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Re: Shouldn't convert_scalars_to_vector call free_dominance_info?
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: Richard Biener <richard dot guenther at gmail dot com>, "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 06:57:35 -0800
- Subject: Re: Shouldn't convert_scalars_to_vector call free_dominance_info?
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On Thu, Mar 10, 2016 at 5:49 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Thu, Mar 10, 2016 at 05:43:27AM -0800, H.J. Lu wrote:
>> > free_dominance_info (CDI_DOMINATORS);
>>
>> Since convert_scalars_to_vector may add instructions, dominance
>> info is no longer up to date.
>
> Adding instructions doesn't change anything on the dominance info, just
> cfg manipulations that don't keep the dominators updated.
> You can try to verify the dominance info at the end of the stv pass,
I added
verify_dominators (CDI_DOMINATORS);
'
It did trigger assert in my 64-bit STV pass in 64-bit libgcc build:
/export/gnu/import/git/sources/gcc/libgcc/config/libbid/bid128_fma.c:
In function \u2018add_and_round.constprop\u2019:
/export/gnu/import/git/sources/gcc/libgcc/config/libbid/bid128_fma.c:629:1:
error: dominator of 158 should be 107, not 101
I will investigate.
> if it passes there, the bug is elsewhere, in whatever breaks the dominance
> info. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68730#c7
> and the related gcc-patches thread for more info.
>
> Jakub
--
H.J.