RE: [PATCH, i386] Avoid 512-bit vector return constant for Intel AVX512 configuration

["Shalnov, Sergey" <sergey dot shalnov at intel dot com>]

Sorry. The patch is changed as you proposed.



-----Original Message-----
From: Uros Bizjak [mailto:ubizjak@gmail.com] 
Sent: Thursday, September 28, 2017 3:17 PM
To: Shalnov, Sergey <sergey.shalnov@intel.com>
Cc: gcc-patches@gcc.gnu.org; kirill.yukhin@gmail.com; Senkevich, Andrew <andrew.senkevich@intel.com>; Ivchenko, Alexander <alexander.ivchenko@intel.com>; Peryt, Sebastian <sebastian.peryt@intel.com>
Subject: Re: [PATCH, i386] Avoid 512-bit vector return constant for Intel AVX512 configuration

On Thu, Sep 28, 2017 at 3:08 PM, Shalnov, Sergey <sergey.shalnov@intel.com> wrote:
> Hi,
> GCC uses full 512-bit register to return the constant from the function.
> The patch avoid 512-bit register usage if "-mprefer-avx256" option used.
>
> 2017-09-28  Sergey Shalnov  <Sergey.Shalnov@intel.com>
>
> gcc/
>         * config/i386/i386.md(*movsf_internal, *movdf_internal):
>         Return 256-bit AVX modes for TARGET_PREFER_AVX256.
>
> gcc/testsuite/
>         * gcc.target/i386/avx512f-constant-float-return.c: New test.
>

-            (match_test "TARGET_AVX512F")
+            (match_test "TARGET_AVX512F && !TARGET_PREFER_AVX256")

Please use

(and (match_test "TARGET_AVX512F)
        (not (match_test "TARGET_PREFER_AVX256)))

Uros.

Attachment: 0001-Avoid-useing-zmm-if-TARGET_PREFER_AVX256.patch
Description: 0001-Avoid-useing-zmm-if-TARGET_PREFER_AVX256.patch