This also allows `Instruction` to be `Copy`, which massively speeds
up `<Instructions as Clone>::clone` since it can now just `memcpy`
the bytes using SIMD instead of having to switch on every single
element. I haven't looked at the disassembly of `InstructionIter::next`
yet, it could be that there are even more improvements yet to be gained
from either:
* Only doing work on `BrTable` (this might already be the case depending
on the whims of the optimiser)
* Using `unsafe` to make it a noop (we really don't want to do this,
obviously, since it means that `Instructions` has to be immovable)
* add default-enabled std feature
* use parity-wasm/std feature only if std is enabled
* drop dependency on std::io
* use hashmap_core instead of std::collections::HashMap
* disable std::error in no_std
* core and alloc all the things
* mention no_std in readme
* add no_std feature and use hashmap_core only on no_std
* rename the no_std feature to core
* drop dependency on byteorder/std
* simplify float impl macro
* remove some trailing whitespace
* use libm for float math in no_std
* add note about no_std panics of libm to readme
* Embed nan-preserving-float crate.
* Add no_std check to the Travis CI config
* add missing dev-dependency
* Hide Instructions implementation behind an iterator
* Hide instruction encoding behind isa::Instructions::push()
* Consistently use u32 for program counter storage
* Refer to instructions by position rather than index
* Define Instruction Set.
* WIP
* WIP 2
* Tests
* Working
* Bunch of other tests.
* WIP
* WIP
* Use Vec instead of VecDeque.
* Calibrate the limits.
* Clean
* Clean
* Another round of cleaning.
* Ignore traces.
* Optimize value stack
* Optimize a bit more.
* Cache memory index.
* Inline always instruction dispatch function.
* Comments.
* Clean
* Clean
* Use vector to keep unresolved references.
* Estimate resulting size.
* do refactoring
* Validate the locals count in the begging
* Introduce Keep and DropKeep structs in isa
* Rename/Split Validator into Reader
* Document stack layout
* Remove println!
* Fix typo.
* Use .last / .last_mut in stack
* Update docs for BrTable.
* Review fixes.
* Merge.
* Add an assert that stack is empty after the exec
Fixes#63
Fix is simple: all labels refered by the br_table instruction must have same value type (or NoResult in case if they don't have result). So we just take the default label and check other labels against it.
These limits seems to be picked arbitrary, and I just made it arbitrary larger.
We need to reconsider these limits, ideally providing to user a way to customize the limits.
FWIW, When the last time I've tried to run gcc's torture testsuite with wasmi it also bumped into this limit.
Fixes#41.