124 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			124 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
// Copyright 2015 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 vm
 | 
						|
 | 
						|
import (
 | 
						|
	"math/big"
 | 
						|
	"time"
 | 
						|
 | 
						|
	"github.com/ethereum/go-ethereum/logger"
 | 
						|
	"github.com/ethereum/go-ethereum/logger/glog"
 | 
						|
)
 | 
						|
 | 
						|
// optimeProgram optimises a JIT program creating segments out of program
 | 
						|
// instructions. Currently covered are multi-pushes and static jumps
 | 
						|
func optimiseProgram(program *Program) {
 | 
						|
	var load []instruction
 | 
						|
 | 
						|
	var (
 | 
						|
		statsJump = 0
 | 
						|
		statsPush = 0
 | 
						|
	)
 | 
						|
 | 
						|
	if glog.V(logger.Debug) {
 | 
						|
		glog.Infof("optimising %x\n", program.Id[:4])
 | 
						|
		tstart := time.Now()
 | 
						|
		defer func() {
 | 
						|
			glog.Infof("optimised %x done in %v with JMP: %d PSH: %d\n", program.Id[:4], time.Since(tstart), statsJump, statsPush)
 | 
						|
		}()
 | 
						|
	}
 | 
						|
 | 
						|
	/*
 | 
						|
		code := Parse(program.code)
 | 
						|
		for _, test := range [][]OpCode{
 | 
						|
			[]OpCode{PUSH, PUSH, ADD},
 | 
						|
			[]OpCode{PUSH, PUSH, SUB},
 | 
						|
			[]OpCode{PUSH, PUSH, MUL},
 | 
						|
			[]OpCode{PUSH, PUSH, DIV},
 | 
						|
		} {
 | 
						|
			matchCount := 0
 | 
						|
			MatchFn(code, test, func(i int) bool {
 | 
						|
				matchCount++
 | 
						|
				return true
 | 
						|
			})
 | 
						|
			fmt.Printf("found %d match count on: %v\n", matchCount, test)
 | 
						|
		}
 | 
						|
	*/
 | 
						|
 | 
						|
	for i := 0; i < len(program.instructions); i++ {
 | 
						|
		instr := program.instructions[i].(instruction)
 | 
						|
 | 
						|
		switch {
 | 
						|
		case instr.op.IsPush():
 | 
						|
			load = append(load, instr)
 | 
						|
		case instr.op.IsStaticJump():
 | 
						|
			if len(load) == 0 {
 | 
						|
				continue
 | 
						|
			}
 | 
						|
			// if the push load is greater than 1, finalise that
 | 
						|
			// segment first
 | 
						|
			if len(load) > 2 {
 | 
						|
				seg, size := makePushSeg(load[:len(load)-1])
 | 
						|
				program.instructions[i-size-1] = seg
 | 
						|
				statsPush++
 | 
						|
			}
 | 
						|
			// create a segment consisting of a pre determined
 | 
						|
			// jump, destination and validity.
 | 
						|
			seg := makeStaticJumpSeg(load[len(load)-1].data, program)
 | 
						|
			program.instructions[i-1] = seg
 | 
						|
			statsJump++
 | 
						|
 | 
						|
			load = nil
 | 
						|
		default:
 | 
						|
			// create a new N pushes segment
 | 
						|
			if len(load) > 1 {
 | 
						|
				seg, size := makePushSeg(load)
 | 
						|
				program.instructions[i-size] = seg
 | 
						|
				statsPush++
 | 
						|
			}
 | 
						|
			load = nil
 | 
						|
		}
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
// makePushSeg creates a new push segment from N amount of push instructions
 | 
						|
func makePushSeg(instrs []instruction) (pushSeg, int) {
 | 
						|
	var (
 | 
						|
		data []*big.Int
 | 
						|
		gas  = new(big.Int)
 | 
						|
	)
 | 
						|
 | 
						|
	for _, instr := range instrs {
 | 
						|
		data = append(data, instr.data)
 | 
						|
		gas.Add(gas, instr.gas)
 | 
						|
	}
 | 
						|
 | 
						|
	return pushSeg{data, gas}, len(instrs)
 | 
						|
}
 | 
						|
 | 
						|
// makeStaticJumpSeg creates a new static jump segment from a predefined
 | 
						|
// destination (PUSH, JUMP).
 | 
						|
func makeStaticJumpSeg(to *big.Int, program *Program) jumpSeg {
 | 
						|
	gas := new(big.Int)
 | 
						|
	gas.Add(gas, _baseCheck[PUSH1].gas)
 | 
						|
	gas.Add(gas, _baseCheck[JUMP].gas)
 | 
						|
 | 
						|
	contract := &Contract{Code: program.code}
 | 
						|
	pos, err := jump(program.mapping, program.destinations, contract, to)
 | 
						|
	return jumpSeg{pos, err, gas}
 | 
						|
}
 |