Merge pull request boriel-basic#674 from boriel/refact/convert_optimi…

…zer_into_class

refact: convert optimizer module into class

src/api/utils.py

@@ -84,7 +84,7 @@ def get_absolute_filename_path(fname: str) -> str:
     return os.path.realpath(os.path.expanduser(fname))
 
 
-def get_relative_filename_path(fname: str, current_dir: str = None) -> str:
+def get_relative_filename_path(fname: str, current_dir: str | None = None) -> str:
     """Given an absolute path, returns it relative to the current directory,
     that is, if the file is in the same folder or any of it children, only
     the path from the current folder onwards is returned. Otherwise, the

src/arch/interface/optimizer.py

@@ -0,0 +1,14 @@
+from abc import ABC, abstractmethod
+
+
+class OptimizerInterface(ABC):
+    """Implements the Peephole Optimizer"""
+
+    @abstractmethod
+    def init(self) -> None:
+        pass
+
+    @abstractmethod
+    def optimize(self, initial_memory: list[str]) -> str:
+        """This will remove useless instructions"""
+        pass

src/arch/z80/optimizer/__init__.py

@@ -1,3 +1,3 @@
-from .main import init, optimize
+from .main import Optimizer
 
-__all__ = "init", "optimize"
+__all__ = ("Optimizer",)

src/arch/z80/optimizer/basicblock.py

@@ -10,7 +10,6 @@
 from src.arch.z80.peephole import evaluator
 
 from . import helpers
-from .common import JUMP_LABELS, LABELS
 from .cpustate import CPUState
 from .helpers import ALL_REGS
 from .labelinfo import LabelInfo
@@ -137,12 +136,12 @@ def labels(self) -> tuple[str, ...]:
         memory"""
         return tuple(cell.inst for cell in self.mem if cell.is_label)
 
-    def get_first_partition_idx(self) -> int | None:
+    def get_first_partition_idx(self, jump_labels: set[str]) -> int | None:
         """Returns the first position where this block can be
         partitioned or None if there's no such point
         """
         for i, mem in enumerate(self):
-            if i > 0 and mem.is_label and mem.inst in JUMP_LABELS:
+            if i > 0 and mem.is_label and mem.inst in jump_labels:
                 return i
 
             if (mem.is_ender or mem.code in src.arch.z80.backend.common.ASMS) and i < len(self) - 1:
@@ -210,7 +209,7 @@ def add_goes_to(self, basic_block: BasicBlock | None) -> None:
         self.goes_to.add(basic_block)
         basic_block.comes_from.add(self)
 
-    def update_next_block(self):
+    def update_next_block(self, labels: dict[str, LabelInfo]) -> None:
         """If the last instruction of this block is a JP, JR or RET (with no
         conditions) then goes_to set contains just a
         single block
@@ -232,11 +231,11 @@ def update_next_block(self):
         if last.inst == "ret":
             return
 
-        if last.opers[0] not in LABELS.keys():
+        if last.opers[0] not in labels.keys():
             __DEBUG__("INFO: %s is not defined. No optimization is done." % last.opers[0], 2)
-            LABELS[last.opers[0]] = LabelInfo(last.opers[0], 0, DummyBasicBlock(ALL_REGS, ALL_REGS))
+            labels[last.opers[0]] = LabelInfo(last.opers[0], 0, DummyBasicBlock(ALL_REGS, ALL_REGS))
 
-        n_block = LABELS[last.opers[0]].basic_block
+        n_block = labels[last.opers[0]].basic_block
         self.add_goes_to(n_block)
 
     def is_used(self, regs: list[str], i: int, top: int | None = None) -> bool:

src/arch/z80/optimizer/flow_graph.py

@@ -1,14 +1,14 @@
 from src.api.debug import __DEBUG__
 
 from .basicblock import BasicBlock, DummyBasicBlock
-from .common import JUMP_LABELS, LABELS
 from .helpers import ALL_REGS
 from .labelinfo import LabelInfo
+from .labels_dict import LabelsDict
 
 __all__ = ("get_basic_blocks",)
 
 
-def split_block(block: BasicBlock, start_of_new_block: int) -> tuple[BasicBlock, BasicBlock]:
+def _split_block(block: BasicBlock, start_of_new_block: int, labels: LabelsDict) -> tuple[BasicBlock, BasicBlock]:
     assert 0 <= start_of_new_block < len(block), f"Invalid split pos: {start_of_new_block}"
     new_block = BasicBlock([])
     new_block.mem = block.mem[start_of_new_block:]
@@ -28,9 +28,9 @@ def split_block(block: BasicBlock, start_of_new_block: int) -> tuple[BasicBlock,
     block.add_goes_to(new_block)
 
     for i, mem in enumerate(new_block):
-        if mem.is_label and mem.inst in LABELS:
-            LABELS[mem.inst].basic_block = new_block
-            LABELS[mem.inst].position = i
+        if mem.is_label and mem.inst in labels:
+            labels[mem.inst].basic_block = new_block
+            labels[mem.inst].position = i
 
     if block[-1].is_ender:
         if not block[-1].condition_flag:  # If it's an unconditional jp, jr, call, ret
@@ -39,28 +39,32 @@ def split_block(block: BasicBlock, start_of_new_block: int) -> tuple[BasicBlock,
     return block, new_block
 
