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Re: [PATCH] Missing Skylake -march=/-mtune= option
- From: Markus Trippelsdorf <markus at trippelsdorf dot de>
- To: Yuri Rumyantsev <ysrumyan at gmail dot com>
- Cc: gcc-patches <gcc-patches at gcc dot gnu dot org>, Uros Bizjak <ubizjak at gmail dot com>, Igor Zamyatin <izamyatin at gmail dot com>, ÐÐÑÑ ÐÐÐÐÐÐÑ <enkovich dot gnu at gmail dot com>
- Date: Thu, 20 Aug 2015 17:49:23 +0200
- Subject: Re: [PATCH] Missing Skylake -march=/-mtune= option
- Authentication-results: sourceware.org; auth=none
- References: <CAEoMCqSAJ1P8XwVAe0w4=+HsnPyShD-kSpbsxHxgBMjFS7UtDw at mail dot gmail dot com>
On 2015.08.13 at 12:31 +0300, Yuri Rumyantsev wrote:
> Hi All,
>
> Here is patch for adding march/mtune options for Skylake.
http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/desktop-6th-gen-core-family-spec-update.pdf
states that BMI1 and BMI2 are not supported. Is this true for all
Skylake CPUs?
Quote from the pdf:
SKD002 CPUID Incorrectly Reports Bit Manipulation Instructions Support
Executing CPUID with EAX = 7 and ECX = 0 may return EBX with bits [3]
and [8] set, incorrectly indicating the presence of BMI1 and BMI2
instruction set extensions.
Attempting to use instructions from the BMI1 or BMI2 instruction set
extensions will result in a #UD exception.
--
Markus