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Re: How can I generate a new function at compile time?


On Tue, Jun 3, 2014 at 3:03 PM, Benedikt Huber
<benedikt.huber@theobroma-systems.com> wrote:
>
> I have not found out why the assertion is violated, yet.
> However I noticed that the original function disappears somehow between
> the passes pass_ipa_comdats and pass_fixup_cfg.
> By that I mean that the function appears from the dump files.
> These passes run several passes after the outlining pass.
> Between the outlining pass and pass_ipa_comdats both functions
> (the generated and the original with the call to the generated) are printed.
> I do not know whether this has anything to do with the assertion but it
> seems strange.
> Do you have any guess why this happens?

It probably vanishes because this is the function you ICE for?

> Thank you,
> Benedikt
>
> On 28 May 2014, at 15:50, Richard Biener <richard.guenther@gmail.com> wrote:
>
>> On Wed, May 28, 2014 at 3:28 PM, Benedikt Huber
>> <benedikt.huber@theobroma-systems.com> wrote:
>>> I ported the pass to the fsf trunk. It is built with âenable-checking.
>>> The patch applied with no changes and also the behaviour is the same.
>>> So I probably mess up the cfg somehow.
>>> Can you suggest any strategy for finding the problem that I could use?
>>>
>>> /home/bhuber/sandbox/fsf/install/bin/gcc -O3 -c -fdump-tree-all-details -fdump-ipa-all-details -fdump-rtl-all-details -fno-ipa-cp -fnop-pass -funinline-innermost-loops -Wall -Wextra /home/bhuber/sandbox/try/outline.c
>>> /home/bhuber/sandbox/try/outline.c: In function '_GLOBAL__N_bar':
>>> /home/bhuber/sandbox/try/outline.c:3:1: internal compiler error: in purge_dead_edges, at cfgrtl.c:3179
>>> bar (int s, int r, unsigned * t, int * k, int * p, int * l)
>>> ^
>>> 0x681195 purge_dead_edges(basic_block_def*)
>>>        ../../src/gcc/cfgrtl.c:3179
>>> 0xe64d8a find_bb_boundaries
>>>        ../../src/gcc/cfgbuild.c:522
>>> 0xe64d8a find_many_sub_basic_blocks(simple_bitmap_def*)
>>>        ../../src/gcc/cfgbuild.c:604
>>> 0x66e689 execute
>>>        ../../src/gcc/cfgexpand.c:5905
>>> Please submit a full bug report,
>>> with preprocessed source if appropriate.
>>> Please include the complete backtrace with any bug report.
>>> See <http://gcc.gnu.org/bugs.html> for instructions.
>>
>> Well, look at the CFG and see if it makes sense and why it expects
>> a single successor and why there is none.  Basically, work back
>> from the ICE ...
>>
>> Richard.
>>
>>> Best regards,
>>> Benedikt
>>>
>>> On 27 May 2014, at 17:35, Benedikt Huber <benedikt.huber@theobroma-systems.com> wrote:
>>>
>>>>
>>>> On 27 May 2014, at 17:25, Richard Biener <richard.guenther@gmail.com> wrote:
>>>>
>>>>> On Tue, May 27, 2014 at 5:17 PM, Benedikt Huber
>>>>> <benedikt.huber@theobroma-systems.com> wrote:
>>>>>>
>>>>>> On 27 May 2014, at 17:09, Richard Biener <richard.guenther@gmail.com> wrote:
>>>>>>
>>>>>>> On Tue, May 27, 2014 at 5:03 PM, Benedikt Huber
>>>>>>> <benedikt.huber@theobroma-systems.com> wrote:
>>>>>>>> (Sorry for the duplicate.)
>>>>>>>>
>>>>>>>> I managed to pass the needed parameters to the generated function.
>>>>>>>> However I cannot pin down the reason why the compilation fails.
