[Bug tree-optimization/36291] GCC is slow and memory-hungry building sipQtGuipart.cpp

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

------- Comment #4 from rguenth at gcc dot gnu dot org  2008-05-22 14:39 -------
I added gcc.c-torture/execute/20080522-1.c which points at two problems.

First we need to add referenced vars as they come (there is already
find_new_referenced_vars and some users,
tree-ssa-ccp.c:get_symbol_constant_value
needs to do it as well).

Second we need to update alias information.  This turns out to be a hard
problem.  For the testcase we need to add 'i' to the symbols SMT.7 aliases
and update all statements that reference SMT.7 - which is not easily possible
and expensive.  We probably also need to update flow-sensitive alias info
which is even harder if not impossible.

So it looks like this is a dead end sofar, but still the root of the
problem remains.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36291