nonet() operator

CHANGELOG.md

@@ -19,7 +19,7 @@
 * Removed command line flag `--detailed-flow`. 
 Detailed flow analysis was slow, broken, hard to maintain, and didn't even help that much.
 
-* Added `*'=` and `<<<<` operators.
+* Added `*'=` and `nonet` operators. (Also, the `<<<<` operator, but it will be phased out before 0.2 and replaced by `nonet(a << b)`.)
 
 * Added support for zeropage pseudoregisters, allowing for some operators work with more types of operands. 
 

doc/abi/generated-labels.md

@@ -36,6 +36,8 @@ where `11111` is a sequential number and `xx` is the type:
 
 * `is` – optimized addition of carry using undocumented instructions
 
+* `no` – nonet to word extension caused by the `nonet` operator
+
 * `od` – end of  a `do-while` statement
 
 * `or` – logical alternative short-circuiting

src/main/scala/millfork/compiler/ExpressionCompiler.scala

@@ -39,6 +39,7 @@ object ExpressionCompiler {
         if (getExpressionType(ctx, lo).size > 1) ErrorReporting.error("Lo byte too large", lo.position)
         w
       case SumExpression(params, _) => b
+      case FunctionCallExpression("nonet", params) => w
       case FunctionCallExpression("not", params) => bool
       case FunctionCallExpression("hi", params) => bool
       case FunctionCallExpression("lo", params) => bool
@@ -805,6 +806,32 @@ object ExpressionCompiler {
                 } else compilation
               }
             }
+          case "nonet" =>
+            if (params.length != 1) {
+              ErrorReporting.error("Invalid number of parameters", f.position)
+              Nil
+            } else {
+              assertAllBytes("Nonet argument has to be a byte", ctx, params)
+              params.head match {
+                case SumExpression(addends, _) =>
+                  if (addends.exists(a => !a._1)) {
+                    ErrorReporting.warn("Nonet subtraction may not work as expected", ctx.options, expr.position)
+                  }
+                  if (addends.size > 2) {
+                    ErrorReporting.warn("Nonet addition works correctly only for two operands", ctx.options, expr.position)
+                  }
+                case FunctionCallExpression("+" | "+'" | "<<" | "<<<<" | "<<'" | "nonet", _) => // ok
+                case _ =>
+                  ErrorReporting.warn("Unspecified nonet operation, results might be unpredictable", ctx.options, expr.position)
+              }
+              val label = MfCompiler.nextLabel("no")
+              compile(ctx, params.head, Some(b -> RegisterVariable(Register.A, b)), BranchSpec.None) ++ List(
+                AssemblyLine.immediate(LDX, 0),
+                AssemblyLine.relative(BCC, label),
+                AssemblyLine.implied(INX),
+                AssemblyLine.label(label)
+              ) ++ expressionStorageFromAX(ctx, exprTypeAndVariable, expr.position)
+            }
           case "&&" =>
             assertBool(ctx, params, 2)
             val a = params.head
@@ -851,6 +878,7 @@ object ExpressionCompiler {
                 BuiltIns.compileNonetOps(ctx, v, r)
             }
           case "<<<<" =>
+            ErrorReporting.warn("`x <<<< y` is obsolete, use `nonet(x << y)`", ctx.options, expr.position)
             assertAllBytes("Long shift ops not supported", ctx, params)
             val (l, r, 1) = assertBinary(ctx, params)
             BuiltIns.compileNonetLeftShift(ctx, l, r)

src/main/scala/millfork/env/Environment.scala

@@ -841,5 +841,5 @@ class Environment(val parent: Option[Environment], val prefix: String) {
 }
 
 object Environment {
-  val predefinedFunctions = Set("not", "hi", "lo")
+  val predefinedFunctions = Set("not", "hi", "lo", "nonet")
 }

src/test/scala/millfork/test/NonetSuite.scala

@@ -1,6 +1,6 @@
 package millfork.test
 
-import millfork.test.emu.EmuUnoptimizedRun
+import millfork.test.emu.{EmuBenchmarkRun, EmuUnoptimizedRun}
 import org.scalatest.{FunSuite, Matchers}
 
 /**
@@ -28,7 +28,7 @@ class NonetSuite extends FunSuite with Matchers {
   }
 
   test("Nonet left shift") {
-    val m = EmuUnoptimizedRun(
+    EmuBenchmarkRun(
       """
         | word output0 @$c000
         | word output1 @$c002
@@ -42,10 +42,34 @@ class NonetSuite extends FunSuite with Matchers {
         |   output2 = a <<<< 6
         |   output3 = a <<<< 7
         | }
-      """.stripMargin)
+      """.stripMargin) { m =>
       m.readWord(0xc000) should equal(0x06)
       m.readWord(0xc002) should equal(0x0C)
       m.readWord(0xc004) should equal(0xC0)
       m.readWord(0xc006) should equal(0x180)
+    }
+  }
+
+  test("Nonet left shift 2") {
+    EmuBenchmarkRun(
+      """
+        | word output0 @$c000
+        | word output1 @$c002
+        | word output2 @$c004
+        | word output3 @$c006
+        | void main () {
+        |   byte a
+        |   a = 3
+        |   output0 = nonet(a << 1)
+        |   output1 = nonet(a << 2)
+        |   output2 = nonet(a << 6)
+        |   output3 = nonet(a << 7)
+        | }
+      """.stripMargin) { m =>
+      m.readWord(0xc000) should equal(0x06)
+      m.readWord(0xc002) should equal(0x0C)
+      m.readWord(0xc004) should equal(0xC0)
+      m.readWord(0xc006) should equal(0x180)
+    }
   }
 }