Commit Graph

357 Commits

Author SHA1 Message Date
Andrea Canciani
9728241bd0 test: Fix fence-image-self-test on Mac
On MacOS X, according to the manpage of mprotect(), "When a program
violates the protections of a page, it gets a SIGBUS or SIGSEGV
signal.", but fence-image-self-test was only accepting a SIGSEGV as
notification of invalid access.

Fixes fence-image-self-test

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
2015-10-16 15:05:02 +03:00
Ben Avison
2876d8d3dd affine-bench: remove 8e margin from COVER area
Patch "Remove the 8e extra safety margin in COVER_CLIP analysis" reduced
the required image area for setting the COVER flags in
pixman.c:analyze_extent(). Do the same reduction in affine-bench.

Leaving the old calculations in place would be very confusing for anyone
reading the code.

Also add a comment that explains how affine-bench wants to hit the COVER
paths. This explains why the intricate extent calculations are copied
from pixman.c.

[Pekka: split patch, change comments, write commit message]
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-09-25 14:26:04 +03:00
Thomas Petazzoni
4297e9058d test: add a check for FE_DIVBYZERO
Some architectures, such as Microblaze and Nios2, currently do not
implement FE_DIVBYZERO, even though they have <fenv.h> and
feenableexcept(). This commit adds a configure.ac check to verify
whether FE_DIVBYZERO is defined or not, and if not, disables the
problematic code in test/utils.c.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
2015-09-20 15:50:04 +03:00
Ben Avison
4c71f595e3 test: Add cover-test v5
This test aims to verify both numerical correctness and the honouring of
array bounds for scaled plots (both nearest-neighbour and bilinear) at or
close to the boundary conditions for applicability of "cover" type fast paths
and iter fetch routines.

It has a secondary purpose: by setting the env var EXACT (to any value) it
will only test plots that are exactly on the boundary condition. This makes
it possible to ensure that "cover" routines are being used to the maximum,
although this requires the use of a debugger or code instrumentation to
verify.

Changes in v4:

  Check the fence page size and skip the test if it is too large. Since
  we need to deal with pixman_fixed_t coordinates that go beyond the
  real image width, make the page size limit 16 kB. A 32 kB or larger
  page size would cause an a8 image width to be 32k or more, which is no
  longer representable in pixman_fixed_t.

  Use a shorthand variable 'filter' in test_cover().

  Whitespace adjustments.

Changes in v5:

  Skip if fenced memory is not supported. Do you know of any such
  platform?

Signed-off-by: Ben Avison <bavison@riscosopen.org>
[Pekka: changes in v4 and v5]
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
Acked-by: Oded Gabbay <oded.gabbay@gmail.com>
2015-09-16 15:34:43 +03:00
Pekka Paalanen
e9ef2cc4de utils.[ch]: add fence_get_page_size()
Add a function to get the page size used for memory fence purposes, and
use it everywhere where getpagesize() was used.

This offers a single point in code to override the page size, in case
one wants to experiment how the tests work with a higher page size than
what the developer's machine has.

This also offers a clean API, without adding #ifdefs, to tests for
checking the page size.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-09-09 11:30:51 +03:00
Pekka Paalanen
82f8c997df utils.c: fix fallback code for fence_image_create_bits()
Used a wrong variable name, causing:
/home/pq/git/pixman/demos/../test/utils.c: In function ‘fence_image_create_bits’:
/home/pq/git/pixman/demos/../test/utils.c:562:46: error: ‘width’ undeclared (first use in this function)

Use the correct variable.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-09-09 11:29:44 +03:00
Pekka Paalanen
0700685382 test: add fence-image-self-test
Tests that fence_malloc and fence_image_create_bits actually work: that
out-of-bounds and out-of-row (unused stride area) accesses trigger
SIGSEGV.

If fence_malloc is a dummy (FENCE_MALLOC_ACTIVE not defined), this test
is skipped.

