Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1626 insertions, 0 deletions

diff --git a/third_party/highway/hwy/ops/scalar-inl.h b/third_party/highway/hwy/ops/scalar-inl.h
new file mode 100644
index 0000000000..c28f7b510f
--- /dev/null
+++ b/third_party/highway/hwy/ops/scalar-inl.h
@@ -0,0 +1,1626 @@
+// 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.
+
+// Single-element vectors and operations.
+// External include guard in highway.h - see comment there.
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "hwy/base.h"
+#include "hwy/ops/shared-inl.h"
+
+HWY_BEFORE_NAMESPACE();
+namespace hwy {
+namespace HWY_NAMESPACE {
+
+// Single instruction, single data.
+template <typename T>
+using Sisd = Simd<T, 1, 0>;
+
+// (Wrapper class required for overloading comparison operators.)
+template <typename T>
+struct Vec1 {
+  using PrivateT = T;                     // only for DFromV
+  static constexpr size_t kPrivateN = 1;  // only for DFromV
+
+  HWY_INLINE Vec1() = default;
+  Vec1(const Vec1&) = default;
+  Vec1& operator=(const Vec1&) = default;
+  HWY_INLINE explicit Vec1(const T t) : raw(t) {}
+
+  HWY_INLINE Vec1& operator*=(const Vec1 other) {
+    return *this = (*this * other);
+  }
+  HWY_INLINE Vec1& operator/=(const Vec1 other) {
+    return *this = (*this / other);
+  }
+  HWY_INLINE Vec1& operator+=(const Vec1 other) {
+    return *this = (*this + other);
+  }
+  HWY_INLINE Vec1& operator-=(const Vec1 other) {
+    return *this = (*this - other);
+  }
+  HWY_INLINE Vec1& operator&=(const Vec1 other) {
+    return *this = (*this & other);
+  }
+  HWY_INLINE Vec1& operator|=(const Vec1 other) {
+    return *this = (*this | other);
+  }
+  HWY_INLINE Vec1& operator^=(const Vec1 other) {
+    return *this = (*this ^ other);
+  }
+
+  T raw;
+};
+
+// 0 or FF..FF, same size as Vec1.
+template <typename T>
+class Mask1 {
+  using Raw = hwy::MakeUnsigned<T>;
+
+ public:
+  static HWY_INLINE Mask1<T> FromBool(bool b) {
+    Mask1<T> mask;
+    mask.bits = b ? static_cast<Raw>(~Raw{0}) : 0;
+    return mask;
+  }
+
+  Raw bits;
+};
+
+template <class V>
+using DFromV = Simd<typename V::PrivateT, V::kPrivateN, 0>;
+
+template <class V>
+using TFromV = typename V::PrivateT;
+
+// ------------------------------ BitCast
+
+template <typename T, typename FromT>
+HWY_API Vec1<T> BitCast(Sisd<T> /* tag */, Vec1<FromT> v) {
+  static_assert(sizeof(T) <= sizeof(FromT), "Promoting is undefined");
+  T to;
+  CopyBytes<sizeof(FromT)>(&v.raw, &to);  // not same size - ok to shrink
+  return Vec1<T>(to);
+}
+
+// ------------------------------ Set
+
+template <typename T>
+HWY_API Vec1<T> Zero(Sisd<T> /* tag */) {
+  return Vec1<T>(T(0));
+}
+
+template <typename T, typename T2>
+HWY_API Vec1<T> Set(Sisd<T> /* tag */, const T2 t) {
+  return Vec1<T>(static_cast<T>(t));
+}
+
+template <typename T>
+HWY_API Vec1<T> Undefined(Sisd<T> d) {
+  return Zero(d);
+}
+
+template <typename T, typename T2>
+HWY_API Vec1<T> Iota(const Sisd<T> /* tag */, const T2 first) {
+  return Vec1<T>(static_cast<T>(first));
+}
+
+template <class D>
+using VFromD = decltype(Zero(D()));
+
+// ================================================== LOGICAL
+
+// ------------------------------ Not
+
+template <typename T>
+HWY_API Vec1<T> Not(const Vec1<T> v) {
+  using TU = MakeUnsigned<T>;
+  const Sisd<TU> du;
+  return BitCast(Sisd<T>(), Vec1<TU>(static_cast<TU>(~BitCast(du, v).raw)));
+}
+
+// ------------------------------ And
+
+template <typename T>
+HWY_API Vec1<T> And(const Vec1<T> a, const Vec1<T> b) {
+  using TU = MakeUnsigned<T>;
+  const Sisd<TU> du;
+  return BitCast(Sisd<T>(), Vec1<TU>(BitCast(du, a).raw & BitCast(du, b).raw));
+}
+template <typename T>
+HWY_API Vec1<T> operator&(const Vec1<T> a, const Vec1<T> b) {
+  return And(a, b);
+}
+
+// ------------------------------ AndNot
+
+template <typename T>
+HWY_API Vec1<T> AndNot(const Vec1<T> a, const Vec1<T> b) {
+  using TU = MakeUnsigned<T>;
+  const Sisd<TU> du;
+  return BitCast(Sisd<T>(), Vec1<TU>(static_cast<TU>(~BitCast(du, a).raw &
+                                                     BitCast(du, b).raw)));
+}
+
+// ------------------------------ Or
+
+template <typename T>
+HWY_API Vec1<T> Or(const Vec1<T> a, const Vec1<T> b) {
+  using TU = MakeUnsigned<T>;
+  const Sisd<TU> du;
+  return BitCast(Sisd<T>(), Vec1<TU>(BitCast(du, a).raw | BitCast(du, b).raw));
+}
+template <typename T>
+HWY_API Vec1<T> operator|(const Vec1<T> a, const Vec1<T> b) {
+  return Or(a, b);
+}
+
+// ------------------------------ Xor
+
+template <typename T>
+HWY_API Vec1<T> Xor(const Vec1<T> a, const Vec1<T> b) {
+  using TU = MakeUnsigned<T>;
+  const Sisd<TU> du;
+  return BitCast(Sisd<T>(), Vec1<TU>(BitCast(du, a).raw ^ BitCast(du, b).raw));
+}
+template <typename T>
+HWY_API Vec1<T> operator^(const Vec1<T> a, const Vec1<T> b) {
+  return Xor(a, b);
+}
+
+// ------------------------------ Xor3
+
+template <typename T>
+HWY_API Vec1<T> Xor3(Vec1<T> x1, Vec1<T> x2, Vec1<T> x3) {
+  return Xor(x1, Xor(x2, x3));
+}
+
+// ------------------------------ Or3
+
+template <typename T>
+HWY_API Vec1<T> Or3(Vec1<T> o1, Vec1<T> o2, Vec1<T> o3) {
+  return Or(o1, Or(o2, o3));
+}
+
+// ------------------------------ OrAnd
+
+template <typename T>
+HWY_API Vec1<T> OrAnd(const Vec1<T> o, const Vec1<T> a1, const Vec1<T> a2) {
+  return Or(o, And(a1, a2));
+}
+
+// ------------------------------ IfVecThenElse
+
+template <typename T>
+HWY_API Vec1<T> IfVecThenElse(Vec1<T> mask, Vec1<T> yes, Vec1<T> no) {
+  return IfThenElse(MaskFromVec(mask), yes, no);
+}
+
+// ------------------------------ CopySign
+
+template <typename T>
+HWY_API Vec1<T> CopySign(const Vec1<T> magn, const Vec1<T> sign) {
+  static_assert(IsFloat<T>(), "Only makes sense for floating-point");
+  const auto msb = SignBit(Sisd<T>());
+  return Or(AndNot(msb, magn), And(msb, sign));
+}
+
+template <typename T>
+HWY_API Vec1<T> CopySignToAbs(const Vec1<T> abs, const Vec1<T> sign) {
+  static_assert(IsFloat<T>(), "Only makes sense for floating-point");
+  return Or(abs, And(SignBit(Sisd<T>()), sign));
+}
+
+// ------------------------------ BroadcastSignBit
+
+template <typename T>
+HWY_API Vec1<T> BroadcastSignBit(const Vec1<T> v) {
+  // This is used inside ShiftRight, so we cannot implement in terms of it.
