set correct rom banks when using floats

compiler/src/prog8/compiler/astprocessing/AstChecker.kt

@@ -9,6 +9,7 @@ import prog8.ast.statements.*
 import prog8.ast.walk.IAstVisitor
 import prog8.compiler.CompilationOptions
 import prog8.compiler.IErrorReporter
+import prog8.compiler.ZeropageType
 import prog8.compiler.functions.BuiltinFunctions
 import prog8.compiler.functions.builtinFunctionReturnType
 import prog8.compiler.target.C64Target
@@ -41,6 +42,11 @@ internal class AstChecker(private val program: Program,
             }
         }
 
+        if(compilerOptions.floats) {
+            if (compilerOptions.zeropage !in setOf(ZeropageType.FLOATSAFE, ZeropageType.BASICSAFE, ZeropageType.DONTUSE ))
+                errors.err("when floats are enabled, zero page type should be 'floatsafe' or 'basicsafe' or 'dontuse'", program.mainModule.position)
+        }
+
         super.visit(program)
     }
 

compiler/src/prog8/compiler/target/cpu6502/codegen/AsmGen.kt

@@ -159,7 +159,11 @@ internal class AsmGen(private val program: Program,
 
         // make sure that on the cx16 and c64, basic rom is banked in again when we exit the program
         when(compTarget.name) {
-            Cx16Target.name -> out("  jsr  main.start |  lda  #4 |  sta  $01 |  rts")
+            Cx16Target.name -> {
+                if(options.floats)
+                    out("  lda  #4 |  sta  $01")    // to use floats, make sure Basic rom is banked in
+                out("  jsr  main.start |  lda  #4 |  sta  $01 |  rts")
+            }
             C64Target.name -> out("  jsr  main.start |  lda  #31 |  sta  $01 |  rts")
             else -> jmp("main.start")
         }

docs/source/todo.rst

@@ -2,8 +2,6 @@
 TODO
 ====
 
-- make the floats lib set rombank 4 on cx16 and set sysinit back to rombank 0 (kernal only)
-- make sure rombank is back to 4 on cx16 when program exits back to basic
 - check use of float NEGOP vs NEGFAC for cx16
 
 - allow inlining of subroutines with params

examples/test.p8

@@ -1,6 +1,6 @@
 %import textio
 %import floats
-%zeropage basicsafe
+%zeropage floatsafe
 
 main {
 
@@ -21,7 +21,7 @@ main {
         f3 = cos(f3)
         floats.print_f(f3)
 
-        cx16.rombank(0)
+        ;cx16.rombank(0)
 
         txt.print("ok!\n")