//go:build !amd64 || purego
// +build !amd64 purego

package common

// Execute an in-place forward NTT on as.
//
// Assumes the coefficients are in Montgomery representation and bounded
// by 2*Q.  The resulting coefficients are again in Montgomery representation,
// but are only bounded bt 18*Q.
func (p *Poly) NTT() {
	p.nttGeneric()
}

// Execute an in-place inverse NTT and multiply by Montgomery factor R
//
// Assumes the coefficients are in Montgomery representation and bounded
// by 2*Q.  The resulting coefficients are again in Montgomery representation
// and bounded by 2*Q.
func (p *Poly) InvNTT() {
	p.invNttGeneric()
}

// Sets p to the polynomial whose coefficients are the pointwise multiplication
// of those of a and b.  The coefficients of p are bounded by 2q.
//
// Assumes a and b are in Montgomery form and that the pointwise product
// of each coefficient is below 2³² q.
func (p *Poly) MulHat(a, b *Poly) {
	p.mulHatGeneric(a, b)
}

// Sets p to a + b.  Does not normalize polynomials.
func (p *Poly) Add(a, b *Poly) {
	p.addGeneric(a, b)
}

// Sets p to a - b.
//
// Warning: assumes coefficients of b are less than 2q.
// Sets p to a + b.  Does not normalize polynomials.
func (p *Poly) Sub(a, b *Poly) {
	p.subGeneric(a, b)
}

// Writes p whose coefficients are in [0, 16) to buf, which must be of
// length N/2.
func (p *Poly) PackLe16(buf []byte) {
	p.packLe16Generic(buf)
}

// Reduces each of the coefficients to <2q.
func (p *Poly) ReduceLe2Q() {
	p.reduceLe2QGeneric()
}

// Reduce each of the coefficients to <q.
func (p *Poly) Normalize() {
	p.normalizeGeneric()
}

// Normalize the coefficients in this polynomial assuming they are already
// bounded by 2q.
func (p *Poly) NormalizeAssumingLe2Q() {
	p.normalizeAssumingLe2QGeneric()
}

// Checks whether the "supnorm" (see sec 2.1 of the spec) of p is equal
// or greater than the given bound.
//
// Requires the coefficients of p to be normalized.
func (p *Poly) Exceeds(bound uint32) bool {
	return p.exceedsGeneric(bound)
}

// Sets p to 2ᵈ q without reducing.
//
// So it requires the coefficients of p  to be less than 2³²⁻ᴰ.
func (p *Poly) MulBy2toD(q *Poly) {
	p.mulBy2toDGeneric(q)
}