+  return v.raw < 0 ? Vec1<T>(T(-1)) : Vec1<T>(0);
+}
+
+// ------------------------------ PopulationCount
+
+#ifdef HWY_NATIVE_POPCNT
+#undef HWY_NATIVE_POPCNT
+#else
+#define HWY_NATIVE_POPCNT
+#endif
+
+template <typename T>
+HWY_API Vec1<T> PopulationCount(Vec1<T> v) {
+  return Vec1<T>(static_cast<T>(PopCount(v.raw)));
+}
+
+// ------------------------------ Mask
+
+template <typename TFrom, typename TTo>
+HWY_API Mask1<TTo> RebindMask(Sisd<TTo> /*tag*/, Mask1<TFrom> m) {
+  static_assert(sizeof(TFrom) == sizeof(TTo), "Must have same size");
+  return Mask1<TTo>{m.bits};
+}
+
+// v must be 0 or FF..FF.
+template <typename T>
+HWY_API Mask1<T> MaskFromVec(const Vec1<T> v) {
+  Mask1<T> mask;
+  CopySameSize(&v, &mask);
+  return mask;
+}
+
+template <typename T>
+Vec1<T> VecFromMask(const Mask1<T> mask) {
+  Vec1<T> v;
+  CopySameSize(&mask, &v);
+  return v;
+}
+
+template <typename T>
+Vec1<T> VecFromMask(Sisd<T> /* tag */, const Mask1<T> mask) {
+  Vec1<T> v;
+  CopySameSize(&mask, &v);
+  return v;
+}
+
+template <typename T>
+HWY_API Mask1<T> FirstN(Sisd<T> /*tag*/, size_t n) {
+  return Mask1<T>::FromBool(n != 0);
+}
+
+// Returns mask ? yes : no.
+template <typename T>
+HWY_API Vec1<T> IfThenElse(const Mask1<T> mask, const Vec1<T> yes,
+                           const Vec1<T> no) {
+  return mask.bits ? yes : no;
+}
+
+template <typename T>
+HWY_API Vec1<T> IfThenElseZero(const Mask1<T> mask, const Vec1<T> yes) {
+  return mask.bits ? yes : Vec1<T>(0);
+}
+
+template <typename T>
+HWY_API Vec1<T> IfThenZeroElse(const Mask1<T> mask, const Vec1<T> no) {
+  return mask.bits ? Vec1<T>(0) : no;
+}
+
+template <typename T>
+HWY_API Vec1<T> IfNegativeThenElse(Vec1<T> v, Vec1<T> yes, Vec1<T> no) {
+  return v.raw < 0 ? yes : no;
+}
+
+template <typename T>
+HWY_API Vec1<T> ZeroIfNegative(const Vec1<T> v) {
+  return v.raw < 0 ? Vec1<T>(0) : v;
+}
+
+// ------------------------------ Mask logical
+
+template <typename T>
+HWY_API Mask1<T> Not(const Mask1<T> m) {
+  return MaskFromVec(Not(VecFromMask(Sisd<T>(), m)));
+}
+
+template <typename T>
+HWY_API Mask1<T> And(const Mask1<T> a, Mask1<T> b) {
+  const Sisd<T> d;
+  return MaskFromVec(And(VecFromMask(d, a), VecFromMask(d, b)));
+}
+
+template <typename T>
+HWY_API Mask1<T> AndNot(const Mask1<T> a, Mask1<T> b) {
+  const Sisd<T> d;
+  return MaskFromVec(AndNot(VecFromMask(d, a), VecFromMask(d, b)));
+}
+
+template <typename T>
+HWY_API Mask1<T> Or(const Mask1<T> a, Mask1<T> b) {
+  const Sisd<T> d;
+  return MaskFromVec(Or(VecFromMask(d, a), VecFromMask(d, b)));
+}
+
+template <typename T>
+HWY_API Mask1<T> Xor(const Mask1<T> a, Mask1<T> b) {
+  const Sisd<T> d;
+  return MaskFromVec(Xor(VecFromMask(d, a), VecFromMask(d, b)));
+}
+
+template <typename T>
+HWY_API Mask1<T> ExclusiveNeither(const Mask1<T> a, Mask1<T> b) {
+  const Sisd<T> d;
+  return MaskFromVec(AndNot(VecFromMask(d, a), Not(VecFromMask(d, b))));
+}
+
+// ================================================== SHIFTS
+
+// ------------------------------ ShiftLeft/ShiftRight (BroadcastSignBit)
+
+template <int kBits, typename T>
+HWY_API Vec1<T> ShiftLeft(const Vec1<T> v) {
+  static_assert(0 <= kBits && kBits < sizeof(T) * 8, "Invalid shift");
+  return Vec1<T>(
+      static_cast<T>(static_cast<hwy::MakeUnsigned<T>>(v.raw) << kBits));
+}
+
+template <int kBits, typename T>
+HWY_API Vec1<T> ShiftRight(const Vec1<T> v) {
+  static_assert(0 <= kBits && kBits < sizeof(T) * 8, "Invalid shift");
+#if __cplusplus >= 202002L
+  // Signed right shift is now guaranteed to be arithmetic (rounding toward
+  // negative infinity, i.e. shifting in the sign bit).
+  return Vec1<T>(static_cast<T>(v.raw >> kBits));
+#else
+  if (IsSigned<T>()) {
+    // Emulate arithmetic shift using only logical (unsigned) shifts, because
+    // signed shifts are still implementation-defined.
+    using TU = hwy::MakeUnsigned<T>;
+    const Sisd<TU> du;
+    const TU shifted = static_cast<TU>(BitCast(du, v).raw >> kBits);
+    const TU sign = BitCast(du, BroadcastSignBit(v)).raw;
+    const size_t sign_shift =
+        static_cast<size_t>(static_cast<int>(sizeof(TU)) * 8 - 1 - kBits);
+    const TU upper = static_cast<TU>(sign << sign_shift);
+    return BitCast(Sisd<T>(), Vec1<TU>(shifted | upper));
+  } else {  // T is unsigned
+    return Vec1<T>(static_cast<T>(v.raw >> kBits));
+  }
+#endif
+}
+
+// ------------------------------ RotateRight (ShiftRight)
+
+namespace detail {
+
+// For partial specialization: kBits == 0 results in an invalid shift count
+template <int kBits>
+struct RotateRight {
+  template <typename T>
+  HWY_INLINE Vec1<T> operator()(const Vec1<T> v) const {
+    return Or(ShiftRight<kBits>(v), ShiftLeft<sizeof(T) * 8 - kBits>(v));
+  }
+};
+
+template <>
+struct RotateRight<0> {
+  template <typename T>
+  HWY_INLINE Vec1<T> operator()(const Vec1<T> v) const {
+    return v;
+  }
+};
+
+}  // namespace detail
+
+template <int kBits, typename T>
+HWY_API Vec1<T> RotateRight(const Vec1<T> v) {
+  static_assert(0 <= kBits && kBits < sizeof(T) * 8, "Invalid shift");
+  return detail::RotateRight<kBits>()(v);
+}
+
+// ------------------------------ ShiftLeftSame (BroadcastSignBit)
+
+template <typename T>
+HWY_API Vec1<T> ShiftLeftSame(const Vec1<T> v, int bits) {
+  return Vec1<T>(
+      static_cast<T>(static_cast<hwy::MakeUnsigned<T>>(v.raw) << bits));
+}
+
+template <typename T>
+HWY_API Vec1<T> ShiftRightSame(const Vec1<T> v, int bits) {
+#if __cplusplus >= 202002L
+  // Signed right shift is now guaranteed to be arithmetic (rounding toward
+  // negative infinity, i.e. shifting in the sign bit).
+  return Vec1<T>(static_cast<T>(v.raw >> bits));
+#else
+  if (IsSigned<T>()) {
+    // Emulate arithmetic shift using only logical (unsigned) shifts, because
+    // signed shifts are still implementation-defined.
+    using TU = hwy::MakeUnsigned<T>;
+    const Sisd<TU> du;
+    const TU shifted = static_cast<TU>(BitCast(du, v).raw >> bits);
+    const TU sign = BitCast(du, BroadcastSignBit(v)).raw;
+    const size_t sign_shift =
+        static_cast<size_t>(static_cast<int>(sizeof(TU)) * 8 - 1 - bits);
+    const TU upper = static_cast<TU>(sign << sign_shift);
+    return BitCast(Sisd<T>(), Vec1<TU>(shifted | upper));
+  } else {  // T is unsigned
+    return Vec1<T>(static_cast<T>(v.raw >> bits));
+  }
+#endif
+}
+
+// ------------------------------ Shl
+
+// Single-lane => same as ShiftLeftSame except for the argument type.
