ir: fix initial chunk linking

codeGenIntermediate/src/prog8/codegen/intermediate/BuiltinFuncGen.kt

@@ -29,7 +29,7 @@ internal class BuiltinFuncGen(private val codeGen: IRCodeGen, private val exprGe
             "rsavex",
             "rrestore",
             "rrestorex" -> ExpressionCodeResult.EMPTY  // vm doesn't have registers to save/restore
-            "callfar" -> throw AssemblyError("callfar() is for cx16 target only")
+            "callfar" -> funcCallfar(call)
             "msb" -> funcMsb(call)
             "lsb" -> funcLsb(call)
             "memory" -> funcMemory(call)
@@ -53,6 +53,18 @@ internal class BuiltinFuncGen(private val codeGen: IRCodeGen, private val exprGe
         }
     }
 
+    private fun funcCallfar(call: PtBuiltinFunctionCall): ExpressionCodeResult {
+        val result = mutableListOf<IRCodeChunkBase>()
+        val bankTr = exprGen.translateExpression(call.args[0])
+        val addressTr = exprGen.translateExpression(call.args[1])
+        val argumentwordTr = exprGen.translateExpression(call.args[2])
+        addToResult(result, bankTr, bankTr.resultReg, -1)
+        addToResult(result, addressTr, addressTr.resultReg, -1)
+        addToResult(result, argumentwordTr, argumentwordTr.resultReg, -1)
+        result += codeGen.makeSyscall(IMSyscall.CALLFAR, listOf(IRDataType.BYTE to bankTr.resultReg, IRDataType.WORD to addressTr.resultReg, IRDataType.WORD to argumentwordTr.resultReg), IRDataType.WORD to argumentwordTr.resultReg)
+        return ExpressionCodeResult(result, IRDataType.WORD, argumentwordTr.resultReg, -1)
+    }
+
     private fun funcDivmod(call: PtBuiltinFunctionCall, type: IRDataType): ExpressionCodeResult {
         val result = mutableListOf<IRCodeChunkBase>()
         val number = call.args[0]

docs/source/todo.rst

@@ -1,7 +1,8 @@
 TODO
 ====
 
-- Fix expericodegen errors (examples/cx16/keyboardhandler, rockrunners etc)
+- Fix wrong unused subroutines in expericodegen with cx16 shell
+- Fix expericodegen errors (chess, assem, musicdemo, rockrunners etc)
 
 ...
 

intermediate/src/prog8/intermediate/IMSyscall.kt

@@ -26,5 +26,6 @@ enum class IMSyscall(val number: Int) {
     CLAMP_BYTE(0x1012),
     CLAMP_UWORD(0x1013),
     CLAMP_WORD(0x1014),
-    CLAMP_FLOAT(0x1015)
+    CLAMP_FLOAT(0x1015),
+    CALLFAR(0x1016),
 }

intermediate/src/prog8/intermediate/IRProgram.kt

@@ -96,9 +96,10 @@ class IRProgram(val name: String,
                 // link globalinits to subsequent chunk
                 val firstBlock = blocks.firstOrNull()
                 if(firstBlock!=null && firstBlock.isNotEmpty()) {
-                    firstBlock.children.forEach { child ->
+                    firstBlock.children.first().let { child ->
                         when(child) {
-                            is IRAsmSubroutine -> throw AssemblyError("cannot link next to asmsub $child")
+                            is IRAsmSubroutine ->
+                                throw AssemblyError("cannot link next to asmsub $child")
                             is IRCodeChunk -> globalInits.next = child
                             is IRInlineAsmChunk -> globalInits.next = child
                             is IRInlineBinaryChunk -> globalInits.next = child

virtualmachine/src/prog8/vm/SysCalls.kt

@@ -52,7 +52,7 @@ SYSCALLS:
 41 = CLAMP_WORD
 42 = CLAMP_UWORD
 43 = CLAMP_FLOAT
-43 = ATAN
+44 = ATAN
 */
 
 enum class Syscall {

virtualmachine/src/prog8/vm/VmProgramLoader.kt

@@ -124,6 +124,7 @@ class VmProgramLoader {
                         IMSyscall.CLAMP_WORD.number -> Syscall.CLAMP_WORD
                         IMSyscall.CLAMP_UWORD.number -> Syscall.CLAMP_UWORD
                         IMSyscall.CLAMP_FLOAT.number -> Syscall.CLAMP_FLOAT
+                        IMSyscall.CALLFAR.number -> throw IRParseException("vm doesn't support the callfar() syscall")
                         else -> null
                     }