Change AArch64 assembly code to use:
ret x<n>
instead of:
br x<n>
"ret x<n>" is already used in a lot of places so this patch makes it
consistent across the code base. This does not change behavior or
performance.
In addition, this change reduces the number of landing pads needed in
a subsequent patch to support the Armv8.5-A Branch Target
Identification (BTI) security feature.
Signed-off-by: Jonathan Wright <jonathan.wright@arm.com>
Signed-off-by: Martin Storsjö <martin@martin.st>
Properly use the b.eq/b.ge forms instead of the nonstandard forms
(which both gas and newer clang accept though), and expand the
register list that used a range (which the Xcode 6.2 clang, based
on clang 3.5 svn, didn't support).
This is cherrypicked from libav commit
a970f9de86.
Signed-off-by: Martin Storsjö <martin@martin.st>
Align the second/third operands as they usually are.
Due to the wildly varying sizes of the written out operands
in aarch64 assembly, the column alignment is usually not as clear
as in arm assembly.
This is cherrypicked from libav commit
7995ebfad1.
Signed-off-by: Martin Storsjö <martin@martin.st>
In the half/quarter cases where we don't use the min_eob array, defer
loading the pointer until we know it will be needed.
This is cherrypicked from libav commit
3a0d5e206d.
Signed-off-by: Martin Storsjö <martin@martin.st>
This matches the order they are in the 16 bpp version.
There they are in this order, to make sure we access them in the
same order they are declared, easing loading only half of the
coefficients at a time.
This makes the 8 bpp version match the 16 bpp version better.
This is cherrypicked from libav commit
b8f66c0838.
Signed-off-by: Martin Storsjö <martin@martin.st>
All elements are used pairwise, except for the first one.
Previously, the 16th element was unused. Move the unused element
to the second slot, to make the later element pairs not split
across registers.
This simplifies loading only parts of the coefficients,
reducing the difference to the 16 bpp version.
This is cherrypicked from libav commit
09eb88a12e.
Signed-off-by: Martin Storsjö <martin@martin.st>
The idct32x32 function actually pushed d8-d15 onto the stack even
though it didn't clobber them; there are plenty of registers that
can be used to allow keeping all the idct coefficients in registers
without having to reload different subsets of them at different
stages in the transform.
After this, we still can skip pushing d12-d15.
Before:
vp9_inv_dct_dct_32x32_sub32_add_neon: 8128.3
After:
vp9_inv_dct_dct_32x32_sub32_add_neon: 8053.3
This is cherrypicked from libav commit
65aa002d54.
Signed-off-by: Martin Storsjö <martin@martin.st>
This work is sponsored by, and copyright, Google.
Before: Cortex A53
vp9_inv_dct_dct_16x16_sub1_add_neon: 235.3
vp9_inv_dct_dct_32x32_sub1_add_neon: 555.1
After:
vp9_inv_dct_dct_16x16_sub1_add_neon: 180.2
vp9_inv_dct_dct_32x32_sub1_add_neon: 475.3
This is cherrypicked from libav commit
3fcf788fbb.
Signed-off-by: Martin Storsjö <martin@martin.st>
The ld1r is a leftover from the arm version, where this trick is
beneficial on some cores.
Use a single-lane load where we don't need the semantics of ld1r.
This is cherrypicked from libav commit
ed8d293306.
Signed-off-by: Martin Storsjö <martin@martin.st>
This work is sponsored by, and copyright, Google.
This avoids loading and calculating coefficients that we know will
be zero, and avoids filling the temp buffer with zeros in places
where we know the second pass won't read.
This gives a pretty substantial speedup for the smaller subpartitions.
The code size increases from 14740 bytes to 24292 bytes.
The idct16/32_end macros are moved above the individual functions; the
instructions themselves are unchanged, but since new functions are added
at the same place where the code is moved from, the diff looks rather
messy.
Before:
vp9_inv_dct_dct_16x16_sub1_add_neon: 236.7
vp9_inv_dct_dct_16x16_sub2_add_neon: 1051.0
vp9_inv_dct_dct_16x16_sub4_add_neon: 1051.0
vp9_inv_dct_dct_16x16_sub8_add_neon: 1051.0
vp9_inv_dct_dct_16x16_sub12_add_neon: 1387.4
vp9_inv_dct_dct_16x16_sub16_add_neon: 1387.6
vp9_inv_dct_dct_32x32_sub1_add_neon: 554.1
vp9_inv_dct_dct_32x32_sub2_add_neon: 5198.5
vp9_inv_dct_dct_32x32_sub4_add_neon: 5198.6
vp9_inv_dct_dct_32x32_sub8_add_neon: 5196.3
vp9_inv_dct_dct_32x32_sub12_add_neon: 6183.4
vp9_inv_dct_dct_32x32_sub16_add_neon: 6174.3
vp9_inv_dct_dct_32x32_sub20_add_neon: 7151.4
vp9_inv_dct_dct_32x32_sub24_add_neon: 7145.3
vp9_inv_dct_dct_32x32_sub28_add_neon: 8119.3
vp9_inv_dct_dct_32x32_sub32_add_neon: 8118.7
After:
vp9_inv_dct_dct_16x16_sub1_add_neon: 236.7
vp9_inv_dct_dct_16x16_sub2_add_neon: 640.8
vp9_inv_dct_dct_16x16_sub4_add_neon: 639.0
vp9_inv_dct_dct_16x16_sub8_add_neon: 842.0
vp9_inv_dct_dct_16x16_sub12_add_neon: 1388.3
vp9_inv_dct_dct_16x16_sub16_add_neon: 1389.3
vp9_inv_dct_dct_32x32_sub1_add_neon: 554.1
vp9_inv_dct_dct_32x32_sub2_add_neon: 3685.5
vp9_inv_dct_dct_32x32_sub4_add_neon: 3685.1
vp9_inv_dct_dct_32x32_sub8_add_neon: 3684.4
vp9_inv_dct_dct_32x32_sub12_add_neon: 5312.2
vp9_inv_dct_dct_32x32_sub16_add_neon: 5315.4
vp9_inv_dct_dct_32x32_sub20_add_neon: 7154.9
vp9_inv_dct_dct_32x32_sub24_add_neon: 7154.5
vp9_inv_dct_dct_32x32_sub28_add_neon: 8126.6
vp9_inv_dct_dct_32x32_sub32_add_neon: 8127.2
This is cherrypicked from libav commit
a63da4511d.