+template <typename T>
+HWY_API Vec1<T> operator<<(const Vec1<T> v, const Vec1<T> bits) {
+  return ShiftLeftSame(v, static_cast<int>(bits.raw));
+}
+
+template <typename T>
+HWY_API Vec1<T> operator>>(const Vec1<T> v, const Vec1<T> bits) {
+  return ShiftRightSame(v, static_cast<int>(bits.raw));
+}
+
+// ================================================== ARITHMETIC
+
+template <typename T>
+HWY_API Vec1<T> operator+(Vec1<T> a, Vec1<T> b) {
+  const uint64_t a64 = static_cast<uint64_t>(a.raw);
+  const uint64_t b64 = static_cast<uint64_t>(b.raw);
+  return Vec1<T>(static_cast<T>((a64 + b64) & static_cast<uint64_t>(~T(0))));
+}
+HWY_API Vec1<float> operator+(const Vec1<float> a, const Vec1<float> b) {
+  return Vec1<float>(a.raw + b.raw);
+}
+HWY_API Vec1<double> operator+(const Vec1<double> a, const Vec1<double> b) {
+  return Vec1<double>(a.raw + b.raw);
+}
+
+template <typename T>
+HWY_API Vec1<T> operator-(Vec1<T> a, Vec1<T> b) {
+  const uint64_t a64 = static_cast<uint64_t>(a.raw);
+  const uint64_t b64 = static_cast<uint64_t>(b.raw);
+  return Vec1<T>(static_cast<T>((a64 - b64) & static_cast<uint64_t>(~T(0))));
+}
+HWY_API Vec1<float> operator-(const Vec1<float> a, const Vec1<float> b) {
+  return Vec1<float>(a.raw - b.raw);
+}
+HWY_API Vec1<double> operator-(const Vec1<double> a, const Vec1<double> b) {
+  return Vec1<double>(a.raw - b.raw);
+}
+
+// ------------------------------ SumsOf8
+
+HWY_API Vec1<uint64_t> SumsOf8(const Vec1<uint8_t> v) {
+  return Vec1<uint64_t>(v.raw);
+}
+
+// ------------------------------ SaturatedAdd
+
+// Returns a + b clamped to the destination range.
+
+// Unsigned
+HWY_API Vec1<uint8_t> SaturatedAdd(const Vec1<uint8_t> a,
+                                   const Vec1<uint8_t> b) {
+  return Vec1<uint8_t>(
+      static_cast<uint8_t>(HWY_MIN(HWY_MAX(0, a.raw + b.raw), 255)));
+}
+HWY_API Vec1<uint16_t> SaturatedAdd(const Vec1<uint16_t> a,
+                                    const Vec1<uint16_t> b) {
+  return Vec1<uint16_t>(
+      static_cast<uint16_t>(HWY_MIN(HWY_MAX(0, a.raw + b.raw), 65535)));
+}
+
+// Signed
+HWY_API Vec1<int8_t> SaturatedAdd(const Vec1<int8_t> a, const Vec1<int8_t> b) {
+  return Vec1<int8_t>(
+      static_cast<int8_t>(HWY_MIN(HWY_MAX(-128, a.raw + b.raw), 127)));
+}
+HWY_API Vec1<int16_t> SaturatedAdd(const Vec1<int16_t> a,
+                                   const Vec1<int16_t> b) {
+  return Vec1<int16_t>(
+      static_cast<int16_t>(HWY_MIN(HWY_MAX(-32768, a.raw + b.raw), 32767)));
+}
+
+// ------------------------------ Saturating subtraction
+
+// Returns a - b clamped to the destination range.
+
+// Unsigned
+HWY_API Vec1<uint8_t> SaturatedSub(const Vec1<uint8_t> a,
+                                   const Vec1<uint8_t> b) {
+  return Vec1<uint8_t>(
+      static_cast<uint8_t>(HWY_MIN(HWY_MAX(0, a.raw - b.raw), 255)));
+}
+HWY_API Vec1<uint16_t> SaturatedSub(const Vec1<uint16_t> a,
+                                    const Vec1<uint16_t> b) {
+  return Vec1<uint16_t>(
+      static_cast<uint16_t>(HWY_MIN(HWY_MAX(0, a.raw - b.raw), 65535)));
+}
+
+// Signed
+HWY_API Vec1<int8_t> SaturatedSub(const Vec1<int8_t> a, const Vec1<int8_t> b) {
+  return Vec1<int8_t>(
+      static_cast<int8_t>(HWY_MIN(HWY_MAX(-128, a.raw - b.raw), 127)));
+}
+HWY_API Vec1<int16_t> SaturatedSub(const Vec1<int16_t> a,
+                                   const Vec1<int16_t> b) {
+  return Vec1<int16_t>(
+      static_cast<int16_t>(HWY_MIN(HWY_MAX(-32768, a.raw - b.raw), 32767)));
+}
+
+// ------------------------------ Average
+
+// Returns (a + b + 1) / 2
+
+HWY_API Vec1<uint8_t> AverageRound(const Vec1<uint8_t> a,
+                                   const Vec1<uint8_t> b) {
+  return Vec1<uint8_t>(static_cast<uint8_t>((a.raw + b.raw + 1) / 2));
+}
+HWY_API Vec1<uint16_t> AverageRound(const Vec1<uint16_t> a,
+                                    const Vec1<uint16_t> b) {
+  return Vec1<uint16_t>(static_cast<uint16_t>((a.raw + b.raw + 1) / 2));
+}
+
+// ------------------------------ Absolute value
+
+template <typename T>
+HWY_API Vec1<T> Abs(const Vec1<T> a) {
+  const T i = a.raw;
+  if (i >= 0 || i == hwy::LimitsMin<T>()) return a;
+  return Vec1<T>(static_cast<T>(-i & T{-1}));
+}
+HWY_API Vec1<float> Abs(Vec1<float> a) {
+  int32_t i;
+  CopyBytes<sizeof(i)>(&a.raw, &i);
+  i &= 0x7FFFFFFF;
+  CopyBytes<sizeof(i)>(&i, &a.raw);
+  return a;
+}
+HWY_API Vec1<double> Abs(Vec1<double> a) {
+  int64_t i;
+  CopyBytes<sizeof(i)>(&a.raw, &i);
+  i &= 0x7FFFFFFFFFFFFFFFL;
+  CopyBytes<sizeof(i)>(&i, &a.raw);
+  return a;
+}
+
+// ------------------------------ Min/Max
+
+// <cmath> may be unavailable, so implement our own.
+namespace detail {
+
+static inline float Abs(float f) {
+  uint32_t i;
+  CopyBytes<4>(&f, &i);
+  i &= 0x7FFFFFFFu;
+  CopyBytes<4>(&i, &f);
+  return f;
+}
+static inline double Abs(double f) {
+  uint64_t i;
+  CopyBytes<8>(&f, &i);
+  i &= 0x7FFFFFFFFFFFFFFFull;
+  CopyBytes<8>(&i, &f);
+  return f;
+}
+
+static inline bool SignBit(float f) {
+  uint32_t i;
+  CopyBytes<4>(&f, &i);
+  return (i >> 31) != 0;
+}
+static inline bool SignBit(double f) {
+  uint64_t i;
+  CopyBytes<8>(&f, &i);
+  return (i >> 63) != 0;
+}
+
+}  // namespace detail
+
+template <typename T, HWY_IF_NOT_FLOAT(T)>
+HWY_API Vec1<T> Min(const Vec1<T> a, const Vec1<T> b) {
+  return Vec1<T>(HWY_MIN(a.raw, b.raw));
+}
+
+template <typename T, HWY_IF_FLOAT(T)>
+HWY_API Vec1<T> Min(const Vec1<T> a, const Vec1<T> b) {
+  if (isnan(a.raw)) return b;
+  if (isnan(b.raw)) return a;
+  return Vec1<T>(HWY_MIN(a.raw, b.raw));
+}
+
+template <typename T, HWY_IF_NOT_FLOAT(T)>
+HWY_API Vec1<T> Max(const Vec1<T> a, const Vec1<T> b) {
+  return Vec1<T>(HWY_MAX(a.raw, b.raw));
+}
+
+template <typename T, HWY_IF_FLOAT(T)>
+HWY_API Vec1<T> Max(const Vec1<T> a, const Vec1<T> b) {
+  if (isnan(a.raw)) return b;
+  if (isnan(b.raw)) return a;
+  return Vec1<T>(HWY_MAX(a.raw, b.raw));
+}
+
+// ------------------------------ Floating-point negate
+
+template <typename T, HWY_IF_FLOAT(T)>
+HWY_API Vec1<T> Neg(const Vec1<T> v) {
+  return Xor(v, SignBit(Sisd<T>()));
+}
+
+template <typename T, HWY_IF_NOT_FLOAT(T)>
+HWY_API Vec1<T> Neg(const Vec1<T> v) {
+  return Zero(Sisd<T>()) - v;
+}
+
+// ------------------------------ mul/div
+
+template <typename T, HWY_IF_FLOAT(T)>
+HWY_API Vec1<T> operator*(const Vec1<T> a, const Vec1<T> b) {
+  return Vec1<T>(static_cast<T>(double{a.raw} * b.raw));
+}
+
+template <typename T, HWY_IF_SIGNED(T)>
+HWY_API Vec1<T> operator*(const Vec1<T> a, const Vec1<T> b) {
+  return Vec1<T>(static_cast<T>(static_cast<uint64_t>(a.raw) *
+                                static_cast<uint64_t>(b.raw)));
+}
+
+template <typename T, HWY_IF_UNSIGNED(T)>
+HWY_API Vec1<T> operator*(const Vec1<T> a, const Vec1<T> b) {
+  return Vec1<T>(static_cast<T>(static_cast<uint64_t>(a.raw) *
+                                static_cast<uint64_t>(b.raw)));
+}
+
+template <typename T>
+HWY_API Vec1<T> operator/(const Vec1<T> a, const Vec1<T> b) {
+  return Vec1<T>(a.raw / b.raw);
+}
+
+// Returns the upper 16 bits of a * b in each lane.
