1package plonky2_verifier
 2
 3import (
 4	"fmt"
 5	. "gnark-plonky2-verifier/field"
 6)
 7
 8// Ideally, this should be serialized in the plonky2 repo
 9const d = 2
10
11type ArithmeticExtensionGate struct {
12	numOps uint64
13}
14
15func NewArithmeticExtensionGate(numOps uint64) *ArithmeticExtensionGate {
16	return &ArithmeticExtensionGate{
17		numOps: numOps,
18	}
19}
20
21func (g *ArithmeticExtensionGate) Id() string {
22	return fmt.Sprintf("ArithmeticExtensionGate { num_ops: %d }", g.numOps)
23}
24
25func (g *ArithmeticExtensionGate) wiresIthMultiplicand0(i uint64) Range {
26	return Range{4 * d * i, 4*d*i + d}
27}
28
29func (g *ArithmeticExtensionGate) wiresIthMultiplicand1(i uint64) Range {
30	return Range{4*d*i + d, 4*d*i + 2*d}
31}
32
33func (g *ArithmeticExtensionGate) wiresIthAddend(i uint64) Range {
34	return Range{4*d*i + 2*d, 4*d*i + 3*d}
35}
36
37func (g *ArithmeticExtensionGate) wiresIthOutput(i uint64) Range {
38	return Range{4*d*i + 3*d, 4*d*i + 4*d}
39}
40
41func (g *ArithmeticExtensionGate) EvalUnfiltered(p *PlonkChip, vars EvaluationVars) []QuadraticExtension {
42	const0 := vars.localConstants[0]
43	const1 := vars.localConstants[1]
44
45	constraints := []QuadraticExtension{}
46	for i := uint64(0); i < g.numOps; i++ {
47		multiplicand0 := vars.GetLocalExtAlgebra(g.wiresIthMultiplicand0(i))
48		multiplicand1 := vars.GetLocalExtAlgebra(g.wiresIthMultiplicand1(i))
49		addend := vars.GetLocalExtAlgebra(g.wiresIthAddend(i))
50		output := vars.GetLocalExtAlgebra(g.wiresIthOutput(i))
51
52		mul := p.qeAPI.MulExtensionAlgebra(multiplicand0, multiplicand1)
53		scaled_mul := p.qeAPI.ScalarMulExtensionAlgebra(const0, mul)
54		computed_output := p.qeAPI.ScalarMulExtensionAlgebra(const1, addend)
55		computed_output = p.qeAPI.AddExtensionAlgebra(computed_output, scaled_mul)
56
57		diff := p.qeAPI.SubExtensionAlgebra(output, computed_output)
58		constraints = append(constraints, diff[0], diff[1])
59	}
60
61	return constraints
62}