[Bug middle-end/50650] New: [4.7 Regression] ICE in vect_is_simple_use_1, at tree-vect-stmts.c:5689

["markus at trippelsdorf dot de" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50650

             Bug #: 50650
           Summary: [4.7 Regression] ICE in vect_is_simple_use_1, at
                    tree-vect-stmts.c:5689
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: markus@trippelsdorf.de


The following ICE happens when building the latest Mozilla JavaScript Engine:

c++ -o /dev/null -S -w -Wfatal-errors -fpermissive -fpreprocessed -O3
LoopState.ii
/var/tmp/mozilla-central/js/src/methodjit/LoopState.cpp: In member function
âbool js::mjit::LoopState::init(jsbytecode*,
js::mjit::MacroAssemblerTypedefs::Jump, jsbytecode*)â:
/var/tmp/mozilla-central/js/src/methodjit/LoopState.cpp:106:1: internal
compiler error: in vect_is_simple_use_1, at tree-vect-stmts.c:5689

A reduced testcase is attached.

 % c++ -w -O3 moz_testcas.ii
moz_testcas.ii: In member function âbool js::mjit::LoopState::init(jsbytecode*,
js::mjit::MacroAssemblerTypedefs::Jump, jsbytecode*)â:
moz_testcas.ii:145:6: internal compiler error: in vect_is_simple_use_1, at
tree-vect-stmts.c:5689

This only happens with -O3.