+HWY_API Vec1<int16_t> MulHigh(const Vec1<int16_t> a, const Vec1<int16_t> b) {
+  return Vec1<int16_t>(static_cast<int16_t>((a.raw * b.raw) >> 16));
+}
+HWY_API Vec1<uint16_t> MulHigh(const Vec1<uint16_t> a, const Vec1<uint16_t> b) {
+  // Cast to uint32_t first to prevent overflow. Otherwise the result of
+  // uint16_t * uint16_t is in "int" which may overflow. In practice the result
+  // is the same but this way it is also defined.
+  return Vec1<uint16_t>(static_cast<uint16_t>(
+      (static_cast<uint32_t>(a.raw) * static_cast<uint32_t>(b.raw)) >> 16));
+}
+
+HWY_API Vec1<int16_t> MulFixedPoint15(Vec1<int16_t> a, Vec1<int16_t> b) {
+  return Vec1<int16_t>(static_cast<int16_t>((2 * a.raw * b.raw + 32768) >> 16));
+}
+
+// Multiplies even lanes (0, 2 ..) and returns the double-wide result.
+HWY_API Vec1<int64_t> MulEven(const Vec1<int32_t> a, const Vec1<int32_t> b) {
+  const int64_t a64 = a.raw;
+  return Vec1<int64_t>(a64 * b.raw);
+}
+HWY_API Vec1<uint64_t> MulEven(const Vec1<uint32_t> a, const Vec1<uint32_t> b) {
+  const uint64_t a64 = a.raw;
+  return Vec1<uint64_t>(a64 * b.raw);
+}
+
+// Approximate reciprocal
+HWY_API Vec1<float> ApproximateReciprocal(const Vec1<float> v) {
+  // Zero inputs are allowed, but callers are responsible for replacing the
+  // return value with something else (typically using IfThenElse). This check
+  // avoids a ubsan error. The return value is arbitrary.
+  if (v.raw == 0.0f) return Vec1<float>(0.0f);
+  return Vec1<float>(1.0f / v.raw);
+}
+
+// Absolute value of difference.
+HWY_API Vec1<float> AbsDiff(const Vec1<float> a, const Vec1<float> b) {
+  return Abs(a - b);
+}
+
+// ------------------------------ Floating-point multiply-add variants
+
+template <typename T>
+HWY_API Vec1<T> MulAdd(const Vec1<T> mul, const Vec1<T> x, const Vec1<T> add) {
+  return mul * x + add;
+}
+
+template <typename T>
+HWY_API Vec1<T> NegMulAdd(const Vec1<T> mul, const Vec1<T> x,
+                          const Vec1<T> add) {
+  return add - mul * x;
+}
+
+template <typename T>
+HWY_API Vec1<T> MulSub(const Vec1<T> mul, const Vec1<T> x, const Vec1<T> sub) {
+  return mul * x - sub;
+}
+
+template <typename T>
+HWY_API Vec1<T> NegMulSub(const Vec1<T> mul, const Vec1<T> x,
+                          const Vec1<T> sub) {
+  return Neg(mul) * x - sub;
+}
+
+// ------------------------------ Floating-point square root
+
+// Approximate reciprocal square root
+HWY_API Vec1<float> ApproximateReciprocalSqrt(const Vec1<float> v) {
+  float f = v.raw;
+  const float half = f * 0.5f;
+  uint32_t bits;
+  CopySameSize(&f, &bits);
+  // Initial guess based on log2(f)
+  bits = 0x5F3759DF - (bits >> 1);
+  CopySameSize(&bits, &f);
+  // One Newton-Raphson iteration
+  return Vec1<float>(f * (1.5f - (half * f * f)));
+}
+
+// Square root
+HWY_API Vec1<float> Sqrt(const Vec1<float> v) {
+#if HWY_COMPILER_GCC && defined(HWY_NO_LIBCXX)
+  return Vec1<float>(__builtin_sqrt(v.raw));
+#else
+  return Vec1<float>(sqrtf(v.raw));
+#endif
+}
+HWY_API Vec1<double> Sqrt(const Vec1<double> v) {
+#if HWY_COMPILER_GCC && defined(HWY_NO_LIBCXX)
+  return Vec1<float>(__builtin_sqrt(v.raw));
+#else
+  return Vec1<double>(sqrt(v.raw));
+#endif
+}
+
+// ------------------------------ Floating-point rounding
+
+template <typename T>
+HWY_API Vec1<T> Round(const Vec1<T> v) {
+  using TI = MakeSigned<T>;
+  if (!(Abs(v).raw < MantissaEnd<T>())) {  // Huge or NaN
+    return v;
+  }
+  const T bias = v.raw < T(0.0) ? T(-0.5) : T(0.5);
+  const TI rounded = static_cast<TI>(v.raw + bias);
+  if (rounded == 0) return CopySignToAbs(Vec1<T>(0), v);
+  // Round to even
+  if ((rounded & 1) && detail::Abs(static_cast<T>(rounded) - v.raw) == T(0.5)) {
+    return Vec1<T>(static_cast<T>(rounded - (v.raw < T(0) ? -1 : 1)));
+  }
+  return Vec1<T>(static_cast<T>(rounded));
+}
+
+// Round-to-nearest even.
+HWY_API Vec1<int32_t> NearestInt(const Vec1<float> v) {
+  using T = float;
+  using TI = int32_t;
+
+  const T abs = Abs(v).raw;
+  const bool is_sign = detail::SignBit(v.raw);
+
+  if (!(abs < MantissaEnd<T>())) {  // Huge or NaN
+    // Check if too large to cast or NaN
+    if (!(abs <= static_cast<T>(LimitsMax<TI>()))) {
+      return Vec1<TI>(is_sign ? LimitsMin<TI>() : LimitsMax<TI>());
+    }
+    return Vec1<int32_t>(static_cast<TI>(v.raw));
+  }
+  const T bias = v.raw < T(0.0) ? T(-0.5) : T(0.5);
+  const TI rounded = static_cast<TI>(v.raw + bias);
+  if (rounded == 0) return Vec1<int32_t>(0);
+  // Round to even
+  if ((rounded & 1) && detail::Abs(static_cast<T>(rounded) - v.raw) == T(0.5)) {
+    return Vec1<TI>(rounded - (is_sign ? -1 : 1));
+  }
+  return Vec1<TI>(rounded);
+}
+
+template <typename T>
+HWY_API Vec1<T> Trunc(const Vec1<T> v) {
+  using TI = MakeSigned<T>;
+  if (!(Abs(v).raw <= MantissaEnd<T>())) {  // Huge or NaN
+    return v;
+  }
+  const TI truncated = static_cast<TI>(v.raw);
+  if (truncated == 0) return CopySignToAbs(Vec1<T>(0), v);
+  return Vec1<T>(static_cast<T>(truncated));
+}
+
+template <typename Float, typename Bits, int kMantissaBits, int kExponentBits,
+          class V>
+V Ceiling(const V v) {
+  const Bits kExponentMask = (1ull << kExponentBits) - 1;
+  const Bits kMantissaMask = (1ull << kMantissaBits) - 1;
+  const Bits kBias = kExponentMask / 2;
+
+  Float f = v.raw;
+  const bool positive = f > Float(0.0);
+
+  Bits bits;
+  CopySameSize(&v, &bits);
+
+  const int exponent =
+      static_cast<int>(((bits >> kMantissaBits) & kExponentMask) - kBias);
+  // Already an integer.
