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Re: [PATCH] i386: Increase Skylake SImode pseudo register store cost
- From: Uros Bizjak <ubizjak at gmail dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Wed, 18 Sep 2019 21:41:03 +0200
- Subject: Re: [PATCH] i386: Increase Skylake SImode pseudo register store cost
- References: <CAMe9rOpED87P7Ri7fXJy4Ess-0sfcVThw__0TLm8=D8TJgshfg@mail.gmail.com>
On Wed, Sep 18, 2019 at 8:04 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Skylake, SImode store cost isn't less than half cost of 128-bit vector
> store. This patch increases Skylake SImode pseudo register store cost to
> make it the same as QImode and HImode.
>
> gcc/
>
> PR target/91446
> * config/i386/x86-tune-costs.h (skylake_cost): Increase SImode
> pseudo register store cost from 3 to 6 to make it the same as
> QImode and HImode.
>
> gcc/testsuite/
>
> PR target/91446
> * gcc.target/i386/pr91446.c: New test.
>
> OK for trunk?
I assume these tunings are backed by some benchmark results. So, OK.
Thanks,
Uros.