Also:
- make sure to apply diversions when determining offsets for code
relaxation.
- select the smallest encoding when selecting a relaxed branch
instruction.
* Use single index for param register allocation for windows callconv (#691)
The used registers depend entirely on the parameter index (1st, 2nd, 3rd, 4th, ... param)
and we cannot shift unused registers to other indexes, if they are not designated for
the use for that parameter index.
This was previously using the following condition to decide that a block
hadn't been visited yet: either dest_offset is non-0 or the block isn't
the entry block. Unfortunately, this didn't work when the first block
would be non-empty but wouldn't generate code at all.
Since the original code would do at least one pass over the entire code,
the first pass that determines initial EBB offsets is done separately,
without considering branch relaxation. This ensures that all EBBs have
been visited and have correct initial offsets, and doesn't require a
special check to know whether an EBB has been visited or not.
Also, say "guard-offset pages" rather than just "guard pages" to describe the
region of a heap which is never accessible and which exists to support
optimizations for heap accesses with offsets.
And, introduce a `Uimm64` immediate type, and make all heap fields use
`Uimm64` instead of `Imm64` since they really are unsigned.
* Fix verifier printing to print instruction encodings consistently.
Use `FuncWriter::write_instruction` for all instructions so that
encodings are printed consistently.
* Make use-before-def errors mention the relevant value.
* When there are verifier errors, print a message at the end.
* Make verifier errors prettier.
Fix the length of the "^~~~~" to match the printed entity, and print the
error messsage on its own line.
* Clean up "test verifier" failure messages.
* Tidy the uses-value-from-itself error.
The use instruction is the same as the def instruction, so don't print
both. Also, the use instruction is already being printed at the
beginning, so don't print it again at the end.
This is a followup to af2a952aabd82cf401cc664d0262b139ff92d86b. It
teaches the spilling pass to use the is_ghost() property to test whether
to visit instructions. This fixes a bug handling multiple return values
with fallthrough_return.
Add an explicit "is_ghost" property to selected instructions, and use
that to determine whether reload and coloring should visit instructions.
This allows them to visit fallthrough_return instructions and insert
fills and register moves as needed.
When one value is used multiple times for separate return values, we
need to copy it to produce a new value, so that each value can be
allocated a different register.
* Introduce a `TargetFrontendConfig` type.
`TargetFrontendConfig` is information specific to the target which is
provided to frontends to allow them to produce Cranelift IR for the
target. Currently this includes the pointer size and the default calling
convention.
The default calling convention is now inferred from the target, rather
than being a setting. cranelift-native is now just a provider of target
information, rather than also being a provider of settings, which gives
it a clearer role.
And instead of having cranelift-frontend routines require the whole
`TargetIsa`, just require the `TargetFrontendConfig`, and add a way to
get the `TargetFrontendConfig` from a `Module`.
Fixes#529.
Fixes#555.
* Rename size to base_size and introduce a compute_size function;
* Add infra to inspect in/outs registers when computing the size of an instruction;
* Remove the GPR_SAFE_DEREF and GPR_ZERO_DEREF_SAFE register classes on x86 (fixes#335);
* Move `return_at_end` out of Settings and into the wasm FuncEnvironment.
The `return_at_end` flag supports users that want to append a custom
epilogue to Cranelift-produced functions. It arranges for functions to
always return via a single return statement at the end, and users are
expected to remove this return to append their code.
This patch makes two changes:
- First, introduce a `fallthrough_return` instruction and use that
instead of adding a `return` at the end. That's simpler than having
users remove the `return` themselves.
- Second, move this setting out of the Settings and into the wasm
FuncEnvironment. This flag isn't something the code generator uses,
it's something that the wasm translator uses. The code generator
needs to preserve the property, however we can give the
`fallthrough_return` instruction properties to ensure this as needed,
such as marking it non-cloneable.
WebAssembly doesn't have non-dense jump tables, and higher-level users
are better served by the facilities in lib/frontend/src/switch.rs for
working with non-dense switches.
This eliminates the concept of "absent" jump table entries, which
were represented as "0" in the text format.
Also, jump table contents are now enclosed in `[` and `]`, so that
we can unambiguously display empty jump tables. Previously, empty jump
tables were displayed as if they had a single absent entry.
* Add encodings for i8 and i16 copy, spill, fill, ireduce.i8.i16
Also adds legalization for srem, irsub_imm, {u,s}extend.i16.i8
Fixes#477 cc #466
* Legalize popcnt, clz and ctz for i8 and i16
* Fix bug in call_memset
* Add 'jump_table_entry' and 'indirect_jump' instructions.
* Update CodeSink to keep track of code size. Pretty up clif-util's disassembly output.
* Only disassemble the machine portion of output. Pretty print the read-only data after it.
* Update switch frontend code to use new br_table instruction w/ default.
* Reorganize the global value kinds.
This:
- renames "deref" global values to "load" and gives it a offset that works
like the "load" instructions' does
- adds an explicit "iadd_imm" global value kind, which replaces the
builtin iadd in "vmctx" and "deref" global values.
- also renames "globalsym" to "symbol"