+  if (exponent >= kMantissaBits) return v;
+  // |v| <= 1 => 0 or 1.
+  if (exponent < 0) return positive ? V(1) : V(-0.0);
+
+  const Bits mantissa_mask = kMantissaMask >> exponent;
+  // Already an integer
+  if ((bits & mantissa_mask) == 0) return v;
+
+  // Clear fractional bits and round up
+  if (positive) bits += (kMantissaMask + 1) >> exponent;
+  bits &= ~mantissa_mask;
+
+  CopySameSize(&bits, &f);
+  return V(f);
+}
+
+template <typename Float, typename Bits, int kMantissaBits, int kExponentBits,
+          class V>
+V Floor(const V v) {
+  const Bits kExponentMask = (1ull << kExponentBits) - 1;
+  const Bits kMantissaMask = (1ull << kMantissaBits) - 1;
+  const Bits kBias = kExponentMask / 2;
+
+  Float f = v.raw;
+  const bool negative = f < Float(0.0);
+
+  Bits bits;
+  CopySameSize(&v, &bits);
+
+  const int exponent =
+      static_cast<int>(((bits >> kMantissaBits) & kExponentMask) - kBias);
+  // Already an integer.
+  if (exponent >= kMantissaBits) return v;
+  // |v| <= 1 => -1 or 0.
+  if (exponent < 0) return V(negative ? Float(-1.0) : Float(0.0));
+
+  const Bits mantissa_mask = kMantissaMask >> exponent;
+  // Already an integer
+  if ((bits & mantissa_mask) == 0) return v;
+
+  // Clear fractional bits and round down
+  if (negative) bits += (kMantissaMask + 1) >> exponent;
+  bits &= ~mantissa_mask;
+
+  CopySameSize(&bits, &f);
+  return V(f);
+}
+
+// Toward +infinity, aka ceiling
+HWY_API Vec1<float> Ceil(const Vec1<float> v) {
+  return Ceiling<float, uint32_t, 23, 8>(v);
+}
+HWY_API Vec1<double> Ceil(const Vec1<double> v) {
+  return Ceiling<double, uint64_t, 52, 11>(v);
+}
+
+// Toward -infinity, aka floor
+HWY_API Vec1<float> Floor(const Vec1<float> v) {
+  return Floor<float, uint32_t, 23, 8>(v);
+}
+HWY_API Vec1<double> Floor(const Vec1<double> v) {
+  return Floor<double, uint64_t, 52, 11>(v);
+}
+
+// ================================================== COMPARE
+
+template <typename T>
+HWY_API Mask1<T> operator==(const Vec1<T> a, const Vec1<T> b) {
+  return Mask1<T>::FromBool(a.raw == b.raw);
+}
+
+template <typename T>
+HWY_API Mask1<T> operator!=(const Vec1<T> a, const Vec1<T> b) {
+  return Mask1<T>::FromBool(a.raw != b.raw);
+}
+
+template <typename T>
+HWY_API Mask1<T> TestBit(const Vec1<T> v, const Vec1<T> bit) {
+  static_assert(!hwy::IsFloat<T>(), "Only integer vectors supported");
+  return (v & bit) == bit;
+}
+
+template <typename T>
+HWY_API Mask1<T> operator<(const Vec1<T> a, const Vec1<T> b) {
+  return Mask1<T>::FromBool(a.raw < b.raw);
+}
+template <typename T>
+HWY_API Mask1<T> operator>(const Vec1<T> a, const Vec1<T> b) {
+  return Mask1<T>::FromBool(a.raw > b.raw);
+}
+
+template <typename T>
+HWY_API Mask1<T> operator<=(const Vec1<T> a, const Vec1<T> b) {
+  return Mask1<T>::FromBool(a.raw <= b.raw);
+}
+template <typename T>
+HWY_API Mask1<T> operator>=(const Vec1<T> a, const Vec1<T> b) {
+  return Mask1<T>::FromBool(a.raw >= b.raw);
+}
+
+// ------------------------------ Floating-point classification (==)
+
+template <typename T>
+HWY_API Mask1<T> IsNaN(const Vec1<T> v) {
+  // std::isnan returns false for 0x7F..FF in clang AVX3 builds, so DIY.
+  MakeUnsigned<T> bits;
+  CopySameSize(&v, &bits);
+  bits += bits;
+  bits >>= 1;  // clear sign bit
+  // NaN if all exponent bits are set and the mantissa is not zero.
+  return Mask1<T>::FromBool(bits > ExponentMask<T>());
+}
+
+HWY_API Mask1<float> IsInf(const Vec1<float> v) {
+  const Sisd<float> d;
+  const RebindToUnsigned<decltype(d)> du;
+  const Vec1<uint32_t> vu = BitCast(du, v);
+  // 'Shift left' to clear the sign bit, check for exponent=max and mantissa=0.
+  return RebindMask(d, (vu + vu) == Set(du, 0xFF000000u));
+}
+HWY_API Mask1<double> IsInf(const Vec1<double> v) {
+  const Sisd<double> d;
+  const RebindToUnsigned<decltype(d)> du;
+  const Vec1<uint64_t> vu = BitCast(du, v);
+  // 'Shift left' to clear the sign bit, check for exponent=max and mantissa=0.
+  return RebindMask(d, (vu + vu) == Set(du, 0xFFE0000000000000ull));
+}
+
+HWY_API Mask1<float> IsFinite(const Vec1<float> v) {
+  const Vec1<uint32_t> vu = BitCast(Sisd<uint32_t>(), v);
+  // Shift left to clear the sign bit, check whether exponent != max value.
+  return Mask1<float>::FromBool((vu.raw << 1) < 0xFF000000u);
+}
+HWY_API Mask1<double> IsFinite(const Vec1<double> v) {
+  const Vec1<uint64_t> vu = BitCast(Sisd<uint64_t>(), v);
+  // Shift left to clear the sign bit, check whether exponent != max value.
+  return Mask1<double>::FromBool((vu.raw << 1) < 0xFFE0000000000000ull);
+}
+
+// ================================================== MEMORY
+
+// ------------------------------ Load
+
+template <typename T>
+HWY_API Vec1<T> Load(Sisd<T> /* tag */, const T* HWY_RESTRICT aligned) {
+  T t;
+  CopySameSize(aligned, &t);
+  return Vec1<T>(t);
+}
+
+template <typename T>
+HWY_API Vec1<T> MaskedLoad(Mask1<T> m, Sisd<T> d,
+                           const T* HWY_RESTRICT aligned) {
+  return IfThenElseZero(m, Load(d, aligned));
+}
+
+template <typename T>
+HWY_API Vec1<T> LoadU(Sisd<T> d, const T* HWY_RESTRICT p) {
+  return Load(d, p);
+}
+
+// In some use cases, "load single lane" is sufficient; otherwise avoid this.
+template <typename T>
+HWY_API Vec1<T> LoadDup128(Sisd<T> d, const T* HWY_RESTRICT aligned) {
+  return Load(d, aligned);
+}
+
+// ------------------------------ Store
+
+template <typename T>
+HWY_API void Store(const Vec1<T> v, Sisd<T> /* tag */,
+                   T* HWY_RESTRICT aligned) {
+  CopySameSize(&v.raw, aligned);
+}
+
+template <typename T>
+HWY_API void StoreU(const Vec1<T> v, Sisd<T> d, T* HWY_RESTRICT p) {
+  return Store(v, d, p);
+}
+
+template <typename T>
+HWY_API void BlendedStore(const Vec1<T> v, Mask1<T> m, Sisd<T> d,
+                          T* HWY_RESTRICT p) {
+  if (!m.bits) return;
+  StoreU(v, d, p);
+}
+
+// ------------------------------ LoadInterleaved2/3/4
+
+// Per-target flag to prevent generic_ops-inl.h from defining StoreInterleaved2.
