From: Richard Henderson <richard.henderson@linaro.org>
To: Andrew Jones <drjones@redhat.com>
Cc: peter.maydell@linaro.org, qemu-devel@nongnu.org,
eric.auger@redhat.com, qemu-arm@nongnu.org,
alex.bennee@linaro.org, Dave.Martin@arm.com
Subject: Re: [PATCH v2] target/arm/arch_dump: Add SVE notes
Date: Thu, 10 Oct 2019 13:33:02 -0400 [thread overview]
Message-ID: <6451070f-9488-cc8f-2f4b-a7577e11f447@linaro.org> (raw)
In-Reply-To: <20191010061600.pwhos4huazbsv6kn@kamzik.brq.redhat.com>
On 10/10/19 2:16 AM, Andrew Jones wrote:
>> It might be best to avoid the ifdef altogether:
>>
>> for (i = 0; i < 32; ++i) {
>> uint64_t *d = (uint64_t *)&buf[sve_zreg_offset(vq, i)];
>> for (j = 0; j < vq * 2; ++j) {
>> d[j] = cpu_to_le64(env->vfp.zregs[i].d[j]);
>> }
>> }
>>
>> The compiler may well transform the inner loop to memcpy for little-endian
>> host, but even if it doesn't core dumping is hardly performance sensitive.
>
> True. I even had something like the above at first, but then
> overcomplicated it with the #ifdef-ing.
Ah, I wonder if you changed things around with the ifdefs due to the pregs.
There's no trivial solution for those. It'd be nice to share the bswapping
subroutine that you add in the SVE KVM patch set, and size the temporary array
using ARM_MAX_VQ.
r~
next prev parent reply other threads:[~2019-10-10 17:34 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-04 12:03 [PATCH v2] target/arm/arch_dump: Add SVE notes Andrew Jones
2019-10-04 19:17 ` no-reply
2019-10-10 0:39 ` Richard Henderson
2019-10-10 6:16 ` Andrew Jones
2019-10-10 17:33 ` Richard Henderson [this message]
2019-10-16 9:13 ` Andrew Jones
2019-10-16 15:39 ` Richard Henderson
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