Otherwise builds without explicit target result in silent no-ops.

This makes sense and takes care of missing build dependencies.

The library versions are stored in the config.mak file and are used
to derive shared library names.

-pie was added to C flags for ThreadSanitizer in commit
19f251a2. Under clang 3.8.0, the -pie
flag causes a compiler warning and a linker error when running configure
--toolchain=clang-tsan. Here is an excerpt from config.log:

clang ... -fsanitize=thread -pie -std=c11 -fomit-frame-pointer -pthread -c -o /tmp/ffconf.A8SsaoCF.o /tmp/ffconf.JdpujQlD.c
clang: warning: argument unused during compilation: '-pie'
clang -fsanitize=thread -pie -Wl,--as-needed -o /tmp/ffconf.2iYA4bsw /tmp/ffconf.A8SsaoCF.o -lm -lm -lbz2 -lz -pthread
/usr/bin/ld: /tmp/ffconf.A8SsaoCF.o: relocation R_X86_64_PC32 against undefined symbol `atan2f@@GLIBC_2.2.5' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: final link failed: Bad value
clang: error: linker command failed with exit code 1 (use -v to see invocation)

To be conservative, I changed -pie to -fPIE. But the documentation seems
to imply just -fsanitize=thread is enough:

http://clang.llvm.org/docs/ThreadSanitizer.html
https://github.com/google/sanitizers/wiki/ThreadSanitizerCppManualSigned-off-by: Wan-Teh Chang <wtc@google.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

The generic parameter names used for CFLAGS in configure must be filtered
for each compiler and replaced by the equivalent flag for that compiler.

This simplifies the code.

This ensures that dependencies are resolved correctly. COMPONENT_LIST
can contain parts that depend on previous entries of CONFIG_LIST.

Handle extralibs in the standard way, add missing pthreads dependency.
Also globally check for -fobj-arc with Objective-C compilers since
that option is useful for other Objective-C code as well.

EXTRALIBS contains general and platform-specific extra libraries
that should be part of all linker commands.

The unadorned package name is needed to derive package-related variable names.

Fixes standalone compilation of the libmp3lame encoder.

It is of doubtful utility, adds complexity and no known users exist.

Supporting the system was a nice joke for the 9 release, but it has
run its course. Nowadays Plan 9 receives no testing and has no
practical usefulness.

The libdc1394 API transition was finished close to a decade ago.

This allows filtering out some warning noise.

Also drop -Winline from set of warning flags as it only produces noise.

Signed-off-by: James Almer <jamrial@gmail.com>

This is how we initialize refcount in libavutil/buffer.c.
Signed-off-by: Wan-Teh Chang <wtc@google.com>
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

Be explicit about which options should be set.

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

This work is sponsored by, and copyright, Google.

Previously all subpartitions except the eob=1 (DC) case ran with
the same runtime:

vp9_inv_dct_dct_16x16_sub16_add_neon:   1373.2
vp9_inv_dct_dct_32x32_sub32_add_neon:   8089.0

By skipping individual 8x16 or 8x32 pixel slices in the first pass,
we reduce the runtime of these functions like this:

vp9_inv_dct_dct_16x16_sub1_add_neon:     235.3
vp9_inv_dct_dct_16x16_sub2_add_neon:    1036.7
vp9_inv_dct_dct_16x16_sub4_add_neon:    1036.7
vp9_inv_dct_dct_16x16_sub8_add_neon:    1036.7
vp9_inv_dct_dct_16x16_sub12_add_neon:   1372.1
vp9_inv_dct_dct_16x16_sub16_add_neon:   1372.1
vp9_inv_dct_dct_32x32_sub1_add_neon:     555.1
vp9_inv_dct_dct_32x32_sub2_add_neon:    5190.2
vp9_inv_dct_dct_32x32_sub4_add_neon:    5180.0
vp9_inv_dct_dct_32x32_sub8_add_neon:    5183.1
vp9_inv_dct_dct_32x32_sub12_add_neon:   6161.5
vp9_inv_dct_dct_32x32_sub16_add_neon:   6155.5
vp9_inv_dct_dct_32x32_sub20_add_neon:   7136.3
vp9_inv_dct_dct_32x32_sub24_add_neon:   7128.4
vp9_inv_dct_dct_32x32_sub28_add_neon:   8098.9
vp9_inv_dct_dct_32x32_sub32_add_neon:   8098.8

I.e. in general a very minor overhead for the full subpartition case due
to the additional cmps, but a significant speedup for the cases when we
only need to process a small part of the actual input data.
Signed-off-by: Martin Storsjö <martin@martin.st>

This work is sponsored by, and copyright, Google.

Previously all subpartitions except the eob=1 (DC) case ran with
the same runtime:

                                     Cortex A7       A8       A9      A53
vp9_inv_dct_dct_16x16_sub16_add_neon:   3188.1   2435.4   2499.0   1969.0
vp9_inv_dct_dct_32x32_sub32_add_neon:  18531.7  16582.3  14207.6  12000.3

By skipping individual 4x16 or 4x32 pixel slices in the first pass,
we reduce the runtime of these functions like this:

vp9_inv_dct_dct_16x16_sub1_add_neon:     274.6    189.5    211.7    235.8
vp9_inv_dct_dct_16x16_sub2_add_neon:    2064.0   1534.8   1719.4   1248.7
vp9_inv_dct_dct_16x16_sub4_add_neon:    2135.0   1477.2   1736.3   1249.5
vp9_inv_dct_dct_16x16_sub8_add_neon:    2446.7   1828.7   1993.6   1494.7
vp9_inv_dct_dct_16x16_sub12_add_neon:   2832.4   2118.3   2266.5   1735.1
vp9_inv_dct_dct_16x16_sub16_add_neon:   3211.7   2475.3   2523.5   1983.1
vp9_inv_dct_dct_32x32_sub1_add_neon:     756.2    456.7    862.0    553.9
vp9_inv_dct_dct_32x32_sub2_add_neon:   10682.2   8190.4   8539.2   6762.5
vp9_inv_dct_dct_32x32_sub4_add_neon:   10813.5   8014.9   8518.3   6762.8
vp9_inv_dct_dct_32x32_sub8_add_neon:   11859.6   9313.0   9347.4   7514.5
vp9_inv_dct_dct_32x32_sub12_add_neon:  12946.6  10752.4  10192.2   8280.2
vp9_inv_dct_dct_32x32_sub16_add_neon:  14074.6  11946.5  11001.4   9008.6
vp9_inv_dct_dct_32x32_sub20_add_neon:  15269.9  13662.7  11816.1   9762.6
vp9_inv_dct_dct_32x32_sub24_add_neon:  16327.9  14940.1  12626.7  10516.0
vp9_inv_dct_dct_32x32_sub28_add_neon:  17462.7  15776.1  13446.2  11264.7
vp9_inv_dct_dct_32x32_sub32_add_neon:  18575.5  17157.0  14249.3  12015.1

I.e. in general a very minor overhead for the full subpartition case due
to the additional loads and cmps, but a significant speedup for the cases
when we only need to process a small part of the actual input data.

In common VP9 content in a few inspected clips, 70-90% of the non-dc-only
16x16 and 32x32 IDCTs only have nonzero coefficients in the upper left
8x8 or 16x16 subpartitions respectively.
Signed-off-by: Martin Storsjö <martin@martin.st>