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// Copyright (c) the JPEG XL 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.
// Block transpose for DCT/IDCT
#if defined(LIB_JXL_TRANSPOSE_INL_H_) == defined(HWY_TARGET_TOGGLE)
#ifdef LIB_JXL_TRANSPOSE_INL_H_
#undef LIB_JXL_TRANSPOSE_INL_H_
#else
#define LIB_JXL_TRANSPOSE_INL_H_
#endif
#include <stddef.h>
#include <hwy/highway.h>
#include <type_traits>
#include "lib/jxl/base/status.h"
#include "lib/jxl/dct_block-inl.h"
HWY_BEFORE_NAMESPACE();
namespace jxl {
namespace HWY_NAMESPACE {
namespace {
#ifndef JXL_INLINE_TRANSPOSE
// Workaround for issue #42 - (excessive?) inlining causes invalid codegen.
#if defined(__arm__)
#define JXL_INLINE_TRANSPOSE HWY_NOINLINE
#else
#define JXL_INLINE_TRANSPOSE HWY_INLINE
#endif
#endif // JXL_INLINE_TRANSPOSE
// Simple wrapper that ensures that a function will not be inlined.
template <typename T, typename... Args>
JXL_NOINLINE void NoInlineWrapper(const T& f, const Args&... args) {
return f(args...);
}
template <bool enabled>
struct TransposeSimdTag {};
// TODO(veluca): it's not super useful to have this in the SIMD namespace.
template <size_t ROWS_or_0, size_t COLS_or_0, class From, class To>
JXL_INLINE_TRANSPOSE void GenericTransposeBlock(
TransposeSimdTag<false> /* tag */, const From& from, const To& to,
size_t ROWSp, size_t COLSp) {
size_t ROWS = ROWS_or_0 == 0 ? ROWSp : ROWS_or_0;
size_t COLS = COLS_or_0 == 0 ? COLSp : COLS_or_0;
for (size_t n = 0; n < ROWS; ++n) {
for (size_t m = 0; m < COLS; ++m) {
to.Write(from.Read(n, m), m, n);
}
}
}
// TODO(veluca): AVX3?
#if HWY_CAP_GE256
constexpr bool TransposeUseSimd(size_t ROWS, size_t COLS) {
return ROWS % 8 == 0 && COLS % 8 == 0;
}
template <size_t ROWS_or_0, size_t COLS_or_0, class From, class To>
JXL_INLINE_TRANSPOSE void GenericTransposeBlock(
TransposeSimdTag<true> /* tag */, const From& from, const To& to,
size_t ROWSp, size_t COLSp) {
size_t ROWS = ROWS_or_0 == 0 ? ROWSp : ROWS_or_0;
size_t COLS = COLS_or_0 == 0 ? COLSp : COLS_or_0;
static_assert(MaxLanes(BlockDesc<8>()) == 8, "Invalid descriptor size");
static_assert(ROWS_or_0 % 8 == 0, "Invalid number of rows");
static_assert(COLS_or_0 % 8 == 0, "Invalid number of columns");
for (size_t n = 0; n < ROWS; n += 8) {
for (size_t m = 0; m < COLS; m += 8) {
const BlockDesc<8> d;
auto i0 = from.LoadPart(d, n + 0, m + 0);
auto i1 = from.LoadPart(d, n + 1, m + 0);
auto i2 = from.LoadPart(d, n + 2, m + 0);
auto i3 = from.LoadPart(d, n + 3, m + 0);
auto i4 = from.LoadPart(d, n + 4, m + 0);
auto i5 = from.LoadPart(d, n + 5, m + 0);
auto i6 = from.LoadPart(d, n + 6, m + 0);
auto i7 = from.LoadPart(d, n + 7, m + 0);
// Surprisingly, this straightforward implementation (24 cycles on port5)
// is faster than load128+insert and LoadDup128+ConcatUpperLower+blend.
