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Re: rfc: auto-casted vector types
- From: Kumar Gala <kumar dot gala at motorola dot com>
- To: Jim Wilson <wilson at redhat dot com>
- Cc: Aldy Hernandez <aldyh at redhat dot com>, GCC Mailinglist <gcc at gcc dot gnu dot org>, Nick Clifton <nickc at redhat dot com>
- Date: Mon, 17 Feb 2003 16:27:33 -0600
- Subject: Re: rfc: auto-casted vector types
The SPE PIM docs are not currently publicly available.
- kumar
On Monday, February 17, 2003, at 04:25 PM, Jim Wilson wrote:
Aldy Hernandez <aldyh@redhat.com> writes:
The PPC E500 API specifies that vector types of type __ev64_opaque__
(V2SImode) can interconvert with other vector types without a cast.
Is there any publicly available documentation? My copy of the draft
docs
say they are Motorola confidential. If there is documentation
available,
it would be useful to point to it somewhere.
I tried searching the Motorola web site. I found Altivec PIM
documentation,
but no SPE PIM documentation.
* doc/tm.texi: Document TARGET_VECTOR_TYPES_COMPATIBLE.
* c-typeck.c (comptypes): Take into account
TARGET_VECTOR_TYPES_COMPATIBLE.
(convert_for_assignment): Same.
...
The patch looks pretty reasonable to me also. I agree with Zack's
suggestions.
It might be useful to note in the comments in the rs6000 file that the
current implementation has a known flaw. It pretends that V2SI is the
opaque
vector type. This means that it accidentally allows conversions
to/from the
V2SI vector type without explicit casts. In order to fix this, we
need to
use a different otherwise unused vector type for the opaque vector
type.
Nick started on a patch to do this, but didn't have enough time to
finish it.
Jim