intermediate program written in blocks

compiler/examples/test.p8

@@ -31,3 +31,11 @@ sub start() {
 }
 
 }
+
+
+~ block2 $c000 {
+
+    str derp="hello"
+    byte v =44
+    return
+}

compiler/src/prog8/CompilerMain.kt

@@ -99,7 +99,7 @@ fun main(args: Array<String>) {
 
         val stackVmFilename =  intermediate.name + "_stackvm.txt"
         val stackvmFile = PrintStream(File(stackVmFilename), "utf-8")
-        intermediate.writeAsText(stackvmFile)
+        intermediate.writeCode(stackvmFile)
         stackvmFile.close()
         println("StackVM program code written to '$stackVmFilename'")
 

compiler/src/prog8/compiler/IntermediateProgram.kt

@@ -0,0 +1,323 @@
+package prog8.compiler
+
+import prog8.ast.DataType
+import prog8.ast.LiteralValue
+import prog8.ast.Position
+import prog8.ast.VarDecl
+import prog8.stackvm.*
+import java.io.PrintStream
+
+
+class IntermediateProgram(val name: String, val heap: HeapValues) {
+
+    private class ProgramBlock(val scopedname: String, val address: Int?) {
+        val instructions = mutableListOf<Instruction>()
+        val variables = mutableMapOf<String, Value>()
+        val labels = mutableMapOf<String, Instruction>()
+
+        val numVariables: Int
+            get() { return variables.size }
+        val numInstructions: Int
+            get() { return instructions.filter { it.opcode!= Opcode.LINE }.size }
+    }
+
+    private val blocks = mutableListOf<ProgramBlock>()
+    private val memory = mutableMapOf<Int, List<Value>>()
+    private lateinit var currentBlock: ProgramBlock
+
+    val numVariables: Int
+        get() = blocks.sumBy { it.numVariables }
+    val numInstructions: Int
+        get() = blocks.sumBy { it.numInstructions }
+
+    fun optimize() {
+        println("Optimizing stackVM code...")
+        optimizeDataConversionAndUselessDiscards()
+        optimizeVariableCopying()
+        optimizeMultipleSequentialLineInstrs()
+        // todo optimize stackvm code more
+
+        // remove nops (that are not a label)
+        for (blk in blocks) {
+            blk.instructions.removeIf { it.opcode== Opcode.NOP && it !is LabelInstr }
+        }
+    }
+
+    private fun optimizeMultipleSequentialLineInstrs() {
+        for(blk in blocks) {
+            val instructionsToReplace = mutableMapOf<Int, Instruction>()
+
+            blk.instructions.asSequence().withIndex().windowed(2).toList().forEach {
+                if (it[0].value.opcode == Opcode.LINE && it[1].value.opcode == Opcode.LINE)
+                    instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
+            }
+
+            for (rins in instructionsToReplace) {
+                blk.instructions[rins.key] = rins.value
+            }
+        }
+    }
+
+    private fun optimizeVariableCopying() {
+        for(blk in blocks) {
+
+            val instructionsToReplace = mutableMapOf<Int, Instruction>()
+
+            blk.instructions.asSequence().withIndex().windowed(2).toList().forEach {
+                when (it[0].value.opcode) {
+                    Opcode.PUSH_VAR_BYTE ->
+                        if (it[1].value.opcode == Opcode.POP_VAR_BYTE) {
+                            if (it[0].value.callLabel != it[1].value.callLabel)
+                                instructionsToReplace[it[0].index] = Instruction(Opcode.COPY_VAR_BYTE, null, it[0].value.callLabel, it[1].value.callLabel)
+                            else
+                                instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
+                            instructionsToReplace[it[1].index] = Instruction(Opcode.NOP)
+                        }
+                    Opcode.PUSH_VAR_WORD ->
+                        if (it[1].value.opcode == Opcode.POP_VAR_WORD) {
+                            if (it[0].value.callLabel != it[1].value.callLabel)
+                                instructionsToReplace[it[0].index] = Instruction(Opcode.COPY_VAR_WORD, null, it[0].value.callLabel, it[1].value.callLabel)
