element_test.go

// Code generated by goff DO NOT EDIT
package ff

import (
	"crypto/rand"
	"math/big"
	mrand "math/rand"
	"testing"
)

func TestELEMENTCorrectnessAgainstBigInt(t *testing.T) {
	modulus, _ := new(big.Int).SetString("21888242871839275222246405745257275088548364400416034343698204186575808495617", 10)
	cmpEandB := func(e *Element, b *big.Int, name string) {
		var _e big.Int
		if e.FromMont().ToBigInt(&_e).Cmp(b) != 0 {
			t.Fatal(name, "failed")
		}
	}
	var modulusMinusOne, one big.Int
	one.SetUint64(1)

	modulusMinusOne.Sub(modulus, &one)

	for i := 0; i < 1000; i++ {

		// sample 2 random big int
		b1, _ := rand.Int(rand.Reader, modulus)
		b2, _ := rand.Int(rand.Reader, modulus)
		rExp := mrand.Uint64()

		// adding edge cases
		// TODO need more edge cases
		switch i {
		case 0:
			rExp = 0
			b1.SetUint64(0)
		case 1:
			b2.SetUint64(0)
		case 2:
			b1.SetUint64(0)
			b2.SetUint64(0)
		case 3:
			rExp = 0
		case 4:
			rExp = 1
		case 5:
			rExp = ^uint64(0) // max uint
		case 6:
			rExp = 2
			b1.Set(&modulusMinusOne)
		case 7:
			b2.Set(&modulusMinusOne)
		case 8:
			b1.Set(&modulusMinusOne)
			b2.Set(&modulusMinusOne)
		}

		rbExp := new(big.Int).SetUint64(rExp)

		var bMul, bAdd, bSub, bDiv, bNeg, bLsh, bInv, bExp, bSquare big.Int

		// e1 = mont(b1), e2 = mont(b2)
		var e1, e2, eMul, eAdd, eSub, eDiv, eNeg, eLsh, eInv, eExp, eSquare, eMulAssign, eSubAssign, eAddAssign Element
		e1.SetBigInt(b1)
		e2.SetBigInt(b2)

		// (e1*e2).FromMont() === b1*b2 mod q ... etc
		eSquare.Square(&e1)
		eMul.Mul(&e1, &e2)
		eMulAssign.Set(&e1)
		eMulAssign.MulAssign(&e2)
		eAdd.Add(&e1, &e2)
		eAddAssign.Set(&e1)
		eAddAssign.AddAssign(&e2)
		eSub.Sub(&e1, &e2)
		eSubAssign.Set(&e1)
		eSubAssign.SubAssign(&e2)
		eDiv.Div(&e1, &e2)
		eNeg.Neg(&e1)
		eInv.Inverse(&e1)
		eExp.Exp(e1, rExp)
		eLsh.Double(&e1)

		// same operations with big int
		bAdd.Add(b1, b2).Mod(&bAdd, modulus)
		bMul.Mul(b1, b2).Mod(&bMul, modulus)
		bSquare.Mul(b1, b1).Mod(&bSquare, modulus)
		bSub.Sub(b1, b2).Mod(&bSub, modulus)
		bDiv.ModInverse(b2, modulus)
		bDiv.Mul(&bDiv, b1).
			Mod(&bDiv, modulus)
		bNeg.Neg(b1).Mod(&bNeg, modulus)

		bInv.ModInverse(b1, modulus)
		bExp.Exp(b1, rbExp, modulus)
		bLsh.Lsh(b1, 1).Mod(&bLsh, modulus)

		cmpEandB(&eSquare, &bSquare, "Square")
		cmpEandB(&eMul, &bMul, "Mul")
		cmpEandB(&eMulAssign, &bMul, "MulAssign")
		cmpEandB(&eAdd, &bAdd, "Add")
		cmpEandB(&eAddAssign, &bAdd, "AddAssign")
		cmpEandB(&eSub, &bSub, "Sub")
		cmpEandB(&eSubAssign, &bSub, "SubAssign")
		cmpEandB(&eDiv, &bDiv, "Div")
		cmpEandB(&eNeg, &bNeg, "Neg")
		cmpEandB(&eInv, &bInv, "Inv")
		cmpEandB(&eExp, &bExp, "Exp")
		cmpEandB(&eLsh, &bLsh, "Lsh")
	}
}

func TestELEMENTIsRandom(t *testing.T) {
	for i := 0; i < 1000; i++ {
		var x, y Element
		x.SetRandom()
		y.SetRandom()
		if x.Equal(&y) {
			t.Fatal("2 random numbers are unlikely to be equal")
		}
	}
}

// -------------------------------------------------------------------------------------------------
// benchmarks
// most benchmarks are rudimentary and should sample a large number of random inputs
// or be run multiple times to ensure it didn't measure the fastest path of the function
// TODO: clean up and push benchmarking branch

var benchResElement Element

func BenchmarkInverseELEMENT(b *testing.B) {
	var x Element
	x.SetRandom()
	benchResElement.SetRandom()
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		benchResElement.Inverse(&x)
	}

}
func BenchmarkExpELEMENT(b *testing.B) {
	var x Element
	x.SetRandom()
	benchResElement.SetRandom()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		benchResElement.Exp(x, mrand.Uint64())
	}
}

func BenchmarkDoubleELEMENT(b *testing.B) {
	benchResElement.SetRandom()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		benchResElement.Double(&benchResElement)
	}
}

func BenchmarkAddELEMENT(b *testing.B) {
	var x Element
	x.SetRandom()
	benchResElement.SetRandom()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		benchResElement.Add(&x, &benchResElement)
	}
}

func BenchmarkSubELEMENT(b *testing.B) {
	var x Element
	x.SetRandom()
	benchResElement.SetRandom()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		benchResElement.Sub(&x, &benchResElement)
	}
}

func BenchmarkNegELEMENT(b *testing.B) {
	benchResElement.SetRandom()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		benchResElement.Neg(&benchResElement)
	}
}

func BenchmarkDivELEMENT(b *testing.B) {
	var x Element
	x.SetRandom()
	benchResElement.SetRandom()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		benchResElement.Div(&x, &benchResElement)
	}
}

func BenchmarkFromMontELEMENT(b *testing.B) {
	benchResElement.SetRandom()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		benchResElement.FromMont()
	}
}

func BenchmarkToMontELEMENT(b *testing.B) {
	benchResElement.SetRandom()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		benchResElement.ToMont()
	}
}
func BenchmarkSquareELEMENT(b *testing.B) {
	benchResElement.SetRandom()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		benchResElement.Square(&benchResElement)
	}
}

func BenchmarkMulAssignELEMENT(b *testing.B) {
	x := Element{
		1997599621687373223,
		6052339484930628067,
		10108755138030829701,
		150537098327114917,
	}
	benchResElement.SetOne()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		benchResElement.MulAssign(&x)
	}
}