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Re: Shouldn't convert_scalars_to_vector call free_dominance_info?
- From: Richard Biener <richard dot guenther at gmail dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: "Enkovich, Ilya" <ilya dot enkovich at intel dot com>, Uros Bizjak <ubizjak at gmail dot com>, GCC Development <gcc at gcc dot gnu dot org>
- Date: Thu, 10 Mar 2016 14:24:27 +0100
- Subject: Re: Shouldn't convert_scalars_to_vector call free_dominance_info?
- Authentication-results: sourceware.org; auth=none
- References: <CAMe9rOqOcS1rTpvJ1n_g2qiWoyPBbNnGZ-R8A1rwqTBheDHpEg at mail dot gmail dot com> <CAFiYyc3HN6Q7OAihgkU7G6i+NdokMGk_qY3jhDnBBym+sJ7SdA at mail dot gmail dot com> <CAMe9rOpOnPH9Fe4k_XfgAfdWvHiGpeMxm4dbnY2VBG7q7_=EDw at mail dot gmail dot com>
On Thu, Mar 10, 2016 at 2:16 PM, H.J. Lu <firstname.lastname@example.org> wrote:
> On Thu, Mar 10, 2016 at 5:01 AM, Richard Biener
> <email@example.com> wrote:
>> On Thu, Mar 10, 2016 at 1:48 PM, H.J. Lu <firstname.lastname@example.org> wrote:
>>> convert_scalars_to_vector in i386.c calls
>>> calculate_dominance_info (CDI_DOMINATORS);
>>> Shouldn't it call
>>> free_dominance_info (CDI_DOMINATORS);
>>> after it is done like other places where calculate_dominance_info is used?
>> Only if it invalidates it. Other than post-dominator info dominator
>> info is kept
>> up-to-date between passes.
>>> When I extend the STV pass to 64-bit and put the 64-bit STV pass before
>>> the CSE pass, I run into
>>> gcc_assert (!dom_info_available_p (CDI_DOMINATORS));
>> That looks like a bogus assert to me. Which one is it? The one in
>> In that case something else should have freed it (the thing that
>> doesn't preserve it)
>> or the condition the assert is guarded is "incorrect".
> cleanup_cfg has
> /* ??? We probably do this way too often. */
> if (current_loops
> && (changed
> || (mode & CLEANUP_CFG_CHANGED)))
> timevar_push (TV_REPAIR_LOOPS);
> /* The above doesn't preserve dominance info if available. */
> gcc_assert (!dom_info_available_p (CDI_DOMINATORS));
> calculate_dominance_info (CDI_DOMINATORS);
> fix_loop_structure (NULL);
> free_dominance_info (CDI_DOMINATORS);
> timevar_pop (TV_REPAIR_LOOPS);
> Should assert be removed?
I think these days we can safely remove it as calculate_dominance_info
will ICE if dom info is said to be present but is incorrect. I put in
to catch this case before we had that.