Signed-off-by: Martin Storsjö <martin@martin.st>
This allows reusing the macro for a separate implementation of the
pass2 function.
This is cherrypicked from libav commit
79d332ebbd.
Signed-off-by: Martin Storsjö <martin@martin.st>
This work is sponsored by, and copyright, Google.
This reduces the code size of libavcodec/aarch64/vp9itxfm_neon.o from
19496 to 14740 bytes.
This gives a small slowdown of a couple of tens of cycles, but makes
it more feasible to add more optimized versions of these transforms.
Before:
vp9_inv_dct_dct_16x16_sub4_add_neon: 1036.7
vp9_inv_dct_dct_16x16_sub16_add_neon: 1372.2
vp9_inv_dct_dct_32x32_sub4_add_neon: 5180.0
vp9_inv_dct_dct_32x32_sub32_add_neon: 8095.7
After:
vp9_inv_dct_dct_16x16_sub4_add_neon: 1051.0
vp9_inv_dct_dct_16x16_sub16_add_neon: 1390.1
vp9_inv_dct_dct_32x32_sub4_add_neon: 5199.9
vp9_inv_dct_dct_32x32_sub32_add_neon: 8125.8
This is cherrypicked from libav commit
115476018d.
Signed-off-by: Martin Storsjö <martin@martin.st>
This avoids concatenation, which can't be used if the whole macro
is wrapped within another macro.
This is also arguably more readable.
This is cherrypicked from libav commit
58d87e0f49.
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:
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.
This is cherrypicked from libav commits
cad42fadcd and
a0c443a398.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The clobbering tests in checkasm are only invoked when testing
correctness, so this bug didn't show up when benchmarking the
dc-only version.
This is cherrypicked from libav commit
4d960a1185.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This work is sponsored by, and copyright, Google.
These are ported from the ARM version; thanks to the larger
amount of registers available, we can do the 16x16 and 32x32
transforms in slices 8 pixels wide instead of 4. This gives
a speedup of around 1.4x compared to the 32 bit version.
The fact that aarch64 doesn't have the same d/q register
aliasing makes some of the macros quite a bit simpler as well.
Examples of runtimes vs the 32 bit version, on a Cortex A53:
ARM AArch64
vp9_inv_adst_adst_4x4_add_neon: 90.0 87.7
vp9_inv_adst_adst_8x8_add_neon: 400.0 354.7
vp9_inv_adst_adst_16x16_add_neon: 2526.5 1827.2
vp9_inv_dct_dct_4x4_add_neon: 74.0 72.7
vp9_inv_dct_dct_8x8_add_neon: 271.0 256.7
vp9_inv_dct_dct_16x16_add_neon: 1960.7 1372.7
vp9_inv_dct_dct_32x32_add_neon: 11988.9 8088.3
vp9_inv_wht_wht_4x4_add_neon: 63.0 57.7
The speedup vs C code (2-4x) is smaller than in the 32 bit case,
mostly because the C code ends up significantly faster (around
1.6x faster, with GCC 5.4) when built for aarch64.
Examples of runtimes vs C on a Cortex A57 (for a slightly older version
of the patch):
A57 gcc-5.3 neon
vp9_inv_adst_adst_4x4_add_neon: 152.2 60.0
vp9_inv_adst_adst_8x8_add_neon: 948.2 288.0
vp9_inv_adst_adst_16x16_add_neon: 4830.4 1380.5
vp9_inv_dct_dct_4x4_add_neon: 153.0 58.6
vp9_inv_dct_dct_8x8_add_neon: 789.2 180.2
vp9_inv_dct_dct_16x16_add_neon: 3639.6 917.1
vp9_inv_dct_dct_32x32_add_neon: 20462.1 4985.0
vp9_inv_wht_wht_4x4_add_neon: 91.0 49.8
The asm is around factor 3-4 faster than C on the cortex-a57 and the asm
is around 30-50% faster on the a57 compared to the a53.
This is an adapted cherry-pick from libav commit
3c9546dfaf.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
