This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH] Fix eipa_sra AAPCS issue (PR target/65956)
- From: Richard Earnshaw <Richard dot Earnshaw at foss dot arm dot com>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: Richard Biener <rguenther at suse dot de>, gcc-patches at gcc dot gnu dot org, Martin Jambor <mjambor at suse dot de>, Alan Lawrence <alan dot lawrence at arm dot com>
- Date: Tue, 05 May 2015 14:20:43 +0100
- Subject: Re: [PATCH] Fix eipa_sra AAPCS issue (PR target/65956)
- Authentication-results: sourceware.org; auth=none
- References: <alpine dot LSU dot 2 dot 11 dot 1505040950230 dot 20496 at zhemvz dot fhfr dot qr> <20150504150011 dot GD1751 at tucnak dot redhat dot com> <20150505073228 dot GH1751 at tucnak dot redhat dot com> <5548A174 dot 4010208 at foss dot arm dot com> <5548A327 dot 3080103 at foss dot arm dot com> <A290B716-CC90-4AB9-A14C-768C7623AA83 at suse dot de> <5548BBBC dot 7060000 at foss dot arm dot com> <5548BC73 dot 8030506 at foss dot arm dot com> <20150505125431 dot GJ1751 at tucnak dot redhat dot com> <5548BF5B dot 9000904 at foss dot arm dot com> <20150505130650 dot GK1751 at tucnak dot redhat dot com>
On 05/05/15 14:06, Jakub Jelinek wrote:
> On Tue, May 05, 2015 at 02:02:19PM +0100, Richard Earnshaw wrote:
>> In a literal sense, yes. However, even K&R & stdarg have standard
>> promotion and conversion rules (size < int => int, floats promoted to
>> double, etc). What are those rules for GCC's overaligned types (ie
>> where in the docs does it say what happens and how a back-end should
>> interpret them)? Shouldn't the mid-end be doing that work so as to
>
> For the middle-end, the TYPE_ALIGN info on expression types is considered
> useless, you can get there anything. There is no conversion rule to what
> you get for myalignedint + int, or (myalignedint) int, or (int)
> myalignedint, etc.
>
>> create a consistent view of the values passed into the back-end? It
>> seems to me that at present the back-end has to be psychic as to what is
>> really happening.
>
> No, the backend just shouldn't consider TYPE_ALIGN on the scalars, and it
> seems only arm ever looks at that.
>
Nothing in the specification for TARGET_FUNCTION_ARG (or any of the
related functions) makes any mention of this...
R.
> Jakub
>