vpx/test/vp9_error_block_test.cc
Geza Lore aa8f85223b Optimize vp9_highbd_block_error_8bit assembly.
A new version of vp9_highbd_error_8bit is now available which is
optimized with AVX assembly. AVX itself does not buy us too much, but
the non-destructive 3 operand format encoding of the 128bit SSEn integer
instructions helps to eliminate move instructions. The Sandy Bridge
micro-architecture cannot eliminate move instructions in the processor
front end, so AVX will help on these machines.

Further 2 optimizations are applied:

1. The common case of computing block error on 4x4 blocks is optimized
as a special case.
2. All arithmetic is speculatively done on 32 bits only. At the end of
the loop, the code detects if overflow might have happened and if so,
the whole computation is re-executed using higher precision arithmetic.
This case however is extremely rare in real use, so we can achieve a
large net gain here.

The optimizations rely on the fact that the coefficients are in the
range [-(2^15-1), 2^15-1], and that the quantized coefficients always
have the same sign as the input coefficients (in the worst case they are
0). These are the same assumptions that the old SSE2 assembly code for
the non high bitdepth configuration relied on. The unit tests have been
updated to take this constraint into consideration when generating test
input data.

Change-Id: I57d9888a74715e7145a5d9987d67891ef68f39b7
2015-10-21 12:30:40 +01:00

212 lines
7.1 KiB
C++

/*
* Copyright (c) 2014 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include <cmath>
#include <cstdlib>
#include <string>
#include "third_party/googletest/src/include/gtest/gtest.h"
#include "./vpx_config.h"
#include "./vp9_rtcd.h"
#include "test/acm_random.h"
#include "test/clear_system_state.h"
#include "test/register_state_check.h"
#include "test/util.h"
#include "vp9/common/vp9_entropy.h"
#include "vpx/vpx_codec.h"
#include "vpx/vpx_integer.h"
using libvpx_test::ACMRandom;
namespace {
#if CONFIG_VP9_HIGHBITDEPTH
const int kNumIterations = 1000;
typedef int64_t (*ErrorBlockFunc)(const tran_low_t *coeff,
const tran_low_t *dqcoeff,
intptr_t block_size,
int64_t *ssz, int bps);
typedef std::tr1::tuple<ErrorBlockFunc, ErrorBlockFunc, vpx_bit_depth_t>
ErrorBlockParam;
class ErrorBlockTest
: public ::testing::TestWithParam<ErrorBlockParam> {
public:
virtual ~ErrorBlockTest() {}
virtual void SetUp() {
error_block_op_ = GET_PARAM(0);
ref_error_block_op_ = GET_PARAM(1);
bit_depth_ = GET_PARAM(2);
}
virtual void TearDown() { libvpx_test::ClearSystemState(); }
protected:
vpx_bit_depth_t bit_depth_;
ErrorBlockFunc error_block_op_;
ErrorBlockFunc ref_error_block_op_;
};
TEST_P(ErrorBlockTest, OperationCheck) {
ACMRandom rnd(ACMRandom::DeterministicSeed());
DECLARE_ALIGNED(16, tran_low_t, coeff[4096]);
DECLARE_ALIGNED(16, tran_low_t, dqcoeff[4096]);
int err_count_total = 0;
int first_failure = -1;
intptr_t block_size;
int64_t ssz;
int64_t ret;
int64_t ref_ssz;
int64_t ref_ret;
const int msb = bit_depth_ + 8 - 1;
for (int i = 0; i < kNumIterations; ++i) {
int err_count = 0;
block_size = 16 << (i % 9); // All block sizes from 4x4, 8x4 ..64x64
for (int j = 0; j < block_size; j++) {
// coeff and dqcoeff will always have at least the same sign, and this
// can be used for optimization, so generate test input precisely.
if (rnd(2)) {
// Positive number
coeff[j] = rnd(1 << msb);
dqcoeff[j] = rnd(1 << msb);
} else {
// Negative number
coeff[j] = -rnd(1 << msb);
dqcoeff[j] = -rnd(1 << msb);
}
}
