[Bug tree-optimization/46130] [4.6 Regression] ICE: SIGSEGV in walk_stmt_load_store_addr_ops (gimple.c:4894) with -O2 -fno-tree-dce

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46130

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-01-19 
16:29:06 UTC ---
Testcase that needs just -O2 -fno-tree-dce:
static void
foo (__builtin_va_list ap)
{
  __builtin_va_arg (ap, char *)[0];
}

int
bar (__builtin_va_list ap)
{
  foo (ap);
  foo (ap);
}

The issue is that I see nothing that checks the SSA_NAMEs in return_bb PHIs
which originate from the split function are just in phi setting retval and
nothing else.
In this case because of -fno-tree-dce there is a dead PHI which the *.part.0
function doesn't pass through to the caller.