got rid of multi-assignments

il65/compile.py

@@ -37,7 +37,6 @@ class PlyParser:
             module.scope.define_builtin_functions()
             self.process_imports(module)
             self.check_and_merge_zeropages(module)
-            self.create_multiassigns(module)
             if not self.imported_module:
                 # the following shall only be done on the main module after all imports have been done:
                 self.check_all_symbolnames(module)
@@ -249,24 +248,6 @@ class PlyParser:
         for node in module.all_nodes(SymbolName):
             check_symbol_definition(node.name, node.my_scope(), node.sourceref)     # type: ignore
 
-    @no_type_check
-    def create_multiassigns(self, module: Module) -> None:
-        # create multi-assign statements from nested assignments (A=B=C=5),
-        def reduce_right(assign: Assignment) -> Assignment:
-            if isinstance(assign.right, Assignment):
-                right = reduce_right(assign.right)
-                for rn in right.left.nodes:
-                    rn.parent = assign.left
-                assign.left.nodes.extend(right.left.nodes)
-                assign.right = right.right
-                assign.right.parent = assign
-            return assign
-
-        for node in module.all_nodes(Assignment):
-            if isinstance(node.right, Assignment):
-                multi = reduce_right(node)
-                assert multi is node and len(multi.left.nodes) > 1 and not isinstance(multi.right, Assignment)
-
     @no_type_check
     def apply_directive_options(self, module: Module) -> None:
         def set_save_registers(scope: Scope, save_dir: Directive) -> None:

il65/optimize.py

@@ -40,7 +40,6 @@ class Optimizer:
         self.optimize_assignments()
         self.remove_superfluous_assignments()
         self.combine_assignments_into_multi()
-        self.optimize_multiassigns()
         # @todo optimize addition with self into shift 1  (A+=A -> A<<=1)
         self.optimize_goto_compare_with_zero()
         self.join_incrdecrs()
@@ -301,19 +300,6 @@ class Optimizer:
                     rvalue = None
                     assignments.clear()
 
-    @no_type_check
-    def optimize_multiassigns(self) -> None:
-        # optimize multi-assign statements (remove duplicate targets, optimize order)
-        for assignment in self.module.all_nodes(Assignment):
-            if len(assignment.left.nodes) > 1:
-                # remove duplicates
-                lvalues = set(assignment.left.nodes)
-                if len(lvalues) != len(assignment.left.nodes):
-                    print("{}: 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.nodes = list(lvalues)
-                    self.optimizations_performed = True
-
     @no_type_check
     def remove_unused_subroutines(self) -> None:
         # some symbols are used by the emitted assembly code from the code generator,

il65/plyparse.py

@@ -846,10 +846,7 @@ class Return(AstNode):
 
 @attr.s(cmp=False, slots=True, repr=False)
 class Assignment(AstNode):
-    # can be single- or multi-assignment
+    # has two subnodes: left (=Register/SymbolName/Dereference ) and right (=Expression)
-    # has two subnodes: left (=Register/SymbolName/Dereference ) and right (=Expression,
-    #    or another Assignment but those will be converted into multi assign)
-
     @property
     def left(self) -> Union[Register, SymbolName, Dereference]:
         return self.nodes[0]    # type: ignore
@@ -1475,7 +1472,6 @@ def p_symbolname(p):
 def p_assignment(p):
     """
     assignment :  assignment_target  IS  expression
-               |  assignment_target  IS  assignment
     """
     p[0] = Assignment(sourceref=_token_sref(p, 2))
     p[0].nodes.append(p[1])

reference.md

@@ -288,13 +288,9 @@ want to work on later, because the contents of the ignored block are not fully p
 
 ### Assignments
 
-Assignment statements assign a single value to one or more variables or memory locations.
+Assignment statements assign a single value to a target variable or memory location.
-If you know that you have to assign the same value to more than one thing at once, it is more
-efficient to write it as a multi-assign instead of several separate assignments. The compiler
-tries to detect this situation however and optimize it itself if it finds the case.
 
         target = value-expression
-        target1 = target2 = target3 [,...] = value-expression
 
