[Bug tree-optimization/42707] New: [4.5 Regression] ICE - segfault in mark_operand_necessary

["doko at ubuntu dot com" <gcc-bugzilla at gcc dot gnu dot org>]

seen with trunk 20100112, not with the 4.4 branch; lowering optimization to -O1
works around the segfault.

$ g++ -c -g -O2 nsTreeRows.ii
/scratch/packages/tmp/rebuild/kompozer-0.8~b1/mozilla/content/xul/templates/src/nsTreeRows.cpp:
In member function 'void nsTreeRows::InvalidateCachedRow()':
/scratch/packages/tmp/rebuild/kompozer-0.8~b1/mozilla/content/xul/templates/src/nsTreeRows.cpp:483:1:
internal compiler error: Segmentation fault
Please submit a full bug report,


Program received signal SIGSEGV, Segmentation fault.
mark_operand_necessary (aggressive=<value optimized out>) at
../../src/gcc/tree-ssa-dce.c:265
265         SET_BIT (bb_contains_live_stmts, gimple_bb (stmt)->index);
(gdb) bt
#0  mark_operand_necessary (aggressive=<value optimized out>) at
../../src/gcc/tree-ssa-dce.c:265
#1  propagate_necessity (aggressive=<value optimized out>) at
../../src/gcc/tree-ssa-dce.c:705
#2  perform_tree_ssa_dce (aggressive=<value optimized out>) at
../../src/gcc/tree-ssa-dce.c:1389
#3  0x000000000070bbae in execute_one_pass (pass=0x1129080) at
../../src/gcc/passes.c:1561
#4  0x000000000070be15 in execute_pass_list (pass=0x1129080) at
../../src/gcc/passes.c:1616
#5  0x000000000070be27 in execute_pass_list (pass=0x1128a20) at
../../src/gcc/passes.c:1617
#6  0x000000000070b668 in do_per_function_toporder (callback=0x70be00
<execute_pass_list>, data=0x1128b40) at ../../src/gcc/passes.c:1142
#7  0x000000000070c08a in execute_ipa_pass_list (pass=0x11289c0) at
../../src/gcc/passes.c:1800
#8  0x0000000000908e29 in ipa_passes () at ../../src/gcc/cgraphunit.c:1768
#9  cgraph_optimize () at ../../src/gcc/cgraphunit.c:1829
#10 0x0000000000908f85 in cgraph_finalize_compilation_unit () at
../../src/gcc/cgraphunit.c:1093
#11 0x00000000004f349c in cp_write_global_declarations () at
../../src/gcc/cp/decl2.c:3798
#12 0x000000000079f3a6 in compile_file (argc=14, argv=0x7fffffffe5f8) at
../../src/gcc/toplev.c:1065
#13 do_compile (argc=14, argv=0x7fffffffe5f8) at ../../src/gcc/toplev.c:2405
#14 toplev_main (argc=14, argv=0x7fffffffe5f8) at ../../src/gcc/toplev.c:2447
#15 0x00007ffff616cabd in __libc_start_main () from /lib/libc.so.6
#16 0x000000000049f179 in _start ()


-- 
           Summary: [4.5 Regression] ICE - segfault in
                    mark_operand_necessary
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: doko at ubuntu dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42707