Changes in v2:

- check FENCE_MALLOC_ACTIVE value, not whether it is defined
- test that reading bytes near the fence pages does not cause a
  segmentation fault

Changes in v3:

- Do not print progress messages unless VERBOSE environment variable is
  set. Avoid spamming the terminal output of 'make check' on some
  versions of autotools.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-09-03 14:00:32 +03:00
Pekka Paalanen
13d93aa120 utils.[ch]: add fence_image_create_bits ()
Useful for detecting out-of-bounds accesses in composite operations.

This will be used by follow-up patches adding new tests.

Changes in v2:

- fix style on fence_image_create_bits args
- add page to stride only if stride_fence
- add comment on the fallback definition about freeing storage

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-09-01 17:06:46 +03:00
Pekka Paalanen
c70ddd5c9e utils.[ch]: add FENCE_MALLOC_ACTIVE
Define a new token to simplify checking whether fence_malloc() actually
can catch out-of-bounds access.

This will be used in the future to skip tests that rely on fence_malloc
checking functionality.

Changes in v2:

- #define FENCE_MALLOC_ACTIVE always, but change its value to help catch
  use of it without including utils.h

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-09-01 17:05:58 +03:00
Ben Avison
a82e519944 scaling-test: list more details when verbose
Add mask details to the output.

[Pekka: redo whitespace and print src,dst,mask x and y.]
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-08-28 14:24:28 +03:00
Pekka Paalanen
fd59569294 lowlevel-blt-bench: make extra arguments an error
If a user gives multiple patterns or extra arguments, only the last one
was used as the pattern while the former were just ignored. This is a
user error silently converted to something possibly unexpected.

In presence of extra arguments, complain and quit.

Cc: Ben Avison <bavison@riscosopen.org>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
2015-08-18 10:23:27 +03:00
Pekka Paalanen
e2d211ac49 lowlevel-blt-bench: add option to skip memcpy measurement
The memcpy speed measurement takes several seconds. When you are running
single tests in a harness that iterates dozens or hundreds of times, the
repeated measurements are redundant and take a lot of time. It is also
an open question whether the measured speed changes over long test runs
due to unidentified platform reasons (Raspberry Pi).

Add a command line option to set the reference memcpy speed, skipping
the measuring.

The speed is mainly used to compute how many iterations do run inside
the bench_*() functions, so for repeated testing on the same hardware,
it makes sense to lock that number to a constant.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-07-06 12:04:50 +03:00
Pekka Paalanen
31cb0d4267 lowlevel-blt-bench: add CSV output mode
Add a command line option for choosing CSV output mode.

In CSV mode, only the results in Mpixels/s are printed in an easily
machine-parseable format. All user-friendly printing is suppressed.

This is intended for cases where you benchmark one particular operation
at a time. Running the "all" set of benchmarks will print just fine, but
you may have trouble matching rows to operations as you have to look at
the tests_tbl[] to see what row is which.

Reviewed-by: Ben Avison <bavison@riscosopen.org>

v2: don't add a space after comma in CSV.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
2015-07-06 12:04:32 +03:00
Pekka Paalanen
9a7e0bc6d0 lowlevel-blt-bench: refactor to Mpx_per_sec()
Refactor the Mpixels/s computations into a function. Easier to read and
better documents what is being computed.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-07-06 12:04:27 +03:00
Pekka Paalanen
6e9c48c579 lowlevel-blt-bench: all bench funcs to return pix_cnt
The bench_* functions, that did not already do it, are modified to
return the number of pixels processed during the benchmark. This moves
the computation to the site that actually determines the number, and
simplifies bench_composite() a bit.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-07-06 12:04:22 +03:00
Pekka Paalanen
9e8f2bcaf5 lowlevel-blt-bench: move speed and scaling printing
Move the printing of the memory speed and scaling mode into a new
function. This will help with implementing a machine-readable output
option.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-07-06 12:04:18 +03:00
Pekka Paalanen
a33c2e6853 lowlevel-blt-bench: print single pattern details
When given just a single test pattern instead of "all", print the test
details. This can be used to verify the pattern parser agrees with the
user, just like scaling settings are printed.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-07-06 12:04:12 +03:00
Pekka Paalanen
3ac7ae2017 lowlevel-blt-bench: make test_entry::testname const
We assign string literals to it, so it better be const.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-07-06 12:04:07 +03:00
Pekka Paalanen
56d8b365f5 lowlevel-blt-bench: move explanation printing
Move explanation printing to a new function. This will help with
implementing a machine-readable output option.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-07-06 12:04:03 +03:00
Pekka Paalanen
bddff993ed lowlevel-blt-bench: move usage to a function
Move printing of usage into a new function and use argv[0] as the
program name. This will help printing usage from multiple places.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-07-06 12:03:28 +03:00
Ben Avison
62a772f2ea test: Fix solid-test for big-endian targets
When generating test data, we need to make sure the interpretation of
the data is the same regardless of endianess. That is, the pixel value
for each channel is the same on both little and big-endians.

