Re: [PATCH] Handle builtin functions with pointer args/returns in PTA and the alias oracle

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

On Fri, Jun 19, 2009 at 1:33 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Jun 19, 2009 at 9:45 AM, Richard Guenther<rguenther@suse.de> wrote:
>> On Thu, 18 Jun 2009, Richard Guenther wrote:
>>
>>>
>>> This implements knowledge about builtin functions with pointer arguments
>>> and return values in points-to analysis as well as in the alias-oracle.
>>> The effect is that arguments to most string and math functions do not
>>> escape and that we know what their return values point to. ?We also
>>> can restrict clobbering to the relevant arguments.
>>>
>>> Bootstrapped and tested on x86_64-unknown-linux-gnu, I'll apply this
>>> tomorrow to let people time to comment.
>>>
>>> I chickened out on all the printf-style stuff due to the usual
>>> problem of glibc allowing hooks here. ?If I missed commonly used
>>> functions other than these please tell me.
>>
>> Reviewing the patch before committing revealed that I added a
>> bunch of handling to the wrong function. ?Fixed and re-tested,
>> the following is what I committed.
>>
>> Richard.
>>
>> 2009-06-19 ?Richard Guenther ?<rguenther@suse.de>
>>
>> ? ? ? ?* tree-ssa-alias.c (ptr_deref_may_alias_decl_p): Handle
>> ? ? ? ?ADDR_EXPR pointers.
>> ? ? ? ?(ptr_derefs_may_alias_p): Likewise.
>> ? ? ? ?(ptr_deref_may_alias_ref_p_1): New function.
>> ? ? ? ?(ptr_deref_may_alias_ref_p): Likewise.
>> ? ? ? ?(ref_maybe_used_by_call_p_1): Handle builtins that are not
>> ? ? ? ?covered by looking at the ESCAPED solution.
>> ? ? ? ?(call_may_clobber_ref_p_1): Likewise.
>> ? ? ? ?* tree-ssa-structalias.c (get_constraint_for_ptr_offset):
>> ? ? ? ?Handle NULL_TREE offset. ?Do not produce redundant constraints.
>> ? ? ? ?(process_all_all_constraints): New helper function.
>> ? ? ? ?(do_structure_copy): Use it.
>> ? ? ? ?(handle_lhs_call): Likewise.
>> ? ? ? ?(find_func_aliases): Handle some builtins with pointer arguments
>> ? ? ? ?and/or return values explicitly.
>>
>> ? ? ? ?* gcc.c-torture/execute/20090618-1.c: New testcase.
>>
>
> This may have caused:
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40495
>

This caused:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43679


-- 
H.J.