Commit Graph

28 Commits

Author SHA1 Message Date
Denis Merigoux
962c945a3c Cretonne IL frontend: ILBuilder (#97)
* API and data structures proposal for the SSA construction module

* Polished API and implemented trivial functions

* API more explicit, Variable now struct parameter

* Sample test written to see how the API could be used

* Implemented local value numbering for SSABuilder

* Implemented SSA within a single Ebb

* Unfinished unoptimized implementation for recursive use and seal

* Working global value numbering
The SSABuilder now create ebb args and modifies jump instructions accordingly

* Updated doc and improved branch argument modifying.
Removed instructions::branch_arguments and instructions::branch_argument_mut

* SSA building: bugfix, asserts and new test case
Missing a key optimization to remove cycles of Phi

* SSA Building: small changes after code review
Created helper function for seal_block (which now contains sanity checks)

* Optimization: removed useless phis (ebb arguments)
Using pessimistic assumption that when using a non-def variable in an unsealed block we create an ebb argument which is removed when sealing if we detect it as useless
Using aliases to avoid rewriting variables

* Changed the semantics of remove_ebb_arg and turned it into a proper API method

* Adapted ssa branch to changes in the DFG API

* Abandonned SparseMaps for EntityMaps, added named structure for headr block data.

* Created skeletton for a Cretonne IL builder frontend

* Frontend IL builder: first draft of implementation with example of instruction methods

* Working basic implementation of the frontend
Missing handling of function arguments and return values

* Interaction with function signature, sample test, more checks

* Test with function verifier, seal and fill sanity check

* Implemented python script to generate ILBuilder methods

* Added support for jump tables and stack slot

* Major API overhaul
* No longer generating rust through Python but implements InstBuilder
* No longer parametrized by user's blocks but use regular `Ebb`
* Reuse of allocated memory via distinction between ILBuilder and FunctionBuilder

* Integrate changes from StackSlot

* Improved error message

* Added support for jump arguments supplied by the user

* Added an ebb_args proxy method needed

* Adapted to Entity_ref splitted into a new module

* Better error messages and fixed tests

* Added method to change jump destination

* We whould be able to add unreachable code

* Added inst_result proxy to frontend

* Import support

* Added optimization for SSA construction:
If multiple predecessors but agree on value don't create EBB argument

* Move unsafe and not write-only funcs apart, improved doc

* Added proxy function for append_ebb_arg

* Support for unreachable code and better layout of the Ebbs

* Fixed a bug yielding an infinite loop in SSA construction

* SSA predecessors lookup code refactoring

* Fixed bug in unreachable definition

* New sanity check and display debug function

* Fixed bug in verifier and added is_pristine ;ethod for frontend

* Extended set of characters printable in function names
To be able to print names of functions in test suite

* Fixes and improvements of SSA construction after code review

* Bugfixes for frontend code simplification

* On-the-fly critical edge splitting in case of br_table with jump arguments

* No more dangling undefined values, now attached as EBB args

* Bugfix: only split corresponding edges on demand, not all br_table edges

* Added signature retrieval method

* Bugfix for critical edge splitting not sealing the ebbs it created

* Proper handling of SSA side effects by the frontend

* Code refactoring: moving frontend and SSA to new crate

* Frontend: small changes and bugfixes after code review
2017-07-11 15:08:57 -07:00
Benjamin Bouvier
29dc723e25 Update rustfmt to 0.8.4; (#81) 2017-05-15 15:10:47 -07:00
Jakob Stoklund Olesen
950838c489 Add a regmove instruction.
This will be used to locally change the register locations of values in
order to satisfy instruction constraints.
2017-05-02 11:32:12 -07:00
Jakob Stoklund Olesen
ee5f035e31 Upgrade to Rust 1.17.
- Remove some uses of 'static in const and static globals that are no
  longer needed.
- Use the new struct initialization shorthand.
2017-04-27 12:46:44 -07:00
Jakob Stoklund Olesen
48b2f421b4 Add a with_results() method to the InsertBuilder.
This makes it possible to reuse one or more result values in the
instruction that is being inserted.

Also add a with_result(v) method for the common case of reusing a single
result value. This could be specialized in the future.
2017-04-13 08:55:18 -07:00
Jakob Stoklund Olesen
b165d9a313 Remove the first_type() methods from InstructionData.
Also remove the type field from all the variants. The type of the first
result value can be recovered from the value table now.
2017-04-12 14:32:13 -07:00
Jakob Stoklund Olesen
78a036fa51 Remove the second_result field from instructions.
Now that result values are stored in value lists in the DFG, these
head-of-list pointers are no longer needed.
2017-04-12 09:14:39 -07:00
Jakob Stoklund Olesen
71338bb31f Simplify the back-end of InstBuilder.
We don't want to distinguish between single-result and multiple-result
instructions any longer.

- Merge the simple_instruction() and complex_instruction() builder
  methods into a single build() that can handle all cases.
- All format constructors now take a ctrl_type argument. Previously,
  some would take a result_type argument.
- Instruction constructors no longer attempt to compute a single result
  type. Just pass a ctrl_type and let the backend decide.

Fix one format constructor call in legalizer/split.rs which now takes a
ctrl_type instead of a result type.
2017-04-12 08:56:20 -07:00
Jakob Stoklund Olesen
322a8db839 Change dfg.inst_results to return a slice.
Now we can access instruction results and arguments as well as EBB
arguments as slices.

