This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH][AArch64] Improve float to int moves
- From: "Richard Earnshaw (lists)" <Richard dot Earnshaw at arm dot com>
- To: Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
- Cc: nd <nd at arm dot com>, James Greenhalgh <James dot Greenhalgh at arm dot com>
- Date: Fri, 5 May 2017 17:20:00 +0100
- Subject: Re: [PATCH][AArch64] Improve float to int moves
- Authentication-results: sourceware.org; auth=none
- References: <AM5PR0802MB2610DDF3A7F7AA8DE2E5446E83110@AM5PR0802MB2610.eurprd08.prod.outlook.com> <e670bed7-4dcb-58d8-c9b4-175cdbf2981e@arm.com> <AM5PR0802MB26105B328D23883EDEF8E22C83EB0@AM5PR0802MB2610.eurprd08.prod.outlook.com>
On 05/05/17 17:10, Wilco Dijkstra wrote:
> Richard Earnshaw (lists) wrote:
>
>> While on the subject, why is the w->w operation also hidden?
>
> No idea, this just fixes one case where it is obvious the use of '*' is
> incorrect.
>
> However I think all uses of '*' in md files are incorrect and the
> feature should
> be removed. '?' already exists for cases where the alternative may be
> expensive.
>
It's not quite as simple as that. It may be, however, that we should
only use it for restricting subclasses (eg generally avoiding high
registers on Thumb1).
However, things have changed somewhat since the move to LRA and what was
once true might be quite different now.
R.
> Wilco