externu256constc_stepGas;///< Once per operation, except for SSTORE, SLOAD, BALANCE, SHA3, CREATE, CALL.
externu256constc_balanceGas;///< Once per BALANCE operation.
externu256constc_sha3Gas;///< Once per SHA3 operation.
externu256constc_sloadGas;///< Once per SLOAD operation.
externu256constc_sstoreGas;///< Once per non-zero storage element in a CREATE call/transaction. Also, once/twice per SSTORE operation depending on whether the zeroness changes (twice iff it changes from zero; nothing at all if to zero) or doesn't (once).
externu256constc_createGas;///< Once per CREATE operation & contract-creation transaction.
externu256constc_callGas;///< Once per CALL operation & message call transaction.
externu256constc_memoryGas;///< Times the address of the (highest referenced byte in memory + 1). NOTE: referencing happens on read, write and in instructions such as RETURN and CALL.