49 lines
1.6 KiB
Python
49 lines
1.6 KiB
Python
"""
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CAP, SSA Intro, Elimination and Optimisations
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Functions to convert a CFG out of SSA Form.
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"""
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from typing import cast, List, Set, Tuple
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from Lib import RiscV
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from Lib.Graphes import DiGraph
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from Lib.CFG import Block, BlockInstr, CFG
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from Lib.Operands import (
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Register, DataLocation,
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Temporary)
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from Lib.Statement import AbsoluteJump
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from Lib.Terminator import BranchingTerminator, Return
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from Lib.PhiNode import PhiNode
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def generate_moves_from_phis(phis: List[PhiNode], parent: Block) -> List[BlockInstr]:
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"""
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`generate_moves_from_phis(phis, parent)` builds a list of move instructions
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to be inserted in a new block between `parent` and the block with phi nodes
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`phis`.
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This is an helper function called during SSA exit.
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"""
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moves: List[BlockInstr] = []
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# TODO compute 'moves', a list of 'mv' instructions to insert under parent
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# (Lab 5a, Exercise 6)
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return moves
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def exit_ssa(cfg: CFG, is_smart: bool) -> None:
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"""
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`exit_ssa(cfg)` replaces phi nodes with move instructions to exit SSA form.
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`is_smart` is set to true when smart register allocation is enabled (Lab 5b).
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"""
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for b in cfg.get_blocks():
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phis = cast(List[PhiNode], b._phis) # Use cast for Pyright
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b._phis = [] # Remove all phi nodes in the block
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parents: List[Block] = b.get_in().copy() # Copy as we modify it by adding blocks
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for parent in parents:
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moves = generate_moves_from_phis(phis, parent)
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# TODO Add the block containing 'moves' to 'cfg'
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# and update edges and jumps accordingly (Lab 5a, Exercise 6)
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raise NotImplementedError("exit_ssa")
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