In the current VM opcode dispatcher, a two-level case statement is
generated that first matches the opcode and then uses another nested
case statement to select the actual implementation based on which fork
it is, causing the dispatcher to grow by `O(opcodes) * O(forks)`.
The fork does not change between instructions causing significant
inefficiency for this approach - not only because it repeats the fork
lookup but also because of code size bloat and missed optimizations.
A second source of inefficiency in dispatching is the tracer code which
in the vast majority of cases is disabled but nevertheless sees multiple
conditionals being evaluated for each instruction only to remain
disabled throughout exeuction.
This PR rewrites the opcode dispatcher macro to generate a separate
dispatcher for each fork and tracer setting and goes on to pick the
right one at the start of the computation.
This has many advantages:
* much smaller dispatcher
* easier to compile
* better inlining
* fewer pointlessly repeated instruction
* simplified macro (!)
* slow "low-compiler-memory" dispatcher code can be removed
Net block import improvement at about 4-6% depending on the contract -
synthetic EVM benchmnarks would show an even better result most likely.
* Remove exception from evm memory
* Remove exception from gas meter
* Remove exception from stack
* Remove exception from precompiles
* Remove exception from gas_costs
* Remove exception from op handlers
* Remove exception from op dispatcher
* Remove exception from call_evm
* Remove exception from EVM
* Fix tools and tests
* Remove exception from EVMC
* fix evmc
* Fix evmc
* Remove remnants of async evm stuff
* Remove superflous error handling
* Proc to func
* Fix errors detected by CI
* Fix EVM op call stack usage
* REmove exception handling from getVmState
* Better error message instead of just doAssert
* Remove unused validation
* Remove superflous catchRaise
* Use results.expect instead of unsafeValue
Why?
Some opcodes such as labeled EIP-2929 changed their behavior from fixed
gas cost to dynamic gas cost.
This changes together with #1715 and #1717 will make the new EVM tracer
to produce trace result identical to geth.
* Recreating some of the speculative-execution code.
Not really using it yet. Also there's some new inefficiency in
memory.nim, but it's fixable - just haven't gotten around to it yet.
The big thing introduced here is the idea of "cells" for stack,
memory, and storage values. A cell is basically just a Future (though
there's also the option of making it an Identity - just a simple
distinct wrapper around a value - if you want to turn off the
asynchrony).
* Bumped nim-eth.
* Cleaned up a few comments.
* Bumped nim-secp256k1.
* Oops.
* Fixing a few compiler errors that show up with EVMC enabled.
Jacek Sieka
andri lim
Adam Spitz