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From: "Alex Bennée" <alex.bennee@linaro.org>
To: Richard Henderson <richard.henderson@linaro.org>
Cc: qemu-devel@nongnu.org, qemu-arm@nongnu.org
Subject: Re: [PATCH v2] target/arm: Speed up aarch64 TBL/TBX
Date: Thu, 25 Feb 2021 09:52:51 +0000	[thread overview]
Message-ID: <874ki0bhi1.fsf@linaro.org> (raw)
In-Reply-To: <20210224230532.276878-1-richard.henderson@linaro.org>


Richard Henderson <richard.henderson@linaro.org> writes:

> Always perform one call instead of two for 16-byte operands.
> Use byte loads/stores directly into the vector register file
> instead of extractions and deposits to a 64-bit local variable.
>
> In order to easily receive pointers into the vector register file,
> convert the helper to the gvec out-of-line signature.  Move the
> helper into vec_helper.c, where it can make use of H1 and clear_tail.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>

Looked marginally slower on the (1!) run I did but probably in the noise
and the generated code looks nicer.

-- 
Alex Bennée

WARNING: multiple messages have this Message-ID (diff)
From: "Alex Bennée" <alex.bennee@linaro.org>
To: Richard Henderson <richard.henderson@linaro.org>
Cc: qemu-arm@nongnu.org, qemu-devel@nongnu.org
Subject: Re: [PATCH v2] target/arm: Speed up aarch64 TBL/TBX
Date: Thu, 25 Feb 2021 09:52:51 +0000	[thread overview]
Message-ID: <874ki0bhi1.fsf@linaro.org> (raw)
In-Reply-To: <20210224230532.276878-1-richard.henderson@linaro.org>


Richard Henderson <richard.henderson@linaro.org> writes:

> Always perform one call instead of two for 16-byte operands.
> Use byte loads/stores directly into the vector register file
> instead of extractions and deposits to a 64-bit local variable.
>
> In order to easily receive pointers into the vector register file,
> convert the helper to the gvec out-of-line signature.  Move the
> helper into vec_helper.c, where it can make use of H1 and clear_tail.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>

Looked marginally slower on the (1!) run I did but probably in the noise
and the generated code looks nicer.

-- 
Alex Bennée


  reply	other threads:[~2021-02-25  9:53 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-24 23:05 [PATCH v2] target/arm: Speed up aarch64 TBL/TBX Richard Henderson
2021-02-25  9:52 ` Alex Bennée [this message]
2021-02-25  9:52   ` Alex Bennée
2021-03-05 11:32   ` Peter Maydell
2021-03-05 11:32     ` Peter Maydell

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