mirror of https://github.com/m-labs/artiq
44 lines
1.4 KiB
Python
44 lines
1.4 KiB
Python
"""
|
|
:class:`ConstantHoister` is a code motion transform:
|
|
it moves any invariant loads to the earliest point where
|
|
they may be executed.
|
|
"""
|
|
|
|
from .. import types, ir
|
|
|
|
class ConstantHoister:
|
|
def process(self, functions):
|
|
for func in functions:
|
|
self.process_function(func)
|
|
|
|
def process_function(self, func):
|
|
entry = func.entry()
|
|
worklist = set(func.instructions())
|
|
moved = set()
|
|
while len(worklist) > 0:
|
|
insn = worklist.pop()
|
|
|
|
if (isinstance(insn, ir.GetAttr) and insn not in moved and
|
|
types.is_instance(insn.object().type) and
|
|
insn.attr in insn.object().type.constant_attributes):
|
|
has_variant_operands = False
|
|
index_in_entry = 0
|
|
for operand in insn.operands:
|
|
if isinstance(operand, ir.Argument):
|
|
pass
|
|
elif isinstance(operand, ir.Instruction) and operand.basic_block == entry:
|
|
index_in_entry = entry.index(operand) + 1
|
|
else:
|
|
has_variant_operands = True
|
|
break
|
|
|
|
if has_variant_operands:
|
|
continue
|
|
|
|
insn.remove_from_parent()
|
|
entry.instructions.insert(index_in_entry, insn)
|
|
moved.add(insn)
|
|
|
|
for use in insn.uses:
|
|
worklist.add(use)
|