This fixes a test failure on ppc64 (big-endian).

Tested-by: Fernando Seiti Furusato <ferseiti@linux.vnet.ibm.com> (ppc64le, ppc64, powerpc)
Tested-by: Ben Avison <bavison@riscosopen.org> (armv6l, armv7l, i686)
[Pekka: added commit message]
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Tested-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk> (x86_64)
2015-06-01 13:11:15 +03:00
Ben Avison
82f9b4faaf test: Add new fuzz tester targeting solid images
This places a heavier emphasis on solid images than the other fuzz testers,
and tests both single-pixel repeating bitmap images as well as those created
using pixman_image_create_solid_fill(). In the former case, it also
exercises the case where the bitmap contents are written to after the
image's first use, which is not a use-case that any other test has
previously covered.

[Pekka: added the default case to the switch in test_solid ().]

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
2015-05-15 16:30:21 +03:00
Ben Avison
e0c0153d8e test: Add a new benchmarker targeting affine operations
Affine-bench is written by following the example of lowlevel-blt-bench.

Affine-bench differs from lowlevel-blt-bench in the following:
- does not test different sized operations fitting to specific caches,
  destination is always 1920x1080
- allows defining the affine transformation parameters
- carefully computes operation extents to hit the COVER_CLIP fast paths

Original version by Ben Avison. Changes by Pekka in v3:
- commit message
- style fixes
- more comments
- refactoring (e.g. bench_info_t)
- help output tweak

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-04-24 10:25:42 +03:00
Pekka Paalanen
58e21d3e45 lowlevel-blt-bench: use a8r8g8b8 for CA solid masks
When doing component alpha with a solid mask, use a mask format that has
all the color channels instead of just a8. As Ben Avison explains it:

"Lowlevel-blt-bench initialises all its images using memset(0xCC) so an
a8 solid image would be converted by _pixman_image_get_solid() to
0xCC000000 whereas an a8r8g8b8 would be 0xCCCCCCCC. When you're not in
component alpha mode, only the alpha byte matters for the mask image,
but in the case of component alpha operations, a fast path might decide
that it can save itself a lot of multiplications if it spots that 3
constant mask components are already 0."

No (default) test so far has a solid mask with CA. This is just
future-proofing lowlevel-blt-bench to do what one would expect.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-04-20 16:18:18 +03:00
Pekka Paalanen
be49f929b6 lowlevel-blt-bench: use the test pattern parser
Let lowlevel-blt-bench parse the test name string from the command line,
allowing to run almost infinitely more tests. One is no longer limited
to the tests listed in the big table.

While you can use the old short-hand names like src_8888_8888, you can
also use all possible operators now, and specify pixel formats exactly
rather than just x888, for instance.

This even allows to run crazy patterns like
conjoint_over_reverse_a8b8g8r8_n_r8g8b8x8.

