optimize

il65/compiler.py

@@ -1,9 +1,20 @@
+"""
+Programming Language for 6502/6510 microprocessors
+This is the compiler of the IL65 code, that prepares the parse tree for code generation.
+
+Written by Irmen de Jong (irmen@razorvine.net)
+License: GNU GPL 3.0, see LICENSE
+"""
+
+import re
 import os
 import sys
 import linecache
-from typing import Optional, Generator, Tuple, Set
-from .plyparser import parse_file, Module, Directive, Block, Subroutine, AstNode
-from .plylexer import SourceRef
+from typing import Optional, Tuple, Set, Dict, Any, List
+from .plyparser import parse_file, Module, Directive, Block, Subroutine, Scope, \
+    SubCall, Goto, Return, Assignment, InlineAssembly, Register, Expression, TargetRegisters
+from .plylexer import SourceRef, print_bold
+from .optimizer import optimize
 
 
 class ParseError(Exception):
@@ -26,41 +37,138 @@ class PlyParser:
         module = parse_file(filename, self.lexer_error)
         try:
             self.check_directives(module)
-            self.remove_empty_blocks(module)
             self.process_imports(module)
+            self.create_multiassigns(module)
+            if not self.parsing_import:
+                self.determine_subroutine_usage(module)
         except ParseError as x:
             self.handle_parse_error(x)
         if self.parse_errors:
-            self.print_bold("\nNo output; there were {:d} errors.\n".format(self.parse_errors))
+            print_bold("\nNo output; there were {:d} errors.\n".format(self.parse_errors))
             raise SystemExit(1)
         return module
 
     def lexer_error(self, sourceref: SourceRef, fmtstring: str, *args: str) -> None:
         self.parse_errors += 1
-        self.print_bold("ERROR: {}: {}".format(sourceref, fmtstring.format(*args)))
+        print_bold("ERROR: {}: {}".format(sourceref, fmtstring.format(*args)))
 
