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Re: [Qemu-devel] [PATCH 0/3] target-arm: support setend instruction
From: |
Peter Maydell |
Subject: |
Re: [Qemu-devel] [PATCH 0/3] target-arm: support setend instruction |
Date: |
Mon, 21 Apr 2014 21:52:47 +0100 |
On 21 April 2014 18:43, Paolo Bonzini <address@hidden> wrote:
> This series adds setend support by using the MO_BE/MO_LE that Richard
> implemented. This is used by Raspbian's faster memcmp implementation.
There are also "by hand" loads done in linux-user/main.c's implementation
of ldrex/strex which need to honour CPSR.E now.
We seem to be OK for the ldrd/strd since we implement these as
a pair of 32 bit loads (unlike the pseudocode which does a 64 bit
load and then parcels the result out to Rt/Rt2 so it gets atomic
64 bit access semantics).
I think we get the various neon load/store insns right, but did you
check the pseudocode against our implementation or are you just
hoping that we never try to combine or split a load/store compared
to the pseudocode spec?
thanks
-- PMM