v8/test/unittests/wasm/simd-shuffle-unittest.cc

// Copyright 2020 the V8 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.

#include "src/wasm/simd-shuffle.h"

#include "test/unittests/test-utils.h"
#include "testing/gmock-support.h"

using ::testing::ElementsAre;

namespace v8 {
namespace internal {
namespace wasm {
// Helper to make calls to private wasm shuffle functions.
class SimdShuffleTest : public ::testing::Test {
 public:
  using Shuffle = std::array<uint8_t, kSimd128Size>;

  struct TestShuffle {
    Shuffle non_canonical;
    Shuffle canonical;
    bool needs_swap;
    bool is_swizzle;
  };

  // Call testing members in wasm.
  static void CanonicalizeShuffle(bool inputs_equal, Shuffle* shuffle,
                                  bool* needs_swap, bool* is_swizzle) {
    SimdShuffle::CanonicalizeShuffle(inputs_equal, &(*shuffle)[0], needs_swap,
                                     is_swizzle);
  }

  static bool TryMatchIdentity(const Shuffle& shuffle) {
    return SimdShuffle::TryMatchIdentity(&shuffle[0]);
  }
  template <int LANES>
  static bool TryMatchSplat(const Shuffle& shuffle, int* index) {
    return SimdShuffle::TryMatchSplat<LANES>(&shuffle[0], index);
  }
  static bool TryMatch32x4Shuffle(const Shuffle& shuffle,
                                  uint8_t* shuffle32x4) {
    return SimdShuffle::TryMatch32x4Shuffle(&shuffle[0], shuffle32x4);
  }
  static bool TryMatch16x8Shuffle(const Shuffle& shuffle,
                                  uint8_t* shuffle16x8) {
    return SimdShuffle::TryMatch16x8Shuffle(&shuffle[0], shuffle16x8);
  }
  static bool TryMatchConcat(const Shuffle& shuffle, uint8_t* offset) {
    return SimdShuffle::TryMatchConcat(&shuffle[0], offset);
  }
  static bool TryMatchBlend(const Shuffle& shuffle) {
    return SimdShuffle::TryMatchBlend(&shuffle[0]);
  }
};

bool operator==(const SimdShuffleTest::Shuffle& a,
                const SimdShuffleTest::Shuffle& b) {
  for (int i = 0; i < kSimd128Size; ++i) {
    if (a[i] != b[i]) return false;
  }
  return true;
}

TEST_F(SimdShuffleTest, CanonicalizeShuffle) {
  const bool kInputsEqual = true;
  const bool kNeedsSwap = true;
  const bool kIsSwizzle = true;

  bool needs_swap;
  bool is_swizzle;

  // Test canonicalization driven by input shuffle.
  TestShuffle test_shuffles[] = {
      // Identity is canonical.
      {{{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}},
       {{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}},
       !kNeedsSwap,
       kIsSwizzle},
      // Non-canonical identity requires a swap.
      {{{16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31}},
       {{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}},
       kNeedsSwap,
       kIsSwizzle},
      // General shuffle, canonical is unchanged.
      {{{0, 16, 1, 17, 2, 18, 3, 19, 4, 20, 5, 21, 6, 22, 7, 23}},
       {{0, 16, 1, 17, 2, 18, 3, 19, 4, 20, 5, 21, 6, 22, 7, 23}},
       !kNeedsSwap,
       !kIsSwizzle},
      // Non-canonical shuffle requires a swap.
      {{{16, 0, 17, 1, 18, 2, 19, 3, 20, 4, 21, 5, 22, 6, 23, 7}},
       {{0, 16, 1, 17, 2, 18, 3, 19, 4, 20, 5, 21, 6, 22, 7, 23}},
       kNeedsSwap,
       !kIsSwizzle},
  };
  for (size_t i = 0; i < arraysize(test_shuffles); ++i) {
    Shuffle shuffle = test_shuffles[i].non_canonical;
    CanonicalizeShuffle(!kInputsEqual, &shuffle, &needs_swap, &is_swizzle);
    EXPECT_EQ(shuffle, test_shuffles[i].canonical);
    EXPECT_EQ(needs_swap, test_shuffles[i].needs_swap);
    EXPECT_EQ(is_swizzle, test_shuffles[i].is_swizzle);
  }