+#ifdef HWY_NATIVE_LOAD_STORE_INTERLEAVED
+#undef HWY_NATIVE_LOAD_STORE_INTERLEAVED
+#else
+#define HWY_NATIVE_LOAD_STORE_INTERLEAVED
+#endif
+
+template <typename T>
+HWY_API void LoadInterleaved2(Sisd<T> d, const T* HWY_RESTRICT unaligned,
+                              Vec1<T>& v0, Vec1<T>& v1) {
+  v0 = LoadU(d, unaligned + 0);
+  v1 = LoadU(d, unaligned + 1);
+}
+
+template <typename T>
+HWY_API void LoadInterleaved3(Sisd<T> d, const T* HWY_RESTRICT unaligned,
+                              Vec1<T>& v0, Vec1<T>& v1, Vec1<T>& v2) {
+  v0 = LoadU(d, unaligned + 0);
+  v1 = LoadU(d, unaligned + 1);
+  v2 = LoadU(d, unaligned + 2);
+}
+
+template <typename T>
+HWY_API void LoadInterleaved4(Sisd<T> d, const T* HWY_RESTRICT unaligned,
+                              Vec1<T>& v0, Vec1<T>& v1, Vec1<T>& v2,
+                              Vec1<T>& v3) {
+  v0 = LoadU(d, unaligned + 0);
+  v1 = LoadU(d, unaligned + 1);
+  v2 = LoadU(d, unaligned + 2);
+  v3 = LoadU(d, unaligned + 3);
+}
+
+// ------------------------------ StoreInterleaved2/3/4
+
+template <typename T>
+HWY_API void StoreInterleaved2(const Vec1<T> v0, const Vec1<T> v1, Sisd<T> d,
+                               T* HWY_RESTRICT unaligned) {
+  StoreU(v0, d, unaligned + 0);
+  StoreU(v1, d, unaligned + 1);
+}
+
+template <typename T>
+HWY_API void StoreInterleaved3(const Vec1<T> v0, const Vec1<T> v1,
+                               const Vec1<T> v2, Sisd<T> d,
+                               T* HWY_RESTRICT unaligned) {
+  StoreU(v0, d, unaligned + 0);
+  StoreU(v1, d, unaligned + 1);
+  StoreU(v2, d, unaligned + 2);
+}
+
+template <typename T>
+HWY_API void StoreInterleaved4(const Vec1<T> v0, const Vec1<T> v1,
+                               const Vec1<T> v2, const Vec1<T> v3, Sisd<T> d,
+                               T* HWY_RESTRICT unaligned) {
+  StoreU(v0, d, unaligned + 0);
+  StoreU(v1, d, unaligned + 1);
+  StoreU(v2, d, unaligned + 2);
+  StoreU(v3, d, unaligned + 3);
+}
+
+// ------------------------------ Stream
+
+template <typename T>
+HWY_API void Stream(const Vec1<T> v, Sisd<T> d, T* HWY_RESTRICT aligned) {
+  return Store(v, d, aligned);
+}
+
+// ------------------------------ Scatter
+
+template <typename T, typename Offset>
+HWY_API void ScatterOffset(Vec1<T> v, Sisd<T> d, T* base,
+                           const Vec1<Offset> offset) {
+  static_assert(sizeof(T) == sizeof(Offset), "Must match for portability");
+  uint8_t* const base8 = reinterpret_cast<uint8_t*>(base) + offset.raw;
+  return Store(v, d, reinterpret_cast<T*>(base8));
+}
+
+template <typename T, typename Index>
+HWY_API void ScatterIndex(Vec1<T> v, Sisd<T> d, T* HWY_RESTRICT base,
+                          const Vec1<Index> index) {
+  static_assert(sizeof(T) == sizeof(Index), "Must match for portability");
+  return Store(v, d, base + index.raw);
+}
+
+// ------------------------------ Gather
+
+template <typename T, typename Offset>
+HWY_API Vec1<T> GatherOffset(Sisd<T> d, const T* base,
+                             const Vec1<Offset> offset) {
+  static_assert(sizeof(T) == sizeof(Offset), "Must match for portability");
+  const intptr_t addr =
+      reinterpret_cast<intptr_t>(base) + static_cast<intptr_t>(offset.raw);
+  return Load(d, reinterpret_cast<const T*>(addr));
+}
+
+template <typename T, typename Index>
+HWY_API Vec1<T> GatherIndex(Sisd<T> d, const T* HWY_RESTRICT base,
+                            const Vec1<Index> index) {
+  static_assert(sizeof(T) == sizeof(Index), "Must match for portability");
+  return Load(d, base + index.raw);
+}
+
+// ================================================== CONVERT
+
+// ConvertTo and DemoteTo with floating-point input and integer output truncate
+// (rounding toward zero).
+
+template <typename FromT, typename ToT>
+HWY_API Vec1<ToT> PromoteTo(Sisd<ToT> /* tag */, Vec1<FromT> from) {
+  static_assert(sizeof(ToT) > sizeof(FromT), "Not promoting");
+  // For bits Y > X, floatX->floatY and intX->intY are always representable.
+  return Vec1<ToT>(static_cast<ToT>(from.raw));
+}
+
+// MSVC 19.10 cannot deduce the argument type if HWY_IF_FLOAT(FromT) is here,
+// so we overload for FromT=double and ToT={float,int32_t}.
+HWY_API Vec1<float> DemoteTo(Sisd<float> /* tag */, Vec1<double> from) {
+  // Prevent ubsan errors when converting float to narrower integer/float
+  if (IsInf(from).bits ||
+      Abs(from).raw > static_cast<double>(HighestValue<float>())) {
+    return Vec1<float>(detail::SignBit(from.raw) ? LowestValue<float>()
+                                                 : HighestValue<float>());
+  }
+  return Vec1<float>(static_cast<float>(from.raw));
+}
+HWY_API Vec1<int32_t> DemoteTo(Sisd<int32_t> /* tag */, Vec1<double> from) {
+  // Prevent ubsan errors when converting int32_t to narrower integer/int32_t
+  if (IsInf(from).bits ||
+      Abs(from).raw > static_cast<double>(HighestValue<int32_t>())) {
+    return Vec1<int32_t>(detail::SignBit(from.raw) ? LowestValue<int32_t>()
+                                                   : HighestValue<int32_t>());
+  }
+  return Vec1<int32_t>(static_cast<int32_t>(from.raw));
+}
+
+template <typename FromT, typename ToT>
+HWY_API Vec1<ToT> DemoteTo(Sisd<ToT> /* tag */, Vec1<FromT> from) {
+  static_assert(!IsFloat<FromT>(), "FromT=double are handled above");
+  static_assert(sizeof(ToT) < sizeof(FromT), "Not demoting");
+
+  // Int to int: choose closest value in ToT to `from` (avoids UB)
+  from.raw = HWY_MIN(HWY_MAX(LimitsMin<ToT>(), from.raw), LimitsMax<ToT>());
+  return Vec1<ToT>(static_cast<ToT>(from.raw));
+}
+
+HWY_API Vec1<float> PromoteTo(Sisd<float> /* tag */, const Vec1<float16_t> v) {
+  uint16_t bits16;
+  CopySameSize(&v.raw, &bits16);
+  const uint32_t sign = static_cast<uint32_t>(bits16 >> 15);
+  const uint32_t biased_exp = (bits16 >> 10) & 0x1F;
+  const uint32_t mantissa = bits16 & 0x3FF;
+
+  // Subnormal or zero
+  if (biased_exp == 0) {
+    const float subnormal =
+        (1.0f / 16384) * (static_cast<float>(mantissa) * (1.0f / 1024));
+    return Vec1<float>(sign ? -subnormal : subnormal);
+  }
+
+  // Normalized: convert the representation directly (faster than ldexp/tables).
+  const uint32_t biased_exp32 = biased_exp + (127 - 15);
+  const uint32_t mantissa32 = mantissa << (23 - 10);
+  const uint32_t bits32 = (sign << 31) | (biased_exp32 << 23) | mantissa32;
+  float out;
+  CopySameSize(&bits32, &out);
+  return Vec1<float>(out);
+}
+
+HWY_API Vec1<float> PromoteTo(Sisd<float> d, const Vec1<bfloat16_t> v) {
+  return Set(d, F32FromBF16(v.raw));
+}
+
+HWY_API Vec1<float16_t> DemoteTo(Sisd<float16_t> /* tag */,
+                                 const Vec1<float> v) {
+  uint32_t bits32;
+  CopySameSize(&v.raw, &bits32);
+  const uint32_t sign = bits32 >> 31;
+  const uint32_t biased_exp32 = (bits32 >> 23) & 0xFF;
+  const uint32_t mantissa32 = bits32 & 0x7FFFFF;
+
+  const int32_t exp = HWY_MIN(static_cast<int32_t>(biased_exp32) - 127, 15);
+
+  // Tiny or zero => zero.
