1package gates
  2
  3import (
  4	"fmt"
  5	"regexp"
  6	"strconv"
  7
  8	"github.com/consensys/gnark/frontend"
  9	"github.com/succinctlabs/gnark-plonky2-verifier/field"
 10)
 11
 12var reducingGateRegex = regexp.MustCompile("ReducingGate { num_coeffs: (?P<numCoeffs>[0-9]+) }")
 13
 14func deserializeReducingGate(parameters map[string]string) Gate {
 15	// Has the format "ReducingGate { num_coeffs: 33 }"
 16	numCoeffs, hasNumCoeffs := parameters["numCoeffs"]
 17	if !hasNumCoeffs {
 18		panic("Missing field num_coeffs in ReducingGate")
 19	}
 20
 21	numCoeffsInt, err := strconv.Atoi(numCoeffs)
 22	if err != nil {
 23		panic("Invalid num_coeffs field in ReducingGate")
 24	}
 25
 26	return NewReducingGate(uint64(numCoeffsInt))
 27}
 28
 29type ReducingGate struct {
 30	numCoeffs uint64
 31}
 32
 33const START_COEFFS_REDUCING_GATE = 3 * field.D
 34
 35func NewReducingGate(numCoeffs uint64) *ReducingGate {
 36	return &ReducingGate{
 37		numCoeffs: numCoeffs,
 38	}
 39}
 40
 41func (g *ReducingGate) Id() string {
 42	return fmt.Sprintf("ReducingExtensionGate { num_ops: %d }", g.numCoeffs)
 43}
 44
 45func (g *ReducingGate) wiresOutput() Range {
 46	return Range{0, field.D}
 47}
 48
 49func (g *ReducingGate) wiresAlpha() Range {
 50	return Range{field.D, 2 * field.D}
 51}
 52
 53func (g *ReducingGate) wiresOldAcc() Range {
 54	return Range{2 * field.D, 3 * field.D}
 55}
 56
 57func (g *ReducingGate) wiresCoeff() Range {
 58	return Range{START_COEFFS_REDUCING_GATE, START_COEFFS_REDUCING_GATE + g.numCoeffs}
 59}
 60
 61func (g *ReducingGate) startAccs() uint64 {
 62	return START_COEFFS_REDUCING_GATE + g.numCoeffs
 63}
 64
 65func (g *ReducingGate) wiresAccs(i uint64) Range {
 66	if i >= g.numCoeffs {
 67		panic("Accumulator index out of bounds")
 68	}
 69
 70	if i == g.numCoeffs-1 {
 71		return g.wiresOutput()
 72	}
 73
 74	return Range{g.startAccs() + field.D*i, g.startAccs() + field.D*(i+1)}
 75}
 76
 77func (g *ReducingGate) EvalUnfiltered(api frontend.API, qeAPI *field.QuadraticExtensionAPI, vars EvaluationVars) []field.QuadraticExtension {
 78	alpha := vars.GetLocalExtAlgebra(g.wiresAlpha())
 79	oldAcc := vars.GetLocalExtAlgebra(g.wiresOldAcc())
 80
 81	coeffs := []field.QuadraticExtension{}
 82	coeffsRange := g.wiresCoeff()
 83	for i := coeffsRange.start; i < coeffsRange.end; i++ {
 84		coeffs = append(coeffs, vars.localWires[i])
 85	}
 86
 87	accs := []field.QEAlgebra{}
 88	for i := uint64(0); i < g.numCoeffs; i++ {
 89		accs = append(accs, vars.GetLocalExtAlgebra(g.wiresAccs(i)))
 90	}
 91
 92	constraints := []field.QuadraticExtension{}
 93	acc := oldAcc
 94	for i := uint64(0); i < g.numCoeffs; i++ {
 95		var coeff field.QEAlgebra
 96		for j := 0; j < field.D; j++ {
 97			coeff[j] = qeAPI.ZERO_QE
 98		}
 99		coeff[0] = coeffs[i]
100		tmp := qeAPI.MulExtensionAlgebra(acc, alpha)
101		tmp = qeAPI.AddExtensionAlgebra(tmp, coeff)
102		tmp = qeAPI.SubExtensionAlgebra(tmp, accs[i])
103		for j := 0; j < field.D; j++ {
104			constraints = append(constraints, tmp[j])
105		}
106		acc = accs[i]
107	}
108
109	return constraints
110}