package examples

import (
	"math/bits"
	unsafeRandom "math/rand/v2"
	"testing"
)

func TestMul64(t *testing.T) {
	mul64, done, err := Mul64()
	if err != nil {
		t.Fatal(err)
	}
	defer done()

	for range 128 {
		a, b := unsafeRandom.Uint64(), unsafeRandom.Uint64()

		expectedHi, expectedLo := bits.Mul64(a, b)
		gotHi, gotLo := mul64(a, b)

		if expectedHi != gotHi || expectedLo != gotLo {
			t.Errorf("Mul64(%x, %x) = (%x %x), want (%x %x)", a, b, gotHi, gotLo, expectedHi, expectedLo)
		}
	}
}