Ebb parameters are appended explicitly by whoever calls create_block,
so they don't need to also be inferred from branches. This makes the
frontend code more flexible for producers that want to create things
in a different order, and it eliminates more temporary allocations.
FunctionBuilder no longer maintains its own list of the function
parameter values; these can be obtained from the ebb parameter list
on the entry block.
switch_to_block doesn't need its jump_args argument, since jump
arguments are handled by the `jump` instruction and others, rather
than on the switch to a new ebb itself.
The main change is that it avoids creating blank lines when processing
docstrings.
This also adds blank lines in various places to make the generated code
prettier.
These tests were only using "test compile" because it doesn't require
any filecheck directives to be present, so just stop requiring filecheck
directives for "test regalloc" and other filecheck-based test drivers.
Fixes#178.
When an instruction with a fixed output operand defines a globally live
SSA value, we need to check if the fixed register is available in the
`regs.global` set of registers that can be used across EBB boundaries.
If the fixed output register is not available in regs.global, set the
replace_global_defines flag so the output operands are rewritten as
local values.
Fixes#175.
The Intel division instructions have fixed input operands that are
clobbered by fixed output operands, so the value passed as an input will
be clobbered just like a tied operand.
The FixedTied operand constraint is used to indicate a fixed input
operand that has a corresponding output operand with the same fixed
register.
Teach the spiller to teach a FixedTied operand the same as a Tied
operand constraint and make sure that the input value is killed by the
instruction.
`stack_addr` and unrestricted loads and stores *can* be used with entirely
defined behavior. The sense in which they're not "safe" is only that it's
possible to misuse them. This subtlety wasn't captured in the definition
of "safe" here, so for now, just remove the definition so that it doesn't
cause confusion.
