Re: PR middle-end/44813 (ICE in Mozilla build in ptr_deref_may_alias_decl_p)

["H.J. Lu" <hjl.tools@gmail.com>]

On Mon, Jul 5, 2010 at 9:18 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
> Hi,
> here is updated patch, with Richard's reduced testcase that solves some furhter
> problems.
> In particular adding the tester down that ipa-split produce new SSA name
> for return value and sets as definining statement the call (that is wrong
> for DECL_BY_REFERENCE)>  I also cleaned up the code a bit there.
> Also ipa-ssa-ccp considers RESULT_DECL as undefined that leads to misoptimization
> after fixing the first problem on libstdc++ vector testcase.
>
> Bootstrapped/regtested x86_64-linux, OK?
>
>        * tree-ssa-uninit.c (ssa_undefined_value_p): Result decl is defined
>        for functions passed by reference.
>        * tree.c (needs_to_live_in_memory): RESULT_DECL don't need to live
>        in memory when passed by reference.
>        * tree-ssa-ccp.c (get_default_value): Only VAR_DECL is undefined at
>        beggining.
>        * ipa-split.c (split_function): Cleanup way return value is passed;
>        handle SSA DECL_BY_REFERENCE retvals.
>        * tree-ssa.c (verify_def): Verify that RESULT_DECL is read only when
>        DECL_BY_REFERENCE is set.
>        * tree-inline.c (remap_gimple_stmt): Handle SSA DECL_BY_REFERENCE
>        returns.
>        * tree-ssa-structalias.c (get_constraint_for_ssa_var, get_fi_for_callee,
>        find_what_p_points_to): Handle RESULT_DECL.
>

This caused:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47313


-- 
H.J.