All individual patterns are now interpreted through the parser. The
pattern "all" runs the same old default test set as before but through
the parser instead of the hard-coded parameters.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-04-15 12:43:01 +03:00
Pekka Paalanen
5b27912108 lowlevel-blt-bench: add test name parser and self-test
This patch is inspired by "lowlevel-blt-bench: Parse test name strings in
general case" by Ben Avison. From Ben's commit message:

"There are many types of composite operation that are useful to benchmark
but which are omitted from the table. Continually having to add extra
entries to the table is a nuisance and is prone to human error, so this
patch adds the ability to break down unknow strings of the format
  <operation>_<src>[_<mask]_<dst>[_ca]
where bitmap formats are specified by number of bits of each component
(assumed in ARGB order) or 'n' to indicate a solid source or mask."

Add the parser to lowlevel-blt-bench.c, but do not hook it up to the
command line just yet. Instead, make it run a self-test.

As we now dynamically parse strings similar to the test names in the
huge table 'tests_tbl', we should make sure we can parse the old
well-known test names and produce exactly the same test parameters. The
self-test goes through this old table and verifies the parsing results.

Unfortunately the old table is not exactly consistent, it contains some
special cases that cannot be produced by the parsing rules. Whether
these special cases are intentional or just an oversight is not always
clear. Anyway, add a small table to reproduce the special cases
verbatim.

If we wanted, we could remove the big old table in a follow-up commit,
but then we would also lose the parser self-test.

The point of this whole excercise to let lowlevel-blt-bench recognize
novel test patterns in the future, following exactly the conventions
used in the old table.

Ben, from what I see, this parser has one major difference to what you
wrote. For a solid mask, your parser uses a8r8g8b8 format, while mine
uses a8 which comes from the old table.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-04-15 12:42:51 +03:00
Pekka Paalanen
1f45bd6565 test/utils: add format aliases used by lowlevel-blt-bench
Lowlevel-blt-bench uses several pixel format shorthands. Pick them from
the great table in lowlevel-blt-bench.c and add them here so that
format_from_string() can recognize them.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-04-15 12:42:45 +03:00
Pekka Paalanen
ef9c28a0e4 test/utils: add operator aliases for lowlevel-blt-bench
Lowlevel-blt-bench uses the operator alias "outrev". Add an alias for it
in the operator-name table.

Also add aliases for overrev, inrev and atoprev, so that
lowlevel-blt-bench can later recognize them for new test cases.

The aliases are added such, that an operator to name lookup will never
return them; it returns the proper names instead.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-04-15 12:42:40 +03:00
Pekka Paalanen
f1f6cc23ce test/utils: support format name aliases
Previously there was a flat list of formats, used to iterate over all
formats when looking up a format from name or listing them. This cannot
support name aliases.

To support name aliases (multiple name strings mapping to the same
format), create a format-name mapping table. Functions format_name(),
format_from_string(), and list_formats() should keep on working exactly
like before, except format_from_string() now recognizes the additional
formats that format_name() already supported.

The only the formats from the old format list are added with ENTRY, so
that list_formats() works as before. The whole list is verified against
the authoritative list in pixman.h, entries missing from the old list
are commented out.

The extra formats supported by the old format_name() are added as
ALIASes. A side-effect of that is that now also format_from_string()
recognizes the following new names: x4c4 / c8, x4g4 / g8, c4, g4, g1,
yuy2, yv12, null, solid, pixbuf, rpixbuf, unknown.

Name aliases will be useful in follow-up patches, where
lowlevel-blt-bench.c is converted to parse short-hand format names from
strings.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-04-15 12:42:33 +03:00
Pekka Paalanen
2c5fac9320 test/utils: support operator name aliases
Previously there was a flat list of operators (pixman_op_t), used to
iterate over all operators when looking up an operator from name or
listing them. This cannot support name aliases.

To support name aliases (multiple name strings mapping to the same
operator), create an operator-name mapping table. Functions
operator_name, operator_from_string, and list_operators should keep on
working exactly like before, except operator_from_string now recognizes
a few aliases too.

Name aliases will be useful in follow-up patches, where
lowlevel-blt-bench.c is converted to parse operator names from strings.
Lowlevel-blt-bench uses shorthand names instead of the usual names. This
change allows lowlevel-blt-bench.s to use operator_from_string in the
future.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Ben Avison <bavison@riscosopen.org>
2015-04-15 12:41:47 +03:00
Ben Avison
f122907dc1 test: Move format and operator string functions to utils.[ch]
This permits format_from_string(), list_formats(), list_operators() and
operator_from_string() to be used from tests other than check-formats.

