Describe built-in Julia functions

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Alex Beregszaszi 2017-04-18 13:41:16 +01:00
parent 2a91eb9538
commit c3a6db7256

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@ -18,7 +18,7 @@ for-loops, switch-statements, expressions and assignments to variables.
JULIA in itself does not even provide operators. If the EVM is targeted,
opcodes will be available as built-in functions, but they can be reimplemented
if the backend changes.
if the backend changes. For a list of mandatory built-in functions, see the section below.
The following example program assumes that the EVM opcodes ``mul``, ``div``
and ``mod`` are available either natively or as functions and computes exponentiation.
@ -187,3 +187,165 @@ For ``(S1, z) = E(S, y)`` let ``(S2, w) = E(S1, x)``. TODO
where hex is the hexadecimal decoding function
E(G, L, n: DecimalNumber) = G, L, dec(n),
where dec is the decimal decoding function
Low-level Functions
-------------------
The following functions must be available:
+---------------------------------------------------------------------------------------------------------------+
| *Arithmetics* |
+---------------------------------------------------------------------------------------------------------------+
| add256(x:256, y:256) -> z:256 | x + y |
+---------------------------------------------------------------------------------------------------------------+
| sub256(x:256, y:256) -> z:256 | x - y |
+---------------------------------------------------------------------------------------------------------------+
| mul256(x:256, y:256) -> z:256 | x * y |
+---------------------------------------------------------------------------------------------------------------+
| div256(x:256, y:256) -> z:256 | x / y |
+---------------------------------------------------------------------------------------------------------------+
| sdiv256(x:256, y:256) -> z:256 | x / y, for signed numbers in two's complement |
+---------------------------------------------------------------------------------------------------------------+
| mod256(x:256, y:256) -> z:256 | x % y |
+---------------------------------------------------------------------------------------------------------------+
| smod256(x:256, y:256) -> z:256 | x % y, for signed numbers in two's complement |
+---------------------------------------------------------------------------------------------------------------+
| signextend256(i:256, x:256) -> z:256 | sign extend from (i*8+7)th bit counting from least significant |
+---------------------------------------------------------------------------------------------------------------+
| exp256(x:256, y:256) -> z:256 | x to the power of y |
+---------------------------------------------------------------------------------------------------------------+
| addmod256(x:256, y:256, m:256) -> z:256 | (x + y) % m with arbitrary precision arithmetics |
+---------------------------------------------------------------------------------------------------------------+
| mulmod256(x:256, y:256, m:256) -> z:256 | (x * y) % m with arbitrary precision arithmetics |
+---------------------------------------------------------------------------------------------------------------+
| lt256(x:256, y:256) -> z:bool | 1 if x < y, 0 otherwise |
+---------------------------------------------------------------------------------------------------------------+
| gt256(x:256, y:256) -> z:bool | 1 if x > y, 0 otherwise |
+---------------------------------------------------------------------------------------------------------------+
| slt256(x:256, y:256) -> z:bool | 1 if x < y, 0 otherwise, for signed numbers in two's complement |
+---------------------------------------------------------------------------------------------------------------+
| sgt256(x:256, y:256) -> z:bool | 1 if x > y, 0 otherwise, for signed numbers in two's complement |
+---------------------------------------------------------------------------------------------------------------+
| eq256(x:256, y:256) -> z:bool | 1 if x == y, 0 otherwise |
+---------------------------------------------------------------------------------------------------------------+
| not256(x:256) -> z:256 | ~x, every bit of x is negated |
+---------------------------------------------------------------------------------------------------------------+
| and256(x:256, y:256) -> z:256 | bitwise and of x and y |
+---------------------------------------------------------------------------------------------------------------+
| or256(x:256, y:256) -> z:256 | bitwise or of x and y |
+---------------------------------------------------------------------------------------------------------------+
| xor256(x:256, y:256) -> z:256 | bitwise xor of x and y |
+---------------------------------------------------------------------------------------------------------------+
| shl256(x:256, y:256) -> z:256 | logical left shift of x by y |
+---------------------------------------------------------------------------------------------------------------+
| shr256(x:256, y:256) -> z:256 | logical right shift of x by y |
+---------------------------------------------------------------------------------------------------------------+
| sar256(x:256, y:256) -> z:256 | arithmetic right shift of x by y |
+---------------------------------------------------------------------------------------------------------------+
| byte(n:256, x:256) -> v:256 | nth byte of x, where the most significant byte is the 0th byte |
| Cannot this be just replaced by and256(shr256(n, x), 0xff) and let it be optimised out by the EVM backend? |
+---------------------------------------------------------------------------------------------------------------+
| *Memory and storage* |
+---------------------------------------------------------------------------------------------------------------+
| mload(p:256) -> v:256 | mem[p..(p+32)) |
+---------------------------------------------------------------------------------------------------------------+
| mstore(p:256, v:256) | mem[p..(p+32)) := v |
+---------------------------------------------------------------------------------------------------------------+
| mstore8(p:256, v:256) | mem[p] := v & 0xff - only modifies a single byte |
+---------------------------------------------------------------------------------------------------------------+
| sload(p:256) -> v:256 | storage[p] |
+---------------------------------------------------------------------------------------------------------------+
| sstore(p:256, v:256) | storage[p] := v |
+---------------------------------------------------------------------------------------------------------------+
| msize() -> size:256 | size of memory, i.e. largest accessed memory index, albeit due |
| | due to the memory extension function, which extends by words, |
| | this will always be a multiple of 32 bytes |
+---------------------------------------------------------------------------------------------------------------+
| *Execution control* |
+---------------------------------------------------------------------------------------------------------------+
| create(v:256, p:256, s:256) | create new contract with code mem[p..(p+s)) and send v wei |
| | and return the new address |
+---------------------------------------------------------------------------------------------------------------+
