[Bug debug/48159] New: [4.7 Regression] ICE: SIGSEGV in build2_stat (tree.c:3802) with -O -ftree-loop-distribution -fno-tree-ch -g

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48159

           Summary: [4.7 Regression] ICE: SIGSEGV in build2_stat
                    (tree.c:3802) with -O -ftree-loop-distribution
                    -fno-tree-ch -g
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 23687
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23687
reduced testcase (same as tree-ssa/pr39007.c)

Compiler output:
$ gcc -O -ftree-loop-distribution -fno-tree-ch -g testcase.c
==25254== Invalid read of size 2
==25254==    at 0xA60576: build2_stat (tree.c:3802)
==25254==    by 0x5E140C: gimple_assign_rhs_to_tree (cfgexpand.c:78)
==25254==    by 0xA0B6F6: insert_debug_temp_for_var_def (tree-ssa.c:398)
==25254==    by 0xA0BB7F: insert_debug_temps_for_defs (tree-ssa.c:496)
==25254==    by 0x74B7F9: gsi_remove (gimple-iterator.c:511)
==25254==    by 0x92D351: distribute_loop (tree-loop-distribution.c:206)
==25254==    by 0x92DD2E: tree_loop_distribution
(tree-loop-distribution.c:1252)
==25254==    by 0x7F8775: execute_one_pass (passes.c:1556)
==25254==    by 0x7F8A74: execute_pass_list (passes.c:1611)
==25254==    by 0x7F8A86: execute_pass_list (passes.c:1612)
==25254==    by 0x7F8A86: execute_pass_list (passes.c:1612)
==25254==    by 0x93BA05: tree_rest_of_compilation (tree-optimize.c:422)
==25254==  Address 0x0 is not stack'd, malloc'd or (recently) free'd
==25254== 
testcase.c: In function 'foo':
testcase.c:1:6: 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:
r171047 - crash
4.6 r170955 - OK