This makes it a little simpler to generate 'match' statements, and
it performs deduplication of identical arms. And it means I don't
have to think about as many strings like '{} {{ {}.. }} => {}'
when I'm trying to think about how instructions work :-).
* Rename `ILBuilder` to `FunctionBuilderContext` and update corresponding
code
* Refactor usages of ILBuilder to become FunctionBuilderContext,
update variable names to reflect this change
* Reformat to ensure that lines stay under 100 char limit
* Apply corrections from `rustfmt` to pass tests
* Rename variables to be more consistent with refactor of ILBuilder
In this case, it's a little nicer to just use more assertions,
which will print their line number indicating how far the test
got, when they fail.
And this allows the tests to be run in no_std configurations.
Compute the bound values for expand_fcvt_to_sint using bitwise integer
arithmetic rather than floating-point arithmetic, to avoid relying on
host floating point arithmetic.
This allows the assertions to be disabled in release builds, so that
the code is faster and smaller, at the expense of not performing the
checks. Assertions can be re-enabled in release builds with the
debug-assertions flag in Cargo.toml, as the top-level Cargo.toml
file does.
Previously, cretonne-wasm used its own Local struct for identifying
local variables. However, now that cretonne-frontend provides a
Variable struct, just use that instead.
Frontends can still use their own types with `ILBuilder` and
`FunctionBuilder`. This just provides a basic `Variable` struct
for frontends that want it.
* Elaborate on Cretonne's rustc backend goals.
* Remove these extra newlines. They don't show up in the rendered form anyway.
* Fix typo.
* The document is meant to speak with the voice of the project.
When relaxing a branch, restrict the set of candidate encodings to those which
have the same input constraints as the original encoding choice. This prevents
situations where relaxation prefers a non-REX-prefixed encoding over a REX
prefixed one because the end of the instruction can be one byte closer to the
destination, in a situation where the encoding needs to be REX-prefixed
because of one of the operand registers.
This also makes the Context class perform encoding verification after
relaxation, to catch similar problems in the future.
Fixes#256.
Cretonne's python scripts aren't run very often, so there's little
benefit in creating .pyc files. And the .pyc files cause trouble for
some vendoring scripts. So disable them.
Emergency stack slots are a new kind of stack slot added relatively
recently. They need to be allocated a stack offset just like explicit
and spill slots.
Also, make StackSlotData's offset field an Option, to catch problems
like this in the future. Previously the value 0 was used when offsets
weren't assigned yet, however that made it non-obvious when the field
meant "not assigned yet" and when it meant "assigned the value 0".
Spiderwasm on 32-bit x86 always uses a 16-byte-aligned stack pointer.
Change the setting for the "native" convention as well, for
compatibility with Linux and Darwin ABIs, and so that if a platform
has different ABI rules, the problem will be detected in code emitted by
Cretonne, rather than somewhere else.
The term "local variables" predated the SSA builder in the front-end
crate, which also provides a way to implement source-language local
variables. The name "explicit stack slot" makes it clear what this
construct is.
