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