Update readme

README.md

@@ -1,16 +1,96 @@
 # Lightbeam
 
-This is an early-stage experimental project to build a single-pass
-linear-time wasm-function-to-machine-code translator.
+Lightbeam is an optimising one-pass streaming compiler for WebAssembly, intended for use in [Wasmtime][wasmtime].
 
-It's currently built with [dynasm](https://crates.io/crates/dynasm) and
-targets x86-64, however the function\_body.rs/backend.rs split is likely
-to evolve towards a configuration point allowing other targets or even
-other assemblers to be supported.
+[wasmtime]: https://github.com/CraneStation/wasmtime
 
-It's a very early stage project, and a good one for learning how
-WebAssembly works at a low level, for learning assembly programming, or
-both! And we're happy to mentor. So welcome, and check out the
-[issue tracker] to see what's happening and how to get involved!
+## Specification compliance
 
+It's hard to judge, since each test in the spec testsuite covers a wide range of features (to check their interactions), but currently 28 out of 77 of the spec suite tests pass when run in Wasmtime with Lightbeam as a backend. Here's the full test output:
+
+```
+running 76 tests
+test misc_testsuite::stack_overflow ... ok
+test spec_testsuite::align ... FAILED
+test spec_testsuite::binary ... ok
+test misc_testsuite::misc_traps ... ok
+test spec_testsuite::address ... FAILED
+test spec_testsuite::br_if ... FAILED
+test spec_testsuite::break_drop ... ok
+test spec_testsuite::block ... FAILED
+test spec_testsuite::call ... FAILED
+test spec_testsuite::comments ... ok
+test spec_testsuite::call_indirect ... FAILED
+test spec_testsuite::const_ ... ok
+test spec_testsuite::custom ... ok
+test spec_testsuite::custom_section ... ok
+test spec_testsuite::data ... ok
+test spec_testsuite::elem ... FAILED
+test spec_testsuite::conversions ... FAILED
+test spec_testsuite::endianness ... FAILED
+test spec_testsuite::exports ... ok
+test spec_testsuite::f32_bitwise ... FAILED
+test spec_testsuite::br ... ok
+test spec_testsuite::br_table ... FAILED
+test spec_testsuite::f32 ... FAILED
+test spec_testsuite::f64_bitwise ... FAILED
+test spec_testsuite::f32_cmp ... FAILED
+test spec_testsuite::fac ... ok
+test spec_testsuite::f64 ... FAILED
+test spec_testsuite::float_memory ... FAILED
+test spec_testsuite::float_literals ... FAILED
+test spec_testsuite::forward ... ok
+test spec_testsuite::func ... FAILED
+test spec_testsuite::func_ptrs ... FAILED
+test spec_testsuite::float_misc ... FAILED
+test spec_testsuite::get_local ... FAILED
+test spec_testsuite::globals ... FAILED
+test spec_testsuite::i64 ... FAILED
+test spec_testsuite::i32 ... FAILED
+test spec_testsuite::float_exprs ... FAILED
+test spec_testsuite::inline_module ... ok
+test spec_testsuite::if_ ... FAILED
+test spec_testsuite::imports ... FAILED
+test spec_testsuite::int_exprs ... FAILED
+test spec_testsuite::left_to_right ... FAILED
+test spec_testsuite::linking ... FAILED
+test spec_testsuite::labels ... ok
+test spec_testsuite::int_literals ... ok
+test spec_testsuite::loop_ ... FAILED
+test spec_testsuite::f64_cmp ... FAILED
+test spec_testsuite::memory ... FAILED
+test spec_testsuite::memory_redundancy ... FAILED
+test spec_testsuite::memory_grow ... FAILED
+test spec_testsuite::resizing ... FAILED
+test spec_testsuite::memory_trap ... FAILED
+test spec_testsuite::return_minimal ... ok
+test spec_testsuite::nop ... FAILED
+test spec_testsuite::set_local ... FAILED
+test spec_testsuite::select ... FAILED
+test spec_testsuite::stack ... FAILED
+test spec_testsuite::start ... FAILED
+test spec_testsuite::store_retval ... ok
+test spec_testsuite::switch ... FAILED
+test spec_testsuite::tee_local ... FAILED
+test spec_testsuite::token ... ok
+test spec_testsuite::traps ... FAILED
+test spec_testsuite::skip_stack_guard_page ... FAILED
+test spec_testsuite::type_ ... ok
+test spec_testsuite::typecheck ... ok
+test spec_testsuite::unreached_invalid ... ok
+test spec_testsuite::unwind ... FAILED
+test spec_testsuite::return_ ... ok
+test spec_testsuite::utf8_custom_section_id ... ok
+test spec_testsuite::utf8_import_field ... ok
+test spec_testsuite::utf8_import_module ... ok
+test spec_testsuite::utf8_invalid_encoding ... ok
+test spec_testsuite::unreachable ... ok
+test spec_testsuite::names ... FAILED
+```
+
+## Getting involved
+
+Our [issue tracker][issue tracker] is pretty barren right now since this is currently more-or-less a one-person project, but if you want to get involved jump into the [CraneStation Gitter room][cranestation-gitter] and someone can direct you to the right place. I wish I could say "the most useful thing you can do is play with it and open issues where you find problems" but until it passes the spec suite that won't be very helpful.
+
+[cranestation-gitter]: https://gitter.im/CraneStation/Lobby
 [issue tracker]: https://github.com/CraneStation/lightbeam/issues