http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46355
Summary: [4.5/4.6 Regression] ICE: SIGSEGV in create_preheader (cfgloopmanip.c:1336) with -O -fstrict-overflow -ftree-loop-distribution Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassig...@gcc.gnu.org ReportedBy: zso...@seznam.cz CC: s...@gcc.gnu.org Host: x86_64-pc-linux-gnu Target: x86_64-pc-linux-gnu Created attachment 22318 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22318 reduced testcase I was reducing a testcase that had the same backtrace as PR45948, but the reduced testcase turned out to cause a bit different ICE. It also started crashing at different revision. I don't know how much is this related to PR45948 and PR45199. Related valgrind output: $ gcc -O -ftree-loop-distribution -fstrict-overflow pr46355.c ==20450== Invalid read of size 8 ==20450== at 0x59BF64: create_preheader (cfgloopmanip.c:1336) ==20450== by 0x8D845D: distribute_loop (tree-loop-distribution.c:180) ==20450== by 0x8D8A0C: tree_loop_distribution (tree-loop-distribution.c:1201) ==20450== by 0x79980E: execute_one_pass (passes.c:1560) ==20450== by 0x799AB4: execute_pass_list (passes.c:1615) ==20450== by 0x799AC6: execute_pass_list (passes.c:1616) ==20450== by 0x799AC6: execute_pass_list (passes.c:1616) ==20450== by 0x8E6715: tree_rest_of_compilation (tree-optimize.c:422) ==20450== by 0xAB6601: cgraph_expand_function (cgraphunit.c:1493) ==20450== by 0xAB8BC9: cgraph_optimize (cgraphunit.c:1552) ==20450== by 0xAB9129: cgraph_finalize_compilation_unit (cgraphunit.c:1016) ==20450== by 0x4AC9AB: c_write_global_declarations (c-decl.c:9831) ==20450== Address 0x8 is not stack'd, malloc'd or (recently) free'd ==20450== pr46355.c: In function 'foo': pr46355.c:2:1: internal compiler error: Segmentation fault Please submit a full bug report, with preprocessed source if appropriate. See <http://gcc.gnu.org/bugs.html> for instructions. Tested revisions: r166414 - crash r153685 - crash 4.5 r165781 - crash 4.4 r165754 - OK