Merge pull request #188 from ethereum/changelog

changelog: Add released notes for 0.2

CHANGELOG.md

@@ -6,32 +6,112 @@ The format is based on [Keep a Changelog],
 and this project adheres to [Semantic Versioning].
 
 ## [0.2.0] - unreleased
+
+This release of evmone is binary compatible with 0.1 and delivers big performance improvements
+– both code preprocessing and execution is **~66%** faster (needs ~40% less time).
+
 ### Added
-- **evm-test** - the testing tool for EVMC-compatible Ethereum Virtual Machine implementations
-  [#85](https://github.com/ethereum/evmone/pull/85).
+- **evm-test** – the testing tool for [EVMC]-compatible EVM implementations.
+  [#85](https://github.com/ethereum/evmone/pull/85)
+- **evmone-fuzzer** – the testing tool that fuzzes evmone execution against [aleth-interpreter][Aleth] execution.
+  Any other [EVMC]-compatible EVM implementation can be added easily.
+  [#162](https://github.com/ethereum/evmone/pull/162)
+  [#184](https://github.com/ethereum/evmone/pull/184)
+- **evmone-standalone** – single static library that bundles evmone with all its static library dependencies 
+  (available on Linux, but support can be extended to other platforms).
+  [#95](https://github.com/ethereum/evmone/pull/95)
+- The **evmone-bench** tool has learned how to benchmark external [EVMC]-compatible EVMs.
+  [#111](https://github.com/ethereum/evmone/pull/111)
+- The **evmone-bench** tool sorts test cases by file names and allows organizing them in subfolders.
+  [#150](https://github.com/ethereum/evmone/pull/150)
+- The docker image [ethereum/evmone](https://hub.docker.com/r/ethereum/evmone)
+  with evmone and modified geth is available on Docker Hub.
+  [#127](https://github.com/ethereum/evmone/pull/127)
+
+
+### Changed
+
+#### Optimizations
+
+- Instead of checking basic block preconditions (base gas cost, stack requirements) in the dispatch loop, 
+  this is now done in the special "BEGINBLOCK" instruction — execution time reduction **-2–8%**.
+  [#74](https://github.com/ethereum/evmone/pull/74)
+- New EVM stack implementation has replaced naïve usage of `std::vector<intx::uint256>` — **-8–16%**.
+  [#79](https://github.com/ethereum/evmone/pull/79)
+- Improvements to interpreter's dispatch loop — **-4–9%**.
+  [#107](https://github.com/ethereum/evmone/pull/107)
+- Optimization of the JUMPDEST map — up to **-34%**.
+  [#80](https://github.com/ethereum/evmone/pull/80)
+- Optimizations to code preprocessing / analysis.
+  [#121](https://github.com/ethereum/evmone/pull/121)
+  [#125](https://github.com/ethereum/evmone/pull/125)
+  [#153](https://github.com/ethereum/evmone/pull/153)
+  [#168](https://github.com/ethereum/evmone/pull/168)
+  [#178](https://github.com/ethereum/evmone/pull/178)
+- Push instructions with values up to 8 bytes (PUSH1–PUSH8)
+  are now handled much more efficiently — up to **-9%**.
+  [#122](https://github.com/ethereum/evmone/pull/122)
+- Pointer to next instruction is now obtained in instruction implementations 
+  (instead of the dispatch loop) and is kept in CPU registers only — **-3–7%**.
+  [#133](https://github.com/ethereum/evmone/pull/133)
+- The run-time information about basic blocks has been compressed.
+  [#139](https://github.com/ethereum/evmone/pull/139)
+  [#144](https://github.com/ethereum/evmone/pull/144)
+
+#### Other changes
+
+- The DUP, SWAP, LOG and CALL instructions are now implemented by individual functions (template instances)
+  instead of a parametrized function handling each family of instructions.
+  [#126](https://github.com/ethereum/evmone/pull/126)
+  [#159](https://github.com/ethereum/evmone/pull/159)
+- [EVMC] upgraded to version [6.3.1](https://github.com/ethereum/evmc/releases/tag/v6.3.1).
+  [#129](https://github.com/ethereum/evmone/pull/129)
+  [#77](https://github.com/ethereum/evmone/pull/77)
+  [#96](https://github.com/ethereum/evmone/pull/96)
+- [intx] upgraded to version [0.4.0](https://github.com/chfast/intx/releases/tag/v0.4.0).
+  [#131](https://github.com/ethereum/evmone/pull/131)
+- The ability to provide custom opcode table for code preprocessing has been dropped.
+  [#167](https://github.com/ethereum/evmone/pull/167)
+
+
+### Fixed
+
+- The gas calculation for blocks containing an undefined instruction has been fixed.
+  This bug could not cause consensus issue because a block with an undefined instruction terminates 
+  with an exception despite incorrect gas checking.
+  However, execution might have ended with a confusing error code.
+  [#93](https://github.com/ethereum/evmone/pull/93)
+- Fix for LOG being emitted after _out-of-gas_ exception.
+  [#120](https://github.com/ethereum/evmone/pull/120)
 
 
 ## [0.1.1] - 2019-09-11
 ### Changed
 - [EVMC] upgraded to version 6.3.1 (still ABI-compatible with evmone 0.1.0).
-  [[#171](https://github.com/ethereum/evmone/pull/171)]
+  [#171](https://github.com/ethereum/evmone/pull/171)
 - Changes to the **evmone-bench** tool backported from 0.2. 
   This allows better performance comparison between 0.1 and 0.2 as both versions
   can run the same set of benchmarks.
-  [[#172](https://github.com/ethereum/evmone/pull/172)]
+  [#172](https://github.com/ethereum/evmone/pull/172)
 
 
 ## [0.1.0] - 2019-06-19
+
+The first release of the evmone project. 
+It delivers fully-compatible and high-speed EVM implementation.
+
 ### Added
-- First release of the evmone project.
 - Support for all current EVM revisions up to Petersburg.
+- Exposes [EVMC] 6 ABI.
 - The [intx 0.2.0](https://github.com/chfast/intx/releases/tag/v0.2.0) library is used for 256-bit precision arithmetic. 
 
 
 [0.2.0]: https://github.com/ethereum/evmone/compare/v0.1.0..master
 [0.1.1]: https://github.com/ethereum/evmone/releases/tag/v0.1.1
 [0.1.0]: https://github.com/ethereum/evmone/releases/tag/v0.1.0
 
+[Aleth]: https://github.com/ethereum/aleth
 [EVMC]: https://github.com/ethereum/evmc
+[intx]: https://github.com/chfast/intx
 [Keep a Changelog]: https://keepachangelog.com/en/1.0.0/
 [Semantic Versioning]: https://semver.org