1 files changed, 455 insertions, 0 deletions
diff --git a/third_party/highway/hwy/tests/combine_test.cc b/third_party/highway/hwy/tests/combine_test.cc
new file mode 100644
index 0000000000..1170361025
--- /dev/null
+++ b/third_party/highway/hwy/tests/combine_test.cc
@@ -0,0 +1,455 @@
+// Copyright 2019 Google LLC
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <string.h>  // memcpy
+
+#include <algorithm>  // std::fill
+
+#undef HWY_TARGET_INCLUDE
+#define HWY_TARGET_INCLUDE "tests/combine_test.cc"
+#include "hwy/foreach_target.h"  // IWYU pragma: keep
+#include "hwy/highway.h"
+#include "hwy/tests/test_util-inl.h"
+
+HWY_BEFORE_NAMESPACE();
+namespace hwy {
+namespace HWY_NAMESPACE {
+
+struct TestLowerHalf {
+  template <class T, class D>
+  HWY_NOINLINE void operator()(T /*unused*/, D d) {
+    const Half<D> d2;
+
+    const size_t N = Lanes(d);
+    auto lanes = AllocateAligned<T>(N);
+    auto lanes2 = AllocateAligned<T>(N);
+    HWY_ASSERT(lanes && lanes2);
+    std::fill(lanes.get(), lanes.get() + N, T(0));
+    std::fill(lanes2.get(), lanes2.get() + N, T(0));
+    const auto v = Iota(d, 1);
+    Store(LowerHalf(d2, v), d2, lanes.get());
+    Store(LowerHalf(v), d2, lanes2.get());  // optionally without D
+    size_t i = 0;
+    for (; i < Lanes(d2); ++i) {
+      HWY_ASSERT_EQ(T(1 + i), lanes[i]);
+      HWY_ASSERT_EQ(T(1 + i), lanes2[i]);
+    }
+    // Other half remains unchanged
+    for (; i < N; ++i) {
+      HWY_ASSERT_EQ(T(0), lanes[i]);
+      HWY_ASSERT_EQ(T(0), lanes2[i]);
+    }
+  }
+};
+
+struct TestLowerQuarter {
+  template <class T, class D>
+  HWY_NOINLINE void operator()(T /*unused*/, D d) {
+    const Half<D> d2;
+    const Half<decltype(d2)> d4;
+
+    const size_t N = Lanes(d);
+    auto lanes = AllocateAligned<T>(N);
+    auto lanes2 = AllocateAligned<T>(N);
+    HWY_ASSERT(lanes && lanes2);
+    std::fill(lanes.get(), lanes.get() + N, T(0));
+    std::fill(lanes2.get(), lanes2.get() + N, T(0));
+    const auto v = Iota(d, 1);
+    const auto lo = LowerHalf(d4, LowerHalf(d2, v));
+    const auto lo2 = LowerHalf(LowerHalf(v));  // optionally without D
+    Store(lo, d4, lanes.get());
+    Store(lo2, d4, lanes2.get());
+    size_t i = 0;
+    for (; i < Lanes(d4); ++i) {
+      HWY_ASSERT_EQ(T(i + 1), lanes[i]);
+      HWY_ASSERT_EQ(T(i + 1), lanes2[i]);
+    }
+    // Upper 3/4 remain unchanged
+    for (; i < N; ++i) {
+      HWY_ASSERT_EQ(T(0), lanes[i]);
+      HWY_ASSERT_EQ(T(0), lanes2[i]);
+    }
+  }
+};
+
+HWY_NOINLINE void TestAllLowerHalf() {
+  ForAllTypes(ForHalfVectors<TestLowerHalf>());
+
+  // The minimum vector size is 128 bits, so there's no guarantee we can have
+  // quarters of 64-bit lanes, hence test 'all' other types.
+  ForHalfVectors<TestLowerQuarter, 2> test_quarter;
+  ForUI8(test_quarter);
+  ForUI16(test_quarter);  // exclude float16_t - cannot compare
+  ForUIF32(test_quarter);
+}
+
+struct TestUpperHalf {
+  template <class T, class D>
+  HWY_NOINLINE void operator()(T /*unused*/, D d) {
+    // Scalar does not define UpperHalf.