+                            else
+                                instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
+                            instructionsToReplace[it[1].index] = Instruction(Opcode.NOP)
+                        }
+                    Opcode.PUSH_VAR_FLOAT ->
+                        if (it[1].value.opcode == Opcode.POP_VAR_FLOAT) {
+                            if (it[0].value.callLabel != it[1].value.callLabel)
+                                instructionsToReplace[it[0].index] = Instruction(Opcode.COPY_VAR_FLOAT, null, it[0].value.callLabel, it[1].value.callLabel)
+                            else
+                                instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
+                            instructionsToReplace[it[1].index] = Instruction(Opcode.NOP)
+                        }
+                    else -> {
+                    }
+                }
+            }
+
+            for (rins in instructionsToReplace) {
+                blk.instructions[rins.key] = rins.value
+            }
+        }
+    }
+
+    private fun optimizeDataConversionAndUselessDiscards() {
+        // - push value followed by a data type conversion -> push the value in the correct type and remove the conversion
+        // - push something followed by a discard -> remove both
+        val instructionsToReplace = mutableMapOf<Int, Instruction>()
+
+        fun optimizeDiscardAfterPush(index0: Int, index1: Int, ins1: Instruction) {
+            if (ins1.opcode == Opcode.DISCARD_FLOAT || ins1.opcode == Opcode.DISCARD_WORD || ins1.opcode == Opcode.DISCARD_BYTE) {
+                instructionsToReplace[index0] = Instruction(Opcode.NOP)
+                instructionsToReplace[index1] = Instruction(Opcode.NOP)
+            }
+        }
+
+        fun optimizeFloatConversion(index0: Int, index1: Int, ins1: Instruction) {
+            when (ins1.opcode) {
+                Opcode.LSB,
+                Opcode.MSB,
+                Opcode.B2WORD,
+                Opcode.UB2UWORD,
+                Opcode.MSB2WORD,
+                Opcode.B2FLOAT,
+                Opcode.UB2FLOAT,
+                Opcode.UW2FLOAT,
+                Opcode.W2FLOAT -> throw CompilerException("invalid conversion following a float")
+                Opcode.DISCARD_FLOAT -> {
+                    instructionsToReplace[index0] = Instruction(Opcode.NOP)
+                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
+                }
+                Opcode.DISCARD_BYTE, Opcode.DISCARD_WORD -> throw CompilerException("invalid discard type following a float")
+                else -> throw CompilerException("invalid conversion opcode ${ins1.opcode}")
+            }
+        }
+
+        fun optimizeWordConversion(index0: Int, ins0: Instruction, index1: Int, ins1: Instruction) {
+            when (ins1.opcode) {
+                Opcode.LSB -> {
+                    val ins = Instruction(Opcode.PUSH_BYTE, Value(DataType.UBYTE, ins0.arg!!.integerValue() and 255))
+                    instructionsToReplace[index0] = ins
+                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
+                }
+                Opcode.MSB -> {
+                    val ins = Instruction(Opcode.PUSH_BYTE, Value(DataType.UBYTE, ins0.arg!!.integerValue() ushr 8 and 255))
+                    instructionsToReplace[index0] = ins
+                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
+                }
+                Opcode.B2WORD,
+                Opcode.UB2UWORD,
+                Opcode.MSB2WORD,
+                Opcode.B2FLOAT,
+                Opcode.UB2FLOAT -> throw CompilerException("invalid conversion following a word")
+                Opcode.W2FLOAT, Opcode.UW2FLOAT -> {
+                    val ins = Instruction(Opcode.PUSH_FLOAT, Value(DataType.FLOAT, ins0.arg!!.integerValue().toDouble()))
+                    instructionsToReplace[index0] = ins
+                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
