Old implementation could view 0x62 byte in
a script as a JMP instruction irregardless of whether it is
a real opcode or a part of a parameter of another instruction.
In this commit instructions are decoded together with parameters
during jump label rewriting.
Creating a new BinReader for every instruction is a bit too much and it adds
about 1% overhead on block import (and actually is quite visible in the VM
profiling statistics). So use a bit more ugly but efficient method.
go vet is not happy about them:
pkg/io/binaryReader.go:92:21: method ReadByte() byte should have signature ReadByte() (byte, error)
pkg/io/binaryWriter.go:75:21: method WriteByte(u8 byte) should have signature WriteByte(byte) error
This seriously improves the serialization/deserialization performance for
several reasons:
* no time spent in `binary` reflection
* no memory allocations being made on every read/write
* uses fast ReadBytes everywhere it's appropriate
It also makes Fixed8 Serializable just for convenience.
This allows easier reuse of opcodes and in some cases allows to eliminate
dependencies on the whole vm package, like in compiler that only needs opcodes
and doesn't care about VM for any other purpose.
And yes, they're opcodes because an instruction is a whole thing with
operands, that's what context.Next() returns.
Same thing done in a2a8981979 for PUSHBYTES,
failing to read the amount of bytes specified should lead to FAULT. Also
makes readUint16() and readUint32() panic as this is the behavior we want in
these cases. Add some tests along the way.
Before:
NEO-GO-VM > loadgo h.go
READY: loaded 16 instructions
NEO-GO-VM > ip
instruction pointer at -1 (PUSH0)
After:
NEO-GO-VM > loadgo h.go
READY: loaded 16 instructions
NEO-GO-VM > ip
instruction pointer at -1 (NOP)
I think NOP is a little less scary.
* renamed test folders and fixed bug where wrong jump labels would be exectuted for rewrite.
* Added support for Osize (len(string)) and factored out the array tests
* Added current instruction number to VM prompt if program is loaded.
* added support for unary expressions.
* updated README of and sorted the help commands
* updated readme of the compiler
* bumped version -> 0.39.0
* changed vm commands to match more of the standard
* fixed Uint16 jmp bug in VM
* moved test to vm + fixed numnotequal bug
* fixed broken tests
* moved compiler tests to vm tests
* added basic for support + inc and dec stmts
* bumped version
* Virtual machine for the NEO blockhain.
* fixed big.Int numeric operation pointer issue.
* added appcall
* Added README for vm package.
* removed main.go
* started VM cli (prompt) integration
* added support for printing the stack.
* moved cli to vm package
* fixed vet errors
* updated readme
* added more test for VM and fixed some edge cases.
* bumped version -> 0.37.0
