diff options
Diffstat (limited to 'common/math/exp.go')
| -rw-r--r-- | common/math/exp.go | 47 |
1 files changed, 0 insertions, 47 deletions
diff --git a/common/math/exp.go b/common/math/exp.go deleted file mode 100644 index 113b76b39..000000000 --- a/common/math/exp.go +++ /dev/null @@ -1,47 +0,0 @@ -// Copyright 2016 The go-ethereum Authors -// This file is part of the go-ethereum library. -// -// The go-ethereum library is free software: you can redistribute it and/or modify -// it under the terms of the GNU Lesser General Public License as published by -// the Free Software Foundation, either version 3 of the License, or -// (at your option) any later version. -// -// The go-ethereum library is distributed in the hope that it will be useful, -// but WITHOUT ANY WARRANTY; without even the implied warranty of -// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -// GNU Lesser General Public License for more details. -// -// You should have received a copy of the GNU Lesser General Public License -// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. - -package math - -import ( - "math/big" - - "github.com/ethereum/go-ethereum/common" -) - -// wordSize is the size number of bits in a big.Int Word. -const wordSize = 32 << (uint64(^big.Word(0)) >> 63) - -// Exp implement exponentiation by squaring algorithm. -// -// Exp return a new variable; base and exponent must -// not be changed under any circumstance. -// -// 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 < wordSize; i++ { - if word&1 == 1 { - common.U256(result.Mul(result, base)) - } - common.U256(base.Mul(base, base)) - word >>= 1 - } - } - return result -} |