1package gates
  2
  3import (
  4	"github.com/consensys/gnark/frontend"
  5	"github.com/succinctlabs/gnark-plonky2-verifier/field"
  6)
  7
  8type EvaluateGatesChip struct {
  9	api   frontend.API
 10	qeAPI *field.QuadraticExtensionAPI
 11
 12	gates              []Gate
 13	numGateConstraints uint64
 14
 15	selectorsInfo SelectorsInfo
 16}
 17
 18func NewEvaluateGatesChip(
 19	api frontend.API,
 20	qeAPI *field.QuadraticExtensionAPI,
 21	gates []Gate,
 22	numGateConstraints uint64,
 23	selectorsInfo SelectorsInfo,
 24) *EvaluateGatesChip {
 25	return &EvaluateGatesChip{
 26		api:   api,
 27		qeAPI: qeAPI,
 28
 29		gates:              gates,
 30		numGateConstraints: numGateConstraints,
 31
 32		selectorsInfo: selectorsInfo,
 33	}
 34}
 35
 36func (g *EvaluateGatesChip) computeFilter(
 37	row uint64,
 38	groupRange Range,
 39	s field.QuadraticExtension,
 40	manySelector bool,
 41) field.QuadraticExtension {
 42	product := g.qeAPI.ONE_QE
 43	for i := groupRange.start; i < groupRange.end; i++ {
 44		if i == uint64(row) {
 45			continue
 46		}
 47
 48		product = g.qeAPI.MulExtension(product, g.qeAPI.SubExtension(g.qeAPI.FieldToQE(field.NewFieldElement(i)), s))
 49	}
 50
 51	if manySelector {
 52		product = g.qeAPI.MulExtension(product, g.qeAPI.SubExtension(g.qeAPI.FieldToQE(field.NewFieldElement(UNUSED_SELECTOR)), s))
 53	}
 54
 55	return product
 56}
 57
 58func (g *EvaluateGatesChip) evalFiltered(
 59	gate Gate,
 60	vars EvaluationVars,
 61	row uint64,
 62	selectorIndex uint64,
 63	groupRange Range,
 64	numSelectors uint64,
 65) []field.QuadraticExtension {
 66	filter := g.computeFilter(row, groupRange, vars.localConstants[selectorIndex], numSelectors > 1)
 67
 68	vars.RemovePrefix(numSelectors)
 69
 70	unfiltered := gate.EvalUnfiltered(g.api, g.qeAPI, vars)
 71	for i := range unfiltered {
 72		unfiltered[i] = g.qeAPI.MulExtension(unfiltered[i], filter)
 73	}
 74	return unfiltered
 75}
 76
 77func (g *EvaluateGatesChip) EvaluateGateConstraints(vars EvaluationVars) []field.QuadraticExtension {
 78	constraints := make([]field.QuadraticExtension, g.numGateConstraints)
 79	for i := range constraints {
 80		constraints[i] = g.qeAPI.ZERO_QE
 81	}
 82
 83	for i, gate := range g.gates {
 84		selectorIndex := g.selectorsInfo.selectorIndices[i]
 85
 86		gateConstraints := g.evalFiltered(
 87			gate,
 88			vars,
 89			uint64(i),
 90			selectorIndex,
 91			g.selectorsInfo.groups[selectorIndex],
 92			g.selectorsInfo.NumSelectors(),
 93		)
 94
 95		for i, constraint := range gateConstraints {
 96			if uint64(i) >= g.numGateConstraints {
 97				panic("num_constraints() gave too low of a number")
 98			}
 99			constraints[i] = g.qeAPI.AddExtension(constraints[i], constraint)
100		}
101	}
102
103	return constraints
104}