1package plonky2_verifier
 2
 3import (
 4	"fmt"
 5	. "gnark-plonky2-verifier/field"
 6)
 7
 8type ReducingExtensionGate struct {
 9	numCoeffs uint64
10}
11
12const START_COEFFS = 3 * D
13
14func NewReducingExtensionGate(numCoeffs uint64) *ReducingExtensionGate {
15	return &ReducingExtensionGate{
16		numCoeffs: numCoeffs,
17	}
18}
19
20func (g *ReducingExtensionGate) Id() string {
21	return fmt.Sprintf("ReducingExtensionGate { num_ops: %d }", g.numCoeffs)
22}
23
24func (g *ReducingExtensionGate) wiresOutput() Range {
25	return Range{0, D}
26}
27
28func (g *ReducingExtensionGate) wiresAlpha() Range {
29	return Range{D, 2 * D}
30}
31
32func (g *ReducingExtensionGate) wiresOldAcc() Range {
33	return Range{2 * D, 3 * D}
34}
35
36func (g *ReducingExtensionGate) wiresCoeff(i uint64) Range {
37	return Range{START_COEFFS + D*i, START_COEFFS + D*(i+1)}
38}
39
40func (g *ReducingExtensionGate) startAccs() uint64 {
41	return START_COEFFS + g.numCoeffs*D
42}
43
44func (g *ReducingExtensionGate) wiresAccs(i uint64) Range {
45	if i >= g.numCoeffs {
46		panic("Accumulator index out of bounds")
47	}
48
49	if i == g.numCoeffs-1 {
50		return g.wiresOutput()
51	}
52
53	return Range{g.startAccs() + D*i, g.startAccs() + D*(i+1)}
54}
55
56func (g *ReducingExtensionGate) EvalUnfiltered(p *PlonkChip, vars EvaluationVars) []QuadraticExtension {
57	alpha := vars.GetLocalExtAlgebra(g.wiresAlpha())
58	oldAcc := vars.GetLocalExtAlgebra(g.wiresOldAcc())
59
60	coeffs := []QEAlgebra{}
61	for i := uint64(0); i < g.numCoeffs; i++ {
62		coeffs = append(coeffs, vars.GetLocalExtAlgebra(g.wiresCoeff(i)))
63	}
64
65	accs := []QEAlgebra{}
66	for i := uint64(0); i < g.numCoeffs; i++ {
67		accs = append(accs, vars.GetLocalExtAlgebra(g.wiresAccs(i)))
68	}
69
70	constraints := []QuadraticExtension{}
71	acc := oldAcc
72	for i := uint64(0); i < g.numCoeffs; i++ {
73		coeff := coeffs[i]
74		tmp := p.qeAPI.MulExtensionAlgebra(acc, alpha)
75		tmp = p.qeAPI.AddExtensionAlgebra(tmp, coeff)
76		tmp = p.qeAPI.SubExtensionAlgebra(tmp, accs[i])
77		for j := uint64(0); j < D; j++ {
78			constraints = append(constraints, tmp[j])
79		}
80		acc = accs[i]
81	}
82
83	return constraints
84}