Important bugfixes; removing empty stores to larger variables

src/main/scala/millfork/assembly/AssemblyLine.scala

@@ -50,14 +50,14 @@ object OpcodeClasses {
     PHX, PHY, PLX, PLY, TAS, LAS
   )
   val ChangesMemoryAlways = Set(
-    STA, STY, STZ,
+    STA, STY, STZ, STX,
-    STX, DEC, INC,
+    TRB, TSB,
     SAX, DCP, ISC,
     SLO, RLA, SRE, RRA,
     AHX, SHY, SHX, TAS, LAS
   )
   val ChangesMemoryIfNotImplied = Set(
-    ASL, ROL, LSR, ROR
+    DEC, INC, ASL, ROL, LSR, ROR
   )
   val ReadsMemoryIfNotImpliedOrImmediate = Set(
     LDY, CPX, CPY,
@@ -305,7 +305,7 @@ case class AssemblyLine(opcode: Opcode.Value, addrMode: AddrMode.Value, var para
 
   def sizeInBytes: Int = addrMode match {
     case Implied => 1
-    case Relative | ZeroPageX | ZeroPage | ZeroPageY | IndexedX | IndexedY | Immediate => 2
+    case Relative | ZeroPageX | ZeroPage | ZeroPageY | ZeroPageIndirect | IndexedX | IndexedY | Immediate => 2
     case AbsoluteIndexedX | AbsoluteX | Absolute | AbsoluteY | Indirect => 3
     case DoesNotExist => 0
   }

src/main/scala/millfork/assembly/opt/CoarseFlowAnalyzer.scala

@@ -195,16 +195,16 @@ object CoarseFlowAnalyzer {
             currentStatus = initialStatus
 
           case AssemblyLine(LDX, Immediate, NumericConstant(nn, _), _) =>
-            val n = nn.toInt
+            val n = nn.toInt & 0xff
             currentStatus = currentStatus.nz(n).copy(x = SingleStatus(n))
           case AssemblyLine(LDY, Immediate, NumericConstant(nn, _), _) =>
-            val n = nn.toInt
+            val n = nn.toInt & 0xff
             currentStatus = currentStatus.nz(n).copy(y = SingleStatus(n))
           case AssemblyLine(LDA, Immediate, NumericConstant(nn, _), _) =>
-            val n = nn.toInt
+            val n = nn.toInt & 0xff
             currentStatus = currentStatus.nz(n).copy(a = SingleStatus(n))
           case AssemblyLine(LAX, Immediate, NumericConstant(nn, _), _) =>
-            val n = nn.toInt
+            val n = nn.toInt & 0xff
             currentStatus = currentStatus.nz(n).copy(a = SingleStatus(n), x = SingleStatus(n))
 
           case AssemblyLine(ADC, Immediate, NumericConstant(nn, _), _) =>
@@ -232,17 +232,17 @@ object CoarseFlowAnalyzer {
               a = currentStatus.a.map(i => (i & n & 0xff) >> 1))
 