>>>>>>>> It seems that the cfg is somehow broken, but I cannot tell how.
>>>>>>>> Do you have any debugging hints?
>>>>>>>>
>>>>>>>> As far as I can tell, the cfg is changed during the generation of the preheader
>>>>>>>> (I do this to find the entry block easily.)
>>>>>>>> and in the function move_sese_region_to_fn.
>>>>>>>>
>>>>>>>> I noticed that after pass 058t.copyrename2 the original function bar disappears
>>>>>>>> and the new function is replaced by _GLOBAL__N_bar.constprop, could this have
>>>>>>>> anything to do with the problem?
>>>>>>>
>>>>>>> Unlikely.  You can disable that by using -fno-ipa-cp.
>>>>>>>
>>>>>>>> The pass runs just after the construction of cfg,  outline.c.011t.cfg.
>>>>>>>>
>>>>>>>> /home/bhuber/sandbox/install/bin/gcc -O3 -I /home/bhuber/sandbox/src -c -fdump-tree-all-details -fdump-ipa-all-details -fdump-rtl-all-details -funinline-innermost-loops -Wall -Wextra /home/bhuber/sandbox/try/outline.c
>>>>>>>> /home/bhuber/sandbox/try/outline.c: In function '_GLOBAL__N_bar.constprop':
>>>>>>>> /home/bhuber/sandbox/try/outline.c:3:1: internal compiler error: in purge_dead_edges, at cfgrtl.c:3183
>>>>>>>
>>>>>>> the line doesn't match anything that would ICE on current trunk, but I suppose
>>>>>>> it's the single_succ_p assert that triggers?
>>>>>> Yes, that is right, it is
>>>>>>
>>>>>> gcc_assert (single_succ_p (bb));
>>>>>>
>>>>>>>
>>>>>>> Either you really got until RTL generation or somehow cfgrtl cfg hooks are
>>>>>>> still active while you are working in your pass.
>>>>>>
>>>>>> The pass that fails, according to the dump files is outline.c.174r.expand
>>>>>> So it already tries to generate RTL.
>>>>>> My problem is that there are so many passes in
>>>>>> between, that I do not know where to start looking.
>>>>>> Any idea?
>>>>>
>>>>> What code-base are you developing on?  Do you build with checking
>>>>> enabled (--enable-checking, the default on trunk but not on release branches).
>>>>
>>>> It is a linaro branch, but I am going to port the pass to the fsf trunk and see
>>>> whether the behaviour changes.
>>>>
>>>> Best regards,
>>>> Benedikt
>>>>
>>>>>
>>>>> Richard.
>>>>>
>>>>>>>
>>>>>>> Richard.
>>>>>>>
>>>>>>>> bar (int s, int r, unsigned * t, int * k, int * p, int * l)
>>>>>>>> ^
>>>>>>>> 0x67e7c4 purge_dead_edges(basic_block_def*)
>>>>>>>>    ../../src/gcc/cfgrtl.c:3183
>>>>>>>> 0xe5a0d6 find_bb_boundaries
>>>>>>>>    ../../src/gcc/cfgbuild.c:522
>>>>>>>> 0xe5a0d6 find_many_sub_basic_blocks(simple_bitmap_def*)
>>>>>>>>    ../../src/gcc/cfgbuild.c:604
>>>>>>>> 0x66c0f5 execute
>>>>>>>>    ../../src/gcc/cfgexpand.c:5873
>>>>>>>> Please submit a full bug report,
>>>>>>>> with preprocessed source if appropriate.
>>>>>>>> Please include the complete backtrace with any bug report.
>>>>>>>> See <http://gcc.gnu.org/bugs.html> for instructions.
>>>>>>>>
>>>>>>>> I attach the transformation pass and the small example program.
>>>>>>>>
>>>>>>>> Thank you again for the help,
>>>>>>>> Benedikt
>>>>>>>>
>>>>>>>> P.s. I am aware that this transformation is not safe in general,
>>>>>>>> however in this case it should work.
>>>>
>>>
>


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