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
2015-04-13 10:11:51 +03:00
Søren Sandmann Pedersen
5a2edb3f2c test: Rearrange tests in order of increasing runtime
Making short tests run first is convenient to catch obvious bugs
early.
2014-06-28 19:24:27 -04:00
Søren Sandmann Pedersen
f5f5dbbbc6 test: Add radial-invalid test program
This program demonstrates a bug in gradient walker, where some integer
overflows cause colors outside the range [0, 255] to be generated,
which in turns cause 'invalid' floating point exceptions when those
colors are converted to uint8_t.

The bug was first reported by Owen Taylor on the #cairo IRC channel.
2014-05-15 13:29:38 -04:00
Siarhei Siamashka
56622140e3 test: Fix OpenMP clauses for the tolerance-test
Compiling with the Intel Compiler reveals a problem:

tolerance-test.c(350): error: index variable "i" of for statement following an OpenMP for pragma must be private
  #       pragma omp parallel for default(none) shared(i) private (result)
  ^

In addition to this, the 'result' variable also should not be private
(otherwise its value does not survive after the end of the loop). It
needs to be either shared or use the reduction clause to describe how
the results from multiple threads are combined together. Reduction
seems to be more appropriate here.
2014-04-02 12:46:09 +03:00
Siarhei Siamashka
840912b311 configure.ac: Check if the compiler supports GCC vector extensions
The Intel Compiler 14.0.0 claims version GCC 4.7.3 compatibility
via __GNUC__/__GNUC__MINOR__ macros, but does not provide the same
level of GCC vector extensions support as the original GCC compiler:
    http://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html

Which results in the following compilation failure:

In file included from ../test/utils.h(7),
                 from ../test/utils.c(3):
../test/utils-prng.h(138): error: expression must have integral type
      uint32x4 e = x->a - ((x->b << 27) + (x->b >> (32 - 27)));
                            ^

The problem is fixed by doing a special check in configure for
this feature.
2014-04-02 12:46:04 +03:00
Ben Avison
c343846625 lowlevel-blt-bench: add in_reverse_8888_8888 test
in_reverse_8888_8888 is one of the more commonly used operations in the
cairo-perf-trace suite that hasn't been in lowlevel-blt-bench until now.

v4, Pekka Paalanen <pekka.paalanen@collabora.co.uk> :
	Split from "Add extra test to lowlevel-blt-bench and fix an
	existing one", new summary.
2014-03-20 08:33:05 -04:00
Ben Avison
898859f3d3 lowlevel-blt-bench: over_reverse_n_8888 needs solid source
v4, Pekka Paalanen <pekka.paalanen@collabora.co.uk> :
	Split from "Add extra test to lowlevel-blt-bench and fix an
	existing one", new summary.
2014-03-20 08:33:05 -04:00
Søren Sandmann Pedersen
94244b0c40 utils.c: Set DEVIATION to 0.0128
Consider a HARD_LIGHT operation with the following pixels:

- source:           15      (6 bits)
- source alpha:     255     (8 bits)
- mask alpha:       223     (8 bits)
- dest              255     (8 bits)
- dest alpha:       0       (8 bits)

Since 2 times the source is less than source alpha, the first branch
of the hard light blend mode is taken:

        (1 - sa) * d + (1 - da) * s + 2 * s * d

Since da is 0 and d is 1, this degenerates to:

        (1 - sa) + 3 * s

Taking (src IN mask) into account along with the fact that sa is 1,
this becomes:

        (1 - ma) + 3 * s * ma

      = (1 - 223/255.0) + 3 * (15/63.0) * (223/255.0)

      = 0.7501400560224089

When computed with the source converted by bit replication to eight
bits, and additionally with the (src IN mask) part rounded to eight
bits, we get:

        ma = 223/255.0

        s * ma = (60 / 255.0) * (223/255.0) which rounds to 52 / 255

and the result is

        (1 - ma) + 3 * s * ma

      = (1 - 223/255.0) + 3 * 52/255.0

      = 0.7372549019607844

so now we have an error of 0.012885.