ref_ret = ref_error_block_op_(coeff, dqcoeff, block_size, &ref_ssz,
bit_depth_);
ASM_REGISTER_STATE_CHECK(ret = error_block_op_(coeff, dqcoeff, block_size,
&ssz, bit_depth_));
err_count += (ref_ret != ret) | (ref_ssz != ssz);
if (err_count && !err_count_total) {
first_failure = i;
}
err_count_total += err_count;
}
EXPECT_EQ(0, err_count_total)
<< "Error: Error Block Test, C output doesn't match optimized output. "
<< "First failed at test case " << first_failure;
}
TEST_P(ErrorBlockTest, ExtremeValues) {
ACMRandom rnd(ACMRandom::DeterministicSeed());
DECLARE_ALIGNED(16, tran_low_t, coeff[4096]);
DECLARE_ALIGNED(16, tran_low_t, dqcoeff[4096]);
int err_count_total = 0;
int first_failure = -1;
intptr_t block_size;
int64_t ssz;
int64_t ret;
int64_t ref_ssz;
int64_t ref_ret;
const int msb = bit_depth_ + 8 - 1;
int max_val = ((1 << msb) - 1);
for (int i = 0; i < kNumIterations; ++i) {
int err_count = 0;
int k = (i / 9) % 9;
// Change the maximum coeff value, to test different bit boundaries
if ( k == 8 && (i % 9) == 0 ) {
max_val >>= 1;
}
block_size = 16 << (i % 9); // All block sizes from 4x4, 8x4 ..64x64
for (int j = 0; j < block_size; j++) {
if (k < 4) {
// Test at positive maximum values
coeff[j] = k % 2 ? max_val : 0;
dqcoeff[j] = (k >> 1) % 2 ? max_val : 0;
} else if (k < 8) {
// Test at negative maximum values
coeff[j] = k % 2 ? -max_val : 0;
dqcoeff[j] = (k >> 1) % 2 ? -max_val : 0;
} else {
if (rnd(2)) {
// Positive number
coeff[j] = rnd(1 << 14);
dqcoeff[j] = rnd(1 << 14);
} else {
// Negative number
coeff[j] = -rnd(1 << 14);
dqcoeff[j] = -rnd(1 << 14);
}
}
}
ref_ret = ref_error_block_op_(coeff, dqcoeff, block_size, &ref_ssz,
bit_depth_);
ASM_REGISTER_STATE_CHECK(ret = error_block_op_(coeff, dqcoeff, block_size,
&ssz, bit_depth_));
err_count += (ref_ret != ret) | (ref_ssz != ssz);
if (err_count && !err_count_total) {
first_failure = i;
}
err_count_total += err_count;
}
EXPECT_EQ(0, err_count_total)
<< "Error: Error Block Test, C output doesn't match optimized output. "
<< "First failed at test case " << first_failure;
}
using std::tr1::make_tuple;
#if CONFIG_USE_X86INC
int64_t wrap_vp9_highbd_block_error_8bit_c(const tran_low_t *coeff,
const tran_low_t *dqcoeff,
intptr_t block_size,
int64_t *ssz, int bps) {
assert(bps == 8);
return vp9_highbd_block_error_8bit_c(coeff, dqcoeff, block_size, ssz);
}
#if HAVE_SSE2
int64_t wrap_vp9_highbd_block_error_8bit_sse2(const tran_low_t *coeff,
const tran_low_t *dqcoeff,
intptr_t block_size,
int64_t *ssz, int bps) {
assert(bps == 8);
return vp9_highbd_block_error_8bit_sse2(coeff, dqcoeff, block_size, ssz);
}
INSTANTIATE_TEST_CASE_P(
SSE2, ErrorBlockTest,
::testing::Values(
make_tuple(&vp9_highbd_block_error_sse2,
&vp9_highbd_block_error_c, VPX_BITS_10),
make_tuple(&vp9_highbd_block_error_sse2,
&vp9_highbd_block_error_c, VPX_BITS_12),
make_tuple(&vp9_highbd_block_error_sse2,
&vp9_highbd_block_error_c, VPX_BITS_8),
make_tuple(&wrap_vp9_highbd_block_error_8bit_sse2,
&wrap_vp9_highbd_block_error_8bit_c, VPX_BITS_8)));
#endif // HAVE_SSE2
#if HAVE_AVX
int64_t wrap_vp9_highbd_block_error_8bit_avx(const tran_low_t *coeff,
const tran_low_t *dqcoeff,
intptr_t block_size,
int64_t *ssz, int bps) {
assert(bps == 8);
return vp9_highbd_block_error_8bit_avx(coeff, dqcoeff, block_size, ssz);
}
INSTANTIATE_TEST_CASE_P(
AVX, ErrorBlockTest,
::testing::Values(
make_tuple(&wrap_vp9_highbd_block_error_8bit_avx,
&wrap_vp9_highbd_block_error_8bit_c, VPX_BITS_8)));
#endif // HAVE_AVX
#endif // CONFIG_USE_X86INC
#endif // CONFIG_VP9_HIGHBITDEPTH
} // namespace