-    def remove_empty_blocks(self, module: Module) -> None:
-        # remove blocks without name and without address, or that are empty
-        for scope, parent in self.recurse_scopes(module):
-            if isinstance(scope, (Subroutine, Block)):
-                if not scope.scope:
-                    continue
-                if all(isinstance(n, Directive) for n in scope.scope.nodes):
-                    empty = True
-                    for n in scope.scope.nodes:
-                        empty = empty and n.name not in {"asmbinary", "asminclude"}
-                    if empty:
-                        self.print_warning("ignoring empty block or subroutine", scope.sourceref)
-                        assert isinstance(parent, (Block, Module))
-                        parent.scope.nodes.remove(scope)
-            if isinstance(scope, Block):
-                if not scope.name and scope.address is None:
-                    self.print_warning("ignoring block without name and address", scope.sourceref)
-                    assert isinstance(parent, Module)
-                    parent.scope.nodes.remove(scope)
+    def create_multiassigns(self, module: Module) -> None:
+        # create multi-assign statements from nested assignments (A=B=C=5),
+        # and optimize TargetRegisters down to single Register if it's just one register.
+        def simplify_targetregisters(targets: List[Any]) -> List[Any]:
+            new_targets = []
+            for t in targets:
+                if isinstance(t, TargetRegisters) and len(t.registers) == 1:
+                    t = t.registers[0]
+                new_targets.append(t)
+            return new_targets
+
+        def reduce_right(assign: Assignment) -> Assignment:
+            if isinstance(assign.right, Assignment):
+                right = reduce_right(assign.right)
+                targets = simplify_targetregisters(right.left)
+                assign.left.extend(targets)
+                assign.right = right.right
+            return assign
+
+        for mnode, parent in module.all_scopes():
+            if mnode.scope:
+                for node in mnode.scope.nodes:
+                    if isinstance(node, Assignment):
+                        node.left = simplify_targetregisters(node.left)
+                        if isinstance(node.right, Assignment):
+                            multi = reduce_right(node)
+                            assert multi is node and len(multi.left) > 1 and not isinstance(multi.right, Assignment)
+
+    def determine_subroutine_usage(self, module: Module) -> None:
+        module.subroutine_usage.clear()
+        for mnode, parent in module.all_scopes():
+            if mnode.scope:
+                for node in mnode.scope.nodes:
+                    if isinstance(node, InlineAssembly):
+                        self._parse_asm_for_subroutine_usage(module.subroutine_usage, node, mnode.scope)
+                    elif isinstance(node, SubCall):
+                        self._parse_subcall_for_subroutine_usages(module.subroutine_usage, node, mnode.scope)
+                    elif isinstance(node, Goto):
+                        self._parse_goto_for_subroutine_usages(module.subroutine_usage, node, mnode.scope)
+                    elif isinstance(node, Return):
+                        self._parse_return_for_subroutine_usages(module.subroutine_usage, node, mnode.scope)
+                    elif isinstance(node, Assignment):
+                        self._parse_assignment_for_subroutine_usages(module.subroutine_usage, node, mnode.scope)
+
+    def _parse_subcall_for_subroutine_usages(self, usages: Dict[Tuple[str, str], Set[str]],
+                                             subcall: SubCall, parent_scope: Scope) -> None:
+        # node.target (relevant if its a symbolname -- a str), node.arguments (list of CallArgument)
+        #   CallArgument.value = expression.
+        if isinstance(subcall.target.target, str):
+            try:
+                scopename, name = subcall.target.target.split('.')
+            except ValueError:
+                scopename = parent_scope.name
+                name = subcall.target.target
+            usages[(scopename, name)].add(str(subcall.sourceref))
+        for arg in subcall.arguments:
+            self._parse_expression_for_subroutine_usages(usages, arg.value, parent_scope)
+
+    def _parse_expression_for_subroutine_usages(self, usages: Dict[Tuple[str, str], Set[str]],
+                                                expr: Any, parent_scope: Scope) -> None:
+        if expr is None or isinstance(expr, (int, str, float, bool, Register)):
+            return
+        elif isinstance(expr, SubCall):
+            self._parse_subcall_for_subroutine_usages(usages, expr, parent_scope)
+        elif isinstance(expr, Expression):
+            self._parse_expression_for_subroutine_usages(usages, expr.left, parent_scope)
+            self._parse_expression_for_subroutine_usages(usages, expr.right, parent_scope)
+        else:
+            print("@todo parse expression for subroutine usage:", expr)    # @todo
+
+    def _parse_goto_for_subroutine_usages(self, usages: Dict[Tuple[str, str], Set[str]],
+                                          goto: Goto, parent_scope: Scope) -> None:
+        # node.target (relevant if its a symbolname -- a str), node.condition (expression)
+        if isinstance(goto.target.target, str):
+            try:
+                symbol = parent_scope[goto.target.target]
+            except LookupError:
+                return
+            if isinstance(symbol, Subroutine):
+                usages[(parent_scope.name, symbol.name)].add(str(goto.sourceref))
+        self._parse_expression_for_subroutine_usages(usages, goto.condition, parent_scope)
+
+    def _parse_return_for_subroutine_usages(self, usages: Dict[Tuple[str, str], Set[str]],
+                                            returnnode: Return, parent_scope: Scope) -> None:
+        # node.value_A (expression), value_X (expression), value_Y (expression)
+        self._parse_expression_for_subroutine_usages(usages, returnnode.value_A, parent_scope)
+        self._parse_expression_for_subroutine_usages(usages, returnnode.value_X, parent_scope)
+        self._parse_expression_for_subroutine_usages(usages, returnnode.value_Y, parent_scope)
+
+    def _parse_assignment_for_subroutine_usages(self, usages: Dict[Tuple[str, str], Set[str]],
+                                                assignment: Assignment, parent_scope: Scope) -> None:
+        # node.right (expression, or another Assignment)
+        if isinstance(assignment.right, Assignment):
+            self._parse_assignment_for_subroutine_usages(usages, assignment.right, parent_scope)
+        else:
+            self._parse_expression_for_subroutine_usages(usages, assignment.right, parent_scope)
+
+    def _parse_asm_for_subroutine_usage(self, usages: Dict[Tuple[str, str], Set[str]],
+                                        asmnode: InlineAssembly, parent_scope: Scope) -> None:
+        # asm can refer to other symbols as well, track subroutine usage
+        for line in asmnode.assembly.splitlines():
+            splits = line.split(maxsplit=1)
+            if len(splits) == 2:
+                for match in re.finditer(r"(?P<symbol>[a-zA-Z_$][a-zA-Z0-9_\.]+)", splits[1]):
+                    name = match.group("symbol")
+                    if name[0] == '$':
+                        continue
+                    try:
+                        symbol = parent_scope[name]
+                    except LookupError:
+                        pass
+                    else:
+                        if isinstance(symbol, Subroutine):
+                            usages[(parent_scope.name, symbol.name)].add(str(asmnode.sourceref))
 
     def check_directives(self, module: Module) -> None:
-        for node, parent in self.recurse_scopes(module):
+        for node, parent in module.all_scopes():
             if isinstance(node, Module):
                 # check module-level directives
                 imports = set()  # type: Set[str]
@@ -84,14 +192,6 @@ class PlyParser:
                             raise ParseError("saveregisters directive should be the first", None, sub_node.sourceref)
                     first_node = False
 