           case AssemblyLine(INX, Implied, _, _) =>
-            currentStatus = currentStatus.copy(n = currentStatus.x.n(_ + 1), z = currentStatus.x.z(_ + 1), x = currentStatus.x.map(_ + 1))
+            currentStatus = currentStatus.copy(n = currentStatus.x.n(_ + 1), z = currentStatus.x.z(_ + 1), x = currentStatus.x.map(v => (v + 1) & 0xff))
           case AssemblyLine(DEX, Implied, _, _) =>
-            currentStatus = currentStatus.copy(n = currentStatus.x.n(_ - 1), z = currentStatus.x.z(_ - 1), x = currentStatus.x.map(_ - 1))
+            currentStatus = currentStatus.copy(n = currentStatus.x.n(_ - 1), z = currentStatus.x.z(_ - 1), x = currentStatus.x.map(v => (v - 1) & 0xff))
           case AssemblyLine(INY, Implied, _, _) =>
-            currentStatus = currentStatus.copy(n = currentStatus.y.n(_ + 1), z = currentStatus.y.z(_ + 1), y = currentStatus.y.map(_ + 1))
+            currentStatus = currentStatus.copy(n = currentStatus.y.n(_ + 1), z = currentStatus.y.z(_ + 1), y = currentStatus.y.map(v => (v + 1) & 0xff))
           case AssemblyLine(DEY, Implied, _, _) =>
-            currentStatus = currentStatus.copy(n = currentStatus.y.n(_ - 1), z = currentStatus.y.z(_ - 1), y = currentStatus.y.map(_ - 1))
+            currentStatus = currentStatus.copy(n = currentStatus.y.n(_ - 1), z = currentStatus.y.z(_ - 1), y = currentStatus.y.map(v => (v - 1) & 0xff))
           case AssemblyLine(INC, Implied, _, _) =>
-            currentStatus = currentStatus.copy(n = currentStatus.a.n(_ + 1), z = currentStatus.a.z(_ + 1), a = currentStatus.a.map(_ + 1))
+            currentStatus = currentStatus.copy(n = currentStatus.a.n(_ + 1), z = currentStatus.a.z(_ + 1), a = currentStatus.a.map(v => (v + 1) & 0xff))
           case AssemblyLine(DEC, Implied, _, _) =>
-            currentStatus = currentStatus.copy(n = currentStatus.a.n(_ - 1), z = currentStatus.a.z(_ - 1), a = currentStatus.a.map(_ - 1))
+            currentStatus = currentStatus.copy(n = currentStatus.a.n(_ - 1), z = currentStatus.a.z(_ - 1), a = currentStatus.a.map(v => (v - 1) & 0xff))
           case AssemblyLine(TAX, _, _, _) =>
             currentStatus = currentStatus.copy(x = currentStatus.a, n = currentStatus.a.n(), z = currentStatus.a.z())
           case AssemblyLine(TXA, _, _, _) =>
@@ -253,7 +253,7 @@ object CoarseFlowAnalyzer {
             currentStatus = currentStatus.copy(a = currentStatus.y, n = currentStatus.y.n(), z = currentStatus.y.z())
 
           case AssemblyLine(ASL, Implied, _, _) =>
-            currentStatus = currentStatus.copy(a = currentStatus.a.map(_ << 1), n = currentStatus.a.n(_ << 1), z = currentStatus.a.z(_ << 1),c = currentStatus.a.map(a => a.&(0xff).!=(0)))
+            currentStatus = currentStatus.copy(a = currentStatus.a.map(v => (v << 1) & 0xff), n = currentStatus.a.n(_ << 1), z = currentStatus.a.z(_ << 1),c = currentStatus.a.map(a => a.&(0xff).!=(0)))
           case AssemblyLine(LSR, Implied, _, _) =>
             currentStatus = currentStatus.copy(a = currentStatus.a.map(a => a.>>(1).&(0x7f)), n = currentStatus.a.n(a => a.>>(1).&(0x7f)), z = currentStatus.a.z(a => a.>>(1).&(0x7f)),c = currentStatus.a.map(a => a.&(1).!=(0)))
 

src/main/scala/millfork/assembly/opt/EmptyMemoryStoreRemoval.scala

@@ -4,6 +4,7 @@ import millfork.CompilationOptions
 import millfork.assembly.AssemblyLine
 import millfork.env._
 import millfork.assembly.Opcode._
+import millfork.assembly.AddrMode._
 import millfork.error.ErrorReporting
 
 import scala.collection.{immutable, mutable}
@@ -14,7 +15,7 @@ import scala.collection.{immutable, mutable}
 object EmptyMemoryStoreRemoval extends AssemblyOptimization {
   override def name = "Removing pointless stores to automatic variables"
 
-  private val storeOpcodes = Set(STA, STX, STY, STZ, SAX)
+  private val storeAddrModes = Set(Absolute, ZeroPage, AbsoluteX, AbsoluteY, ZeroPageX, ZeroPageY)
 
   override def optimize(f: NormalFunction, code: List[AssemblyLine], options: CompilationOptions): List[AssemblyLine] = {
     val paramVariables = f.params match {
@@ -26,11 +27,13 @@ object EmptyMemoryStoreRemoval extends AssemblyOptimization {
     }
     val stillUsedVariables = code.flatMap {
       case AssemblyLine(_, _, MemoryAddressConstant(th), _) => Some(th.name)
+      case AssemblyLine(_, _, CompoundConstant(MathOperator.Plus, MemoryAddressConstant(th), NumericConstant(_, _)), _) => Some(th.name)
       case _ => None
     }.toSet
-    val localVariables = f.environment.getAllLocalVariables.filter {
+    val allLocalVariables = f.environment.getAllLocalVariables
-      case MemoryVariable(name, typ, VariableAllocationMethod.Auto) =>
+    val localVariables = allLocalVariables.filter {
-        typ.size == 1 && !paramVariables(name) && stillUsedVariables(name)
+      case MemoryVariable(name, typ, VariableAllocationMethod.Auto | VariableAllocationMethod.Zeropage) =>
+        typ.size > 0 && !paramVariables(name) && stillUsedVariables(name)
       case _ => false
     }
 