 
 ### Augmented Assignments

testsource/dtypes.ill

@@ -153,8 +153,6 @@ start:
 	A = 0
 	A = '@'
 	A = 1.2345
-	A=X=Y= true
-	A=XY= true
 	A = false
 	A = 255
 	A = X
@@ -180,8 +178,6 @@ start:
 	XY = uninitbyte1
 	XY = "text-immediate"
 	AY = "text-immediate"
-	; AX = &"text-immediate"          ; equivalent to simply assigning the string directly
-	; AX = & "text-immediate"         ; equivalent to simply assigning the string directly
 	AX = ctext3
 	AX = ""
 	AX = XY
@@ -190,7 +186,7 @@ start:
 	XY = membyte2
 	XY = memword1
 	XY = sin
-	; XY = &sin     ; @todo not yet implemented
+	XY = &sin     ; @todo not yet implemented
 
 
 	[$c000] = A
@@ -214,7 +210,7 @@ start:
 	[$c000.word] = ""
 	[$c000.word] = uninitbyte1
 	[$c000.word] = membyte2
-	; [$c000.word] = &membyte2              ; @todo not yet implemented
+	[$c000.word] = &membyte2              ; @todo not yet implemented
 	[$c000.word] = [cword2]
 	[$c000.word] = memword1
 	[$c000.float] = 65535
@@ -228,7 +224,7 @@ start:
         [$c112.word] = [$c223.byte]
 	[$c222.word] = [$c333.word]
 	[$c333.word] = sin
-	; [$c333.word] = &sin           ; @todo not yet implemented
+	[$c333.word] = &sin           ; @todo not yet implemented
 
 
 	SC = 0
@@ -264,7 +260,7 @@ start:
 	uninitfloat = 9.8765
 	uninitfloat = '@'
 	initword1 = sin
-	; initword1 = &sin    ; @todo not yet implemented
+	initword1 = &sin    ; @todo not yet implemented
 
 
         membyte1 = A
@@ -280,7 +276,7 @@ start:
         memword1 = 2233
         memfloat = 3.4567
 	memword1 = sin
-	; memword1 = &sin               ; @todo not yet implemented
+	memword1 = &sin               ; @todo not yet implemented
 
         membyte1 = A
         memword1 = A

testsource/numbergame.ill

@@ -15,7 +15,7 @@ start:
         A = c64.VMCSB
         A |= 2
         c64.VMCSB = A
-        ;c64.VMCSB |= 2     ;  @todo when this works it replaces the three lines above
+        c64.VMCSB |= 2     ;  @todo when this works it replaces the three lines above
 
         ; greeting
         c64scr.print_string("Enter your name: ")

testsource/source1.ill

@@ -33,7 +33,19 @@ start:   ;foo
 	Y = X
 	X = 66
 	screen = 0
-	screen = border =  cursor = X = Y = A = X = Y = A = border = cursor = border = cursor = 66  ; multi-assign!
+	screen = 66
+	border = 66
+	cursor = 66
+	X = 66
+	Y = 66
+	A = 66
+	X = 66
+	Y = 66
+	A = 66
+	border = 66
+	cursor = 66
+	border = 66
+	cursor = 66
 	border = false
 	border = true
 	border = 0
@@ -58,7 +70,9 @@ start:   ;foo
 	Y = 2
 	Y = true
 	Y = false
-	A = Y = X = 0		; multi assign!
+	A = 0
+	Y = 0
+	X = 0
 
 	; [646,Y] = [$d020,X]
 
@@ -130,8 +144,19 @@ somelabel1:
 
         goto somelabel1
         goto block2.somelabel1222
-	A=X=Y=A=X=Y=A=X=Y=99
+	A=99
-	[$d020]=[$d021]=[$d020]=[$d021]=55
+	X=99
+	Y=99
+	A=99
+	X=99
+	Y=99
+	A=99
+	X=99
+	Y=99
+	[$d020]=55
+	[$d021]=55
+	[$d020]=55
+	[$d021]=55
 
 	A=1
 	X=1

testsource/source3.ill

@@ -67,7 +67,8 @@ start:
 ~ global2 {
 
 make_screen_black:
-		c64.EXTCOL = c64.BGCOL0 = 0
+		c64.EXTCOL = 0
+		c64.BGCOL0 = 0
 		c64.COLOR = 3
 		Y = true
 		return

testsource/source4.ill

@@ -53,7 +53,8 @@ start2:
 ~ global2 {
 
 make_screen_black:
-		c64.EXTCOL = c64.BGCOL0 = 0
+		c64.EXTCOL = 0
+		c64.BGCOL0 = 0
 		c64.COLOR = 3
 		return