This can be related to pr41371, but I think it is not duplicate. This one ends in endless loop, as can be seen from -fdump-rtl-vartrack dumps - there are about 50 lines periodically repeating. I thought it's a dup of pr41371, but the compilation (of nonreduced testcase) didn't finish even after one week. Reduced testcase compilation finishes "in miliseconds" with -fno-var-tracking, but takes forever without it. It's not slowly eating memory, so it never crashes.
Command line: gcc -O3 -g -fgcse-sm -ftracer testcase.c Tested revisions (x86_64): r156217 - fail r156038 - fail r155945 - fail (x86) r155920 - fail r155917 - fail r155902 - OK r155844 - OK (x86) r155833 - OK r155363 - OK r154886 - OK r153685 - OK 4.4 branch, r155365 - OK Output (manually terminated): $ time /mnt/svn/gcc-trunk/binary-155920-lto/libexec/gcc/x86_64-unknown-linux-gnu/4.5.0/cc1 -v -O3 -g -fgcse-sm -ftracer testcase.c ignoring nonexistent directory "/usr/local/include" ignoring nonexistent directory "/mnt/svn/gcc-trunk/binary-155920-lto/lib/gcc/x86_64-unknown-linux-gnu/4.5.0/../../../../x86_64-unknown-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /mnt/svn/gcc-trunk/binary-155920-lto/include /mnt/svn/gcc-trunk/binary-155920-lto/lib/gcc/x86_64-unknown-linux-gnu/4.5.0/include /mnt/svn/gcc-trunk/binary-155920-lto/lib/gcc/x86_64-unknown-linux-gnu/4.5.0/include-fixed /usr/include End of search list. baz bar foo Analyzing compilation unit Performing interprocedural optimizations <visibility> <*free_lang_data> <early_local_cleanups> <whole-program> <cp> <inline> <static-var> <pure-const>Assembling functions: foo^C real 76m32.295s user 74m33.830s sys 0m0.730s -- Summary: [4.5 Regression] deadlock in var tracking in recent builds Product: gcc Version: 4.5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: zsojka at seznam dot cz GCC host triplet: x86(_64)-pc-linux-gnu GCC target triplet: x86(_64)-pc-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42873