Without making changes to the way pixman does integer
rounding/arithmetic, this error must then be considered
acceptable. Due to conservative computations in the test suite we can
however get away with 0.0128 as the acceptable deviation.

This fixes the remaining failures in pixel-test.
2014-01-04 16:13:27 -05:00
Søren Sandmann
15aa37adec Use floating point combiners for all operators that involve divisions
Consider a DISJOINT_ATOP operation with the following pixels:

- source:	0xff (8 bits)
- source alpha:	0x01 (8 bits)
- mask alpha:	0x7b (8 bits)
- dest:		0x00 (8 bits)
- dest alpha:	0xff (8 bits)

When (src IN mask) is computed in 8 bits, the resulting alpha channel
is 0 due to rounding:

     floor ((0x01 * 0x7b) / 255.0 + 0.5) = floor (0.9823) = 0

which means that since Render defines any division by zero as
infinity, the Fa and Fb for this operator end up as follows:

     Fa = max (1 - (1 - 1) / 0, 0) = 0

     Fb = min (1, (1 - 0) / 1) = 1

and so since dest is 0x00, the overall result is 0.

However, when computed in full precision, the alpha value no longer
rounds to 0, and so Fa ends up being

     Fa = max (1 - (1 - 1) / 0.0001, 0) = 1

and so the result is now

     s * ma * Fa + d * Fb

   = (1.0 * (0x7b / 255.0) * 1) + d * 0

   = 0x7b / 255.0

   = 0.4823

so the error in this case ends up being 0.48235294, which is clearly
not something that can be considered acceptable.

In order to avoid this problem, we need to do all arithmetic in such a
way that a multiplication of two tiny numbers can never end up being
zero unless one of the input numbers is itself zero.

This patch makes all computations that involve divisions take place in
floating point, which is sufficient to fix the test cases

This brings the number of failures in pixel-test down to 14.
2014-01-04 16:13:27 -05:00
Søren Sandmann
8f38243163 Soft Light: Consistent approach to division by zero
The Soft Light operator has several branches. One them is decided
based on whether 2 * s is less than or equal to 2 * sa. In floating
point implementations, when those two values are very close to each
other, it may not be completely predictable which branch we hit.

This is a problem because in one branch, when destination alpha is
zero, we get the result

      r = d * as

and in the other we get

      r = 0

So when d and as are not 0, this causes two different results to be
returned from essentially identical input values. In other words,
there is a discontinuity in the current implementation.

This patch randomly changes the second branch such that it now returns
d * sa instead. There is no deep meaning behind this, because
essentially this is an attempt to assign meaning to division by zero,
and all that is requires is that that meaning doesn't depend on minute
differences in input values.

This makes the number of failed pixels in pixel-test go down to 347.
2014-01-04 16:13:27 -05:00
Søren Sandmann Pedersen
89662adf77 pixman-combine32.c: Fix bugs related to integer promotion
In the component alpha part of the PDF_SEPARABLE_BLEND_MODE macro, the
expression ~RED_8 (m) is used. Because RED_8(m) gets promoted to int
before ~ is applied, the whole expression typically becomes some
negative value rather than (255 - RED_8(m)) as desired.

Fix this by using unsigned temporary variables.

This reduces the number of failures in pixel-test to 363.
2014-01-04 16:13:27 -05:00
Søren Sandmann Pedersen
e7a99b3b0f pixman/pixman-combine32.c: Bug fixes for separable blend modes
This commit fixes four separate bugs:

1. In the computation

      (1 - sa) * d + (1 - da) * s + sa * da * B(s, d)

   we were using regular addition for all four channels, but for
   superluminescent pixels, the addition could overflow causing
   nonsensical results.

