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.
The value_list flag can be inferred from the presence of VARIABLE_ARGS
in the operand list.
The boxed_storage flag is obsolete. We don't need boxed storage anywhere
no that we have value lists instead.
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.
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.
Instruction formats are now identified by a signature that doesn't
include the ordering of value operands relative to immediate operands.
This means that the BinaryRev instruction format becomes redundant, so
delete it. The isub_imm instruction was the only one using that format.
Rename it to irsub_imm to make it clear what it does now that it is
printed as 'irsub_imm v2, 45'.
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.
The Branch format also stores its fixed argument in the value list. This
requires the value pool to be passed to a few more functions.
Note that this actually makes the Branch and Jump variants of
InstructionData identical. The instruction format hashing does not yet
understand that all value operands are stored in the value list. We'll
fix that in a later patch.
Also convert IndirectCall, noting that Call and IndirectCall remain
separate instruction formats because they have different immediate
fields.
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.
