[Bug tree-optimization/50644] New: ICE in set_is_used added today

["andi-gcc at firstfloor dot org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50644

             Bug #: 50644
           Summary: ICE in set_is_used added today
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: andi-gcc@firstfloor.org


Since updating to today's trunk I get a ICE in set_is_used while building
a LTOed linux kernel. Yesterday it didn't happen

Running a bisect.

Here's the crash

#7  <signal handler called> 
#8  set_is_used (var=<value optimized out>) at
+../../gcc/gcc/tree-flow-inline.h:562
#9  mark_all_vars_used_1 (var=<value optimized out>) at
+../../gcc/gcc/tree-ssa-live.c:379
#10 0x0000000000860b3e in walk_tree_1 (tp=0x2b11d2f00c00, func=0x7a4390
+<mark_all_vars_used_1(tree*, int*, void*)>, 
    data=0x4296a40, pset=0x0, lh=0) at ../../gcc/gcc/tree.c:10448
#11 0x0000000000860f89 in walk_tree_1 (tp=0x2b11d2efacd0, func=0x7a4390
+<mark_all_vars_used_1(tree*, int*, void*)>, 
    data=0x4296a40, pset=0x0, lh=0) at ../../gcc/gcc/tree.c:10526
#12 0x00000000007a4eb5 in mark_all_vars_used (data=<value optimized out>,
+expr_p=<value optimized out>)
    at ../../gcc/gcc/tree-ssa-live.c:595
#13 remove_unused_locals (data=<value optimized out>, expr_p=<value optimized
+out>)
    at ../../gcc/gcc/tree-ssa-live.c:798
#14 0x000000000068c268 in execute_function_todo (data=Unhandled dwarf
+expression opcode 0xf3
) at ../../gcc/gcc/passes.c:1695
#15 0x000000000068d114 in execute_todo (flags=2132516) at
+../../gcc/gcc/passes.c:1741
#16 0x000000000068f3ce in execute_one_ipa_transform_pass (ipa_pass=0x10ac6e0,
+node=0x2b11e3116ea0)
    at ../../gcc/gcc/passes.c:1919
#17 execute_all_ipa_transforms (ipa_pass=0x10ac6e0, node=0x2b11e3116ea0) at
+../../gcc/gcc/passes.c:1947
#18 0x000000000075fd20 in tree_rest_of_compilation (fndecl=0x2b11d2ed7300) at
+../../gcc/gcc/tree-optimize.c:413
#19 0x000000000051b8a6 in cgraph_expand_function (node=0x2b11e3116ea0) at
+../../gcc/gcc/cgraphunit.c:1805
#20 0x000000000051d182 in cgraph_output_in_order () at
+../../gcc/gcc/cgraphunit.c:1962
#21 cgraph_optimize () at ../../gcc/gcc/cgraphunit.c:2136

...
(gdb) up
#8  set_is_used (var=<value optimized out>) at
+../../gcc/gcc/tree-flow-inline.h:562
562       ann->used = true;
(gdb) p ann
$1 = (var_ann_d *) 0x0