go-pulse/core/vm/analysis.go
Martin Holst Swende 89a32451ae core/vm: faster create/create2 (#17806)
* core/vm/runtim: benchmark create/create2

* core/vm: do less hashing in CREATE2

* core/vm: avoid storing jumpdest analysis for initcode

* core/vm: avoid unneccesary lookups, remove unused fields

* core/vm: go formatting tests

* core/vm: save jumpdest analysis locally

* core/vm: use common.Hash instead of nil, fix review comments

* core/vm: removed type destinations

* core/vm: correct check for empty hash

* eth: more elegant api_tracer

* core/vm: address review concerns
2018-10-04 18:15:37 +03:00

63 lines
1.9 KiB
Go

// Copyright 2014 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
// bitvec is a bit vector which maps bytes in a program.
// An unset bit means the byte is an opcode, a set bit means
// it's data (i.e. argument of PUSHxx).
type bitvec []byte
func (bits *bitvec) set(pos uint64) {
(*bits)[pos/8] |= 0x80 >> (pos % 8)
}
func (bits *bitvec) set8(pos uint64) {
(*bits)[pos/8] |= 0xFF >> (pos % 8)
(*bits)[pos/8+1] |= ^(0xFF >> (pos % 8))
}
// codeSegment checks if the position is in a code segment.
func (bits *bitvec) codeSegment(pos uint64) bool {
return ((*bits)[pos/8] & (0x80 >> (pos % 8))) == 0
}
// codeBitmap collects data locations in code.
func codeBitmap(code []byte) bitvec {
// The bitmap is 4 bytes longer than necessary, in case the code
// ends with a PUSH32, the algorithm will push zeroes onto the
// bitvector outside the bounds of the actual code.
bits := make(bitvec, len(code)/8+1+4)
for pc := uint64(0); pc < uint64(len(code)); {
op := OpCode(code[pc])
if op >= PUSH1 && op <= PUSH32 {
numbits := op - PUSH1 + 1
pc++
for ; numbits >= 8; numbits -= 8 {
bits.set8(pc) // 8
pc += 8
}
for ; numbits > 0; numbits-- {
bits.set(pc)
pc++
}
} else {
pc++
}
}
return bits
}