* Only save callee-saved registers that are actually being used.
* Rename AllocatableSet to RegisterSet
* Style cleanup and small renames for readability.
* Adjust x86 prologue-epilogue test to account for callee-saved register optimization.
* Add more tests for prologue-epilogue optimizations.
Merge the `use` parts of the `no_std` branch. This reduces the diffs
between master and the `no_std` branch, making it easier to maintain.
Most of these changes are derived from patches by @lachlansneff in
https://github.com/Cretonne/cretonne/tree/no_std.
Add EBB parameter and EBB argument to the langref glossary to clarify
the distinction between formal EBB parameter values and arguments passed
to branches.
- Replace "ebb_arg" with "ebb_param" in function names that deal with
EBB parameters.
- Rename the ValueDef variants to Result and Param.
- A bunch of other small langref fixes.
No functional changes intended.
Replace the isa::Legalize enumeration with a function pointer. This
allows an ISA to define its own specific legalization actions instead of
relying on the default two.
Generate a LEGALIZE_ACTIONS table for each ISA which contains
legalization function pointers indexed by the legalization codes that
are already in the encoding tables. Include this table in
isa/*/enc_tables.rs.
Give the `Encodings` iterator a reference to the action table and change
its `legalize()` method to return a function pointer instead of an
ISA-specific code.
The Result<> returned from TargetIsa::encode() no longer implements
Debug, so eliminate uses of unwrap and expect on that type.
The new encoding format allows entries that mean "stop with this
legalization code" which makes it possible to configure legalization
actions per instruction, instead of only per controlling type variable.
This patch adds the Rust side of the legalization codes:
- Add an `Encodings::legalize()` method on the encoding iterator which
can be called after the iterator has returned `None`. The returned
code is either the default legalization action for the type, or a
specific code encountered in the encoding list.
- Change `lookup_enclist` to return a full iterator instead of just an
offset. The two-phase lookup can bail at multiple points, each time
with a default legalization code from the level 1 table. This default
legalization code is stored in the returned iterator.
- Change all the implementations of legal_encodings() in the ISA
implementations.
This change means that we don't need to return a Result any longer. The
`Encodings` iterator can be empty with an associated legalization code.
Instead of generating a single `check_instp()` function, create an array
of individual function pointers for checking instruction predicates.
This makes explicit the jump table in the old check_instp() method and
it gives us a way of determining the number of instruction predicates
that exists.
It turns out that most encoding predicates are expressed as recipe
predicates. This means that the encoding tables can be more compact
since we can check the recipe predicate separately from individual
instruction predicates, and the recipe number is already present in the
table.
- Don't combine recipe and encoding-specific predicates when creating an
Encoding. Keep them separate.
- Generate a table of recipe predicates with function pointers. Many of
these are null.
- Check any recipe predicate before accepting a recipe+bits pair.
This has the effect of making almost all instruction predicates
CODE_ALWAYS.
The encoding tables contain references to numbered ISA predicates.
- Give the ISA Flags types a predicate_view() method which returns a
PredicateView.
- Delete the old predicate_bytes() method which returned a raw &[u8].
- Use a 'static lifetime for the encoding list slice in the Encodings
iterator, and a single 'a lifetime for everything else.
Register locations can change throughout an EBB. Make sure the
emit_inst() function considers this when encoding instructions and
update the register diversion tracker.
This function will emit the binary machine code into contiguous raw
memory while sending relocations to a RelocSink.
Add a MemoryCodeSink for generating machine code directly into memory
efficiently. Allow the TargetIsa to provide emit_function
implementations that are specialized to the MemoryCodeSink type to avoid
needless small virtual callbacks to put1() et etc.
Fixes#11.
Presets are groups of settings and values applied at once. This is used
as a shorthand in test files, so for example "isa intel nehalem" enables
all of the CPUID bits that the Nehalem micro-architecture provides.
* Implement an iterator over encodings
* Implement TargetIsa::legal_encodings
* Exclude non-boolean settings of isa flags bytes
* Address flake8 long line error
The legalize_signature() function will return ArgumentLoc::Reg arguments
that contain a register unit. However, the register also needs to be
able to associate a register class with the argument values to fully
track the used registers.
When values are defined by instructions, the register class is part for
the operand constraints for the instruction. For values defined on ABI
boundaries like function arguments and return values from a call, the
register class is provided by the new regclass_for_abi_type() function.
Provide implementations of this function in abi modules of all the
targets, even those that don't have a legalize_signature()
implementation yet.
Since we're adding abi modules to all targets, move the
legalize_signature() stubs in there and make the function mandatory in
TargetIsa. All targets will eventually need this function.
These special-purpose arguments and return values are only relevant for
the function being compiled, so add a `current` flag to
legalize_signature().
- Add the necessary argument values to the entry block to represent
the special-purpose arguments.
- Propagate the link and sret arguments to return instructions if the
legalized signature asks for it.
All values are now references into the value table, so drop the
distinction between direct and table values. Direct values don't exist
any more.
Also remove the parser support for the 'vxNN' syntax. Only 'vNN' values
can be parsed now.
Soon, InstructionData won't have sufficient information to compute this.
Give TargetIsa::encode() an explicit ctrl_typevar argument. This
function does not require the instruction to be inserted in the DFG
tables.
The tables returned by recipe_names() and recipe_constraints() are now
collected into an EncInfo struct that is available from
TargetIsa::encoding_info(). This is equivalent to the register bank
tables available fro TargetIsa::register_info().
This cleans of the TargetIsa interface and makes it easier to add
encoding-related information.
Not all br_icmp opcodes are present in the ISA. The missing ones can be
reached by commuting operands.
Don't attempt to encode EBB offsets yet. For now just emit an EBB
relocation for the branch instruction.
Use the meta language encoding recipes to generate an emit_inst()
function for each ISA. The generated calls into recipe_*() functions
that must be implemented by hand.
Implement recipe_*() functions for the RISC-V recipes.
Add the TargetIsa::emit_inst() entry point which emits an instruction to
a CodeSink trait object.
This entry point will be used for controlling ABI conventions when
legalizing.
Provide an empty implementation for RISC-V and let the other ISAs crash
in legalization.
This is just the scaffolding. We still need to:
- Rewrite the entry block arguments to match the legalized signature.
- Rewrite call and return instructions.
- Implement the legalize_signature() function for all ISAs.
- Add shared generic types to help with the legalize_signature()
functions.
Some polymorphic instructions don't return the controlling type
variable, so it has to be computed from the designated operand instead.
- Add a requires_typevar_operand() method to the operand constraints
which indicates that.
- Add a ctrl_typevar(dfg) method to InstructionData which computes the
controlling type variable correctly, and returns VOID for monomorphic
instructions.
- Use ctrl_typevar(dfg) to drive the level-1 encoding table lookups.
Every encoding recipe must specify register constraints on input and
output values.
Generate recipe constraint tables along with the other encoding tables.
Give these crates each a more standard directory layout with sources in
a 'src' sub-sirectory and Cargo.toml in the top lib/foo directory.
Add license and description fields to each.
The build script for the cretonne crate now lives in
'lib/cretonne/build.rs' separating it from the normal library sources
under 'lib/cretonne/src'.
