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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?

-- PMM

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