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Re: [Qemu-devel] [RFC PATCH v2 1/3] target-arm: Use Neon for zero checki
From: |
Peter Maydell |
Subject: |
Re: [Qemu-devel] [RFC PATCH v2 1/3] target-arm: Use Neon for zero checking |
Date: |
Mon, 11 Apr 2016 11:40:19 +0100 |
On 9 April 2016 at 23:45, Richard Henderson <address@hidden> wrote:
> On 04/07/2016 02:58 AM, address@hidden wrote:
>>
>> +#elif defined __aarch64__
>> +#include "arm_neon.h"
>
>
> A better test is __NEON__, which asserts that neon is available at compile
> time (which will be true basically always for aarch64), and then you don't
> need a runime test for neon.
You don't need a runtime test for neon on aarch64 anyway, because
it will always be present.
> You also get support for armv7 with neon.
But if you do care about armv7 then you do need a runtime test,
because the defacto standard compile options are for armhf which
has FP but doesn't assume Neon.
Personally I think we should not worry about armv7 here, because
it's not actually a likely virtualization server platform, and
we shouldn't include code in QEMU we're not even compile testing.
So I think __aarch64__ here is fine.
thanks
-- PMM
- [Qemu-devel] [RFC PATCH v2 0/3] ARM64: Live migration optimization, vijayak, 2016/04/07
- [Qemu-devel] [RFC PATCH v2 1/3] target-arm: Use Neon for zero checking, vijayak, 2016/04/07
- [Qemu-devel] [RFC PATCH v2 2/3] utils: Add cpuinfo helper to fetch /proc/cpuinfo, vijayak, 2016/04/07
- Re: [Qemu-devel] [RFC PATCH v2 2/3] utils: Add cpuinfo helper to fetch /proc/cpuinfo, Peter Maydell, 2016/04/07
- Re: [Qemu-devel] [RFC PATCH v2 2/3] utils: Add cpuinfo helper to fetch /proc/cpuinfo, Vijay Kilari, 2016/04/07
- Re: [Qemu-devel] [RFC PATCH v2 2/3] utils: Add cpuinfo helper to fetch /proc/cpuinfo, Peter Maydell, 2016/04/07
- Re: [Qemu-devel] [RFC PATCH v2 2/3] utils: Add cpuinfo helper to fetch /proc/cpuinfo, Vijay Kilari, 2016/04/08
- Re: [Qemu-devel] [RFC PATCH v2 2/3] utils: Add cpuinfo helper to fetch /proc/cpuinfo, Peter Maydell, 2016/04/08
- Re: [Qemu-devel] [RFC PATCH v2 2/3] utils: Add cpuinfo helper to fetch /proc/cpuinfo, Vijay Kilari, 2016/04/11
- Re: [Qemu-devel] [RFC PATCH v2 2/3] utils: Add cpuinfo helper to fetch /proc/cpuinfo, Suzuki K Poulose, 2016/04/11
- Re: [Qemu-devel] [RFC PATCH v2 2/3] utils: Add cpuinfo helper to fetch /proc/cpuinfo, Vijay Kilari, 2016/04/13
- Re: [Qemu-devel] [RFC PATCH v2 2/3] utils: Add cpuinfo helper to fetch /proc/cpuinfo, Suzuki K Poulose, 2016/04/13