[Bug rtl-optimization/46585] New: [4.6 Regression] ICE: SIGSEGV in vinsn_create (sel-sched-ir.c:1189) with -fno-dce -fschedule-insns -fselective-scheduling

["zsojka at seznam dot cz" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46585

           Summary: [4.6 Regression] ICE: SIGSEGV in vinsn_create
                    (sel-sched-ir.c:1189) with -fno-dce -fschedule-insns
                    -fselective-scheduling
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 22473
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22473
reduced testcase

Compiler output:
$ gcc -fno-dce -fschedule-insns -fselective-scheduling testcase.c
==3603== Invalid read of size 1
==3603==    at 0x8539FE: vinsn_create (sel-sched-ir.c:1189)
==3603==    by 0x854303: init_global_and_expr_for_insn (sel-sched-ir.c:2907)
==3603==    by 0xFBE824: init_insns_in_bb.isra.10 (haifa-sched.c:5329)
==3603==    by 0xFCC0B7: sched_scan (haifa-sched.c:5376)
==3603==    by 0x8570A8: sel_init_global_and_expr (sel-sched-ir.c:2929)
==3603==    by 0x87A1B6: sel_sched_region (sel-sched.c:6864)
==3603==    by 0x87BF71: run_selective_scheduling (sel-sched.c:7651)
==3603==    by 0x84A85C: rest_of_handle_sched (sched-rgn.c:3508)
==3603==    by 0x7C094E: execute_one_pass (passes.c:1564)
==3603==    by 0x7C0C14: execute_pass_list (passes.c:1619)
==3603==    by 0x7C0C26: execute_pass_list (passes.c:1620)
==3603==    by 0x905065: tree_rest_of_compilation (tree-optimize.c:422)
==3603==  Address 0x2 is not stack'd, malloc'd or (recently) free'd
==3603== 
testcase.c: In function 'foo':
testcase.c:9:1: 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:
r166976 - crash
r161659 - crash
r159696 - OK
4.5 r166509 - OK