 
-def compute_calls(basic_blocks: list[BasicBlock], jump_labels: set[str]) -> None:
+def _compute_calls(
+    basic_blocks: list[BasicBlock],
+    labels: LabelsDict,
+    jump_labels: set[str],
+) -> None:
     calling_blocks: dict[BasicBlock, BasicBlock] = {}
 
     # Compute which blocks use jump labels
     for bb in basic_blocks:
-        if bb[-1].is_ender and (op := bb[-1].branch_arg) in LABELS:
-            LABELS[op].used_by.add(bb)
+        if bb[-1].is_ender and (op := bb[-1].branch_arg) in labels:
+            labels[op].used_by.add(bb)
 
     # For these blocks, add the referenced block in the goes_to
     for label in jump_labels:
-        for bb in LABELS[label].used_by:
-            bb.add_goes_to(LABELS[label].basic_block)
+        for bb in labels[label].used_by:
+            bb.add_goes_to(labels[label].basic_block)
 
     # Annotate which blocks uses call (which should be the last instruction)
     for bb in basic_blocks:
         if bb[-1].inst != "call":
             continue
 
         op = bb[-1].branch_arg
-        if op in LABELS:
-            LABELS[op].basic_block.called_by.add(bb)
-            calling_blocks[bb] = LABELS[op].basic_block
+        if op in labels:
+            labels[op].basic_block.called_by.add(bb)
+            calling_blocks[bb] = labels[op].basic_block
 
     # For the annotated blocks, trace their goes_to, and their goes_to from
     # their goes_to and so on, until ret (unconditional or not) is found, and
@@ -91,7 +95,7 @@ def compute_calls(basic_blocks: list[BasicBlock], jump_labels: set[str]) -> None
                 pending.add((caller, bb.next))
 
 
-def get_jump_labels(main_basic_block: BasicBlock) -> set[str]:
+def _get_jump_labels(main_basic_block: BasicBlock, labels: LabelsDict) -> set[str]:
     """Given the main basic block (which contain the entire program), populate
     the global JUMP_LABEL set with LABELS used by CALL, JR, JP (i.e JP LABEL0)
     Also updates the global LABELS index with the pertinent information.
@@ -103,8 +107,8 @@ def get_jump_labels(main_basic_block: BasicBlock) -> set[str]:
 
     for i, mem in enumerate(main_basic_block):
         if mem.is_label:
-            LABELS.pop(mem.inst)
-            LABELS[mem.inst] = LabelInfo(
+            labels.pop(mem.inst)
+            labels[mem.inst] = LabelInfo(
                 label=mem.inst, addr=i, basic_block=main_basic_block, position=i  # Unknown yet
             )
             continue
@@ -118,28 +122,32 @@ def get_jump_labels(main_basic_block: BasicBlock) -> set[str]:
 
         jump_labels.add(lbl)
 
-        if lbl not in LABELS:
+        if lbl not in labels:
             __DEBUG__(f"INFO: {lbl} is not defined. No optimization is done.", 2)
-            LABELS[lbl] = LabelInfo(lbl, 0, DummyBasicBlock(ALL_REGS, ALL_REGS))
+            labels[lbl] = LabelInfo(lbl, 0, DummyBasicBlock(ALL_REGS, ALL_REGS))
 
     return jump_labels
 
 
-def get_basic_blocks(block: BasicBlock) -> list[BasicBlock]:
+def get_basic_blocks(
+    block: BasicBlock,
+    labels: LabelsDict,
+    jump_labels: set[str],
+) -> list[BasicBlock]:
     """If a block is not partitionable, returns a list with the same block.
     Otherwise, returns a list with the resulting blocks.
     """
     result: list[BasicBlock] = [block]
-    JUMP_LABELS.clear()
-    JUMP_LABELS.update(get_jump_labels(block))
+    jump_labels.clear()
+    jump_labels.update(_get_jump_labels(block, labels))
 
     # Split basic blocks per label or branch instruction
-    split_pos = block.get_first_partition_idx()
+    split_pos = block.get_first_partition_idx(jump_labels)
     while split_pos is not None:
-        _, block = split_block(block, split_pos)
+        _, block = _split_block(block, split_pos, labels)
         result.append(block)
-        split_pos = block.get_first_partition_idx()
+        split_pos = block.get_first_partition_idx(jump_labels)
 
