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Re: [GOOGLE] More strict checking for call args
- From: Xinliang David Li <davidxl at google dot com>
- To: Dehao Chen <dehao at google dot com>
- Cc: Richard Biener <richard dot guenther at gmail dot com>, Duncan Sands <baldrick at free dot fr>, GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 6 Jun 2013 09:14:59 -0700
- Subject: Re: [GOOGLE] More strict checking for call args
- References: <CAO2gOZWs7maFPDo=EZUe1mPARfNFxxnA5Yg3z0Wo0WS1+2ji2Q at mail dot gmail dot com> <51A85C16 dot 1030505 at free dot fr> <CAAkRFZL7aPp9WSxsj1yaujdBWrs91D=H0d_+KxVcgnh=xnt7Ng at mail dot gmail dot com> <CAO2gOZUZ0xTXoMPmLyhsCRkyFQehu7A7EiuqS1E40hBvd8yvxQ at mail dot gmail dot com> <CAFiYyc2q4nGUWNqDbqcpMunEPr-jQN0f2==h-rmMUCjqTWtTUw at mail dot gmail dot com> <CAO2gOZXqae0ju2nMK=f_XSKZFMOscdmL__P=MYf7x01BBs=jOw at mail dot gmail dot com> <CAAkRFZK4rfGvcaJ2PH34TGXtGaC41Wk8SeJ5hEyiC_eU9LTiTA at mail dot gmail dot com> <CAO2gOZViTTifco=SJ8sFqGjdAzg2h8Dzs87xtLa0ZVGaAJzGLg at mail dot gmail dot com> <20130606141124 dot GB30912 at virgil dot suse> <CAO2gOZWYMEa5y9F++nrfZm9JapTP2kCSEeHv-ad_aPNvRdS4-A at mail dot gmail dot com>
gimple_check_call_matching_types is called by check_ic_target. Instead
of moving the check out of this guard function, may be enhancing the
interface to allow it to guard with different strictness?
David
On Thu, Jun 6, 2013 at 8:10 AM, Dehao Chen <dehao@google.com> wrote:
> Hi, Martin,
>
> Yes, your patch can fix my case. Thanks a lot for the fix.
>
> With the fix, value profiling will still promote the wrong indirect
> call target. Though it will not be inlining, but it results in an
> additional check. How about in check_ic_target, after calling
> gimple_check_call_matching_types, we also check if number of args
> match number of params in target->symbol.decl?
>
> Thanks,
> Dehao
>
>
> On Thu, Jun 6, 2013 at 7:11 AM, Martin Jambor <mjambor@suse.cz> wrote:
>>
>> Hi,
>>
>> On Tue, Jun 04, 2013 at 05:19:02PM -0700, Dehao Chen wrote:
>> > attached is a testcase that would cause problem when source has changed:
>> >
>> > $ g++ test.cc -O2 -fprofile-generate -DOLD
>> > $ ./a.out
>> > $ g++ test.cc -O2 -fprofile-use
>> > test.cc:34:1: internal compiler error: in operator[], at vec.h:815
>> > }
>> > ^
>> > 0x512740 vec<tree_node*, va_heap, vl_embed>::operator[](unsigned int)
>> > ../../gcc/vec.h:815
>> > 0x512740 vec<tree_node*, va_heap, vl_ptr>::operator[](unsigned int)
>> > ../../gcc/vec.h:1244
>> > 0xf24464 vec<tree_node*, va_heap, vl_embed>::operator[](unsigned int)
>> > ../../gcc/vec.h:815
>> > 0xf24464 vec<tree_node*, va_heap, vl_ptr>::operator[](unsigned int)
>> > ../../gcc/vec.h:1244
>> > 0xf24464 ipa_get_indirect_edge_target_1
>> > ../../gcc/ipa-cp.c:1535
>> > 0x971b9a estimate_edge_devirt_benefit
>> > ../../gcc/ipa-inline-analysis.c:2757
>>
>> Hm, this seems rather like an omission in ipa_get_indirect_edge_target_1.
>> Since it is called also from inlining, we can have parameter count
>> mismatches... and in fact in non-virtual paths of that function we do
>> check that we don't. Because all callers have to pass known_vals
>> describing all formal parameters of the inline tree root, we should
>> apply the fix below (I've only just started running a bootstrap and
>> testsuite on x86_64, though).
>>
>> OTOH, while I understand that FDO can change inlining sufficiently so
>> that this error occurs, IMHO this should not be caused by outdated
>> profiles but there is somewhere a parameter mismatch in the source.
>>
>> Dehao, can you please check that this patch helps?
>>
>> Richi, if it does and the patch passes bootstrap and tests, is it OK
>> for trunk and 4.8 branch?
>>
>> Thanks and sorry for the trouble,
>>
>> Martin
>>
>>
>> 2013-06-06 Martin Jambor <mjambor@suse.cz>
>>
>> * ipa-cp.c (ipa_get_indirect_edge_target_1): Check that param_index is
>> within bounds at the beginning of the function.
>>
>> Index: src/gcc/ipa-cp.c
>> ===================================================================
>> --- src.orig/gcc/ipa-cp.c
>> +++ src/gcc/ipa-cp.c
>> @@ -1481,7 +1481,8 @@ ipa_get_indirect_edge_target_1 (struct c
>> tree otr_type;
>> tree t;
>>
>> - if (param_index == -1)
>> + if (param_index == -1
>> + || known_vals.length () <= (unsigned int) param_index)
>> return NULL_TREE;
>>
>> if (!ie->indirect_info->polymorphic)
>> @@ -1516,8 +1517,7 @@ ipa_get_indirect_edge_target_1 (struct c
>> t = NULL;
>> }
>> else
>> - t = (known_vals.length () > (unsigned int) param_index
>> - ? known_vals[param_index] : NULL);
>> + t = NULL;
>>
>> if (t &&
>> TREE_CODE (t) == ADDR_EXPR