gnark-plonky2-verifier/plonk/gates/arithmetic_extension_gate.go
plonk/gates/arithmetic_extension_gate.goRaw
1package gates
2
3import (
4 "fmt"
5 "regexp"
6 "strconv"
7
8 "github.com/consensys/gnark/frontend"
9 gl "github.com/succinctlabs/gnark-plonky2-verifier/goldilocks"
10)
11
12var aritheticExtensionGateRegex = regexp.MustCompile("ArithmeticExtensionGate { num_ops: (?P<numOps>[0-9]+) }")
13
14func deserializeExtensionArithmeticGate(parameters map[string]string) Gate {
15 // Has the format "ArithmeticExtensionGate { num_ops: 10 }"
16 numOps, hasNumOps := parameters["numOps"]
17 if !hasNumOps {
18 panic("Missing field num_ops in ArithmeticExtensionGate")
19 }
20
21 numOpsInt, err := strconv.Atoi(numOps)
22 if err != nil {
23 panic("Invalid num_ops field in ArithmeticExtensionGate")
24 }
25
26 return NewArithmeticExtensionGate(uint64(numOpsInt))
27}
28
29type ArithmeticExtensionGate struct {
30 numOps uint64
31}
32
33func NewArithmeticExtensionGate(numOps uint64) *ArithmeticExtensionGate {
34 return &ArithmeticExtensionGate{
35 numOps: numOps,
36 }
37}
38
39func (g *ArithmeticExtensionGate) Id() string {
40 return fmt.Sprintf("ArithmeticExtensionGate { num_ops: %d }", g.numOps)
41}
42
43func (g *ArithmeticExtensionGate) wiresIthMultiplicand0(i uint64) Range {
44 return Range{4 * gl.D * i, 4*gl.D*i + gl.D}
45}
46
47func (g *ArithmeticExtensionGate) wiresIthMultiplicand1(i uint64) Range {
48 return Range{4*gl.D*i + gl.D, 4*gl.D*i + 2*gl.D}
49}
50
51func (g *ArithmeticExtensionGate) wiresIthAddend(i uint64) Range {
52 return Range{4*gl.D*i + 2*gl.D, 4*gl.D*i + 3*gl.D}
53}
54
55func (g *ArithmeticExtensionGate) wiresIthOutput(i uint64) Range {
56 return Range{4*gl.D*i + 3*gl.D, 4*gl.D*i + 4*gl.D}
57}
58
59func (g *ArithmeticExtensionGate) EvalUnfiltered(
60 api frontend.API,
61 glApi gl.Chip,
62 vars EvaluationVars,
63) []gl.QuadraticExtensionVariable {
64 const0 := vars.localConstants[0]
65 const1 := vars.localConstants[1]
66
67 constraints := []gl.QuadraticExtensionVariable{}
68 for i := uint64(0); i < g.numOps; i++ {
69 multiplicand0 := vars.GetLocalExtAlgebra(g.wiresIthMultiplicand0(i))
70 multiplicand1 := vars.GetLocalExtAlgebra(g.wiresIthMultiplicand1(i))
71 addend := vars.GetLocalExtAlgebra(g.wiresIthAddend(i))
72 output := vars.GetLocalExtAlgebra(g.wiresIthOutput(i))
73
74 mul := glApi.MulExtensionAlgebra(multiplicand0, multiplicand1)
75 scaled_mul := glApi.ScalarMulExtensionAlgebra(const0, mul)
76 computed_output := glApi.ScalarMulExtensionAlgebra(const1, addend)
77 computed_output = glApi.AddExtensionAlgebra(computed_output, scaled_mul)
78
79 diff := glApi.SubExtensionAlgebra(output, computed_output)
80 for j := 0; j < gl.D; j++ {
81 constraints = append(constraints, diff[j])
82 }
83 }
84
85 return constraints
86}