-    def recurse_scopes(self, module: Module) -> Generator[Tuple[AstNode, AstNode], None, None]:
-        # generator that recursively yields through the scopes (preorder traversal), yields (node, parent_node) tuples.
-        yield module, None
-        for block in list(module.scope.filter_nodes(Block)):
-            yield block, module
-            for subroutine in list(block.scope.filter_nodes(Subroutine)):
-                yield subroutine, block
-
     def process_imports(self, module: Module) -> None:
         # (recursively) imports the modules
         imported = []
@@ -141,18 +241,6 @@ class PlyParser:
                 return filename
         return None
 
-    def print_warning(self, text: str, sourceref: SourceRef=None) -> None:
-        if sourceref:
-            self.print_bold("warning: {}: {:s}".format(sourceref, text))
-        else:
-            self.print_bold("warning: " + text)
-
-    def print_bold(self, text: str) -> None:
-        if sys.stdout.isatty():
-            print("\x1b[1m" + text + "\x1b[0m", flush=True)
-        else:
-            print(text)
-
     def handle_parse_error(self, exc: ParseError) -> None:
         self.parse_errors += 1
         if sys.stderr.isatty():
@@ -176,6 +264,9 @@ class PlyParser:
 
 
 if __name__ == "__main__":
+    description = "Compiler for IL65 language, code name 'Sick'"
+    print("\n" + description)
     plyparser = PlyParser()
     m = plyparser.parse_file(sys.argv[1])
-    print(str(m)[:400], "...")
+    optimize(m)
+    print()

il65/handwritten/optimize.py

@@ -131,7 +131,7 @@ class Optimizer:
         for sub in list(block.symbols.iter_subroutines()):
             usages = self.parsed.subroutine_usage[(sub.blockname, sub.name)]
             if not usages and sub.blockname + '.' + sub.name not in never_remove:
-                block.symbols.discard_sub(sub.name)
+                block.symbols.remove_node(sub.name)
                 discarded.append(sub.name)
         if discarded:
             print("{}: discarded {:d} unused subroutines from block '{:s}'".format(block.sourceref, len(discarded), block.name))

