simplify ZeroPage reserved locations handling a bit

codeGeneration/src/prog8/compiler/target/c64/C64MachineDefinition.kt

@@ -89,7 +89,6 @@ object C64MachineDefinition: IMachineDefinition {
             if (options.zeropage == ZeropageType.FULL) {
                 free.addAll(0x04..0xf9)
                 free.add(0xff)
-                free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_W1, SCRATCH_W1 + 1, SCRATCH_W2, SCRATCH_W2 + 1))
                 free.removeAll(listOf(0xa0, 0xa1, 0xa2, 0x91, 0xc0, 0xc5, 0xcb, 0xf5, 0xf6))        // these are updated by IRQ
             } else {
                 if (options.zeropage == ZeropageType.KERNALSAFE || options.zeropage == ZeropageType.FLOATSAFE) {
@@ -133,13 +132,8 @@ object C64MachineDefinition: IMachineDefinition {
                     free.clear()
                 }
             }
-            require(SCRATCH_B1 !in free)
-            require(SCRATCH_REG !in free)
-            require(SCRATCH_W1 !in free)
-            require(SCRATCH_W2 !in free)
 
-            for (reserved in options.zpReserved)
+            removeReservedFromFreePool()
-                reserve(reserved)
         }
     }
 

codeGeneration/src/prog8/compiler/target/cx16/CX16MachineDefinition.kt

@@ -104,16 +104,13 @@ object CX16MachineDefinition: IMachineDefinition {
             when (options.zeropage) {
                 ZeropageType.FULL -> {
                     free.addAll(0x22..0xff)
-                    free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_W1, SCRATCH_W1 + 1, SCRATCH_W2, SCRATCH_W2 + 1))
                 }
                 ZeropageType.KERNALSAFE -> {
                     free.addAll(0x22..0x7f)
                     free.addAll(0xa9..0xff)
-                    free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_W1, SCRATCH_W1 + 1, SCRATCH_W2, SCRATCH_W2 + 1))
                 }
                 ZeropageType.BASICSAFE -> {
                     free.addAll(0x22..0x7f)
-                    free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_W1, SCRATCH_W1 + 1, SCRATCH_W2, SCRATCH_W2 + 1))
                 }
                 ZeropageType.DONTUSE -> {
                     free.clear() // don't use zeropage at all
@@ -121,13 +118,7 @@ object CX16MachineDefinition: IMachineDefinition {
                 else -> throw CompilerException("for this machine target, zero page type 'floatsafe' is not available. ${options.zeropage}")
             }
 
-            require(SCRATCH_B1 !in free)
+            removeReservedFromFreePool()
-            require(SCRATCH_REG !in free)
-            require(SCRATCH_W1 !in free)
-            require(SCRATCH_W2 !in free)
-
-            for (reserved in options.zpReserved)
-                reserve(reserved)
         }
     }
 }

compilerInterfaces/src/prog8/compilerinterface/Zeropage.kt

@@ -19,6 +19,13 @@ abstract class Zeropage(protected val options: CompilationOptions) {
 
     val allowedDatatypes = NumericDatatypes
 
+    fun removeReservedFromFreePool() {
+        for (reserved in options.zpReserved)
+            reserve(reserved)
+
+        free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_W1, SCRATCH_W1 + 1, SCRATCH_W2, SCRATCH_W2 + 1))
+    }
+
     fun availableBytes() = if(options.zeropage== ZeropageType.DONTUSE) 0 else free.size
     fun hasByteAvailable() = if(options.zeropage== ZeropageType.DONTUSE) false else free.isNotEmpty()
     fun availableWords(): Int {

compilerInterfaces/test/TestZeropage.kt

@@ -24,25 +24,24 @@ class TestZeropage {
                 compTarget
             )
         )
-        assertEquals(256-4-16, zp.free.size)
+        assertEquals(256-6-16, zp.free.size)
     }
 
     class DummyCompilationTarget: ICompilationTarget {
-        override val name: String
+        override val name: String = "dummy"
-            get() = TODO("Not yet implemented")
         override val machine: IMachineDefinition
-            get() = TODO("Not yet implemented")
+            get() = throw NotImplementedError("dummy")
 
         override fun encodeString(str: String, altEncoding: Boolean): List<Short> {
-            TODO("Not yet implemented")
+            throw NotImplementedError("dummy")
         }
 
         override fun decodeString(bytes: List<Short>, altEncoding: Boolean): String {
-            TODO("Not yet implemented")
+            throw NotImplementedError("dummy")
         }
 
         override fun memorySize(dt: DataType): Int {
-            TODO("Not yet implemented")
+            throw NotImplementedError("dummy")
         }
 
     }
@@ -50,21 +49,13 @@ class TestZeropage {
     class DummyZeropage(options: CompilationOptions) : Zeropage(options) {
         override val SCRATCH_B1: Int = 0x10
         override val SCRATCH_REG: Int = 0x11
-        override val SCRATCH_W1: Int= 0x12
+        override val SCRATCH_W1: Int= 0x20
-        override val SCRATCH_W2: Int = 0x13
+        override val SCRATCH_W2: Int = 0x30
 
         init {
             free.addAll(0..255)
 
-            // TODO should be in class:
+            removeReservedFromFreePool()
-            free.remove(SCRATCH_B1)
-            free.remove(SCRATCH_REG)
-            free.remove(SCRATCH_W1)
-            free.remove(SCRATCH_W2)
-
-            // TODO should be in class:
-            for (reserved in options.zpReserved)
-                reserve(reserved)
         }
     }
 

docs/source/todo.rst

@@ -4,6 +4,7 @@ TODO
 For next compiler release (7.2)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 - fix the asm-labels problem (github issue #62)
+- find a way to optimize if-statement codegen so that "if var & %10000" doesn't use stack & subroutine call, but also that the simple case "if X {...}" remains fast
 
 
 Blocked by Commander-x16 v39 release
@@ -15,7 +16,7 @@ Blocked by Commander-x16 v39 release
 Future
 ^^^^^^
 - get rid of all TODO's in the code
-- improve testability further, add more tests, address more questions/issues from the testability discussions.
+- improve testability further, add more tests
 - replace certain uses of inferredType.getOr(DataType.UNDEFINED) by i.getOrElse({ errorhandler })
 - see if we can remove more "[InferredType].getOr(DataType.UNDEFINED)"
 - use more of Result<> and Either<> to handle errors/ nulls better
@@ -37,7 +38,6 @@ Future
 
 More code optimization ideas
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-- a way to optimize if-statement codegen so that "if var & %10000" doesn't use stack & subroutine call, but also that the simple case "if X {...}" remains fast
 - detect variables that are written but never read - mark those as unused too and remove them, such as ``uword unused = memory("unused222", 20)`` - also remove this memory slab allocation
 - rewrite expression tree evaluation such that it doesn't use an eval stack but flatten the tree into linear code that uses a fixed number of predetermined value 'variables'
 - this removes the need for the BinExprSplitter (which is problematic now)