http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46167
Summary: [4.5/4.6 Regression] ICE: SEIGSEGV in flow_bb_inside_loop_p (cfgloop.c:776) with -O -ftree-vectorize Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassig...@gcc.gnu.org ReportedBy: zso...@seznam.cz Created attachment 22148 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22148 reduced testcase valgrind output : $ gcc -O -ftree-vectorize pr46167.c ==21601== Invalid read of size 8 ==21601== at 0x5933E8: flow_bb_inside_loop_p (cfgloop.c:776) ==21601== by 0x100FA9F: vect_recog_dot_prod_pattern (tree-vect-patterns.c:260) ==21601== by 0x10104A5: vect_pattern_recog (tree-vect-patterns.c:683) ==21601== by 0x9DE777: vect_analyze_loop (tree-vect-loop.c:1406) ==21601== by 0x9EC288: vectorize_loops (tree-vectorizer.c:219) ==21601== by 0x797A5E: execute_one_pass (passes.c:1560) ==21601== by 0x797CF4: execute_pass_list (passes.c:1615) ==21601== by 0x797D06: execute_pass_list (passes.c:1616) ==21601== by 0x797D06: execute_pass_list (passes.c:1616) ==21601== by 0x8E4B65: tree_rest_of_compilation (tree-optimize.c:422) ==21601== by 0xAAF281: cgraph_expand_function (cgraphunit.c:1494) ==21601== by 0xAB1849: cgraph_optimize (cgraphunit.c:1553) ==21601== Address 0x18 is not stack'd, malloc'd or (recently) free'd ==21601== pr46167.c: In function 'foo': pr46167.c:1:5: 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: r165915 - crash r163636 - crash r161659 - OK r159696 - OK 4.5 r165781 - crash 4.5.1 - OK 4.4 r165754 - OK