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From: Richard Henderson <richard.henderson@linaro.org>
To: Peter Maydell <peter.maydell@linaro.org>, qemu-devel@nongnu.org
Cc: Thomas Huth <thuth@redhat.com>
Subject: Re: [PATCH] target/nios2 : Explicitly ask for target-endian loads and stores
Date: Mon, 26 Jun 2023 10:31:19 +0200	[thread overview]
Message-ID: <1b18a3f0-078c-7b9b-79f6-8d82a3490b04@linaro.org> (raw)
In-Reply-To: <20230623172556.1951974-1-peter.maydell@linaro.org>

On 6/23/23 19:25, Peter Maydell wrote:
> When we generate code for guest loads and stores, at the moment they
> end up being requests for a host-endian access. So for target-system-nios2
> (little endian) a load like
>     ldw        r3,0(r4)
> results on an x86 host in the TCG IR
>     qemu_ld_a32_i32 r3,loc2,al+leul,0
> but on s390 it is
>     qemu_ld_a32_i32 r3,loc2,al+beul,0
> 
> The result is that guests don't work on big-endian hosts.
> 
> Use the MO_TE* memops rather than the plain ones.
> 
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1693
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> Presumably this got lost in a recent conversion somewhere,
> but I can't figure out where, so maybe it's been broken much
> longer...

It has been broken since initial commit: 032c76bc6f9 was already wrong.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~


  parent reply	other threads:[~2023-06-26  8:31 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-23 17:25 [PATCH] target/nios2 : Explicitly ask for target-endian loads and stores Peter Maydell
2023-06-23 22:18 ` Philippe Mathieu-Daudé
2023-06-26  8:31 ` Richard Henderson [this message]
2023-06-30 18:15 ` Richard Henderson

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