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author | Jeffrey Wilcke <jeffrey@ethereum.org> | 2017-02-08 20:39:26 +0800 |
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committer | Jeffrey Wilcke <jeffrey@ethereum.org> | 2017-02-13 22:15:12 +0800 |
commit | 57f4e9025757254536a738bb4771712038f1e763 (patch) | |
tree | 5d2f140139f3763a7da3c20a88acff96b58ec8ad /core/vm/common.go | |
parent | f8f428cc18c5f70814d7b3937128781bac14bffd (diff) | |
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Revert "params: core, core/vm, miner: 64bit gas instructions (#3514)"
This reverts commit 8b57c494908637a5c0e74f8f7a13b3218e026757.
Diffstat (limited to 'core/vm/common.go')
-rw-r--r-- | core/vm/common.go | 78 |
1 files changed, 67 insertions, 11 deletions
diff --git a/core/vm/common.go b/core/vm/common.go index b7b9a6a9c..2878b92d2 100644 --- a/core/vm/common.go +++ b/core/vm/common.go @@ -21,11 +21,28 @@ import ( "math/big" "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/params" +) + +// Type is the VM type accepted by **NewVm** +type Type byte + +const ( + StdVmTy Type = iota // Default standard VM + JitVmTy // LLVM JIT VM + MaxVmTy ) var ( + Pow256 = common.BigPow(2, 256) // Pow256 is 2**256 + U256 = common.U256 // Shortcut to common.U256 S256 = common.S256 // Shortcut to common.S256 + + Zero = common.Big0 // Shortcut to common.Big0 + One = common.Big1 // Shortcut to common.Big1 + + max = big.NewInt(math.MaxInt64) // Maximum 64 bit integer ) // calculates the memory size required for a step @@ -37,6 +54,48 @@ func calcMemSize(off, l *big.Int) *big.Int { return new(big.Int).Add(off, l) } +// calculates the quadratic gas +func quadMemGas(mem *Memory, newMemSize, gas *big.Int) { + if newMemSize.Cmp(common.Big0) > 0 { + newMemSizeWords := toWordSize(newMemSize) + newMemSize.Mul(newMemSizeWords, u256(32)) + + if newMemSize.Cmp(u256(int64(mem.Len()))) > 0 { + // be careful reusing variables here when changing. + // The order has been optimised to reduce allocation + oldSize := toWordSize(big.NewInt(int64(mem.Len()))) + pow := new(big.Int).Exp(oldSize, common.Big2, Zero) + linCoef := oldSize.Mul(oldSize, params.MemoryGas) + quadCoef := new(big.Int).Div(pow, params.QuadCoeffDiv) + oldTotalFee := new(big.Int).Add(linCoef, quadCoef) + + pow.Exp(newMemSizeWords, common.Big2, Zero) + linCoef = linCoef.Mul(newMemSizeWords, params.MemoryGas) + quadCoef = quadCoef.Div(pow, params.QuadCoeffDiv) + newTotalFee := linCoef.Add(linCoef, quadCoef) + + fee := newTotalFee.Sub(newTotalFee, oldTotalFee) + gas.Add(gas, fee) + } + } +} + +// Simple helper +func u256(n int64) *big.Int { + return big.NewInt(n) +} + +// Mainly used for print variables and passing to Print* +func toValue(val *big.Int) interface{} { + // Let's assume a string on right padded zero's + b := val.Bytes() + if b[0] != 0 && b[len(b)-1] == 0x0 && b[len(b)-2] == 0x0 { + return string(b) + } + + return val +} + // getData returns a slice from the data based on the start and size and pads // up to size with zero's. This function is overflow safe. func getData(data []byte, start, size *big.Int) []byte { @@ -47,17 +106,14 @@ func getData(data []byte, start, size *big.Int) []byte { return common.RightPadBytes(data[s.Uint64():e.Uint64()], int(size.Uint64())) } -// bigUint64 returns the integer casted to a uint64 and returns whether it -// overflowed in the process. -func bigUint64(v *big.Int) (uint64, bool) { - return v.Uint64(), v.BitLen() > 64 -} - -// toWordSize returns the ceiled word size required for memory expansion. -func toWordSize(size uint64) uint64 { - if size > math.MaxUint64-31 { - return math.MaxUint64/32 + 1 +// useGas attempts to subtract the amount of gas and returns whether it was +// successful +func useGas(gas, amount *big.Int) bool { + if gas.Cmp(amount) < 0 { + return false } - return (size + 31) / 32 + // Sub the amount of gas from the remaining + gas.Sub(gas, amount) + return true } |