  // Test canonicalization when inputs are equal (explicit swizzle).
  TestShuffle test_swizzles[] = {
      // Identity is canonical.
      {{{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}},
       {{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}},
       !kNeedsSwap,
       kIsSwizzle},
      // Non-canonical identity requires a swap.
      {{{16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31}},
       {{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}},
       !kNeedsSwap,
       kIsSwizzle},
      // Canonicalized to swizzle.
      {{{0, 16, 1, 17, 2, 18, 3, 19, 4, 20, 5, 21, 6, 22, 7, 23}},
       {{0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7}},
       !kNeedsSwap,
       kIsSwizzle},
      // Canonicalized to swizzle.
      {{{16, 0, 17, 1, 18, 2, 19, 3, 20, 4, 21, 5, 22, 6, 23, 7}},
       {{0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7}},
       !kNeedsSwap,
       kIsSwizzle},
  };
  for (size_t i = 0; i < arraysize(test_swizzles); ++i) {
    Shuffle shuffle = test_swizzles[i].non_canonical;
    CanonicalizeShuffle(kInputsEqual, &shuffle, &needs_swap, &is_swizzle);
    EXPECT_EQ(shuffle, test_swizzles[i].canonical);
    EXPECT_EQ(needs_swap, test_swizzles[i].needs_swap);
    EXPECT_EQ(is_swizzle, test_swizzles[i].is_swizzle);
  }
}

TEST_F(SimdShuffleTest, TryMatchIdentity) {
  // Match shuffle that returns first source operand.
  EXPECT_TRUE(TryMatchIdentity(
      {{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}}));
  // The non-canonicalized identity shuffle doesn't match.
  EXPECT_FALSE(TryMatchIdentity(
      {{16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31}}));
  // Even one lane out of place is not an identity shuffle.
  EXPECT_FALSE(TryMatchIdentity(
      {{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 31}}));
}

TEST_F(SimdShuffleTest, TryMatchSplat) {
  int index;
  // All lanes from the same 32 bit source lane.
  EXPECT_TRUE(TryMatchSplat<4>(
      {{4, 5, 6, 7, 4, 5, 6, 7, 4, 5, 6, 7, 4, 5, 6, 7}}, &index));
  EXPECT_EQ(1, index);
  // It shouldn't match for other vector shapes.
  EXPECT_FALSE(TryMatchSplat<8>(
      {{4, 5, 6, 7, 4, 5, 6, 7, 4, 5, 6, 7, 4, 5, 6, 7}}, &index));
  EXPECT_FALSE(TryMatchSplat<16>(
      {{4, 5, 6, 7, 4, 5, 6, 7, 4, 5, 6, 7, 4, 5, 6, 7}}, &index));
  // All lanes from the same 16 bit source lane.
  EXPECT_TRUE(TryMatchSplat<8>(
      {{16, 17, 16, 17, 16, 17, 16, 17, 16, 17, 16, 17, 16, 17, 16, 17}},
      &index));
  EXPECT_EQ(8, index);
  // It shouldn't match for other vector shapes.
  EXPECT_FALSE(TryMatchSplat<4>(
      {{16, 17, 16, 17, 16, 17, 16, 17, 16, 17, 16, 17, 16, 17, 16, 17}},
      &index));
  EXPECT_FALSE(TryMatchSplat<16>(
      {{16, 17, 16, 17, 16, 17, 16, 17, 16, 17, 16, 17, 16, 17, 16, 17}},
      &index));
  // All lanes from the same 8 bit source lane.
  EXPECT_TRUE(TryMatchSplat<16>(
      {{7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7}}, &index));
  EXPECT_EQ(7, index);
  // It shouldn't match for other vector shapes.
  EXPECT_FALSE(TryMatchSplat<4>(
      {{7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7}}, &index));
  EXPECT_FALSE(TryMatchSplat<8>(
      {{7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7}}, &index));
}

TEST_F(SimdShuffleTest, TryMatchConcat) {
  uint8_t offset;
  // Ascending indices, jump at end to same input (concatenating swizzle).
  EXPECT_TRUE(TryMatchConcat(
      {{3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1, 2}}, &offset));
  EXPECT_EQ(3, offset);
  // Ascending indices, jump at end to other input (concatenating shuffle).
  EXPECT_TRUE(TryMatchConcat(
      {{4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19}}, &offset));
  EXPECT_EQ(4, offset);

  // Shuffles that should not match:
  // Ascending indices, but jump isn't at end/beginning.
  EXPECT_FALSE(TryMatchConcat(
      {{3, 4, 5, 6, 7, 8, 9, 10, 11, 0, 1, 2, 3, 4, 5, 6}}, &offset));
  // Ascending indices, but multiple jumps.
  EXPECT_FALSE(TryMatchConcat(
      {{0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3}}, &offset));
}

