vm: fixed non-byte array indexing

codeGenVirtual/src/prog8/codegen/virtual/CodeGen.kt

@@ -701,7 +701,7 @@ class CodeGen(internal val program: PtProgram,
                     code += VmCodeInstruction(Opcode.STOREZM, VmDataType.FLOAT, value=variableAddr)
                 } else {
                     val indexReg = vmRegisters.nextFree()
-                    code += expressionEval.translateExpression(array.index, indexReg, -1)
+                    code += loadIndexReg(array, itemsize, indexReg)
                     code += VmCodeInstruction(Opcode.STOREZX, VmDataType.FLOAT, reg1=indexReg, value=variableAddr)
                 }
             } else {
@@ -711,7 +711,7 @@ class CodeGen(internal val program: PtProgram,
                         code += VmCodeInstruction(Opcode.STOREM, vmDt, fpReg1 = resultFpRegister, value=variableAddr)
                     } else {
                         val indexReg = vmRegisters.nextFree()
-                        code += expressionEval.translateExpression(array.index, indexReg, -1)
+                        code += loadIndexReg(array, itemsize, indexReg)
                         code += VmCodeInstruction(Opcode.STOREX, vmDt, reg1 = resultRegister, reg2=indexReg, value=variableAddr)
                     }
                 } else {
@@ -720,7 +720,7 @@ class CodeGen(internal val program: PtProgram,
                         code += VmCodeInstruction(Opcode.STOREM, vmDt, reg1 = resultRegister, value=variableAddr)
                     } else {
                         val indexReg = vmRegisters.nextFree()
-                        code += expressionEval.translateExpression(array.index, indexReg, -1)
+                        code += loadIndexReg(array, itemsize, indexReg)
                         code += VmCodeInstruction(Opcode.STOREX, vmDt, reg1 = resultRegister, reg2=indexReg, value=variableAddr)
                     }
                 }
@@ -751,6 +751,20 @@ class CodeGen(internal val program: PtProgram,
         return code
     }
 
+    private fun loadIndexReg(array: PtArrayIndexer, itemsize: Int, indexReg: Int): VmCodeChunk {
+        val code = VmCodeChunk()
+        if(itemsize==1) {
+            code += expressionEval.translateExpression(array.index, indexReg, -1)
+        }
+        else {
+            val mult = PtBinaryExpression("*", DataType.UBYTE, array.position)
+            mult.children += array.index
+            mult.children += PtNumber(DataType.UBYTE, itemsize.toDouble(), array.position)
+            code += expressionEval.translateExpression(mult, indexReg, -1)
+        }
+        return code
+    }
+
     private fun translate(ret: PtReturn): VmCodeChunk {
         val code = VmCodeChunk()
         val value = ret.value

docs/source/todo.rst

@@ -3,7 +3,6 @@ TODO
 
 For next release
 ^^^^^^^^^^^^^^^^
-- vm: animals example game breaks after adding first new animal...
 - vm: add more instructions operating directly on memory instead of only registers? (translate assignment self-assigns)
 - complete the Inliner
 - add McCarthy evaluation to shortcircuit and/or expressions. First do ifs by splitting them up? Then do expressions that compute a value?

examples/animals.p8

@@ -4,19 +4,19 @@
 ; Animal guessing game where the computer gets smarter every time.
 ; Note: this program is compatible with C64 and CX16.
 
-
 main {
     const ubyte database_size = 100
 
-    uword animal_names_buf = memory("animalnames", 500, 0)
+    uword animal_names_buf = memory("animalnames", 500, 0)      ; area to store all animal names in, in sequence
-    uword questions_buf = memory("questions", 2000, 0)
+    uword questions_buf = memory("questions", 2000, 0)          ; area to store all question texts in, in sequence
     uword animal_names_ptr
     uword questions_ptr
 
-    uword[database_size] animals
+    uword[database_size] animals               ; pointers to the animal names
-    uword[database_size] questions
+    uword[database_size] questions             ; pointers to the question texts
-    uword[database_size] answers_questions
+    uword[database_size] answers_questions     ; tree entries for question choices, indexed by question id, pair of (msb=yes, lsb=no) follow up question id (or 0 if it's an animal leaf node)
-    uword[database_size] answers_animals
+    uword[database_size] answers_animals       ; tree entries for animal leafs, indexed by question id, pair of (msb=yes, lsb=no) animal id
+
     ubyte new_animal_number
     ubyte new_question_number
     str userinput = "x"*80
@@ -137,6 +137,5 @@ main {
         new_question_number++
 
         txt.print("\n\nthanks, i know more animals now! let's try again.\n")
-
     }
 }

examples/test.p8

@@ -22,57 +22,33 @@ main {
         return first * second
     }
 
+    ubyte ix
+
     sub start() {
 
-        ubyte @shared value = inline_candidate()
+        uword[] array = [1111,2222,3333,4444]
 
-        str name = "irmen123ABC"
+        sub pa() {
-        str other = "zrmen123zzz"
+            uword ww
+            for ww in array {
+                txt.print_uw(ww)
+                txt.spc()
+            }
+            txt.nl()
+        }
 
-        txt.print(name)
+;        pa()
-        txt.nl()
+;        array[2] = 9999
-        uword otherptr = &other + 2
+;        pa()
-        name = otherptr
+        ix=2
-
+        array[ix]= 8888     ; TODO fix indexing offset in vm
-        txt.print(name)
+        pa()
-        txt.nl()
+        txt.print_uw(array[ix])
-        txt.nl()
+        txt.spc()
-
+        txt.print_uw(array[ix+1])
-        txt.print_ub(string.upper(name))
-        txt.print(name)
-        txt.nl()
-        txt.print_ub(string.lower(name))
-        txt.print(name)
-        txt.nl()
-
-        uword otheraddr = &other
-        txt.print_ub(name!=other)
-        txt.spc()
-        txt.print_ub(name==other)
-        txt.nl()
-        txt.print_ub(name>other)
-        txt.spc()
-        txt.print_ub(name>=other)
-        txt.nl()
-        txt.print_ub(name<other)
-        txt.spc()
-        txt.print_ub(name<=other)
-        txt.nl()
-        txt.nl()
-        other[0]='i'
-        txt.print_ub(name!=other)
-        txt.spc()
-        txt.print_ub(name==other)
-        txt.nl()
-        txt.print_ub(name>other)
-        txt.spc()
-        txt.print_ub(name>=other)
-        txt.nl()
-        txt.print_ub(name<other)
-        txt.spc()
-        txt.print_ub(name<=other)
         txt.nl()
 
+;        ubyte @shared value = inline_candidate()
 
 ;        txt.print_ub(inline_candidate())
 ;        txt.nl()