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.
This significantly speeds up block import at the cost of less protection
against invalid data, potentially resulting in an invalid database
getting stored.
The risk is small given that import is used only for validated data -
evaluating the right level of of validation vs performance is left for a
future PR.
A side effect of this approach is that there is no cached stated root in
the database - computing it currently requires a lot of memory since the
intermediate roots get cached in memory in full while the computation is
ongoing - a future PR will need to address this deficiency, for example
by streaming the already-computed hashes directly to the database.
* 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
* Attempt to roll back stateless mode implementation in a single PR
why:
+ Stateless mode is not fully working and in the way
+ Single PR should make it feasible to investigate for a possible
re-implementation
* Fix copyright year
* Fix annotation for exception (evmc mode)
* Activate `LedgerRef` wrapper for `AccountsCache`
details:
`accounts_cache.nim` methods are indirectly processed by the wrapper
methods from `ledger.nim`.
This works for all sources except `test_state_db.nim` where the source
`accounts_cache.nim` is included (rather than imported) in order to
access objects privy to the very source.
* Provide facility to switch to a preselected `LedgerRef` type
details:
Can be set as suggestion when initialising `CommonRef`
* Update `CoreDb` test suite for better time tracking
details:
+ Allow time logging by pre-defined block intervals
+ Print `CoreDb`/`Ledger`profiling results (if enabled)
* CoreDB: Re-org API
details:
Legacy API internally uses vertex ID for root node abstraction
* Cosmetics: Move some unit test helpers to common sub-directory
* Extract constant from `accouns_cache.nim` => `constants.nim`
* Fix tracer methods
why:
Logger dump data were wrongly dumped from the production database. This
caused an assert exception when iterating over the persistent database
(instead of the memory logger.) This event in turn was enabled after
fixing another inconsistency which just set up an empty iterator. Unit
tests failed to detect that.
Also embed evmc_status_code to computation.error, and make
the tracer produce cleaner output. No more "Revert opcode executed"
error message. We can distinguish error code between REVERT
and FAILURE in a more cleaner way.
simplify EVM and delegete those things to accounts cache.
also no more manual state clearing, accounts cache will be
responsible for both collecting touched account and perform
state clearing.
* Silence some compiler gossip -- part 6, evm
details:
Adding some missing exception annotation
* Update evmc cases
why:
were previously missing
* Increase Windows stack needed to run EVMC unit tests
why:
After annotating functions to trace exceptions some unit tests started
to fail on Windows without clear error report.
EVMC works recursively and now there seems to be a stack problem
reported by the nim compiler. Increasing the NIM stack ass sugessted by
NIM (using -d:nimCallDepthLimit=###) had some effect but no clear
solution.
Note that this patch set unrolls some NIM compiler settings
* Reduce Nim 1.6 compiler warnings/hints for Fluffy and Nimbus proxy
Mostly raises Defect removals, TaintedString removal and some
unnecessary imports.
Also updating the copyright years alongside.
* Further reduce Nim 1.6 compiler warnings/hints for Nimbus
* Silence some compiler gossip -- part 5, common
details:
Mostly removing redundant imports and `Defect` tracer after switch
to nim 1.6
* Silence some compiler gossip -- part 6, db, rpc, utils
details:
Mostly removing redundant imports and `Defect` tracer after switch
to nim 1.6
* Silence some compiler gossip -- part 7, randomly collected source files
details:
Mostly removing redundant imports and `Defect` tracer after switch
to nim 1.6
* Silence some compiler gossip -- part 8, assorted tests
details:
Mostly removing redundant imports and `Defect` tracer after switch
to nim 1.6
* Clique update
why:
More impossible exceptions (undoes temporary fix from previous PR)
tersec
Jacek Sieka
andri lim
Jordan Hrycaj
Adam Spitz
Kim De Mey