This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: IMA vs tree-ssa
- From: law at redhat dot com
- To: Dale Johannesen <dalej at apple dot com>
- Cc: GCC List <gcc at gcc dot gnu dot org>
- Date: Thu, 26 Feb 2004 15:42:36 -0700
- Subject: Re: IMA vs tree-ssa
- Reply-to: law at redhat dot com
In message <F0209661-68A9-11D8-8C0E-000A95D7CD40@apple.com>, Dale Johannesen wr
ites:
>There are several places where tree-ssa does type comparison by
>comparing TYPE_MAIN_VARIANT() for equality.
Yup.
> This doesn't work with IMA, and leads to several different ICEs in
> various SPECmarks (you can probably figure out which one the example
> came from :)
When the tree-ssa optimizers look at TYPE_MAIN_VARIANT, they are trying to
determine if they can either eliminate an expression or eliminate a copy.
If the main variants are not equal, then all that ought to happen is a
optimization opportunity is missed.
If we're getting aborts and such, then I'd be very curious to know precisely
how the TYPE_MAIN_VARIANTs are being used and how the mis-matched types
lead to failures.
jeff