From: Richard Henderson <richard.henderson@linaro.org>
To: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>,
qemu-devel@nongnu.org, qemu-ppc@nongnu.org,
david@gibson.dropbear.id.au, lvivier@redhat.com
Subject: Re: [Qemu-devel] [RFC PATCH v2 4/9] target/ppc: delay writeback of avr{l, h} during lvx instruction
Date: Mon, 17 Dec 2018 08:46:17 -0800 [thread overview]
Message-ID: <2bd3dead-354e-31ca-bc19-fb1ed3191f15@linaro.org> (raw)
In-Reply-To: <20181217122405.18732-5-mark.cave-ayland@ilande.co.uk>
On 12/17/18 4:24 AM, Mark Cave-Ayland wrote:
> During review of the previous patch, Richard pointed out an existing bug that
> the writeback to the avr{l,h} registers should be delayed until after any
> exceptions have been raised.
>
> Perform both 64-bit loads into separate temporaries and then write them into
> the avr{l,h} registers together to ensure that this is always the case.
>
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> ---
> target/ppc/translate/vmx-impl.inc.c | 24 +++++++++++++-----------
> 1 file changed, 13 insertions(+), 11 deletions(-)
I feel a bit silly. There was no bug, since the address is forced to be
aligned on a 16-byte boundary. The second memory access will be to the same
page and cannot trap.
That said, I think the cleanup looks good.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~
next prev parent reply other threads:[~2018-12-17 16:46 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-17 12:23 [Qemu-devel] [RFC PATCH v2 0/9] target/ppc: convert VMX instructions to use TCG vector operations Mark Cave-Ayland
2018-12-17 12:23 ` [Qemu-devel] [RFC PATCH v2 1/9] target/ppc: introduce get_fpr() and set_fpr() helpers for FP register access Mark Cave-Ayland
2018-12-17 16:40 ` Richard Henderson
2018-12-17 17:20 ` Mark Cave-Ayland
2018-12-17 12:23 ` [Qemu-devel] [RFC PATCH v2 2/9] target/ppc: introduce get_avr64() and set_avr64() helpers for VMX " Mark Cave-Ayland
2018-12-17 12:23 ` [Qemu-devel] [RFC PATCH v2 3/9] target/ppc: introduce get_cpu_vsr{l, h}() and set_cpu_vsr{l, h}() helpers for VSR " Mark Cave-Ayland
2018-12-17 16:43 ` Richard Henderson
2018-12-17 12:24 ` [Qemu-devel] [RFC PATCH v2 4/9] target/ppc: delay writeback of avr{l, h} during lvx instruction Mark Cave-Ayland
2018-12-17 16:46 ` Richard Henderson [this message]
2018-12-17 17:23 ` Mark Cave-Ayland
2018-12-17 12:24 ` [Qemu-devel] [RFC PATCH v2 5/9] target/ppc: switch FPR, VMX and VSX helpers to access data directly from cpu_env Mark Cave-Ayland
2018-12-17 12:24 ` [Qemu-devel] [RFC PATCH v2 6/9] target/ppc: merge ppc_vsr_t and ppc_avr_t union types Mark Cave-Ayland
2018-12-17 16:47 ` Richard Henderson
2018-12-17 12:24 ` [Qemu-devel] [RFC PATCH v2 7/9] target/ppc: move FP and VMX registers into aligned vsr register array Mark Cave-Ayland
2018-12-17 16:58 ` Richard Henderson
2018-12-17 12:24 ` [Qemu-devel] [RFC PATCH v2 8/9] target/ppc: convert VMX logical instructions to use vector operations Mark Cave-Ayland
2018-12-17 12:24 ` [Qemu-devel] [RFC PATCH v2 9/9] target/ppc: convert vaddu[b, h, w, d] and vsubu[b, h, w, d] over " Mark Cave-Ayland
2018-12-17 17:39 ` [Qemu-devel] [RFC PATCH v2 0/9] target/ppc: convert VMX instructions to use TCG " Richard Henderson
2018-12-17 18:49 ` Mark Cave-Ayland
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