il65/optimizer.py

@@ -0,0 +1,99 @@
+"""
+Programming Language for 6502/6510 microprocessors
+This is the code to optimize the parse tree.
+
+Written by Irmen de Jong (irmen@razorvine.net)
+License: GNU GPL 3.0, see LICENSE
+"""
+
+from .plyparser import Module, Subroutine, Block, Directive, Assignment, AugAssignment
+from .plylexer import print_warning, print_bold
+
+
+class Optimizer:
+    def __init__(self, mod: Module) -> None:
+        self.num_warnings = 0
+        self.module = mod
+
+    def optimize(self) -> None:
+        self.num_warnings = 0
+        # self.remove_augmentedassign_incrdecr_nops(block)   # @todo
+        self.remove_useless_assigns()
+        # self.combine_assignments_into_multi(block)   # @todo
+        self.optimize_multiassigns()
+        self.remove_unused_subroutines()
+        # self.optimize_compare_with_zero(block)  # @todo
+        self.remove_empty_blocks()
+
+    def remove_useless_assigns(self) -> None:
+        # remove assignment statements that do nothing (A=A)
+        for mnode, parent in self.module.all_scopes():
+            if mnode.scope:
+                for assignment in list(mnode.scope.nodes):
+                    if isinstance(assignment, Assignment):
+                        assignment.left = [lv for lv in assignment.left if lv != assignment.right]
+                        if not assignment.left:
+                            mnode.scope.remove_node(assignment)
+                            self.num_warnings += 1
+                            print_warning("{}: removed assignment statement that has no effect".format(assignment.sourceref))
+
+    def optimize_multiassigns(self) -> None:
+        # optimize multi-assign statements (remove duplicate targets, optimize order)
+        for mnode, parent in self.module.all_scopes():
+            if mnode.scope:
+                for assignment in mnode.scope.nodes:
+                    if isinstance(assignment, Assignment) and len(assignment.left) > 1:
+                        # remove duplicates
+                        lvalues = set(assignment.left)
+                        if len(lvalues) != len(assignment.left):
+                            self.num_warnings += 1
+                            print_warning("{}: removed duplicate assignment targets".format(assignment.sourceref))
+                        # @todo change order: first registers, then zp addresses, then non-zp addresses, then the rest (if any)
+                        assignment.left = list(lvalues)
+
+    def remove_unused_subroutines(self) -> None:
+        # some symbols are used by the emitted assembly code from the code generator,
+        # and should never be removed or the assembler will fail
+        never_remove = {"c64.FREADUY", "c64.FTOMEMXY", "c64.FADD", "c64.FSUB",
+                        "c64flt.GIVUAYF", "c64flt.copy_mflt", "c64flt.float_add_one", "c64flt.float_sub_one",
+                        "c64flt.float_add_SW1_to_XY", "c64flt.float_sub_SW1_from_XY"}
+        num_discarded = 0
+        for sub, parent in self.module.all_scopes():
+            if isinstance(sub, Subroutine):
+                usages = self.module.subroutine_usage[(parent.name, sub.name)]
+                if not usages and parent.name + '.' + sub.name not in never_remove:
+                    parent.scope.remove_node(sub)
+                    num_discarded += 1
+        print("discarded {:d} unused subroutines".format(num_discarded))
+
+    def remove_empty_blocks(self) -> None:
+        # remove blocks without name and without address, or that are empty
+        for node, parent in self.module.all_scopes():
+            if isinstance(node, (Subroutine, Block)):
+                if not node.scope:
+                    continue
+                if all(isinstance(n, Directive) for n in node.scope.nodes):
+                    empty = True
+                    for n in node.scope.nodes:
+                        empty = empty and n.name not in {"asmbinary", "asminclude"}
+                    if empty:
+                        self.num_warnings += 1
+                        print_warning("ignoring empty block or subroutine", node.sourceref)
+                        assert isinstance(parent, (Block, Module))
+                        parent.scope.nodes.remove(node)
+            if isinstance(node, Block):
+                if not node.name and node.address is None:
+                    self.num_warnings += 1
+                    print_warning("ignoring block without name and address", node.sourceref)
+                    assert isinstance(parent, Module)
+                    parent.scope.nodes.remove(node)
+
+
+def optimize(mod: Module) -> None:
+    opt = Optimizer(mod)
+    opt.optimize()
+    if opt.num_warnings:
+        if opt.num_warnings == 1:
+            print_bold("there is one optimization warning.")
+        else:
+            print_bold("there are {:d} optimization warnings.".format(opt.num_warnings))

il65/plylexer.py

@@ -147,11 +147,10 @@ reserved = {
 # rules for tokens with some actions
 
 def t_inlineasm(t):
-    r"%asm\s*\{\s*"
+    r"%asm\s*\{[^\S\n]*"
     t.lexer.code_start = t.lexer.lexpos     # Record start position
     t.lexer.level = 1                       # initial brace level
     t.lexer.begin("inlineasm")             # enter state 'inlineasm'
-    t.lexer.lineno += 1
 
 
 def t_inlineasm_lbrace(t):
@@ -320,6 +319,20 @@ def find_tok_column(token):
     return token.lexpos - last_cr
 
 
+def print_warning(text: str, sourceref: SourceRef = None) -> None:
+    if sourceref:
+        print_bold("warning: {}: {:s}".format(sourceref, text))
+    else:
+        print_bold("warning: " + text)
+
+
+def print_bold(text: str) -> None:
+    if sys.stdout.isatty():
+        print("\x1b[1m" + text + "\x1b[0m", flush=True)
+    else:
+        print(text)
+
+
 lexer = ply.lex.lex()
 
 

il65/plyparser.py

@@ -6,9 +6,10 @@ Written by Irmen de Jong (irmen@razorvine.net)
 License: GNU GPL 3.0, see LICENSE
 """
 
+from collections import defaultdict
 import attr
 from ply.yacc import yacc
-from typing import Union, Generator
+from typing import Union, Generator, Tuple, List
 from .plylexer import SourceRef, tokens, lexer, find_tok_column
 
 
@@ -104,11 +105,26 @@ class Scope(AstNode):
             if isinstance(node, nodetype):
                 yield node
 
+    def remove_node(self, node: AstNode) -> None:
+        if hasattr(node, "name"):
+            del self.symbols[node.name]
+        self.nodes.remove(node)
+
 
