mirror of
https://gitlab.com/pulsechaincom/erigon-pulse.git
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cf799157cc
* Jumpdest skipping optimisation * Fix formatting * Move skipAnalysis into vmConfig, introduce tracing ability * Improve detection logging * Added release instructions * Fix lint
47 lines
1.5 KiB
Go
47 lines
1.5 KiB
Go
// Copyright 2014 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package vm
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import (
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)
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// codeBitmap collects data locations in code.
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func codeBitmap(code []byte) []uint64 {
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// The bitmap is 4 bytes longer than necessary, in case the code
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// ends with a PUSH32, the algorithm will push zeroes onto the
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// bitvector outside the bounds of the actual code.
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bits := make([]uint64, (len(code)+32+63)/64)
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for pc := 0; pc < len(code); {
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op := OpCode(code[pc])
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pc++
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if op >= PUSH1 && op <= PUSH32 {
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numbits := int(op - PUSH1 + 1)
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x := uint64(1) << (op - PUSH1)
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x = x | (x - 1) // Smear the bit to the right
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idx := pc / 64
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shift := pc & 63
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bits[idx] |= x << shift
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if shift+shift > 64 {
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bits[idx+1] |= x >> (64 - shift)
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}
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pc += numbits
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}
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}
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return bits
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}
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