+                }
+                Opcode.DISCARD_WORD -> {
+                    instructionsToReplace[index0] = Instruction(Opcode.NOP)
+                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
+                }
+                Opcode.DISCARD_BYTE, Opcode.DISCARD_FLOAT -> throw CompilerException("invalid discard type following a byte")
+                else -> throw CompilerException("invalid conversion opcode ${ins1.opcode}")
+            }
+        }
+
+        fun optimizeByteConversion(index0: Int, ins0: Instruction, index1: Int, ins1: Instruction) {
+            when (ins1.opcode) {
+                Opcode.LSB -> instructionsToReplace[index1] = Instruction(Opcode.NOP)
+                Opcode.MSB -> throw CompilerException("msb of a byte")
+                Opcode.UB2UWORD -> {
+                    val ins = Instruction(Opcode.PUSH_WORD, Value(DataType.UWORD, ins0.arg!!.integerValue()))
+                    instructionsToReplace[index0] = ins
+                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
+                }
+                Opcode.B2WORD -> {
+                    val ins = Instruction(Opcode.PUSH_WORD, Value(DataType.WORD, ins0.arg!!.integerValue()))
+                    instructionsToReplace[index0] = ins
+                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
+                }
+                Opcode.MSB2WORD -> {
+                    val ins = Instruction(Opcode.PUSH_WORD, Value(DataType.UWORD, 256 * ins0.arg!!.integerValue()))
+                    instructionsToReplace[index0] = ins
+                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
+                }
+                Opcode.B2FLOAT, Opcode.UB2FLOAT -> {
+                    val ins = Instruction(Opcode.PUSH_FLOAT, Value(DataType.FLOAT, ins0.arg!!.integerValue().toDouble()))
+                    instructionsToReplace[index0] = ins
+                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
+                }
+                Opcode.W2FLOAT, Opcode.UW2FLOAT -> throw CompilerException("invalid conversion following a byte")
+                Opcode.DISCARD_BYTE -> {
+                    instructionsToReplace[index0] = Instruction(Opcode.NOP)
+                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
+                }
+                Opcode.DISCARD_WORD, Opcode.DISCARD_FLOAT -> throw CompilerException("invalid discard type following a byte")
+                else -> throw CompilerException("invalid conversion opcode ${ins1.opcode}")
+            }
+        }
+
+        for(blk in blocks) {
+            instructionsToReplace.clear()
+
+            val typeConversionOpcodes = setOf(
+                    Opcode.LSB,
+                    Opcode.MSB,
+                    Opcode.B2WORD,
+                    Opcode.UB2UWORD,
+                    Opcode.MSB2WORD,
+                    Opcode.B2FLOAT,
+                    Opcode.UB2FLOAT,
+                    Opcode.W2FLOAT,
+                    Opcode.UW2FLOAT,
+                    Opcode.DISCARD_BYTE,
+                    Opcode.DISCARD_WORD,
+                    Opcode.DISCARD_FLOAT
+            )
+            blk.instructions.asSequence().withIndex().windowed(2).toList().forEach {
+                if (it[1].value.opcode in typeConversionOpcodes) {
+                    when (it[0].value.opcode) {
+                        Opcode.PUSH_BYTE -> optimizeByteConversion(it[0].index, it[0].value, it[1].index, it[1].value)
+                        Opcode.PUSH_WORD -> optimizeWordConversion(it[0].index, it[0].value, it[1].index, it[1].value)
+                        Opcode.PUSH_FLOAT -> optimizeFloatConversion(it[0].index, it[1].index, it[1].value)
+                        Opcode.PUSH_VAR_FLOAT,
+                        Opcode.PUSH_VAR_WORD,
+                        Opcode.PUSH_VAR_BYTE,
+                        Opcode.PUSH_MEM_B, Opcode.PUSH_MEM_UB,