+  Vec1<float16_t> out;
+  if (exp < -24) {
+    const uint16_t zero = 0;
+    CopySameSize(&zero, &out.raw);
+    return out;
+  }
+
+  uint32_t biased_exp16, mantissa16;
+
+  // exp = [-24, -15] => subnormal
+  if (exp < -14) {
+    biased_exp16 = 0;
+    const uint32_t sub_exp = static_cast<uint32_t>(-14 - exp);
+    HWY_DASSERT(1 <= sub_exp && sub_exp < 11);
+    mantissa16 = static_cast<uint32_t>((1u << (10 - sub_exp)) +
+                                       (mantissa32 >> (13 + sub_exp)));
+  } else {
+    // exp = [-14, 15]
+    biased_exp16 = static_cast<uint32_t>(exp + 15);
+    HWY_DASSERT(1 <= biased_exp16 && biased_exp16 < 31);
+    mantissa16 = mantissa32 >> 13;
+  }
+
+  HWY_DASSERT(mantissa16 < 1024);
+  const uint32_t bits16 = (sign << 15) | (biased_exp16 << 10) | mantissa16;
+  HWY_DASSERT(bits16 < 0x10000);
+  const uint16_t narrowed = static_cast<uint16_t>(bits16);  // big-endian safe
+  CopySameSize(&narrowed, &out.raw);
+  return out;
+}
+
+HWY_API Vec1<bfloat16_t> DemoteTo(Sisd<bfloat16_t> d, const Vec1<float> v) {
+  return Set(d, BF16FromF32(v.raw));
+}
+
+template <typename FromT, typename ToT, HWY_IF_FLOAT(FromT)>
+HWY_API Vec1<ToT> ConvertTo(Sisd<ToT> /* tag */, Vec1<FromT> from) {
+  static_assert(sizeof(ToT) == sizeof(FromT), "Should have same size");
+  // float## -> int##: return closest representable value. We cannot exactly
+  // represent LimitsMax<ToT> in FromT, so use double.
+  const double f = static_cast<double>(from.raw);
+  if (IsInf(from).bits ||
+      Abs(Vec1<double>(f)).raw > static_cast<double>(LimitsMax<ToT>())) {
+    return Vec1<ToT>(detail::SignBit(from.raw) ? LimitsMin<ToT>()
+                                               : LimitsMax<ToT>());
+  }
+  return Vec1<ToT>(static_cast<ToT>(from.raw));
+}
+
+template <typename FromT, typename ToT, HWY_IF_NOT_FLOAT(FromT)>
+HWY_API Vec1<ToT> ConvertTo(Sisd<ToT> /* tag */, Vec1<FromT> from) {
+  static_assert(sizeof(ToT) == sizeof(FromT), "Should have same size");
+  // int## -> float##: no check needed
+  return Vec1<ToT>(static_cast<ToT>(from.raw));
+}
+
+HWY_API Vec1<uint8_t> U8FromU32(const Vec1<uint32_t> v) {
+  return DemoteTo(Sisd<uint8_t>(), v);
+}
+
+// ------------------------------ Truncations
+
+HWY_API Vec1<uint8_t> TruncateTo(Sisd<uint8_t> /* tag */,
+                                 const Vec1<uint64_t> v) {
+  return Vec1<uint8_t>{static_cast<uint8_t>(v.raw & 0xFF)};
+}
+
+HWY_API Vec1<uint16_t> TruncateTo(Sisd<uint16_t> /* tag */,
+                                  const Vec1<uint64_t> v) {
+  return Vec1<uint16_t>{static_cast<uint16_t>(v.raw & 0xFFFF)};
+}
+
+HWY_API Vec1<uint32_t> TruncateTo(Sisd<uint32_t> /* tag */,
+                                  const Vec1<uint64_t> v) {
+  return Vec1<uint32_t>{static_cast<uint32_t>(v.raw & 0xFFFFFFFFu)};
+}
+
+HWY_API Vec1<uint8_t> TruncateTo(Sisd<uint8_t> /* tag */,
+                                 const Vec1<uint32_t> v) {
+  return Vec1<uint8_t>{static_cast<uint8_t>(v.raw & 0xFF)};
+}
+
+HWY_API Vec1<uint16_t> TruncateTo(Sisd<uint16_t> /* tag */,
+                                  const Vec1<uint32_t> v) {
+  return Vec1<uint16_t>{static_cast<uint16_t>(v.raw & 0xFFFF)};
+}
+
+HWY_API Vec1<uint8_t> TruncateTo(Sisd<uint8_t> /* tag */,
+                                 const Vec1<uint16_t> v) {
+  return Vec1<uint8_t>{static_cast<uint8_t>(v.raw & 0xFF)};
+}
+
+// ================================================== COMBINE
+// UpperHalf, ZeroExtendVector, Combine, Concat* are unsupported.
+
+template <typename T>
+HWY_API Vec1<T> LowerHalf(Vec1<T> v) {
+  return v;
+}
+
+template <typename T>
+HWY_API Vec1<T> LowerHalf(Sisd<T> /* tag */, Vec1<T> v) {
+  return v;
+}
+
+// ================================================== SWIZZLE
+
+template <typename T>
+HWY_API T GetLane(const Vec1<T> v) {
+  return v.raw;
+}
+
+template <typename T>
+HWY_API T ExtractLane(const Vec1<T> v, size_t i) {
+  HWY_DASSERT(i == 0);
+  (void)i;
+  return v.raw;
+}
+
+template <typename T>
+HWY_API Vec1<T> InsertLane(Vec1<T> v, size_t i, T t) {
+  HWY_DASSERT(i == 0);
+  (void)i;
+  v.raw = t;
+  return v;
+}
+
+template <typename T>
+HWY_API Vec1<T> DupEven(Vec1<T> v) {
+  return v;
+}
+// DupOdd is unsupported.
+
+template <typename T>
+HWY_API Vec1<T> OddEven(Vec1<T> /* odd */, Vec1<T> even) {
+  return even;
+}
+
+template <typename T>
+HWY_API Vec1<T> OddEvenBlocks(Vec1<T> /* odd */, Vec1<T> even) {
+  return even;
+}
+
+// ------------------------------ SwapAdjacentBlocks
+
+template <typename T>
+HWY_API Vec1<T> SwapAdjacentBlocks(Vec1<T> v) {
+  return v;
+}
+
+// ------------------------------ TableLookupLanes
+
+// Returned by SetTableIndices for use by TableLookupLanes.
+template <typename T>
+struct Indices1 {
+  MakeSigned<T> raw;
+};
+
+template <typename T, typename TI>
+HWY_API Indices1<T> IndicesFromVec(Sisd<T>, Vec1<TI> vec) {
+  static_assert(sizeof(T) == sizeof(TI), "Index size must match lane size");
+  HWY_DASSERT(vec.raw == 0);
+  return Indices1<T>{vec.raw};
+}
+
+template <typename T, typename TI>
+HWY_API Indices1<T> SetTableIndices(Sisd<T> d, const TI* idx) {
+  return IndicesFromVec(d, LoadU(Sisd<TI>(), idx));
+}
+
+template <typename T>
+HWY_API Vec1<T> TableLookupLanes(const Vec1<T> v, const Indices1<T> /* idx */) {
+  return v;
+}
+
+// ------------------------------ ReverseBlocks
+
+// Single block: no change
+template <typename T>
+HWY_API Vec1<T> ReverseBlocks(Sisd<T> /* tag */, const Vec1<T> v) {
+  return v;
+}
+
+// ------------------------------ Reverse
+
+template <typename T>
+HWY_API Vec1<T> Reverse(Sisd<T> /* tag */, const Vec1<T> v) {
+  return v;
+}
+
+// Must not be called:
+template <typename T>
+HWY_API Vec1<T> Reverse2(Sisd<T> /* tag */, const Vec1<T> v) {
+  return v;
+}
+
+template <typename T>
+HWY_API Vec1<T> Reverse4(Sisd<T> /* tag */, const Vec1<T> v) {
+  return v;
+}
+
+template <typename T>
+HWY_API Vec1<T> Reverse8(Sisd<T> /* tag */, const Vec1<T> v) {
+  return v;
+}
+
+// ================================================== BLOCKWISE
+// Shift*Bytes, CombineShiftRightBytes, Interleave*, Shuffle* are unsupported.
