diff options
Diffstat (limited to 'media/highway/src/hwy/contrib/algo/find-inl.h')
-rw-r--r-- | media/highway/src/hwy/contrib/algo/find-inl.h | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/media/highway/src/hwy/contrib/algo/find-inl.h b/media/highway/src/hwy/contrib/algo/find-inl.h new file mode 100644 index 0000000000..388842e988 --- /dev/null +++ b/media/highway/src/hwy/contrib/algo/find-inl.h @@ -0,0 +1,109 @@ +// Copyright 2022 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. + +// Per-target include guard +#if defined(HIGHWAY_HWY_CONTRIB_ALGO_FIND_INL_H_) == \ + defined(HWY_TARGET_TOGGLE) +#ifdef HIGHWAY_HWY_CONTRIB_ALGO_FIND_INL_H_ +#undef HIGHWAY_HWY_CONTRIB_ALGO_FIND_INL_H_ +#else +#define HIGHWAY_HWY_CONTRIB_ALGO_FIND_INL_H_ +#endif + +#include "hwy/highway.h" + +HWY_BEFORE_NAMESPACE(); +namespace hwy { +namespace HWY_NAMESPACE { + +// Returns index of the first element equal to `value` in `in[0, count)`, or +// `count` if not found. +template <class D, typename T = TFromD<D>> +size_t Find(D d, T value, const T* HWY_RESTRICT in, size_t count) { + const size_t N = Lanes(d); + const Vec<D> broadcasted = Set(d, value); + + size_t i = 0; + for (; i + N <= count; i += N) { + const intptr_t pos = FindFirstTrue(d, Eq(broadcasted, LoadU(d, in + i))); + if (pos >= 0) return i + static_cast<size_t>(pos); + } + + if (i != count) { +#if HWY_MEM_OPS_MIGHT_FAULT + // Scan single elements. + const CappedTag<T, 1> d1; + using V1 = Vec<decltype(d1)>; + const V1 broadcasted1 = Set(d1, GetLane(broadcasted)); + for (; i < count; ++i) { + if (AllTrue(d1, Eq(broadcasted1, LoadU(d1, in + i)))) { + return i; + } + } +#else + const size_t remaining = count - i; + HWY_DASSERT(0 != remaining && remaining < N); + const Mask<D> mask = FirstN(d, remaining); + const Vec<D> v = MaskedLoad(mask, d, in + i); + // Apply mask so that we don't 'find' the zero-padding from MaskedLoad. + const intptr_t pos = FindFirstTrue(d, And(Eq(broadcasted, v), mask)); + if (pos >= 0) return i + static_cast<size_t>(pos); +#endif // HWY_MEM_OPS_MIGHT_FAULT + } + + return count; // not found +} + +// Returns index of the first element in `in[0, count)` for which `func(d, vec)` +// returns true, otherwise `count`. +template <class D, class Func, typename T = TFromD<D>> +size_t FindIf(D d, const T* HWY_RESTRICT in, size_t count, const Func& func) { + const size_t N = Lanes(d); + + size_t i = 0; + for (; i + N <= count; i += N) { + const intptr_t pos = FindFirstTrue(d, func(d, LoadU(d, in + i))); + if (pos >= 0) return i + static_cast<size_t>(pos); + } + + if (i != count) { +#if HWY_MEM_OPS_MIGHT_FAULT + // Scan single elements. + const CappedTag<T, 1> d1; + for (; i < count; ++i) { + if (AllTrue(d1, func(d1, LoadU(d1, in + i)))) { + return i; + } + } +#else + const size_t remaining = count - i; + HWY_DASSERT(0 != remaining && remaining < N); + const Mask<D> mask = FirstN(d, remaining); + const Vec<D> v = MaskedLoad(mask, d, in + i); + // Apply mask so that we don't 'find' the zero-padding from MaskedLoad. + const intptr_t pos = FindFirstTrue(d, And(func(d, v), mask)); + if (pos >= 0) return i + static_cast<size_t>(pos); +#endif // HWY_MEM_OPS_MIGHT_FAULT + } + + return count; // not found +} + +// NOLINTNEXTLINE(google-readability-namespace-comments) +} // namespace HWY_NAMESPACE +} // namespace hwy +HWY_AFTER_NAMESPACE(); + +#endif // HIGHWAY_HWY_CONTRIB_ALGO_FIND_INL_H_ |