| call(g:256, a:256, v:256, in:256, | call contract at address a with input mem[in..(in+insize)) |
| insize:256, out:256, outsize:256) -> r:256 | providing g gas and v wei and output area |
| | mem[out..(out+outsize)) returning 0 on error (eg. out of gas) |
| | and 1 on success |
+---------------------------------------------------------------------------------------------------------------+
| callcode(g:256, a:256, v:256, in:256, | identical to `call` but only use the code from a and stay |
| insize:256, out:256, outsize:256) -> r:256 | in the context of the current contract otherwise |
+---------------------------------------------------------------------------------------------------------------+
| delegatecall(g:256, a:256, in:256, | identical to `callcode` but also keep ``caller`` |
| insize:256, out:256, outsize:256) -> r:256 | and ``callvalue`` |
+---------------------------------------------------------------------------------------------------------------+
| stop() | stop execution, identical to return(0,0) |
| Perhaps it would make sense retiring this as it equals to return(0,0). It can be an optimisation by the EVM |
| backend. |
+---------------------------------------------------------------------------------------------------------------+
| abort() | abort (equals to invalid instruction on EVM) |
+---------------------------------------------------------------------------------------------------------------+
| return(p:256, s:256) | end execution, return data mem[p..(p+s)) |
+---------------------------------------------------------------------------------------------------------------+
| revert(p:256, s:256) | end execution, revert state changes, return data mem[p..(p+s)) |
+---------------------------------------------------------------------------------------------------------------+
| selfdestruct(a:256) | end execution, destroy current contract and send funds to a |
+---------------------------------------------------------------------------------------------------------------+
| log0(p:256, s:256) | log without topics and data mem[p..(p+s)) |
+---------------------------------------------------------------------------------------------------------------+
| log1(p:256, s:256, t1:256) | log with topic t1 and data mem[p..(p+s)) |
+---------------------------------------------------------------------------------------------------------------+
| log2(p:256, s:256, t1:256, t2:256) | log with topics t1, t2 and data mem[p..(p+s)) |
+---------------------------------------------------------------------------------------------------------------+
| log3(p:256, s:256, t1:256, t2:256, | log with topics t, t2, t3 and data mem[p..(p+s)) |
| t3:256) | |
+---------------------------------------------------------------------------------------------------------------+
| log4(p:256, s:256, t1:256, t2:256, | log with topics t1, t2, t3, t4 and data mem[p..(p+s)) |
| t3:256, t4:256) | |
+---------------------------------------------------------------------------------------------------------------+
| *State queries* |
+---------------------------------------------------------------------------------------------------------------+
| blockcoinbase() -> address:256 | current mining beneficiary |
+---------------------------------------------------------------------------------------------------------------+
| blockdifficulty() -> difficulty:256 | difficulty of the current block |
+---------------------------------------------------------------------------------------------------------------+
| blockgaslimit() -> limit:256 | block gas limit of the current block |
+---------------------------------------------------------------------------------------------------------------+
| blockhash(b:256) -> hash:256 | hash of block nr b - only for last 256 blocks excluding current |
+---------------------------------------------------------------------------------------------------------------+
| blocknumber() -> block:256 | current block number |
+---------------------------------------------------------------------------------------------------------------+
| blocktimestamp() -> timestamp:256 | timestamp of the current block in seconds since the epoch |
+---------------------------------------------------------------------------------------------------------------+
| txorigin() -> address:256 | transaction sender |
+---------------------------------------------------------------------------------------------------------------+
| txgasprice() -> price:256 | gas price of the transaction |
+---------------------------------------------------------------------------------------------------------------+
| gasleft() -> gas:256 | gas still available to execution |
+---------------------------------------------------------------------------------------------------------------+
| balance(a:256) -> v:256 | wei balance at address a |
+---------------------------------------------------------------------------------------------------------------+
| this() -> address:256 | address of the current contract / execution context |
+---------------------------------------------------------------------------------------------------------------+
| caller() -> address:256 | call sender (excluding delegatecall) |
+---------------------------------------------------------------------------------------------------------------+
| callvalue() -> v:256 | wei sent together with the current call |
+---------------------------------------------------------------------------------------------------------------+
| calldataload(p:256) -> v:256 | call data starting from position p (32 bytes) |
+---------------------------------------------------------------------------------------------------------------+
| calldatasize() -> v:256 | size of call data in bytes |
+---------------------------------------------------------------------------------------------------------------+
| calldatacopy(t:256, f:256, s:256) | copy s bytes from calldata at position f to mem at position t |
+---------------------------------------------------------------------------------------------------------------+
| codesize() -> size:256 | size of the code of the current contract / execution context |
+---------------------------------------------------------------------------------------------------------------+
| codecopy(t:256, f:256, s:256) | copy s bytes from code at position f to mem at position t |
+---------------------------------------------------------------------------------------------------------------+
| extcodesize(a:256) -> size:256 | size of the code at address a |
+---------------------------------------------------------------------------------------------------------------+
| extcodecopy(a:256, t:256, f:256, s:256) | like codecopy(t, f, s) but take code at address a |
+---------------------------------------------------------------------------------------------------------------+
| *Others* |
+---------------------------------------------------------------------------------------------------------------+
| discard256(unused:256) | discard value |
+---------------------------------------------------------------------------------------------------------------+
| sha3(p:256, s:256) -> v:256 | keccak(mem[p...(p+s))) |
+---------------------------------------------------------------------------------------------------------------+