Register allocation

register_allocation

X86RegisterAllocator

Bases: BlockNaiveAllocator

Source code in xdsl/backend/x86/register_allocation.py

class X86RegisterAllocator(BlockNaiveAllocator):
    def __init__(self, available_registers: RegisterStack) -> None:
        super().__init__(available_registers, registers.X86RegisterType)

    def allocate_func(self, func: x86_func.FuncOp) -> None:
        """
        Allocates values in function passed in to registers.
        The whole function must have been lowered to the relevant x86 dialects
        and it must contain no unrealized casts.
        """
        if not func.body.blocks:
            # External function declaration
            return

        if len(func.body.blocks) != 1:
            raise NotImplementedError(
                f"Cannot register allocate func with {len(func.body.blocks)} blocks."
            )

        preallocated = {
            reg
            for reg in RegisterAllocatableOperation.iter_all_used_registers(func.body)
            if isinstance(reg, registers.X86RegisterType)
        }

        for pa_reg in preallocated:
            self.available_registers.exclude_register(pa_reg)

        block = func.body.block

        self.live_ins_per_block = live_ins_per_block(block)
        assert not self.live_ins_per_block[block]

        self.allocate_block(block)

__init__(available_registers: RegisterStack) -> None

Source code in xdsl/backend/x86/register_allocation.py

def __init__(self, available_registers: RegisterStack) -> None:
    super().__init__(available_registers, registers.X86RegisterType)

allocate_func(func: x86_func.FuncOp) -> None

Allocates values in function passed in to registers. The whole function must have been lowered to the relevant x86 dialects and it must contain no unrealized casts.

Source code in xdsl/backend/x86/register_allocation.py

def allocate_func(self, func: x86_func.FuncOp) -> None:
    """
    Allocates values in function passed in to registers.
    The whole function must have been lowered to the relevant x86 dialects
    and it must contain no unrealized casts.
    """
    if not func.body.blocks:
        # External function declaration
        return

    if len(func.body.blocks) != 1:
        raise NotImplementedError(
            f"Cannot register allocate func with {len(func.body.blocks)} blocks."
        )

    preallocated = {
        reg
        for reg in RegisterAllocatableOperation.iter_all_used_registers(func.body)
        if isinstance(reg, registers.X86RegisterType)
    }

    for pa_reg in preallocated:
        self.available_registers.exclude_register(pa_reg)

    block = func.body.block

    self.live_ins_per_block = live_ins_per_block(block)
    assert not self.live_ins_per_block[block]

    self.allocate_block(block)