From b92564c014890048b86c277dac271755261814fe Mon Sep 17 00:00:00 2001
From: Aaron Chen <aaronchen.lisp@gmail.com>
Date: Sat, 9 Mar 2024 13:29:42 +0800
Subject: [PATCH] common/math: delete unused function Exp

---
 common/math/big.go      | 20 --------------------
 common/math/big_test.go | 16 ----------------
 2 files changed, 36 deletions(-)

diff --git a/common/math/big.go b/common/math/big.go
index 013c0ba4b6..fb7a721b24 100644
--- a/common/math/big.go
+++ b/common/math/big.go
@@ -248,23 +248,3 @@ func S256(x *big.Int) *big.Int {
 	}
 	return new(big.Int).Sub(x, tt256)
 }
-
-// Exp implements exponentiation by squaring.
-// Exp returns a newly-allocated big integer and does not change
-// base or exponent. The result is truncated to 256 bits.
-//
-// Courtesy @karalabe and @chfast
-func Exp(base, exponent *big.Int) *big.Int {
-	result := big.NewInt(1)
-
-	for _, word := range exponent.Bits() {
-		for i := 0; i < wordBits; i++ {
-			if word&1 == 1 {
-				U256(result.Mul(result, base))
-			}
-			U256(base.Mul(base, base))
-			word >>= 1
-		}
-	}
-	return result
-}
diff --git a/common/math/big_test.go b/common/math/big_test.go
index 803b5e1cc6..051074bbf3 100644
--- a/common/math/big_test.go
+++ b/common/math/big_test.go
@@ -306,19 +306,3 @@ func TestS256(t *testing.T) {
 		}
 	}
 }
-
-func TestExp(t *testing.T) {
-	tests := []struct{ base, exponent, result *big.Int }{
-		{base: big.NewInt(0), exponent: big.NewInt(0), result: big.NewInt(1)},
-		{base: big.NewInt(1), exponent: big.NewInt(0), result: big.NewInt(1)},
-		{base: big.NewInt(1), exponent: big.NewInt(1), result: big.NewInt(1)},
-		{base: big.NewInt(1), exponent: big.NewInt(2), result: big.NewInt(1)},
-		{base: big.NewInt(3), exponent: big.NewInt(144), result: MustParseBig256("507528786056415600719754159741696356908742250191663887263627442114881")},
-		{base: big.NewInt(2), exponent: big.NewInt(255), result: MustParseBig256("57896044618658097711785492504343953926634992332820282019728792003956564819968")},
-	}
-	for _, test := range tests {
-		if result := Exp(test.base, test.exponent); result.Cmp(test.result) != 0 {
-			t.Errorf("Exp(%d, %d) = %d, want %d", test.base, test.exponent, result, test.result)
-		}
-	}
-}