+                        Opcode.PUSH_MEM_W, Opcode.PUSH_MEM_UW,
+                        Opcode.PUSH_MEM_FLOAT -> optimizeDiscardAfterPush(it[0].index, it[1].index, it[1].value)
+                        else -> {
+                        }
+                    }
+                }
+            }
+
+            for (rins in instructionsToReplace) {
+                blk.instructions[rins.key] = rins.value
+            }
+        }
+    }
+
+    fun variable(scopedname: String, decl: VarDecl) {
+        val value = when(decl.datatype) {
+            DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD, DataType.FLOAT -> Value(decl.datatype, (decl.value as LiteralValue).asNumericValue!!)
+            DataType.STR, DataType.STR_P, DataType.STR_S, DataType.STR_PS -> {
+                val litval = (decl.value as LiteralValue)
+                if(litval.heapId==null)
+                    throw CompilerException("string should already be in the heap")
+                Value(decl.datatype, litval.heapId)
+            }
+            DataType.ARRAY_B, DataType.ARRAY_W, DataType.MATRIX_B, DataType.MATRIX_UB,
+            DataType.ARRAY_UB, DataType.ARRAY_UW, DataType.ARRAY_F -> {
+                val litval = (decl.value as LiteralValue)
+                if(litval.heapId==null)
+                    throw CompilerException("array/matrix should already be in the heap")
+                Value(decl.datatype, litval.heapId)
+            }
+        }
+        currentBlock.variables[scopedname] = value
+    }
+
+    fun instr(opcode: Opcode, arg: Value? = null, callLabel: String? = null) {
+        currentBlock.instructions.add(Instruction(opcode, arg, callLabel))
+    }
+
+    fun label(labelname: String) {
+        val instr = LabelInstr(labelname)
+        currentBlock.instructions.add(instr)
+        currentBlock.labels[labelname] = instr
+    }
+
+    fun line(position: Position) {
+        currentBlock.instructions.add(Instruction(Opcode.LINE, callLabel = "${position.line} ${position.file}"))
+    }
+
+    fun newBlock(scopedname: String, address: Int?) {
+        currentBlock = ProgramBlock(scopedname, address)
+        blocks.add(currentBlock)
+    }
+
+    fun writeCode(out: PrintStream, embeddedLabels: Boolean=true) {
+        out.println("; stackVM program code for '$name'")
+        out.println("%memory")
+        if(memory.isNotEmpty()) {
+            TODO("print out initial memory load")
+        }
+        out.println("%end_memory")
+        out.println("%heap")
+        heap.allStrings().forEach {
+            out.println("${it.index}  ${it.value.type.toString().toLowerCase()}  \"${it.value.str}\"")
+        }
+        heap.allArrays().forEach {
+            out.println("${it.index}  ${it.value.type.toString().toLowerCase()}  ${it.value.array!!.toList()}")
+        }
+        heap.allDoubleArrays().forEach {
+            out.println("${it.index}  ${it.value.type.toString().toLowerCase()}  ${it.value.doubleArray!!.toList()}")
+        }
+        out.println("%end_heap")
+        for(blk in blocks) {
+            out.println("\n%block ${blk.scopedname} ${blk.address?.toString(16) ?: ""}")
+
+            out.println("%variables")
+            for(variable in blk.variables) {
+                val valuestr = variable.value.toString()
+                out.println("${variable.key}  ${variable.value.type.toString().toLowerCase()}  $valuestr")
+            }
+            out.println("%end_variables")
+            out.println("%instructions")
+            val labels = blk.labels.entries.associateBy({it.value}) {it.key}
+            for(instr in blk.instructions) {
+                if(!embeddedLabels) {
+                    val label = labels[instr]
+                    if (label != null)
+                        out.println("$label:")
+                } else {
+                    out.println(instr)
+                }
+            }
+            out.println("%end_instructions")
+
+            out.println("%end_block")
+        }
+    }
+}

