src/simd/archsimd/internal/simd_test/simd_arm64_test.go

// Copyright 2026 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build goexperiment.simd && arm64

package simd_test

import (
	"simd/archsimd"
	"testing"
)

func TestLookupOrZero(t *testing.T) {
	// Out-of-range indices produce zero lane value.
	x := []uint8{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}
	indices := []uint8{7, 6, 5, 4, 3, 2, 1, 0, 0xff, 8, 16, 9, 128, 10, 20, 11}
	want := []uint8{8, 7, 6, 5, 4, 3, 2, 1, 0, 9, 0, 10, 0, 11, 0, 12}
	got := make([]uint8, len(x))
	archsimd.LoadUint8x16(x).LookupOrZero(archsimd.LoadUint8x16(indices)).Store(got)
	checkSlices(t, got, want)
}

func TestClMul(t *testing.T) {
	var x = archsimd.LoadUint64x2([]uint64{1, 5})
	var y = archsimd.LoadUint64x2([]uint64{3, 9})

	foo := func(v archsimd.Uint64x2, s []uint64) {
		r := make([]uint64, 2, 2)
		v.Store(r)
		checkSlices[uint64](t, r, s)
	}

	foo(x.CarrylessMultiplyEven(y), []uint64{3, 0})
	foo(x.CarrylessMultiplyEvenOdd(y), []uint64{9, 0})
	foo(x.CarrylessMultiplyOddEven(y), []uint64{15, 0})
	foo(x.CarrylessMultiplyOdd(y), []uint64{45, 0})
	foo(y.CarrylessMultiplyEven(y), []uint64{5, 0})
}