RLE decoding test

src/test/scala/millfork/test/AlgorithmSuite.scala

@@ -0,0 +1,67 @@
+package millfork.test
+
+import millfork.test.emu.{EmuBenchmarkRun, EmuUltraBenchmarkRun}
+import org.scalatest.{FunSuite, Matchers}
+
+/**
+  * @author Karol Stasiak
+  */
+class AlgorithmSuite extends FunSuite with Matchers {
+
+  test("RLE decoding") {
+    EmuBenchmarkRun(
+      """
+        | array output [4000] @$c000
+        | array input = [
+        | 2, 2,
+        | $83, 6, 7, 8,
+        | 3, 1,
+        | 0]
+        | void main () {
+        |   rle_unpack(input, output)
+        | }
+        | void rle_unpack(pointer source, pointer target) {
+        |   byte action
+        |   byte i
+        |   byte b
+        |
+        |   // currently the variable inliner is too dumb to notice
+        |   // that `i` can be put safely into Y if used in multiple loops,
+        |   // so another variable is created so it can be inlined too
+        |   // TODO:
+        |   // make the variable inliner smarter so a single variable can be reused
+        |   byte j
+        |
+        |   while true {
+        |     action = source[0]
+        |     if action == 0 { return }
+        |     if action & $80 != 0 {
+        |       source += 1
+        |       action &= $7f
+        |       for i, 0, paralleluntil, action {
+        |         target[i] = source[i]
+        |       }
+        |       target += action
+        |       source += action
+        |     } else {
+        |       b = source[1]
+        |       for j, 0, paralleluntil, action {
+        |         target[j] = b
+        |       }
+        |       target += action
+        |       source += 2
+        |     }
+        |   }
+        | }
+      """.stripMargin) {m =>
+      m.readByte(0xc000) should equal(2)
+      m.readByte(0xc001) should equal(2)
+      m.readByte(0xc002) should equal(6)
+      m.readByte(0xc003) should equal(7)
+      m.readByte(0xc004) should equal(8)
+      m.readByte(0xc005) should equal(1)
+      m.readByte(0xc006) should equal(1)
+      m.readByte(0xc007) should equal(1)
+    }
+  }
+}