https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87615
Bug ID: 87615 Summary: Possible excessive compile time with -O2 Product: gcc Version: 8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: dcb314 at hotmail dot com Target Milestone: --- Created attachment 44842 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44842&action=edit gzipped C source code The attached C code, when compiled by a release version of recent gcc trunk, and flag -O2, seems to take about nine minutes 50 seconds to compile. According to -ftime-report, phase opt and generate : 511.78 (100%) 2.60 ( 69%) 518.59 (100%) 474628 kB ( 92%) alias stmt walking : 265.80 ( 52%) 0.41 ( 11%) 267.65 ( 51%) 3 kB ( 0%) tree VRP : 90.34 ( 18%) 0.18 ( 5%) 91.33 ( 18%) 58202 kB ( 11%) tree FRE : 86.43 ( 17%) 1.22 ( 32%) 88.79 ( 17%) 1833 kB ( 0%) $ ~/gcc/results.265139.release/bin/gcc -v Using built-in specs. COLLECT_GCC=/home/dcb/gcc/results.265139.release/bin/gcc COLLECT_LTO_WRAPPER=/home/dcb/gcc/results.265139.release/libexec/gcc/x86_64-pc-linux-gnu/9.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../trunk/configure --prefix=/home/dcb/gcc/results.265139.release --disable-bootstrap --disable-multilib --disable-werror --enable-checking=release --enable-languages=c,c++,fortran Thread model: posix gcc version 9.0.0 20181013 (experimental) (GCC) $