Delete the Values iterator which was traversing the linked lists of
values. It is no longer needed.
2017-04-11 16:57:15 -07:00
Jakob Stoklund Olesen
aad6ebebb5 Add load and store instructions.
Define a MemFlags class, currently holding a notrap and aligned flag.
2017-04-11 09:54:55 -07:00
Jakob Stoklund Olesen
b474485c0d Add heap_load, heap_store, and heap_addr instructions.
These are used when lowering WebAssembly sandbox code.
2017-04-10 15:04:33 -07:00
Jakob Stoklund Olesen
222ae8af22 Define stack_load, stack_store, and stack_addr instructions. 2017-04-10 13:56:57 -07:00
Jakob Stoklund Olesen
1984c96f7c rustfmt 0.8.1 2017-04-05 09:00:11 -07:00
Jakob Stoklund Olesen
910e4e6174 Coalesce some formats into MultiAry.
Allow some flexibility in the signature matching for instruction
formats. In particular, look for a value list format as a second chance
option.

The Return, ReturnReg, and TernaryOverflow formats all fit the single
MultiAry catch-all format for instructions without immediate operands.
2017-03-10 12:32:44 -08:00
Jakob Stoklund Olesen
9fbfd0d2a6 Remove the vconst instruction and the UnaryImmVector format.
No instruction sets actually have single instructions for materializing
vector constants. You always need to use a constant pool.

Cretonne doesn't have constant pools yet, but it will in the future, and
that is how vector constants should be represented.
2017-03-10 11:57:49 -08:00
Jakob Stoklund Olesen
d301fb9f2b Convert return formats to value lists.
With the Return and ReturnReg formats converted to using value lists for
storing their arguments, thee are no remaining instruction formats with
variable argument lists in boxed storage.

The Return and ReturnReg formats are also going to be merged since
they are identical now.
2017-03-09 15:56:33 -08:00
Jakob Stoklund Olesen
a6c2cc71df Use value lists for call arguments.
Add a new kind of instruction format that keeps all of its value
arguments in a value list. These value lists are all allocated out of
the dfg.value_lists memory pool.

Instruction formats with the value_list property set store *all* of
their value arguments in a single value list. There is no distinction
between fixed arguments and variable arguments.

Change the Call instruction format to use the value list representation
for its arguments.

This change is only the beginning. The intent is to eliminate the
boxed_storage instruction formats completely. Value lists use less
memory, and when the transition is complete, InstructionData will have a
trivial Drop implementation.
2017-03-09 14:34:07 -08:00
Jakob Stoklund Olesen
f8e4d4e839 Speling. 2017-02-03 12:49:40 -08:00
Jakob Stoklund Olesen
0d77b19708 Use PackedOption<Value> instead of NO_VALUE.
- Remove NO_VALUE and ExpandedValue::None.
- Remove the Default implelmentation for Value.
- InstructionData::second_result() returns an Option<Value>.
- InstructionData::second_result() returns a reference to the packed
  option.
2017-01-19 15:55:18 -08:00
Jakob Stoklund Olesen
31e033af49 File stale path references.
After rearranging the directory layout, some paths in documentation
needed updating.

Fix some typos too.
2016-10-24 13:27:10 -07:00
Jakob Stoklund Olesen
e7a17a1b59 Properly infer result type for single-result instructions.
Polymorphic single-result instructions don't always return the
controlling type variable as their first result. They may use a derived
type variable, as for example icmp does.
2016-10-21 11:10:26 -07:00
Jakob Stoklund Olesen
8422976d78 Add a ReplaceBuilder instruction builder.
The DataFlowGraph::replace(inst) method returns an instruction builder
that will replace an instruction in-place.

This will be used when transforming instructions, replacing an old
instruction with a new (legal) way of computing its primary value. Since
primary result values are essentially instruction pointers, this is the
only way of replacing the definition of a value.

If secondary result values match the old instruction in both number and
types, they can be reused. If not, added a detach_secondary_results()
method for detaching old secondary values.
2016-10-20 13:33:49 -07:00
Jakob Stoklund Olesen
d763bedeaa Rename Builder to InsertBuilder.
This instruction builder inserts an instruction at the cursor position.
We'll add other kinds of builders shortly.
2016-10-20 11:16:58 -07:00
Jakob Stoklund Olesen
5f140eddf7 Switch InstrBuilder to the one-shot builder pattern.
All the InstrBuilder methods now consume the builder, and the non-leaf
methods return the dfg mutable reference they were holding.

This makes it possible to construct instruction builders that are only
safe to use once because they are doing more advanced value rewriting.
2016-10-19 19:33:48 -07:00
Jakob Stoklund Olesen
4cd33b210e Use more precise lifetimes for Builder.
Distinguish the lifetime of the Cursor and its referenced function
layout.

Use two separate function lifetimes: 'fc and 'fd. The borrow checker
seems to get confused if we don't.
2016-10-19 19:32:57 -07:00
Jakob Stoklund Olesen
eef5de1cf0 Generate an InstBuilder trait.
All of the instruction format an opcode methods are emitted as an
InstBuilder trait instead of adding them to the Bulder struct directly.
The methods only make use of the InstBuilderBase methods to create new
instructions.

This makes it possible to reuse the InstBuilder trait for different ways
of inserting instructions.
2016-10-19 18:21:17 -07:00
Jakob Stoklund Olesen
bdc95990d4 Add call and call_indirect instructions.
Add a new IndirectCall instruction format which has a value callee as
well as the call arguments.

Define call and call_indirect instructions.
2016-10-18 10:04:06 -07:00
Jakob Stoklund Olesen
846db00a21 Move library crates under 'lib/'.
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'.
2016-10-17 14:44:43 -07:00