TEST_F(SimdShuffleTest, TryMatch32x4Shuffle) {
  uint8_t shuffle32x4[4];
  // Match if each group of 4 bytes is from the same 32 bit lane.
  EXPECT_TRUE(TryMatch32x4Shuffle(
      {{12, 13, 14, 15, 8, 9, 10, 11, 4, 5, 6, 7, 16, 17, 18, 19}},
      shuffle32x4));
  EXPECT_EQ(3, shuffle32x4[0]);
  EXPECT_EQ(2, shuffle32x4[1]);
  EXPECT_EQ(1, shuffle32x4[2]);
  EXPECT_EQ(4, shuffle32x4[3]);
  // Bytes must be in order in the 32 bit lane.
  EXPECT_FALSE(TryMatch32x4Shuffle(
      {{12, 13, 14, 14, 8, 9, 10, 11, 4, 5, 6, 7, 16, 17, 18, 19}},
      shuffle32x4));
  // Each group must start with the first byte in the 32 bit lane.
  EXPECT_FALSE(TryMatch32x4Shuffle(
      {{13, 14, 15, 12, 8, 9, 10, 11, 4, 5, 6, 7, 16, 17, 18, 19}},
      shuffle32x4));
}

TEST_F(SimdShuffleTest, TryMatch16x8Shuffle) {
  uint8_t shuffle16x8[8];
  // Match if each group of 2 bytes is from the same 16 bit lane.
  EXPECT_TRUE(TryMatch16x8Shuffle(
      {{12, 13, 30, 31, 8, 9, 26, 27, 4, 5, 22, 23, 16, 17, 2, 3}},
      shuffle16x8));
  EXPECT_EQ(6, shuffle16x8[0]);
  EXPECT_EQ(15, shuffle16x8[1]);
  EXPECT_EQ(4, shuffle16x8[2]);
  EXPECT_EQ(13, shuffle16x8[3]);
  EXPECT_EQ(2, shuffle16x8[4]);
  EXPECT_EQ(11, shuffle16x8[5]);
  EXPECT_EQ(8, shuffle16x8[6]);
  EXPECT_EQ(1, shuffle16x8[7]);
  // Bytes must be in order in the 16 bit lane.
  EXPECT_FALSE(TryMatch16x8Shuffle(
      {{12, 13, 30, 30, 8, 9, 26, 27, 4, 5, 22, 23, 16, 17, 2, 3}},
      shuffle16x8));
  // Each group must start with the first byte in the 16 bit lane.
  EXPECT_FALSE(TryMatch16x8Shuffle(
      {{12, 13, 31, 30, 8, 9, 26, 27, 4, 5, 22, 23, 16, 17, 2, 3}},
      shuffle16x8));
}

TEST_F(SimdShuffleTest, TryMatchBlend) {
  // Match if each byte remains in place.
  EXPECT_TRUE(TryMatchBlend(
      {{0, 17, 2, 19, 4, 21, 6, 23, 8, 25, 10, 27, 12, 29, 14, 31}}));
  // Identity is a blend.
  EXPECT_TRUE(
      TryMatchBlend({{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}}));
  // Even one lane out of place is not a blend.
  EXPECT_FALSE(TryMatchBlend(
      {{1, 17, 2, 19, 4, 21, 6, 23, 8, 25, 10, 27, 12, 29, 14, 31}}));
}

TEST(SimdShufflePackTest, PackShuffle4) {
  uint8_t arr[4]{0b0001, 0b0010, 0b0100, 0b1000};
  EXPECT_EQ(0b00001001, SimdShuffle::PackShuffle4(arr));
}

TEST(SimdShufflePackTest, PackBlend8) {
  uint8_t arr[8]{0, 2, 4, 6, 8, 10, 12, 14};
  EXPECT_EQ(0b11110000, SimdShuffle::PackBlend8(arr));
}

TEST(SimdShufflePackTest, PackBlend4) {
  uint8_t arr[4]{0, 2, 4, 6};
  EXPECT_EQ(0b11110000, SimdShuffle::PackBlend4(arr));
}

TEST(SimdShufflePackTest, Pack4Lanes) {
  uint8_t arr[4]{0x01, 0x08, 0xa0, 0x7c};
  EXPECT_EQ(0x7ca00801, SimdShuffle::Pack4Lanes(arr));
}

TEST(SimdShufflePackTest, Pack16Lanes) {
  uint8_t arr[16]{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
  uint32_t imms[4]{0};
  SimdShuffle::Pack16Lanes(imms, arr);
  EXPECT_THAT(imms,
              ElementsAre(0x03020100, 0x07060504, 0x0b0a0908, 0x0f0e0d0c));
}

}  // namespace wasm
}  // namespace internal
}  // namespace v8