Instructions scheduling improved in the code responsible for fetching r5g6b5
pixels and converting them to the intermediate x8r8g8b8 color format used in
the interpolation part of code. Still a lot of NEON stalls are remaining,
which can be resolved later by the use of pipelining.
Benchmark on ARM Cortex-A8 r2p2 @1GHz, 32-bit LPDDR @200MHz:
Microbenchmark (scaling 2000x2000 image with scale factor close to 1x):
before: op=1, src=10020565, dst=10020565, speed=32.29 MPix/s
op=1, src=10020565, dst=20020888, speed=36.82 MPix/s
after: op=1, src=10020565, dst=10020565, speed=41.35 MPix/s
op=1, src=10020565, dst=20020888, speed=49.16 MPix/s
This is a cleanup for old and now duplicated code. The performance improvement
is mostly coming from the enabled use of software prefetch, but instructions
scheduling is also slightly better.
Benchmark on ARM Cortex-A8 r2p2 @1GHz, 32-bit LPDDR @200MHz:
Microbenchmark (scaling 2000x2000 image with scale factor close to 1x):
before: op=1, src=20028888, dst=20028888, speed=53.24 MPix/s
after: op=1, src=20028888, dst=20028888, speed=74.36 MPix/s
This allows to generate bilinear scanline scaling functions targeting
various source and destination color formats. Right now a8r8g8b8/x8r8g8b8
and r5g6b5 color formats are supported. More formats can be added if needed.
Initial NEON optimization for bilinear scaling. Can be probably
improved more.
Benchmark on ARM Cortex-A8:
Microbenchmark (scaling 2000x2000 image with scale factor close to 1x):
before: op=1, src=20028888, dst=20028888, speed=6.70 MPix/s
after: op=1, src=20028888, dst=20028888, speed=44.27 MPix/s
A primitive naive implementation of bilinear scaling using SSE2 intrinsics,
which only handles one pixel at a time. It is approximately 2x faster than
pixman general compositing path. Single pass processing without intermediate
temporary buffer contributes to ~15% and loop unrolling contributes to ~20%
of this speedup.
Benchmark on Intel Core i7 (x86-64):
Using cairo-perf-trace:
before: image firefox-planet-gnome 12.566 12.610 0.23% 6/6
after: image firefox-planet-gnome 10.961 11.013 0.19% 5/6
Microbenchmark (scaling 2000x2000 image with scale factor close to 1x):
before: op=1, src=20028888, dst=20028888, speed=70.48 MPix/s
after: op=1, src=20028888, dst=20028888, speed=165.38 MPix/s
Individual correctness check for the new bilinear scaling related
supplementary function. This test program uses a bit wider range
of input arguments, not covered by other tests.
Can be used for implementing SIMD optimized fast path
functions which work with bilinear scaled source images.
Similar to the template for nearest scaling main loop, the
following types of mask are supported:
1. no mask
2. non-scaled a8 mask with SAMPLES_COVER_CLIP flag
3. solid mask
PAD repeat is fully supported. NONE repeat is partially
supported (right now only works if source image has alpha
channel or when alpha channel of the source image does not
have any effect on the compositing operation).
MSVC does not notice non-returning functions (abort() / assert(0))
and warns about paths which end with them in non-void functions:
c:\cygwin\home\ranma42\code\fdo\pixman\test\fetch-test.c(114) :
warning C4715: 'reader' : not all control paths return a value
c:\cygwin\home\ranma42\code\fdo\pixman\test\stress-test.c(133) :
warning C4715: 'real_reader' : not all control paths return a value
c:\cygwin\home\ranma42\code\fdo\pixman\test\composite.c(431) :
warning C4715: 'calc_op' : not all control paths return a value
These warnings can be silenced by adding a return after the
termination call.
The Microsoft C compiler cannot handle subobject initialization and
Win32 does not provide snprintf.
Work around these limitations by using normal struct initialization
and using sprintf (a manual check shows that the buffer size is
sufficient).
Previously 'make check' would compile and run tests first, and only
then proceed to compiling demos. Which is not very convenient
because of the need to scroll back console output to see the
tests verdict. Swapping order of SUBDIRS variable entries in
Makefile.am resolves this.
This allows some more code to be deleted from the X server. The
implementation consists of converting to trapezoids, and is shared
with pixman_composite_triangles().
