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Re: [Google] X86_TUNE_USE_VECTOR_CONVERTS adjustment
- From: Xinliang David Li <davidxl at google dot com>
- To: Wei Mi <wmi at google dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 15 Aug 2013 10:09:10 -0700
- Subject: Re: [Google] X86_TUNE_USE_VECTOR_CONVERTS adjustment
- References: <CA+4CFy5yrLmyKSJpGe31SR756GzuPDgaQbyTyqKPY9wi0_3o1g at mail dot gmail dot com>
yes.
thanks,
David
On Thu, Aug 15, 2013 at 9:50 AM, Wei Mi <wmi@google.com> wrote:
> Turning off X86_TUNE_USE_VECTOR_CONVERTS uses cvtss2sd instead of
> unpcklps+cvtps2pd, which is better for some recent intel micro arch
> such as westmere and sandybridge. So turn it off for m_GENERIC and
> m_CORE_ALL.
>
> regression and bootstrap ok. ok for 4.8 branch?
>
> Index: config/i386/i386.c
> ===================================================================
> --- config/i386/i386.c (revision 201675)
> +++ config/i386/i386.c (working copy)
> @@ -1995,7 +1995,7 @@ static unsigned int initial_ix86_tune_fe
>
> /* X86_TUNE_USE_VECTOR_FP_CONVERTS: Prefer vector packed SSE conversion
> from FP to FP. */
> - m_CORE_ALL | m_AMDFAM10 | m_GENERIC,
> + m_AMDFAM10,
>
> /* X86_TUNE_USE_VECTOR_CONVERTS: Prefer vector packed SSE conversion
> from integer to FP. */