+
+// ------------------------------ Broadcast/splat any lane
+
+template <int kLane, typename T>
+HWY_API Vec1<T> Broadcast(const Vec1<T> v) {
+  static_assert(kLane == 0, "Scalar only has one lane");
+  return v;
+}
+
+// ------------------------------ TableLookupBytes, TableLookupBytesOr0
+
+template <typename T, typename TI>
+HWY_API Vec1<TI> TableLookupBytes(const Vec1<T> in, const Vec1<TI> indices) {
+  uint8_t in_bytes[sizeof(T)];
+  uint8_t idx_bytes[sizeof(T)];
+  uint8_t out_bytes[sizeof(T)];
+  CopyBytes<sizeof(T)>(&in, &in_bytes);  // copy to bytes
+  CopyBytes<sizeof(T)>(&indices, &idx_bytes);
+  for (size_t i = 0; i < sizeof(T); ++i) {
+    out_bytes[i] = in_bytes[idx_bytes[i]];
+  }
+  TI out;
+  CopyBytes<sizeof(TI)>(&out_bytes, &out);
+  return Vec1<TI>{out};
+}
+
+template <typename T, typename TI>
+HWY_API Vec1<TI> TableLookupBytesOr0(const Vec1<T> in, const Vec1<TI> indices) {
+  uint8_t in_bytes[sizeof(T)];
+  uint8_t idx_bytes[sizeof(T)];
+  uint8_t out_bytes[sizeof(T)];
+  CopyBytes<sizeof(T)>(&in, &in_bytes);  // copy to bytes
+  CopyBytes<sizeof(T)>(&indices, &idx_bytes);
+  for (size_t i = 0; i < sizeof(T); ++i) {
+    out_bytes[i] = idx_bytes[i] & 0x80 ? 0 : in_bytes[idx_bytes[i]];
+  }
+  TI out;
+  CopyBytes<sizeof(TI)>(&out_bytes, &out);
+  return Vec1<TI>{out};
+}
+
+// ------------------------------ ZipLower
+
+HWY_API Vec1<uint16_t> ZipLower(const Vec1<uint8_t> a, const Vec1<uint8_t> b) {
+  return Vec1<uint16_t>(static_cast<uint16_t>((uint32_t{b.raw} << 8) + a.raw));
+}
+HWY_API Vec1<uint32_t> ZipLower(const Vec1<uint16_t> a,
+                                const Vec1<uint16_t> b) {
+  return Vec1<uint32_t>((uint32_t{b.raw} << 16) + a.raw);
+}
+HWY_API Vec1<uint64_t> ZipLower(const Vec1<uint32_t> a,
+                                const Vec1<uint32_t> b) {
+  return Vec1<uint64_t>((uint64_t{b.raw} << 32) + a.raw);
+}
+HWY_API Vec1<int16_t> ZipLower(const Vec1<int8_t> a, const Vec1<int8_t> b) {
+  return Vec1<int16_t>(static_cast<int16_t>((int32_t{b.raw} << 8) + a.raw));
+}
+HWY_API Vec1<int32_t> ZipLower(const Vec1<int16_t> a, const Vec1<int16_t> b) {
+  return Vec1<int32_t>((int32_t{b.raw} << 16) + a.raw);
+}
+HWY_API Vec1<int64_t> ZipLower(const Vec1<int32_t> a, const Vec1<int32_t> b) {
+  return Vec1<int64_t>((int64_t{b.raw} << 32) + a.raw);
+}
+
+template <typename T, typename TW = MakeWide<T>, class VW = Vec1<TW>>
+HWY_API VW ZipLower(Sisd<TW> /* tag */, Vec1<T> a, Vec1<T> b) {
+  return VW(static_cast<TW>((TW{b.raw} << (sizeof(T) * 8)) + a.raw));
+}
+
+// ================================================== MASK
+
+template <typename T>
+HWY_API bool AllFalse(Sisd<T> /* tag */, const Mask1<T> mask) {
+  return mask.bits == 0;
+}
+
+template <typename T>
+HWY_API bool AllTrue(Sisd<T> /* tag */, const Mask1<T> mask) {
+  return mask.bits != 0;
+}
+
+// `p` points to at least 8 readable bytes, not all of which need be valid.
+template <typename T>
+HWY_API Mask1<T> LoadMaskBits(Sisd<T> /* tag */,
+                              const uint8_t* HWY_RESTRICT bits) {
+  return Mask1<T>::FromBool((bits[0] & 1) != 0);
+}
+
+// `p` points to at least 8 writable bytes.
+template <typename T>
+HWY_API size_t StoreMaskBits(Sisd<T> d, const Mask1<T> mask, uint8_t* bits) {
+  *bits = AllTrue(d, mask);
+  return 1;
+}
+
+template <typename T>
+HWY_API size_t CountTrue(Sisd<T> /* tag */, const Mask1<T> mask) {
+  return mask.bits == 0 ? 0 : 1;
+}
+
+template <typename T>
+HWY_API intptr_t FindFirstTrue(Sisd<T> /* tag */, const Mask1<T> mask) {
+  return mask.bits == 0 ? -1 : 0;
+}
+
+template <typename T>
+HWY_API size_t FindKnownFirstTrue(Sisd<T> /* tag */, const Mask1<T> /* m */) {
+  return 0;  // There is only one lane and we know it is true.
+}
+
+// ------------------------------ Compress, CompressBits
+
+template <typename T>
+struct CompressIsPartition {
+  enum { value = 1 };
+};
+
+template <typename T>
+HWY_API Vec1<T> Compress(Vec1<T> v, const Mask1<T> /* mask */) {
+  // A single lane is already partitioned by definition.
+  return v;
+}
+
+template <typename T>
+HWY_API Vec1<T> CompressNot(Vec1<T> v, const Mask1<T> /* mask */) {
+  // A single lane is already partitioned by definition.
+  return v;
+}
+
+// ------------------------------ CompressStore
+template <typename T>
+HWY_API size_t CompressStore(Vec1<T> v, const Mask1<T> mask, Sisd<T> d,
+                             T* HWY_RESTRICT unaligned) {
+  StoreU(Compress(v, mask), d, unaligned);
+  return CountTrue(d, mask);
+}
+
+// ------------------------------ CompressBlendedStore
+template <typename T>
+HWY_API size_t CompressBlendedStore(Vec1<T> v, const Mask1<T> mask, Sisd<T> d,
+                                    T* HWY_RESTRICT unaligned) {
+  if (!mask.bits) return 0;
+  StoreU(v, d, unaligned);
+  return 1;
+}
+
+// ------------------------------ CompressBits
+template <typename T>
+HWY_API Vec1<T> CompressBits(Vec1<T> v, const uint8_t* HWY_RESTRICT /*bits*/) {
+  return v;
+}
+
+// ------------------------------ CompressBitsStore
+template <typename T>
+HWY_API size_t CompressBitsStore(Vec1<T> v, const uint8_t* HWY_RESTRICT bits,
+                                 Sisd<T> d, T* HWY_RESTRICT unaligned) {
+  const Mask1<T> mask = LoadMaskBits(d, bits);
+  StoreU(Compress(v, mask), d, unaligned);
+  return CountTrue(d, mask);
+}
+
+// ------------------------------ ReorderWidenMulAccumulate (MulAdd, ZipLower)
+
+HWY_API Vec1<float> ReorderWidenMulAccumulate(Sisd<float> /* tag */,
+                                              Vec1<bfloat16_t> a,
+                                              Vec1<bfloat16_t> b,
+                                              const Vec1<float> sum0,
+                                              Vec1<float>& /* sum1 */) {
+  return MulAdd(Vec1<float>(F32FromBF16(a.raw)),
+                Vec1<float>(F32FromBF16(b.raw)), sum0);
+}
+
+HWY_API Vec1<int32_t> ReorderWidenMulAccumulate(Sisd<int32_t> /* tag */,
+                                                Vec1<int16_t> a,
+                                                Vec1<int16_t> b,
+                                                const Vec1<int32_t> sum0,
+                                                Vec1<int32_t>& /* sum1 */) {
+  return Vec1<int32_t>(a.raw * b.raw + sum0.raw);
+}
+
+// ------------------------------ RearrangeToOddPlusEven
+template <typename TW>
+HWY_API Vec1<TW> RearrangeToOddPlusEven(const Vec1<TW> sum0,
+                                        Vec1<TW> /* sum1 */) {
+  return sum0;  // invariant already holds
+}
+
+// ================================================== REDUCTIONS
+
+// Sum of all lanes, i.e. the only one.
+template <typename T>
+HWY_API Vec1<T> SumOfLanes(Sisd<T> /* tag */, const Vec1<T> v) {
+  return v;
+}
+template <typename T>
+HWY_API Vec1<T> MinOfLanes(Sisd<T> /* tag */, const Vec1<T> v) {
+  return v;
+}
+template <typename T>
+HWY_API Vec1<T> MaxOfLanes(Sisd<T> /* tag */, const Vec1<T> v) {
+  return v;
+}
+
+// NOLINTNEXTLINE(google-readability-namespace-comments)
+}  // namespace HWY_NAMESPACE
+}  // namespace hwy
+HWY_AFTER_NAMESPACE();