Basic gas usage (per bit of executed code)
Each instruction consumes a fixed amount of10 gas and 1 gas for each bit of this instruction, not including variable-length operands and references.
Examples:
Cell operations
When any instruction internally finalizes aBuilder to a Cell, it consumes 500 gas. When a Cell is loaded as a Slice, it consumes 100 gas for the first access in current smart contract invocation, and 25 gas for each subsequent load from cache. Cells are identified by representation hash, e.g., loading cell with the same hash for the second time will always cost 25 gas.
This applies to all instructions that internally operate with cells (including dictionary operations). The only exceptions are:
BTOSconverts aBuilderto aSlicewithout consuming gas for cell operations.HASHBUcomputes hash without consuming gas for convertingBuilderto aCell
Exceptions
TVM consumes50 gas when any exception is thrown, both explicitly by THROW-like instructions or implicitly during execution of other instructions. This happens before the jump to the exception handler c2.
Implicit jumps and returns
When the current continuation ends and there is a remaining reference, TVM jumps to it and consumes10 gas. When there are no instructions to execute and references to jump to, implicit return to c0 occurs, which consumes 5 gas.
Nested continuations
Calling more than8 extraordinary continuations in a chain consumes 1 gas for each subsequent continuation.
Tuple operations
TUPLE, TUPLEVAR, UNTUPLE, UNTUPLEVAR, UNPACKFIRST, UNPACKFIRSTVAR, EXPLODE, EXPLODEVAR consumes 1 gas for each entry been pushed or popped into a tuple. TPUSH, TPOP, SETINDEX, SETINDEXVAR, SETINDEXQ/SETINDEXVARQ consumes len(tuple) gas for the resulting tuple size after push/pop/set. Same applies to instructions operating with c7: SETGLOB/SETGLOBVAR, RANDU256/RAND, SETRAND, ADDRAND.
Stack operations
TVM consumes 1 gas for each stack element deeper than 32 elements inside the resulting new stack each time stack gets copied: when calling or jumping to a continuation with a non-empty argument number, an initial stack, or both, when extending a continuation stack usingSETCONTARGS and similar instructions, when using RUNVM (both for initial and resulting stacks of the vm).
Extra currency
The first5 executions of GETEXTRABALANCE consume at most 200 gas each. For example, if the gas cost was 1000, then 200 gas will be consumed, and the remaining 800 is free.
RUNVM
RUNVM and RUNVMX consume 40 extra gas before starting a VM.
Cryptography
CHKSIGNS/CHKSIGNU
CHKSIGNS and CHKSIGNU can be invoked 10 times without extra gas cost. Next checks will cost 4000 gas each.
HASHEXT
HASHEXT* instructions always consume 1 extra gas for each part of the input. Additionally, the following gas is consumed for each hashed byte:
Only the integer part of the gas is consumed; for example, 0-32 bytes of SHA256 cost 0 gas, 33-64 bytes cost 1 gas, and so on.
RIST255
Instructions consume constant extra gas.Other instructions
ECRECOVER consumes 1500 extra gas.
SECP256K1_XONLY_PUBKEY_TWEAK_ADD consumes 1250 extra gas.
P256_CHKSIGNU and P256_CHKSIGNS consume 3500 extra gas.
BLS
Signature verification and aggregation
G1 group helpers
BLS_G1_MULTIEXP consumes 11375 + 630 * n + (8820 * n) / max(log₂ n, 4) extra gas, where n is the number of (point, scalar) pairs.
Instructions BLS_G1_ZERO and BLS_G1_ISZERO do not charge additional gas.
G2 group helpers
BLS_G2_MULTIEXP consumes 30388 + 1280 * n + (22840 * n) / max(log₂ n, 4) gas, where n is the number of (point, scalar) pairs.
Instructions BLS_G2_ZERO and BLS_G2_ISZERO do not charge additional gas.
Pairing and constants
BLS_PUSHR do not charge additional gas.