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.
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.
This is the first step of a larger refactoring to represent instruction
results as value lists instead of using linked lists. The refactoring
will also eliminate the special treatment of first results such that all
result values can be detached and redefined.
This change put us in a temporary state where results are represented
both as linked lists and ValueList vectors.
- Add a dfg.results table.
- Add the first result in make_inst(). This behavior will change.
- Recompute the result list in make_inst_results().
- Make dfg.first_result(inst) crash if the instruction has no results.
This is the same as slice::first(), except it returns the first element
by value.
The implementation can avoid checking the list length since empty lists
already have a special representation.
- Add a dfg.is_inst_valid() method for the verifier.
- Use the inst_args_mut() method when rewriting values in the parser.
- Add a new branch_destination_mut() to use when rewriting EBBs.
This also gets rid of one of the large instruction format switches in
the parser.
Now that we have a value list of the arguments, we can get rid of:
- The first_arg and last_arg members in EbbData,
- The next member in the ValueData::Arg variant.
Rather than returning the head of a linked list of EBB arguments, just
return the whole value list of all the arguments.
Delete the next_ebb_arg() method which was only used for traversing that
list.
This is the first step of the value list refactoring which will replace
linked lists of values with value lists.
- Keep a ValueList in the EbbData struct containing all the EBB
arguments.
- Change dfg.ebb_args() to return a slice instead of an iterator.
This leaves us in a temporary hybrid state where we maintain both a
linked list and a ValueList vector of the EBB arguments.
Any *.cton files in the docs directory are now included when running the
test-all.sh script. This is to ensure that the examples are in fact
correct IL.
Always print NaN and Inf floats with a sign. Print the positive ones as
+NaN and +Inf to make them easier to parse.
This affects the comparison instructions which now read "icmp ult a, b".
This mimics LLVM's style and makes it simpler to add instruction flags
in the future, such as "load v1" -> "load aligned v1".
These enumerated operands and flags feel like opcode modifiers rather
than value operands, so displaying them differently makes sense.
Value and numeric operands are still comma separated.
Compute exact EBB header offsets and check that branches are in range.
Not implemented yet: Relax branches that are not in range.
Invoke the relax_branches() pass from the 'test binemit' file tests so
they can verify the proper encoding of branch instructions too.
Two new pieces of information are available for all encoding recipes:
- The size in bytes of an encoded instruction, and
- The range of a branch encoded with the recipe, if any.
In the meta language, EncRecipe takes two new constructor arguments. The
size is required for all encodings and branch_range is required for all
recipes used to encode branches.
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.
This instruction behaves like icmp fused with brnz, and it can be used
to represent fused compare+branch instruction on Intel when optimizing
for macro-op fusion.
RISC-V provides compare-and-branch instructions directly, and it is
needed there too.
Compare a scalar integer to an immediate constant. Both Intel and RISC-V
ISAs have this operation.
This requires the addition of a new IntCompareImm instruction format.
When defining an instruction encoding, allow part of the instruction
predicate to be provided as operands on the instruction opcode:
icmp.i32(intcc.ult, x, y)
This generates an instruction predicate that checks
IntCompare.cond == IntCC::UnsignedLessThan
Compute an instruction predicate from any constant values given as
arguments for the immediate operands in an instruction pattern.
Allows for patterns like icmp.i32(intcc.ugt, x, y) or iadd_imm.i32(x, 1)
Trap these predicates in the legalizer code generator since we can't
actually handle them yet.
Consolidate the imm_members and imm_kinds into this list so the
FormatField is the single definition of these properties.
This makes it easier to access the precomputed FormatFields
parametrically, avoiding going through getattr().
This is better for type checking too.