compiler/src/prog8/stackvm/Program.kt

@@ -4,25 +4,33 @@ import prog8.ast.DataType
 import prog8.compiler.HeapValues
 import prog8.compiler.unescape
 import java.io.File
-import java.io.PrintStream
 import java.util.*
 import java.util.regex.Pattern
 
 class Program (val name: String,
-               prog: MutableList<Instruction>,
+               val program: MutableList<Instruction>,
+               val variables: Map<String, Value>,
                val labels: Map<String, Instruction>,
-               val variables: Map<String, Map<String, Value>>,
                val memory: Map<Int, List<Value>>,
                val heap: HeapValues)
 {
+    init {
+        // add end of program marker and some sentinel instructions, to correctly connect all others
+        program.add(LabelInstr("____program_end"))
+        program.add(Instruction(Opcode.TERMINATE))
+        program.add(Instruction(Opcode.NOP))
+        connect()
+    }
+
     companion object {
         fun load(filename: String): Program {
             val lines = File(filename).readLines().withIndex().iterator()
             val memory = mutableMapOf<Int, List<Value>>()
-            val vars = mutableMapOf<String, MutableMap<String, Value>>()
-            var instructions = mutableListOf<Instruction>()
-            var labels = mapOf<String, Instruction>()
             val heap = HeapValues()
+            val program = mutableListOf<Instruction>()
+            val variables = mutableMapOf<String, Value>()
+            val labels = mutableMapOf<String, Instruction>()
+
             while(lines.hasNext()) {
                 val (lineNr, line) = lines.next()
                 if(line.startsWith(';') || line.isEmpty())
@@ -31,16 +39,33 @@ class Program (val name: String,
                     loadMemory(lines, memory)
                 else if(line=="%heap")
                     loadHeap(lines, heap)
-                else if(line=="%variables")
-                    loadVars(lines, vars)
-                else if(line=="%instructions") {
-                    val (insResult, labelResult) = loadInstructions(lines, heap)
-                    instructions = insResult
-                    labels = labelResult
-                }
+                else if(line.startsWith("%block "))
+                    loadBlock(lines, heap, program, variables, labels)
                 else throw VmExecutionException("syntax error at line ${lineNr + 1}")
             }
-            return Program(filename, instructions, labels, vars, memory, heap)
+            return Program(filename, program, variables, labels, memory, heap)
+        }
+
+        private fun loadBlock(lines: Iterator<IndexedValue<String>>,
+                              heap: HeapValues,
+                              program: MutableList<Instruction>,
+                              variables: MutableMap<String, Value>,
+                              labels: MutableMap<String, Instruction>)
+        {
+            while(true) {
+                val (lineNr, line) = lines.next()
+                if(line.isEmpty())
+                    continue
+                else if(line=="%end_block")
+                    return
+                else if(line=="%variables")
+                    loadVars(lines, variables)
+                else if(line=="%instructions") {
+                    val (blockInstructions, blockLabels) = loadInstructions(lines, heap)
+                    program.addAll(blockInstructions)
+                    labels.putAll(blockLabels)
+                }
+            }
         }
 
         private fun loadHeap(lines: Iterator<IndexedValue<String>>, heap: HeapValues) {
@@ -156,7 +181,7 @@ class Program (val name: String,
         }
 
         private fun loadVars(lines: Iterator<IndexedValue<String>>,
-                             vars: MutableMap<String, MutableMap<String, Value>>): Map<String, Map<String, Value>> {
+                             vars: MutableMap<String, Value>): Map<String, Value> {
             val splitpattern = Pattern.compile("\\s+")
             while(true) {
                 val (lineNr, line) = lines.next()
@@ -197,10 +222,7 @@ class Program (val name: String,
                         }
                     }
                 }
-                val blockname = name.substringBefore('.')
-                val blockvars = vars[blockname] ?: mutableMapOf()
-                vars[blockname] = blockvars
-                blockvars[name] = value
+                vars[name] = value
             }
         }
 
@@ -229,15 +251,6 @@ class Program (val name: String,
         }
     }
 
-    val program: List<Instruction>
-
-    init {
-        prog.add(LabelInstr("____program_end"))
-        prog.add(Instruction(Opcode.TERMINATE))
-        prog.add(Instruction(Opcode.NOP))
-        program = prog
-        connect()
-    }
 
     private fun connect() {
         val it1 = program.iterator()
@@ -283,43 +296,4 @@ class Program (val name: String,
             }
         }
     }
-
-    fun print(out: PrintStream, embeddedLabels: Boolean=true) {
-        out.println("; stackVM program code for '$name'")
-        out.println("%memory")
-        if(memory.isNotEmpty()) {
-            TODO("print out initial memory load")
-        }
-        out.println("%end_memory")
-        out.println("%heap")
-        heap.allStrings().forEach {
-            out.println("${it.index}  ${it.value.type.toString().toLowerCase()}  \"${it.value.str}\"")
-        }
-        heap.allArrays().forEach {
-            out.println("${it.index}  ${it.value.type.toString().toLowerCase()}  ${it.value.array!!.toList()}")
-        }
-        heap.allDoubleArrays().forEach {
-            out.println("${it.index}  ${it.value.type.toString().toLowerCase()}  ${it.value.doubleArray!!.toList()}")
-        }
-        out.println("%end_heap")
-        out.println("%variables")
-        // just flatten all block vars into one global list for now...
-        for(variable in variables.flatMap { e->e.value.entries}) {
-            val valuestr = variable.value.toString()
-            out.println("${variable.key}  ${variable.value.type.toString().toLowerCase()}  $valuestr")
-        }
-        out.println("%end_variables")
-        out.println("%instructions")
-        val labels = this.labels.entries.associateBy({it.value}) {it.key}
-        for(instr in this.program) {
-            if(!embeddedLabels) {
-                val label = labels[instr]
-                if (label != null)
-                    out.println("$label:")
-            } else {
-                out.println(instr)
-            }
-        }
-        out.println("%end_instructions")
-    }
 }

