improved De Morgan rewrite rules

compiler/src/prog8/compiler/astprocessing/NotExpressionAndIfComparisonExprChanger.kt

@@ -6,6 +6,7 @@ import prog8.ast.base.FatalAstException
 import prog8.ast.expressions.BinaryExpression
 import prog8.ast.expressions.NumericLiteral
 import prog8.ast.expressions.PrefixExpression
+import prog8.ast.expressions.invertCondition
 import prog8.ast.walk.AstWalker
 import prog8.ast.walk.IAstModification
 import prog8.code.core.*
@@ -74,6 +75,22 @@ internal class NotExpressionAndIfComparisonExprChanger(val program: Program, val
                     }
                 }
             }
+
+            // mixed cases
+            if(leftC!=null && rightP!=null && leftC.operator=="==" && rightP.operator=="not") {
+                // mixed case 1:   x==V or not y  ->  not(x!=V and y)
+                val invertedLeftExpression = invertCondition(leftC, program)
+                val inner = BinaryExpression(invertedLeftExpression, newOper, rightP.expression, expr.position)
+                val notExpr = PrefixExpression("not", inner, expr.position)
+                return listOf(IAstModification.ReplaceNode(expr, notExpr, parent))
+            }
+            else if(rightC!=null && leftP!=null && rightC.operator=="==" && leftP.operator=="not") {
+                // mixed case 1:   not x or y==V  ->  not(x and y!=V)
+                val invertedRightExpression = invertCondition(rightC, program)
+                val inner = BinaryExpression(leftP.expression, newOper, invertedRightExpression, expr.position)
+                val notExpr = PrefixExpression("not", inner, expr.position)
+                return listOf(IAstModification.ReplaceNode(expr, notExpr, parent))
+            }
         }
 
         return noModifications

compiler/test/TestOptimization.kt

@@ -782,17 +782,29 @@ main {
             cx16.r0++
         if not a1 and not a2
             cx16.r0++
+            
+        if cx16.r0L==42 or not a2
+            cx16.r0L++
+        if not a2 or cx16.r0L==42
+            cx16.r0L++
+            
     }
 }"""
         val result = compileText(Cx16Target(), true, src, writeAssembly = false)!!
         val st = result.compilerAst.entrypoint.statements
-        st.size shouldBe 6
+        st.size shouldBe 8
         val if1c = (st[4] as IfElse).condition as PrefixExpression
         val if2c = (st[5] as IfElse).condition as PrefixExpression
+        val if3c = (st[6] as IfElse).condition as PrefixExpression
+        val if4c = (st[7] as IfElse).condition as PrefixExpression
         if1c.operator shouldBe "not"
         if2c.operator shouldBe "not"
+        if3c.operator shouldBe "not"
+        if4c.operator shouldBe "not"
         (if1c.expression as BinaryExpression).operator shouldBe "and"
         (if2c.expression as BinaryExpression).operator shouldBe "or"
+        (if3c.expression as BinaryExpression).operator shouldBe "and"
+        (if4c.expression as BinaryExpression).operator shouldBe "and"
     }
 
     test("absorption laws") {

docs/source/todo.rst

@@ -1,7 +1,6 @@
 TODO
 ====
 
-examples/maze is larger than on 10.1
 rockrunner is a lot bigger still than on 10.1
 paint is bigger than on 10.1
 

examples/test.p8

@@ -9,17 +9,11 @@ main {
     word[4] words
 
     byte @shared sbb
-    float @shared fl=3.3
-    float @shared fl2=4.3
 
     sub start() {
 
-;        cx16.r0L = fl==fl2 as ubyte
-;        cx16.r1L = fl!=fl2 as ubyte
-        cx16.r0L = cx16.r0 == cx16.r1   as ubyte
-        cx16.r1L = cx16.r0 != cx16.r1   as ubyte
-        cx16.r0L = cx16.r0L == cx16.r1L as ubyte
-        cx16.r1L = cx16.r0L != cx16.r1L as ubyte
+        if cx16.r0 > cx16.r1
+            cx16.r0L++
 
         ; TODO all this for uwords