From ea7303ee2ab8d26ecde3478f3dd1743fec8e4186 Mon Sep 17 00:00:00 2001
From: Youssef El Housni <youssef.housni21@gmail.com>
Date: Tue, 4 Feb 2025 14:24:18 -0500
Subject: [PATCH] refactor: clean code

---
 std/algebra/native/sw_grumpkin/hints.go | 95 -------------------------
 std/algebra/native/sw_grumpkin/inner.go |  6 --
 2 files changed, 101 deletions(-)
 delete mode 100644 std/algebra/native/sw_grumpkin/hints.go

diff --git a/std/algebra/native/sw_grumpkin/hints.go b/std/algebra/native/sw_grumpkin/hints.go
deleted file mode 100644
index f91b2f6ae..000000000
--- a/std/algebra/native/sw_grumpkin/hints.go
+++ /dev/null
@@ -1,95 +0,0 @@
-package sw_grumpkin
-
-import (
-	"errors"
-	"math/big"
-
-	"github.com/consensys/gnark-crypto/ecc"
-	"github.com/consensys/gnark/constraint/solver"
-	"github.com/consensys/gnark/frontend"
-	"github.com/consensys/gnark/std/math/emulated"
-	"github.com/consensys/gnark/std/math/emulated/emparams"
-)
-
-func GetHints() []solver.Hint {
-	return []solver.Hint{
-		decomposeScalar,
-		decompose,
-	}
-}
-
-func init() {
-	solver.RegisterHint(GetHints()...)
-}
-
-func decomposeScalar(nativeMod *big.Int, nativeInputs, nativeOutputs []*big.Int) error {
-	return emulated.UnwrapHintWithNativeInput(nativeInputs, nativeOutputs, func(nnMod *big.Int, nninputs, nnOutputs []*big.Int) error {
-		if len(nninputs) != 1 {
-			return errors.New("expecting one input")
-		}
-		if len(nnOutputs) != 2 {
-			return errors.New("expecting two outputs")
-		}
-		cc := getInnerCurveConfig(nativeMod)
-		sp := ecc.SplitScalar(nninputs[0], cc.glvBasis)
-		nnOutputs[0].Set(&(sp[0]))
-		nnOutputs[1].Neg(&(sp[1]))
-
-		return nil
-	})
-}
-
-func callDecomposeScalar(api frontend.API, s frontend.Variable) (s1, s2 frontend.Variable) {
-	var fr emparams.GRUMPKINFr
-	cc := getInnerCurveConfig(api.Compiler().Field())
-	sapi, err := emulated.NewField[emparams.GRUMPKINFr](api)
-	if err != nil {
-		panic(err)
-	}
-	// compute the decomposition using a hint. We have to use the emulated
-	// version which takes native input and outputs non-native outputs.
-	//
-	// the hints allow to decompose the scalar s into s1 and s2 such that
-	//     s1 + λ * s2 == s mod r,
-	// where λ is third root of one in 𝔽_r.
-	sd, err := sapi.NewHintWithNativeInput(decomposeScalar, 2, s)
-	if err != nil {
-		panic(err)
-	}
-	// lambda as nonnative element
-	lambdaEmu := sapi.NewElement(cc.lambda)
-	// the scalar as nonnative element. We need to split at 64 bits.
-	limbs, err := api.NewHint(decompose, int(fr.NbLimbs()), s)
-	if err != nil {
-		panic(err)
-	}
-	semu := sapi.NewElement(limbs)
-	// s1 + λ * s2 == s mod r
-	lhs := sapi.MulNoReduce(sd[1], lambdaEmu)
-	lhs = sapi.Sub(sd[0], lhs)
-
-	sapi.AssertIsEqual(semu, semu)
-
-	s1 = 0
-	s2 = 0
-	b := big.NewInt(1)
-	for i := range sd[0].Limbs {
-		s1 = api.Add(s1, api.Mul(sd[0].Limbs[i], b))
-		s2 = api.Add(s2, api.Mul(sd[1].Limbs[i], b))
-		b.Lsh(b, 64)
-	}
-	return s1, s2
-}
-
-func decompose(mod *big.Int, inputs, outputs []*big.Int) error {
-	if len(inputs) != 1 && len(outputs) != 4 {
-		return errors.New("input/output length mismatch")
-	}
-	tmp := new(big.Int).Set(inputs[0])
-	mask := new(big.Int).SetUint64(^uint64(0))
-	for i := 0; i < 4; i++ {
-		outputs[i].And(tmp, mask)
-		tmp.Rsh(tmp, 64)
-	}
-	return nil
-}
diff --git a/std/algebra/native/sw_grumpkin/inner.go b/std/algebra/native/sw_grumpkin/inner.go
index 689374985..63c95ca0b 100644
--- a/std/algebra/native/sw_grumpkin/inner.go
+++ b/std/algebra/native/sw_grumpkin/inner.go
@@ -29,12 +29,6 @@ func (cc *innerConfig) phi1(api frontend.API, res, P *G1Affine) *G1Affine {
 	return res
 }
 
-func (cc *innerConfig) phi2Neg(api frontend.API, res, P *G1Affine) *G1Affine {
-	res.X = api.Mul(P.X, cc.thirdRootOne2)
-	res.Y = api.Sub(0, P.Y)
-	return res
-}
-
 // getInnerCurveConfig returns the configuration of the inner elliptic curve
 // which can be defined on the scalars of outer curve.
 func getInnerCurveConfig(outerCurveScalarField *big.Int) *innerConfig {