curtailed somewhat by -fno-var-tracking-assignments). The compiler command (from the uncompressed pre-processed source) is: /usr/libexec/gcc/x86_64-pc-linux-gnu/10.1.0/cc1plus -fpreprocessed main.ii -march=skylake -mmmx -mno-3dnow -msse -msse2 -msse3 -mssse3 -mno-sse4a -mcx16 -msahf -mmovbe -maes -mno-sha -mpclmul -mpopcnt -mabm -mno-lwp -mfma -mno-fma4 -mno-xop -mbmi -msgx -mbmi2 -mno-pconfig -mno-wbnoinvd -mno-tbm -mavx -mavx2 -msse4.2 -msse4.1 -mlzcnt -mrtm -mhle -mrdrnd -mf16c -mfsgsbase -mrdseed -mprfchw -madx -mfxsr -mxsave -mxsaveopt -mno-avx512f -mno-avx512er -mno-avx512cd -mno-avx512pf -mno-prefetchwt1-mclflushopt -mxsavec -mxsaves -mno-avx512dq -mno-avx512bw -mno-avx512vl -mno-avx512ifma -mno-avx512vbmi -mno-avx5124fmaps -mno-avx5124vnniw -mno-clwb -mno-mwaitx -mno-clzero -mno-pku -mno-rdpid -mno-gfni -mno-shstk -mno-avx512vbmi2 -mno-avx512vnni -mno-vaes -mno-vpclmulqdq -mno-avx512bitalg -mno-movdiri -mno-movdir64b -mno-waitpkg -mno-cldemote -mno-ptwrite -mno-avx512bf16 -mno-enqcmd -mno-avx512vp2intersect --param l1-cache-size=32 --param l1-cache-line-size=64 --param l2-cache-size=6144-mtune=skylake -quiet -dumpbase main.cpp -auxbase-strip CMakeFiles/polyquad.dir/src/main.cpp.o -O3 -Wno-deprecated -std=c++17 -version -fno-var-tracking-assignments-o main.s