compiler/src/prog8/stackvm/StackVm.kt

@@ -384,9 +384,7 @@ class StackVm(private var traceOutputFile: String?) {
         this.heap = program.heap
         this.canvas = canvas
         canvas?.requestFocusInWindow()
-        variables.clear()
-        for(variable in program.variables.flatMap { e->e.value.entries })
-            variables[variable.key] = variable.value
+        variables = program.variables.toMutableMap()
 
         if("A" in variables || "X" in variables || "Y" in variables ||
                 "XY" in variables || "AX" in variables ||"AY" in variables)

compiler/test/StackVMOpcodeTests.kt

@@ -50,18 +50,8 @@ class TestStackVmOpcodes {
                  vars: Map<String, Value>?=null,
                  labels: Map<String, Instruction>?=null,
                  mem: Map<Int, List<Value>>?=null) : Program {
-
-        val blockvars = mutableMapOf<String, MutableMap<String, Value>>()
-        if(vars!=null) {
-            for (blockvar in vars) {
-                val blockname = blockvar.key.substringBefore('.')
-                val variables = blockvars[blockname] ?: mutableMapOf()
-                blockvars[blockname] = variables
-                variables[blockvar.key] = blockvar.value
-            }
-        }
         val heap = HeapValues()
-        return Program("test", ins, labels ?: mapOf(), blockvars, mem ?: mapOf(), heap)
+        return Program("test", ins, vars ?: mapOf(), labels ?: mapOf(), mem ?: mapOf(), heap)
     }
 
     @Test
@@ -252,7 +242,6 @@ class TestStackVmOpcodes {
         assertEquals(42.25, vm.mem.getFloat(0x4000))
     }
 
-
     @Test
     fun testPopVar() {
         val ins = mutableListOf(

compiler/test/UnitTests.kt

@@ -25,15 +25,28 @@ class TestCompiler {
         assertEquals("10", 10.toHex())
         assertEquals("10", 10.99.toHex())
         assertEquals("15", 15.toHex())
-        assertEquals("$10", 16.toHex())
+        assertEquals("\$10", 16.toHex())
         assertEquals("\$ff", 255.toHex())
-        assertEquals("$0100", 256.toHex())
-        assertEquals("$4e5c", 20060.toHex())
+        assertEquals("\$0100", 256.toHex())
+        assertEquals("\$4e5c", 20060.toHex())
+        assertEquals("\$c382", 50050.toHex())
         assertEquals("\$ffff", 65535.toHex())
         assertEquals("\$ffff", 65535L.toHex())
+        assertEquals("0", 0.toHex())
+        assertEquals("-1", (-1).toHex())
+        assertEquals("-1", (-1.234).toHex())
+        assertEquals("-10", (-10).toHex())
+        assertEquals("-10", (-10.99).toHex())
+        assertEquals("-15", (-15).toHex())
+        assertEquals("-\$10", (-16).toHex())
+        assertEquals("-\$ff", (-255).toHex())
+        assertEquals("-\$0100", (-256).toHex())
+        assertEquals("-\$4e5c", (-20060).toHex())
+        assertEquals("-\$c382", (-50050).toHex())
+        assertEquals("-\$ffff", (-65535).toHex())
+        assertEquals("-\$ffff", (-65535L).toHex())
         assertFailsWith<CompilerException> { 65536.toHex()  }
-        assertFailsWith<CompilerException> { (-1).toHex()  }
-        assertFailsWith<CompilerException> { (-1.99).toHex()  }
+        assertFailsWith<CompilerException> { 65536L.toHex()  }
     }