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Date: Sun, 07 Feb 2010 10:24:00 -0000
Subject: [Bug c/42991]  New: cfgexpand.c:2487: Conditional jump or move depends on uninitialised value(s)
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I just tried to compile the Linux kernel 2.6.33-rc6 under valgrind
with the C compiler version 4.5 snapshot 20100128 and valgrind said

==17102== Conditional jump or move depends on uninitialised value(s)
==17102==    at 0x56D105: expand_debug_expr (cfgexpand.c:2487)
==17102==    by 0x56C912: expand_debug_expr (cfgexpand.c:2876)
==17102==    by 0x570D54: gimple_expand_cfg (cfgexpand.c:2981)
==17102==    by 0x722ECA: execute_one_pass (passes.c:1561)
==17102==    by 0x723154: execute_pass_list (passes.c:1616)
==17102==    by 0x818C94: tree_rest_of_compilation (tree-optimize.c:413)
==17102==    by 0x99A420: cgraph_expand_function (cgraphunit.c:1543)
==17102==    by 0x99CE44: cgraph_optimize (cgraphunit.c:1622)
==17102==    by 0x99D3A4: cgraph_finalize_compilation_unit (cgraphunit.c:1093)
==17102==    by 0x4B0602: c_write_global_declarations (c-decl.c:9537)
==17102==    by 0x7C7AFB: toplev_main (toplev.c:1065)
==17102==    by 0x6568A7C: (below main) (in /lib64/libc-2.10.1.so)
==17102==

Line 2487 of cfgexpand.c is

        if (bitsize == 0)
          return NULL;

Preprocessed source code attached. Flags -Os -g required.


-- 
           Summary: cfgexpand.c:2487: Conditional jump or move depends on
                    uninitialised value(s)
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dcb314 at hotmail dot com
  GCC host triplet: x86_64-suse-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42991