-    compute_calls(result, JUMP_LABELS)
+    _compute_calls(result, labels, jump_labels)
 
     return result

src/arch/z80/optimizer/helpers.py

@@ -1,53 +1,117 @@
 # -*- coding: utf-8 -*-
 
-from typing import Any, Iterable, TypeVar
+from typing import Any, Final, Iterable, TypeVar, cast
+
+from . import patterns
+
+__all__ = (
+    "ALL_REGS",
+    "END_PROGRAM_LABEL",
+    "init",
+    "new_tmp_val",
+    "new_tmp_val16",
+    "new_tmp_val16_from_label",
+    "is_unknown",
+    "is_unknown8",
+    "is_unknown16",
+    "get_orig_label_from_unknown16",
+    "get_L_from_unknown_value",
+    "get_H_from_unknown_value",
+    "is_mem_access",
+    "is_number",
+    "is_label",
+    "valnum",
+    "simplify_arg",
+    "simplify_asm_args",
+    "is_register",
+    "is_8bit_normal_register",
+    "is_8bit_idx_register",
+    "is_8bit_oper_register",
+    "is_16bit_normal_register",
+    "is_16bit_idx_register",
+    "is_16bit_composed_register",
+    "is_16bit_oper_register",
+    "LO16",
+    "HI16",
+    "single_registers",
+    "idx_args",
+    "LO16_val",
+    "HI16_val",
+    "dict_intersection",
+)
 
-from . import common, patterns
 
 T = TypeVar("T")
 K = TypeVar("K")
 
 
 # All 'single' registers (even f FLAG one). SP is not decomposable so it's 'single' already
-ALL_REGS = {"a", "b", "c", "d", "e", "f", "h", "l", "ixh", "ixl", "iyh", "iyl", "r", "i", "sp"}
+ALL_REGS: Final[frozenset[str]] = frozenset(
+    [
+        "a",
+        "b",
+        "c",
+        "d",
+        "e",
+        "f",
+        "h",
+        "l",
+        "ixh",
+        "ixl",
+        "iyh",
+        "iyl",
+        "r",
+        "i",
+        "sp",
+    ]
+)
 
 # The set of all registers as they can appear in any instruction as operands
-REGS_OPER_SET = {
-    "a",
-    "b",
-    "c",
-    "d",
-    "e",
-    "h",
-    "l",
-    "bc",
-    "de",
-    "hl",
-    "sp",
-    "ix",
-    "iy",
-    "ixh",
-    "ixl",
-    "iyh",
-    "iyl",
-    "af",
-    "af'",
-    "i",
-    "r",
-}
+REGS_OPER_SET: Final[frozenset[str]] = frozenset(
+    [
+        "a",
+        "b",
+        "c",
+        "d",
+        "e",
+        "h",
+        "l",
+        "bc",
+        "de",
+        "hl",
+        "sp",
+        "ix",
+        "iy",
+        "ixh",
+        "ixl",
+        "iyh",
+        "iyl",
+        "af",
+        "af'",
+        "i",
+        "r",
+    ]
+)
 
 # Instructions that marks the end of a basic block (any branching instruction)
-BLOCK_ENDERS = {"jr", "jp", "call", "ret", "reti", "retn", "djnz", "rst"}
+BLOCK_ENDERS: Final[frozenset[str]] = frozenset(["jr", "jp", "call", "ret", "reti", "retn", "djnz", "rst"])
+UNKNOWN_PREFIX: Final[str] = "*UNKNOWN_"
+END_PROGRAM_LABEL: Final[str] = "__END_PROGRAM"  # Label for end program
+HL_SEP: Final[str] = "|"  # Hi/Low separator
+_RAND_COUNT: int = 0  # Counter for unknown values
 
-UNKNOWN_PREFIX = "*UNKNOWN_"
-END_PROGRAM_LABEL = "__END_PROGRAM"  # Label for end program
-HL_SEP = "|"  # Hi/Low separator
+
+def init() -> None:
+    global _RAND_COUNT
+    _RAND_COUNT = 0
 
 
 def new_tmp_val() -> str:
     """Generates an 8-bit unknown value"""
-    common.RAND_COUNT += 1
-    return f"{UNKNOWN_PREFIX}{common.RAND_COUNT}"
+    global _RAND_COUNT
+
+    _RAND_COUNT += 1
+    return f"{UNKNOWN_PREFIX}{_RAND_COUNT}"
 
 
 def new_tmp_val16() -> str:
@@ -390,7 +454,7 @@ def LO16_val(x: int | str | None) -> str:
     if not is_unknown(x):
         return new_tmp_val()
 
-    return x.split(HL_SEP)[-1]
+    return cast(str, x).split(HL_SEP)[-1]
 
 
 def HI16_val(x: int | str | None) -> str: