[Pixman] [PATCH] MIPS: DSPr2: Added over_n_8888_8888_ca and over_n_8888_0565_ca fast paths.

[Lukic, Nemanja]

Hi Soren,

I usually select cairo-perf-trace that utilize optimized fast path the most.
In this case, xfce4-terminal-a1 proved to be that one. I use oprofile to check CPU utilization. Here is oprofile log I got for the xfce4-terminal-a1:

CPU: MIPS 74K, speed 0 MHz (estimated)
Counted CYCLES events (Cycles) with a unit mask of 0x00 (No unit mask) count 40000
samples  %        image name               app name                 symbol name
2658517  50.3337  no-vmlinux               no-vmlinux               /no-vmlinux
1216517  23.0323  libpixman-1.so           libpixman-1.so           pixman_composite_over_n_8888_8888_ca_asm_mips
270995    5.1308  libc-2.11.2.so           libc-2.11.2.so           memset
165057    3.1250  libm-2.11.2.so           libm-2.11.2.so           floor
139880    2.6483  libpixman-1.so           libpixman-1.so           pixman_fill_buff32_mips_dsp
136303    2.5806  libpixman-1.so           libpixman-1.so           fetch_scanline_a8
61821     1.1705  libc-2.11.2.so           libc-2.11.2.so           memcpy
...

All other traces don't utilize this fast-path that much (this is what my oprofile runs on the test system showed).
If you know some more suitable trace (or system configuration I need to have, like fonts installed, etc), please let me know, and I'll re-run the benchmarks and update the commit.

Thanks,
Nemanja Lukic

-----Original Message-----
From: Siarhei Siamashka [mailto:siarhei.siamashka at gmail.com] 
Sent: Monday, March 12, 2012 10:05 PM
To: Søren Sandmann
Cc: Lukic, Nemanja; pixman at lists.freedesktop.org; nemanja.lukic at rt-rk.com
Subject: Re: [Pixman] [PATCH] MIPS: DSPr2: Added over_n_8888_8888_ca and over_n_8888_0565_ca fast paths.

On Mon, Mar 12, 2012 at 10:48 PM, Søren Sandmann <sandmann at cs.au.dk> wrote:
> Nemanja Lukic <nlukic at mips.com> writes:
>
>> [ # ]  backend                         test   min(s) median(s) stddev. count
>> [ # ]    image: pixman 0.25.3
>> [  0]    image            xfce4-terminal-a1  138.223  139.070   0.33%    6/6
>> [ # ]  image16: pixman 0.25.3
>> [  0]  image16            xfce4-terminal-a1  132.763  132.939   0.06%    5/6
>
> I'm curious why you chose this particular benchmark? The main path that
> xfce4-terminal-a1 exercises is over_n_1_8888 and add_1_1. As far as I
> can tell it doesn't actually hit the two fast paths that you added,
> which makes it suspicious where the speed-up is coming from.

I think it may actually depend on what fonts are installed in the
system and I vaguely remember encountering this at least once. If the
suitable bitmap fonts are missing, then the benchmark might fallback
to some other font and exercise different fast paths.

-- 
Best regards,
Siarhei Siamashka