common/math, core/vm: implement fast EXP (#3214)

* common/math, core/vm: implement fast EXP.

Courtesy @chfast & @karalabe

* common/math: fix go vet issues on exp calculation
This commit is contained in:
Jeffrey Wilcke
2016-11-02 12:43:15 +01:00
committed by Péter Szilágyi
parent 36956da4d2
commit 1b73c79234
2 changed files with 31 additions and 2 deletions

View File

@ -21,6 +21,7 @@ import (
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/params"
)
@ -192,8 +193,8 @@ func opSmod(instr instruction, pc *uint64, env Environment, contract *Contract,
}
func opExp(instr instruction, pc *uint64, env Environment, contract *Contract, memory *Memory, stack *Stack) {
x, y := stack.pop(), stack.pop()
stack.push(U256(x.Exp(x, y, Pow256)))
base, exponent := stack.pop(), stack.pop()
stack.push(math.Exp(base, exponent))
}
func opSignExtend(instr instruction, pc *uint64, env Environment, contract *Contract, memory *Memory, stack *Stack) {