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authorJeffrey Wilcke <jeffrey@ethereum.org>2017-02-08 20:39:26 +0800
committerJeffrey Wilcke <jeffrey@ethereum.org>2017-02-13 22:15:12 +0800
commit57f4e9025757254536a738bb4771712038f1e763 (patch)
tree5d2f140139f3763a7da3c20a88acff96b58ec8ad /core/vm/common.go
parentf8f428cc18c5f70814d7b3937128781bac14bffd (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.go78
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
}