+#if HWY_TARGET != HWY_SCALAR
+    const Half<D> d2;
+    const size_t N2 = Lanes(d2);
+    if (N2 < 2) return;
+    HWY_ASSERT_EQ(N2 * 2, Lanes(d));
+    auto expected = AllocateAligned<T>(N2);
+    HWY_ASSERT(expected);
+    size_t i = 0;
+    for (; i < N2; ++i) {
+      expected[i] = static_cast<T>(N2 + 1 + i);
+    }
+    HWY_ASSERT_VEC_EQ(d2, expected.get(), UpperHalf(d2, Iota(d, 1)));
+#else
+    (void)d;
+#endif
+  }
+};
+
+HWY_NOINLINE void TestAllUpperHalf() {
+  ForAllTypes(ForHalfVectors<TestUpperHalf>());
+}
+
+struct TestZeroExtendVector {
+  template <class T, class D>
+  HWY_NOINLINE void operator()(T /*unused*/, D d) {
+    const Twice<D> d2;
+
+    const auto v = Iota(d, 1);
+    const size_t N = Lanes(d);
+    const size_t N2 = Lanes(d2);
+    // If equal, then N was already MaxLanes(d) and it's not clear what
+    // Combine or ZeroExtendVector should return.
+    if (N2 == N) return;
+    HWY_ASSERT(N2 == 2 * N);
+    auto lanes = AllocateAligned<T>(N2);
+    HWY_ASSERT(lanes);
+    Store(v, d, &lanes[0]);
+    Store(v, d, &lanes[N]);
+
+    const VFromD<decltype(d2)> ext = ZeroExtendVector(d2, v);
+    Store(ext, d2, lanes.get());
+
+    // Lower half is unchanged
+    HWY_ASSERT_VEC_EQ(d, v, Load(d, &lanes[0]));
+    // Upper half is zero
+    HWY_ASSERT_VEC_EQ(d, Zero(d), Load(d, &lanes[N]));
+  }
+};
+
+HWY_NOINLINE void TestAllZeroExtendVector() {
+  ForAllTypes(ForExtendableVectors<TestZeroExtendVector>());
+}
+
+struct TestCombine {
+  template <class T, class D>
+  HWY_NOINLINE void operator()(T /*unused*/, D d) {
+    const Twice<D> d2;
+    const size_t N2 = Lanes(d2);
+    if (N2 < 2) return;
+    auto lanes = AllocateAligned<T>(N2);
+    HWY_ASSERT(lanes);
+
+    const Vec<D> lo = Iota(d, 1);
+    const Vec<D> hi = Iota(d, static_cast<T>(N2 / 2 + 1));
+    const Vec<decltype(d2)> combined = Combine(d2, hi, lo);
+    Store(combined, d2, lanes.get());
+
+    const Vec<decltype(d2)> expected = Iota(d2, 1);
+    HWY_ASSERT_VEC_EQ(d2, expected, combined);
+  }
+};
+
+HWY_NOINLINE void TestAllCombine() {
+  ForAllTypes(ForExtendableVectors<TestCombine>());
+}
+
+struct TestConcat {
+  template <class T, class D>
+  HWY_NOINLINE void operator()(T /*unused*/, D d) {
+    const size_t N = Lanes(d);
+    if (N == 1) return;
+    const size_t half_bytes = N * sizeof(T) / 2;
+
+    auto hi = AllocateAligned<T>(N);
+    auto lo = AllocateAligned<T>(N);
+    auto expected = AllocateAligned<T>(N);
+    HWY_ASSERT(hi && lo && expected);
+    RandomState rng;
+    for (size_t rep = 0; rep < 10; ++rep) {
+      for (size_t i = 0; i < N; ++i) {
+        hi[i] = static_cast<T>(Random64(&rng) & 0xFF);
+        lo[i] = static_cast<T>(Random64(&rng) & 0xFF);
+      }
+
+      {