const auto q0 = InterleaveLower(d, i0, i2);
const auto q1 = InterleaveLower(d, i1, i3);
const auto q2 = InterleaveUpper(d, i0, i2);
const auto q3 = InterleaveUpper(d, i1, i3);
const auto q4 = InterleaveLower(d, i4, i6);
const auto q5 = InterleaveLower(d, i5, i7);
const auto q6 = InterleaveUpper(d, i4, i6);
const auto q7 = InterleaveUpper(d, i5, i7);
const auto r0 = InterleaveLower(d, q0, q1);
const auto r1 = InterleaveUpper(d, q0, q1);
const auto r2 = InterleaveLower(d, q2, q3);
const auto r3 = InterleaveUpper(d, q2, q3);
const auto r4 = InterleaveLower(d, q4, q5);
const auto r5 = InterleaveUpper(d, q4, q5);
const auto r6 = InterleaveLower(d, q6, q7);
const auto r7 = InterleaveUpper(d, q6, q7);
i0 = ConcatLowerLower(d, r4, r0);
i1 = ConcatLowerLower(d, r5, r1);
i2 = ConcatLowerLower(d, r6, r2);
i3 = ConcatLowerLower(d, r7, r3);
i4 = ConcatUpperUpper(d, r4, r0);
i5 = ConcatUpperUpper(d, r5, r1);
i6 = ConcatUpperUpper(d, r6, r2);
i7 = ConcatUpperUpper(d, r7, r3);
to.StorePart(d, i0, m + 0, n + 0);
to.StorePart(d, i1, m + 1, n + 0);
to.StorePart(d, i2, m + 2, n + 0);
to.StorePart(d, i3, m + 3, n + 0);
to.StorePart(d, i4, m + 4, n + 0);
to.StorePart(d, i5, m + 5, n + 0);
to.StorePart(d, i6, m + 6, n + 0);
to.StorePart(d, i7, m + 7, n + 0);
}
}
}
#elif HWY_TARGET != HWY_SCALAR
constexpr bool TransposeUseSimd(size_t ROWS, size_t COLS) {
return ROWS % 4 == 0 && COLS % 4 == 0;
}
template <size_t ROWS_or_0, size_t COLS_or_0, class From, class To>
JXL_INLINE_TRANSPOSE void GenericTransposeBlock(
TransposeSimdTag<true> /* tag */, const From& from, const To& to,
size_t ROWSp, size_t COLSp) {
size_t ROWS = ROWS_or_0 == 0 ? ROWSp : ROWS_or_0;
size_t COLS = COLS_or_0 == 0 ? COLSp : COLS_or_0;
static_assert(MaxLanes(BlockDesc<4>()) == 4, "Invalid descriptor size");
static_assert(ROWS_or_0 % 4 == 0, "Invalid number of rows");
static_assert(COLS_or_0 % 4 == 0, "Invalid number of columns");
for (size_t n = 0; n < ROWS; n += 4) {
for (size_t m = 0; m < COLS; m += 4) {
const BlockDesc<4> d;
const auto p0 = from.LoadPart(d, n + 0, m + 0);
const auto p1 = from.LoadPart(d, n + 1, m + 0);
const auto p2 = from.LoadPart(d, n + 2, m + 0);
const auto p3 = from.LoadPart(d, n + 3, m + 0);
const auto q0 = InterleaveLower(d, p0, p2);
const auto q1 = InterleaveLower(d, p1, p3);
const auto q2 = InterleaveUpper(d, p0, p2);
const auto q3 = InterleaveUpper(d, p1, p3);
const auto r0 = InterleaveLower(d, q0, q1);
const auto r1 = InterleaveUpper(d, q0, q1);
const auto r2 = InterleaveLower(d, q2, q3);
const auto r3 = InterleaveUpper(d, q2, q3);
to.StorePart(d, r0, m + 0, n + 0);
to.StorePart(d, r1, m + 1, n + 0);
to.StorePart(d, r2, m + 2, n + 0);
to.StorePart(d, r3, m + 3, n + 0);
}
}
}
#else
constexpr bool TransposeUseSimd(size_t ROWS, size_t COLS) { return false; }
#endif
template <size_t N, size_t M, typename = void>
struct Transpose {
template <typename From, typename To>
static void Run(const From& from, const To& to) {
// This does not guarantee anything, just saves from the most stupid
// mistakes.
JXL_DASSERT(from.Address(0, 0) != to.Address(0, 0));
TransposeSimdTag<TransposeUseSimd(N, M)> tag;
GenericTransposeBlock<N, M>(tag, from, to, N, M);
}
};
// Avoid inlining and unrolling transposes for large blocks.
template <size_t N, size_t M>
struct Transpose<
N, M, typename std::enable_if<(N >= 8 && M >= 8 && N * M >= 512)>::type> {
template <typename From, typename To>
static void Run(const From& from, const To& to) {
// This does not guarantee anything, just saves from the most stupid
// mistakes.
JXL_DASSERT(from.Address(0, 0) != to.Address(0, 0));
TransposeSimdTag<TransposeUseSimd(N, M)> tag;
constexpr void (*transpose)(TransposeSimdTag<TransposeUseSimd(N, M)>,
const From&, const To&, size_t, size_t) =
GenericTransposeBlock<0, 0, From, To>;
NoInlineWrapper(transpose, tag, from, to, N, M);
}
};
} // namespace
// NOLINTNEXTLINE(google-readability-namespace-comments)
} // namespace HWY_NAMESPACE
} // namespace jxl
HWY_AFTER_NAMESPACE();
#endif // LIB_JXL_TRANSPOSE_INL_H_