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[Bug debug/54402] [4.8 Regression] var-tracking does not scale


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54402

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |jakub at gcc dot gnu.org

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-10-29 09:48:59 UTC ---
Haven't gathered var-tracking statistics yet, but from quick glance at
i686 reflect_test..import routine it looks like with LRA more memory accesses
are %ebp based, while with old reload they were %esp based:
-       movl    %eax, 84(%esp)
+       movl    %eax, -7592(%ebp)
etc.  As the var-tracking problem seems to be in the memory disambiguation code
(added by Alex for 4.8+ for PR49888) perhaps that could have an effect.
LRA code looks shorter (reflect all_tests.go)).


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