 @attr.s(cmp=False, repr=False)
 class Module(AstNode):
     name = attr.ib(type=str)     # filename
     scope = attr.ib(type=Scope)
+    subroutine_usage = attr.ib(type=defaultdict, init=False, default=attr.Factory(lambda: defaultdict(set)))    # will be populated later
+
+    def all_scopes(self) -> Generator[Tuple[AstNode, AstNode], None, None]:
+        # generator that recursively yields through the scopes (preorder traversal), yields (node, parent_node) tuples.
+        # it iterates of copies of the node collections, so it's okay to modify the scopes you iterate over.
+        yield self, None
+        for block in list(self.scope.filter_nodes(Block)):
+            yield block, self
+            for subroutine in list(block.scope.filter_nodes(Subroutine)):
+                yield subroutine, block
 
 
 @attr.s(cmp=False, repr=False)
@@ -130,6 +146,19 @@ class Label(AstNode):
 class Register(AstNode):
     name = attr.ib(type=str)
 
+    def __hash__(self) -> int:
+        return hash(self.name)
+
+    def __eq__(self, other) -> bool:
+        if not isinstance(other, Register):
+            return NotImplemented
+        return self.name == other.name
+
+    def __lt__(self, other) -> bool:
+        if not isinstance(other, Register):
+            return NotImplemented
+        return self.name < other.name
+
 
 @attr.s(cmp=False, repr=False)
 class PreserveRegs(AstNode):
@@ -138,13 +167,16 @@ class PreserveRegs(AstNode):
 
 @attr.s(cmp=False, repr=False)
 class Assignment(AstNode):
-    left = attr.ib()     # type: Union[str, TargetRegisters, Dereference]
+    # can be single- or multi-assignment
+    left = attr.ib(type=list)     # type: List[Union[str, TargetRegisters, Dereference]]
     right = attr.ib()
 
 
 @attr.s(cmp=False, repr=False)
-class AugAssignment(Assignment):
+class AugAssignment(AstNode):
+    left = attr.ib()
     operator = attr.ib(type=str)
+    right = attr.ib()
 
 
 @attr.s(cmp=False, repr=False)
@@ -153,6 +185,9 @@ class SubCall(AstNode):
     preserve_regs = attr.ib()
     arguments = attr.ib()
 
+    def __attrs_post_init__(self):
+        self.arguments = self.arguments or []
+
 
 @attr.s(cmp=False, repr=False)
 class Return(AstNode):
@@ -689,14 +724,14 @@ def p_assignment(p):
     assignment :  assignment_target  IS  expression
                |  assignment_target  IS  assignment
     """
-    p[0] = Assignment(left=p[1], right=p[3], sourceref=_token_sref(p, 1))
+    p[0] = Assignment(left=[p[1]], right=p[3], sourceref=_token_sref(p, 2))
 
 
 def p_aug_assignment(p):
     """
     aug_assignment :  assignment_target  AUGASSIGN  expression
     """
-    p[0] = AugAssignment(left=p[1], operator=p[2], right=p[3], sourceref=_token_sref(p, 1))
+    p[0] = AugAssignment(left=p[1], operator=p[2], right=p[3], sourceref=_token_sref(p, 2))
 
 
 precedence = (
@@ -721,7 +756,7 @@ def p_expression(p):
                |  expression  EQUALS  expression
                |  expression  NOTEQUALS  expression
     """
-    p[0] = Expression(left=p[1], operator=p[2], right=p[3], sourceref=_token_sref(p, 1))
+    p[0] = Expression(left=p[1], operator=p[2], right=p[3], sourceref=_token_sref(p, 2))
 
 
 def p_expression_uminus(p):

todo.ill

@@ -24,6 +24,12 @@ start:
         c64.CHROUT('\n')
         return
 
+	screen = border =  cursor = X = Y = A = X = Y = A = border = cursor = border = cursor = 66  ; multi-assign!
+	X = Y = A = X = Y = A = X = Y = A = X = Y = AX = Y = A = X = AY = XY =A = 123  ; multi-assign!
+	XY = XY
+	A= A
+	A=X=Y=A
+
 
 rndloop:
         XY = math.randword()
@@ -126,6 +132,7 @@ rndloop:
                 bne  -
         }
 
+
 loop   :
         A=c64.GETIN()
         if_not goto loop
@@ -172,9 +179,9 @@ loop   :
 
 sub sub1 () -> () {
 
-	%breakpoint
 	%saveregisters off
 	%breakpoint
+	%breakpoint
 
 label:
 	return