+        memcpy(&expected[N / 2], &hi[N / 2], half_bytes);
+        memcpy(&expected[0], &lo[0], half_bytes);
+        const auto vhi = Load(d, hi.get());
+        const auto vlo = Load(d, lo.get());
+        HWY_ASSERT_VEC_EQ(d, expected.get(), ConcatUpperLower(d, vhi, vlo));
+      }
+
+      {
+        memcpy(&expected[N / 2], &hi[N / 2], half_bytes);
+        memcpy(&expected[0], &lo[N / 2], half_bytes);
+        const auto vhi = Load(d, hi.get());
+        const auto vlo = Load(d, lo.get());
+        HWY_ASSERT_VEC_EQ(d, expected.get(), ConcatUpperUpper(d, vhi, vlo));
+      }
+
+      {
+        memcpy(&expected[N / 2], &hi[0], half_bytes);
+        memcpy(&expected[0], &lo[N / 2], half_bytes);
+        const auto vhi = Load(d, hi.get());
+        const auto vlo = Load(d, lo.get());
+        HWY_ASSERT_VEC_EQ(d, expected.get(), ConcatLowerUpper(d, vhi, vlo));
+      }
+
+      {
+        memcpy(&expected[N / 2], &hi[0], half_bytes);
+        memcpy(&expected[0], &lo[0], half_bytes);
+        const auto vhi = Load(d, hi.get());
+        const auto vlo = Load(d, lo.get());
+        HWY_ASSERT_VEC_EQ(d, expected.get(), ConcatLowerLower(d, vhi, vlo));
+      }
+    }
+  }
+};
+
+HWY_NOINLINE void TestAllConcat() {
+  ForAllTypes(ForShrinkableVectors<TestConcat>());
+}
+
+struct TestConcatOddEven {
+  template <class T, class D>
+  HWY_NOINLINE void operator()(T /*unused*/, D d) {
+#if HWY_TARGET != HWY_SCALAR
+    const size_t N = Lanes(d);
+    const auto hi = Iota(d, static_cast<T>(N));
+    const auto lo = Iota(d, 0);
+    const auto even = Add(Iota(d, 0), Iota(d, 0));
+    const auto odd = Add(even, Set(d, 1));
+    HWY_ASSERT_VEC_EQ(d, odd, ConcatOdd(d, hi, lo));
+    HWY_ASSERT_VEC_EQ(d, even, ConcatEven(d, hi, lo));
+
+    const auto v_1 = Set(d, T{1});
+    const auto v_2 = Set(d, T{2});
+    const auto v_3 = Set(d, T{3});
+    const auto v_4 = Set(d, T{4});
+
+    const Half<decltype(d)> dh;
+    const auto v_12 = InterleaveLower(v_1, v_2); /* {1, 2, 1, 2, ...} */
+    const auto v_34 = InterleaveLower(v_3, v_4); /* {3, 4, 3, 4, ...} */
+    const auto v_13 =
+        ConcatLowerLower(d, v_3, v_1); /* {1, 1, ..., 3, 3, ...} */
+    const auto v_24 =
+        ConcatLowerLower(d, v_4, v_2); /* {2, 2, ..., 4, 4, ...} */
+
+    const auto concat_even_1234_result = ConcatEven(d, v_34, v_12);
+    const auto concat_odd_1234_result = ConcatOdd(d, v_34, v_12);
+
+    HWY_ASSERT_VEC_EQ(d, v_13, concat_even_1234_result);
+    HWY_ASSERT_VEC_EQ(d, v_24, concat_odd_1234_result);
+    HWY_ASSERT_VEC_EQ(dh, LowerHalf(dh, v_3),
+                      UpperHalf(dh, concat_even_1234_result));
+    HWY_ASSERT_VEC_EQ(dh, LowerHalf(dh, v_4),
+                      UpperHalf(dh, concat_odd_1234_result));
+
+    // This test catches inadvertent saturation.
+    const auto min = Set(d, LowestValue<T>());
+    const auto max = Set(d, HighestValue<T>());
+    HWY_ASSERT_VEC_EQ(d, max, ConcatOdd(d, max, max));
+    HWY_ASSERT_VEC_EQ(d, max, ConcatEven(d, max, max));
+    HWY_ASSERT_VEC_EQ(d, min, ConcatOdd(d, min, min));
+    HWY_ASSERT_VEC_EQ(d, min, ConcatEven(d, min, min));
+#else
+    (void)d;
+#endif  // HWY_TARGET != HWY_SCALAR
+  }
+};
+
+HWY_NOINLINE void TestAllConcatOddEven() {
+  ForAllTypes(ForShrinkableVectors<TestConcatOddEven>());
+}
+
+class TestTruncatingResizeBitCast {
+#if HWY_TARGET != HWY_SCALAR
+ private:
+  template <class DTo, class DFrom>
+  static HWY_INLINE void DoTruncResizeBitCastTest(DTo d_to, DFrom d_from) {
+    const VFromD<DFrom> v = Iota(d_from, 1);
+    const VFromD<DTo> expected = Iota(d_to, 1);
+
+    const VFromD<DTo> actual_1 = ResizeBitCast(d_to, v);
+    HWY_ASSERT_VEC_EQ(d_to, expected, actual_1);
+
+    const VFromD<DTo> actual_2 = ZeroExtendResizeBitCast(d_to, d_from, v);
+    HWY_ASSERT_VEC_EQ(d_to, expected, actual_2);
+  }
+#endif  // HWY_TARGET != HWY_SCALAR
+ public:
+  template <class T, class D>
+  HWY_NOINLINE void operator()(T /*unused*/, D d) {
+#if HWY_TARGET != HWY_SCALAR
+    const Half<D> dh;
+    DoTruncResizeBitCastTest(dh, d);
+
+    const auto v_full = Iota(d, 1);
+    const VFromD<decltype(dh)> expected_full_to_half = LowerHalf(dh, v_full);
+    HWY_ASSERT_VEC_EQ(dh, expected_full_to_half, ResizeBitCast(dh, v_full));
+    HWY_ASSERT_VEC_EQ(dh, expected_full_to_half,
+                      ZeroExtendResizeBitCast(dh, d, v_full));
+
+    constexpr size_t kMaxLanes = MaxLanes(d);
+#if HWY_TARGET == HWY_RVV
+    constexpr int kFromVectPow2 = DFromV<VFromD<D>>().Pow2();
+    static_assert(kFromVectPow2 >= -3 && kFromVectPow2 <= 3,
+                  "kFromVectPow2 must be between -3 and 3");
+
+    constexpr size_t kScaledMaxLanes =
+        HWY_MAX((kMaxLanes << 3) >> (kFromVectPow2 + 3), 1);
+    constexpr int kMinPow2 = -3 + static_cast<int>(FloorLog2(sizeof(T)));
+    static_assert(kMinPow2 >= -3 && kMinPow2 <= 0,
+                  "kMinPow2 must be between -3 and 0");
+
+    constexpr size_t kQuarterScaledMaxLanes = kScaledMaxLanes;
+    constexpr size_t kEighthScaledMaxLanes = kScaledMaxLanes;
+    constexpr int kQuarterPow2 = HWY_MAX(kFromVectPow2 - 2, kMinPow2);
+    constexpr int kEighthPow2 = HWY_MAX(kFromVectPow2 - 3, kMinPow2);
+#else
+    constexpr size_t kQuarterScaledMaxLanes = HWY_MAX(kMaxLanes / 4, 1);
+    constexpr size_t kEighthScaledMaxLanes = HWY_MAX(kMaxLanes / 8, 1);
+    constexpr int kQuarterPow2 = 0;
+    constexpr int kEighthPow2 = 0;
+#endif
+
+    const CappedTag<T, kQuarterScaledMaxLanes, kQuarterPow2> d_quarter;
+    const CappedTag<T, kEighthScaledMaxLanes, kEighthPow2> d_eighth;
+    if (MaxLanes(d_quarter) == kMaxLanes / 4) {
+      DoTruncResizeBitCastTest(d_quarter, d);
+      if (MaxLanes(d_eighth) == kMaxLanes / 8) {
+        DoTruncResizeBitCastTest(d_eighth, d);
+      }
+    }
+#else
+    (void)d;
+#endif  // HWY_TARGET != HWY_SCALAR
+  }
+};
+
+HWY_NOINLINE void TestAllTruncatingResizeBitCast() {
+  ForAllTypes(ForShrinkableVectors<TestTruncatingResizeBitCast>());
+}
+
+class TestExtendingResizeBitCast {
+#if HWY_TARGET != HWY_SCALAR
+ private:
+  template <class DTo, class DFrom>
+  static HWY_INLINE void DoExtResizeBitCastTest(DTo d_to, DFrom d_from) {
+    const size_t N = Lanes(d_from);
+    const auto active_elements_mask = FirstN(d_to, N);
+
+    const VFromD<DTo> expected =
+        IfThenElseZero(active_elements_mask, Iota(d_to, 1));
+    const VFromD<DFrom> v = Iota(d_from, 1);
+
+    const VFromD<DTo> actual_1 = ResizeBitCast(d_to, v);
+    const VFromD<DTo> actual_2 = ZeroExtendResizeBitCast(d_to, d_from, v);
+
+    HWY_ASSERT_VEC_EQ(d_to, expected,
+                      IfThenElseZero(active_elements_mask, actual_1));
+    HWY_ASSERT_VEC_EQ(d_to, expected, actual_2);
+  }
+  template <class DFrom>
+  static HWY_INLINE void DoExtResizeBitCastToTwiceDTest(DFrom d_from) {
+    using DTo = Twice<DFrom>;
+    const DTo d_to;
+    DoExtResizeBitCastTest(d_to, d_from);
+
+    const VFromD<DFrom> v = Iota(d_from, 1);
+    const VFromD<DTo> expected = ZeroExtendVector(d_to, v);
+
+    const VFromD<DTo> actual_1 = ResizeBitCast(d_to, v);
+    const VFromD<DTo> actual_2 = ZeroExtendResizeBitCast(d_to, d_from, v);
+
+    HWY_ASSERT_VEC_EQ(d_from, v, LowerHalf(d_from, actual_1));
+    HWY_ASSERT_VEC_EQ(d_from, v, LowerHalf(d_from, actual_2));
+    HWY_ASSERT_VEC_EQ(d_to, expected, actual_2);
+  }
+#endif  // HWY_TARGET != HWY_SCALAR
+ public:
+  template <class T, class D>
+  HWY_NOINLINE void operator()(T /*unused*/, D d) {
+#if HWY_TARGET != HWY_SCALAR
+    DoExtResizeBitCastToTwiceDTest(d);
+
+    constexpr size_t kMaxLanes = MaxLanes(d);
+#if HWY_TARGET == HWY_RVV
+    constexpr int kFromVectPow2 = DFromV<VFromD<D>>().Pow2();
+    static_assert(kFromVectPow2 >= -3 && kFromVectPow2 <= 3,
+                  "kFromVectPow2 must be between -3 and 3");
+
+    constexpr size_t kScaledMaxLanes =
+        HWY_MAX((kMaxLanes << 3) >> (kFromVectPow2 + 3), 1);
+    constexpr size_t kQuadrupleScaledLimit = kScaledMaxLanes;
+    constexpr size_t kOctupleScaledLimit = kScaledMaxLanes;
+    constexpr int kQuadruplePow2 = HWY_MIN(kFromVectPow2 + 2, 3);
+    constexpr int kOctuplePow2 = HWY_MIN(kFromVectPow2 + 3, 3);
+#else
+    constexpr size_t kQuadrupleScaledLimit = kMaxLanes * 4;
+    constexpr size_t kOctupleScaledLimit = kMaxLanes * 8;
+    constexpr int kQuadruplePow2 = 0;
+    constexpr int kOctuplePow2 = 0;
+#endif
+
+    const CappedTag<T, kQuadrupleScaledLimit, kQuadruplePow2> d_quadruple;
+    const CappedTag<T, kOctupleScaledLimit, kOctuplePow2> d_octuple;
+
+    if (MaxLanes(d_quadruple) == kMaxLanes * 4) {
+      DoExtResizeBitCastTest(d_quadruple, d);
+      if (MaxLanes(d_octuple) == kMaxLanes * 8) {
+        DoExtResizeBitCastTest(d_octuple, d);
+      }
+    }
+#else
+    (void)d;
+#endif  // HWY_TARGET != HWY_SCALAR
+  }
+};
+
+HWY_NOINLINE void TestAllExtendingResizeBitCast() {
+  ForAllTypes(ForExtendableVectors<TestExtendingResizeBitCast>());
+}
+
+// NOLINTNEXTLINE(google-readability-namespace-comments)
+}  // namespace HWY_NAMESPACE
+}  // namespace hwy
+HWY_AFTER_NAMESPACE();
+
+#if HWY_ONCE
+
+namespace hwy {
+HWY_BEFORE_TEST(HwyCombineTest);
+HWY_EXPORT_AND_TEST_P(HwyCombineTest, TestAllLowerHalf);
+HWY_EXPORT_AND_TEST_P(HwyCombineTest, TestAllUpperHalf);
+HWY_EXPORT_AND_TEST_P(HwyCombineTest, TestAllZeroExtendVector);
+HWY_EXPORT_AND_TEST_P(HwyCombineTest, TestAllCombine);
+HWY_EXPORT_AND_TEST_P(HwyCombineTest, TestAllConcat);
+HWY_EXPORT_AND_TEST_P(HwyCombineTest, TestAllConcatOddEven);
+HWY_EXPORT_AND_TEST_P(HwyCombineTest, TestAllTruncatingResizeBitCast);
+HWY_EXPORT_AND_TEST_P(HwyCombineTest, TestAllExtendingResizeBitCast);
+}  // namespace hwy
+
+#endif  // HWY_ONCE