This EIP tries to resolve the problem of high gas consumption when calling precompiled contracts with a small gas cost. Using this opcode for calling precompiled contracts allows to define precompiled contracts whose effective cost it is less than 700.
As an example, SHA256 precompiled contract costs 60 and ECADD costs 500 (proposed to costs only 50 in [EIP1108](https://github.com/ethereum/EIPs/pull/1108) . When a precompiled contract is called, 700 gas is consumed just for the CALL opcode besides the costs of the precompiled contract.
If `block.number >= XXXXX`, define a new opcode named PRECOMPILEDCALL with code value 0xfb .
The gas cost of the OPCODE is 2 (Gbase) plus the Specific gas cost defined for each specific precompiled smart contract.
The OPCODE takes 5 words from the stack and returns 1 word to the stack.
The input stack values are:
mu_s[0] = The address of the precompiled smart contract that is called.
mu_s[1] = Pointer to memory for the input parameters.
mu_s[2] = Length of the input parametes in bytes.
mu_s[3] = Pointer to memory where the output is stored
mu_s[4] = Length of the output buffer.
The return will be 1 in case of success call and 0 in any of the next cases:
1.- mu_s[0] is an address of an undefined precompiled smart contract.
2.- The precompiled smart contract fails (as defined on each smart contract). Invalid input parameters for example.
Precompiled smart contracs, does not execute opcodes, so there is no need to pass a gas parameter as a normal CALL. If the available gas is less that 2 plus the required gas required for the specific precompiled smart cotract, the context just STOPS executing with an "Out of Gas" error.
There is no stack check for this call.
The normal CALLs to the precompiled smart contracts continue to work with the exact same behavior.
A PRECOMPILEDCALL to a regular address or regular smart contract, is considered a call to an "undefined smart contract", so the VM MUST not execute it and the opcode must return 0x0 .
