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

Lukic, Nemanja nlukic at mips.com
Mon Mar 12 14:20:10 PDT 2012

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.

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

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