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Re: [Qemu-devel] [PATCH v2 3/3] s390x/tcg: add basic MSA features
From: |
Richard Henderson |
Subject: |
Re: [Qemu-devel] [PATCH v2 3/3] s390x/tcg: add basic MSA features |
Date: |
Wed, 20 Sep 2017 08:23:32 -0500 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 |
On 09/19/2017 02:36 PM, David Hildenbrand wrote:
> On 19.09.2017 19:47, Richard Henderson wrote:
>> On 09/19/2017 09:26 AM, David Hildenbrand wrote:
>>> + const uint8_t fc = env->regs[0] & 0x7fULL;
>>
>> Don't mask here...
>
> Bit 56 is the mod bit (see variable "mod") and is checked inside the
> switch(). The function code really is just composed of bit 57 - 63, so
> this is correct.
"mod bit"?
# Bit 56 of general register 0 must be zero; oth-
# erwise, a specification exception is recognized.
I don't suppose this is a change in PoO v11? I'm still looking at v10.
> E.g. for KMAC (7-187):
>
> "A specification exception is recognized and no other
> action is taken if any of the following occurs:
> [...]
> The R2 field designates an odd-numbered regis-
> ter or general register 0."
Hmm, ok. There's different text earlier on page 7-178 that describes the
even-odd requirement but omits the non-zero requirement. Irritating.
r~
[Qemu-devel] [PATCH v2 2/3] s390x/tcg: move wrap_address() to internal.h, David Hildenbrand, 2017/09/19
Re: [Qemu-devel] [PATCH v2 0/3] Implement basic MSA functions, Cornelia Huck, 2017/09/20