@@ -46,17 +49,43 @@ object EmptyMemoryStoreRemoval extends AssemblyOptimization {
       val lifetime = VariableLifetime.apply(v.name, code)
       val lastaccess = lifetime.last
       if (lastaccess >= 0) {
-        if (code(lastaccess).opcode match {
+        val lastVariableAccess = code(lastaccess)
-          case  STA | STX | STY | SAX =>
+        if (lastVariableAccess.elidable && storeAddrModes(lastVariableAccess.addrMode) && (lastVariableAccess.opcode match {
+          case STA | STX | STY | SAX | STZ | SHX | SHY | AHX =>
             true
+          case TSB | TRB =>
+            if (importances eq null) importances = ReverseFlowAnalyzer.analyze(f, code)
+            importances(lastaccess).z != Important
           case INC | DEC =>
-            if (importances eq null) {
+            if (importances eq null) importances = ReverseFlowAnalyzer.analyze(f, code)
-              importances = ReverseFlowAnalyzer.analyze(f, code)
+            importances(lastaccess).z != Important &&
-            }
+              importances(lastaccess).n != Important
-            importances(lastaccess).z != Important && importances(lastaccess).n != Important
+          case ASL | LSR | ROL | ROR | DCP =>
+            if (importances eq null) importances = ReverseFlowAnalyzer.analyze(f, code)
+            importances(lastaccess).z != Important &&
+              importances(lastaccess).n != Important &&
+              importances(lastaccess).c != Important
+          case ISC =>
+            if (importances eq null) importances = ReverseFlowAnalyzer.analyze(f, code)
+            importances(lastaccess).z != Important &&
+              importances(lastaccess).n != Important &&
+              importances(lastaccess).a != Important
+          case DCP | SLO | SRE | RLA =>
+            if (importances eq null) importances = ReverseFlowAnalyzer.analyze(f, code)
+            importances(lastaccess).z != Important &&
+              importances(lastaccess).n != Important &&
+              importances(lastaccess).c != Important &&
+              importances(lastaccess).a != Important
+          case RRA =>
+            if (importances eq null) importances = ReverseFlowAnalyzer.analyze(f, code)
+            importances(lastaccess).z != Important &&
+              importances(lastaccess).n != Important &&
+              importances(lastaccess).c != Important &&
+              importances(lastaccess).a != Important &&
+              importances(lastaccess).v != Important
           case _ => // last variable access is important, or we're in a loop, do not remove
             false
-        }) {
+        })) {
           badVariables += v.name
           toRemove += lastaccess
         }

src/main/scala/millfork/assembly/opt/VariableLifetime.scala

@@ -9,11 +9,11 @@ import millfork.error.ErrorReporting
   */
 object VariableLifetime {
 
-  // TODO: This only works for 1-byte non-stack variables.
+  // This only works for non-stack variables.
-  // Should be fixed to also work with larger variables.
   def apply(variableName: String, code: List[AssemblyLine]): Range = {
     val flags = code.map(_.parameter match {
       case MemoryAddressConstant(MemoryVariable(n, _, _)) if n == variableName => true
+      case CompoundConstant(MathOperator.Plus, MemoryAddressConstant(MemoryVariable(n, _, _)), NumericConstant(_, 1)) if n == variableName => true
       case _ => false
     })
     if (flags.forall(!_)) return Range(0, 0)

src/main/scala/millfork/output/Assembler.scala

@@ -708,6 +708,7 @@ object Assembler {
   cm(TRB, ZeroPage, 0x14)
   cm(TRB, Absolute, 0x1C)
 
+  cm(BRA, Relative, 0x80)
   cm(BIT, ZeroPageX, 0x34)
   cm(BIT, AbsoluteX, 0x3C)
   cm(INC, Implied, 0x1A)