diff options
Diffstat (limited to 'core/vm/gas.go')
| -rw-r--r-- | core/vm/gas.go | 34 |
1 files changed, 27 insertions, 7 deletions
diff --git a/core/vm/gas.go b/core/vm/gas.go index eb2c16346..fdbc0df7f 100644 --- a/core/vm/gas.go +++ b/core/vm/gas.go @@ -35,8 +35,27 @@ var ( GasStop = big.NewInt(0) GasContractByte = big.NewInt(200) + + n64 = big.NewInt(64) ) +// calcGas returns the actual gas cost of the call. +// +// The cost of gas was changed during the homestead price change HF. To allow for EIP150 +// to be implemented. The returned gas is gas - base * 63 / 64. +func callGas(gasTable params.GasTable, availableGas, base, callCost *big.Int) *big.Int { + if gasTable.CreateBySuicide != nil { + availableGas = new(big.Int).Sub(availableGas, base) + g := new(big.Int).Div(availableGas, n64) + g.Sub(availableGas, g) + + if g.Cmp(callCost) < 0 { + return g + } + } + return callCost +} + // baseCheck checks for any stack error underflows func baseCheck(op OpCode, stack *Stack, gas *big.Int) error { // PUSH and DUP are a bit special. They all cost the same but we do want to have checking on stack push limit @@ -127,18 +146,19 @@ var _baseCheck = map[OpCode]req{ MSIZE: {0, GasQuickStep, 1}, GAS: {0, GasQuickStep, 1}, BLOCKHASH: {1, GasExtStep, 1}, - BALANCE: {1, GasExtStep, 1}, - EXTCODESIZE: {1, GasExtStep, 1}, - EXTCODECOPY: {4, GasExtStep, 0}, + BALANCE: {1, Zero, 1}, + EXTCODESIZE: {1, Zero, 1}, + EXTCODECOPY: {4, Zero, 0}, SLOAD: {1, params.SloadGas, 1}, SSTORE: {2, Zero, 0}, SHA3: {2, params.Sha3Gas, 1}, CREATE: {3, params.CreateGas, 1}, - CALL: {7, params.CallGas, 1}, - CALLCODE: {7, params.CallGas, 1}, - DELEGATECALL: {6, params.CallGas, 1}, - JUMPDEST: {0, params.JumpdestGas, 0}, + // Zero is calculated in the gasSwitch + CALL: {7, Zero, 1}, + CALLCODE: {7, Zero, 1}, + DELEGATECALL: {6, Zero, 1}, SUICIDE: {1, Zero, 0}, + JUMPDEST: {0, params.JumpdestGas, 0}, RETURN: {2, Zero, 0}, PUSH1: {0, GasFastestStep, 1}, DUP1: {0, Zero, 1}, |