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Date:      Sat, 15 Nov 2014 07:47:38 +0000
From:      bugzilla-noreply@freebsd.org
To:        freebsd-arm@FreeBSD.org
Subject:   [Bug 194635] Speed optimisation for framebuffer console driver on Raspberry Pi
Message-ID:  <bug-194635-7-7YEUsbWM1P@https.bugs.freebsd.org/bugzilla/>
In-Reply-To: <bug-194635-7@https.bugs.freebsd.org/bugzilla/>
References:  <bug-194635-7@https.bugs.freebsd.org/bugzilla/>

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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=194635

--- Comment #7 from Stefan Berndt <stefan.berndt@imoriath.com> ---
I think it is not related to alignment. Arm code can not be aligned wrong, this
cpu cannot do unaligned work. 

Its more simple, done in my first post:
- one 32bit access is faster than two 16bit or four 8bit access
- using pre-calculated color values, not need to shrink 32bit colors to 24 or
16bit on every draw of a pixel
- moving calculations of not changing values out of a loop
- sorting loops in optimal order

The last thing i have made in this assembler file is to remove every kind of
loops, not load the font image but use special code for every character.
Instead of my fist post this one should not be used in official kernel. The
resulting code is more than 100 times larger! And you cannot change the font
anymore. Its just for fun, education and impression.

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