2. The variables and return types used for the results of the blend
   mode calculations were unsigned, but for various blend modes (and
   especially with superluminescent pixels), the blend mode
   calculations could be negative, resulting in underflows.

3. The blend mode computations were returned as 8-bit values, which is
   not sufficient precision (especially considering that we need
   signed results).

4. The value before the final division by 255 was not properly clamped
   to [0, 255].

This patch fixes all those bugs. The blend mode computations are now
returned as signed 16 bit values with 1 represented as 255 * 255.

With these fixes, the number of failing pixels in pixel-test goes down
from 431 to 384.
2014-01-04 16:13:27 -05:00
Søren Sandmann
fe3504d03f pixel-test.c: Add a number of pixels that have failed at some point
This commit adds a large number of pixel regressions to
pixel-test. All of these have at some point been failing in
blend-mode-test, and most of them do fail currently.

To be specific, with this commit, pixel-test reports 431 failed tests.
2014-01-04 16:13:27 -05:00
Søren Sandmann Pedersen
bd94c17937 test/tolerance-test: New test program
This new test program is similar to test/composite in that it relies
on the pixel_checker_t API to do tolerance based verification. But
unlike the composite test, which verifies combinations of a fixed set
of pixels, this one generates random images and verifies that those
composite correctly.

Also unlike composite, tolerance-test supports all the separable blend
mode operators in addition to the original Render operators.

When tests fail, a C struct is printed that can be pasted into
pixel-test for regression purposes.

There is an option "--forever" which causes the random seed to be set
to the current time, and then the test runs until interrupted. This is
useful for overnight runs.

This test currently fails badly due to various bugs in the blend mode
operators. Later commits will fix those.
2014-01-04 16:13:27 -05:00
Søren Sandmann
c2fd65dba3 pixel-test: Command line argument to specify the regression to run
A new command line argument allows the user to specify which one of
the regressions should be run.
2014-01-04 16:13:27 -05:00
Søren Sandmann
a692e01600 pixel-test: Add support for mask pixels
Support is added to pixel-test for verifying operations involving
masks. If a regression includes a mask, it is verified with the
pixel_checker API in in both unified and component alpha modes.
2014-01-04 16:13:27 -05:00
Søren Sandmann Pedersen
779ca46e98 test/check-formats.c: Add support for separable blend modes 2014-01-04 16:13:27 -05:00
Søren Sandmann Pedersen
a42af27fc0 test/utils.c: Add support for separable blend mode ops to do_composite()
The implementations are copied from the floating point pipeline, but
use double precision instead of single precision.
2014-01-04 16:13:27 -05:00
Søren Sandmann
9ba3a34797 general: Support component alpha for all image types
Currently, if you attempt to use component alpha on source images or
images without RGB channels, Pixman will silently just use unified
alpha instead. This patch makes such images supported for component
alpha.

There is no particularly compelling usecase at the moment, but this
patch does get rid of a bit of special-case code both in
pixman-general.c and in test/composite.c.
2013-11-23 20:30:33 -05:00
Søren Sandmann
f473fd1e75 test/utils.c: Make the stack unaligned only on 32 bit Windows
The call_test_function() contains some assembly that deliberately
causes the stack to be aligned to 32 bits rather than 128 bits on
x86-32. The intention is to catch bugs that surface when pixman is
called from code that only uses a 32 bit alignment.

However, recent versions of GCC apparently make the assumption (either
accidentally or deliberately) that that the incoming stack is aligned
to 128 bits, where older versions only seemed to make this assumption
when compiling with -msse2. This causes the vector code in the PRNG to
now segfault when called from call_test_function() on x86-32.

This patch fixes that by only making the stack unaligned on 32 bit
Windows, where it would definitely be incorrect for GCC to assume that
the incoming stack is aligned to 128 bits.

V2: Put "defined(...)" around __GNUC__

Reviewed-and-Tested-by: Matt Turner <mattst88@gmail.com>
Bugzilla: https://bugs.gentoo.org/show_bug.cgi?id=491110
2013-11-17 17:44:51 -08:00