65816: Emulator bugfixes

.gitignore

@@ -6,6 +6,7 @@ project/project/target/
 stuff
 releases
 src/test/scala/experiments/
+src/test/java/experiments/
 # doesn't work yet
 examples/lunix/
 # older copies

src/test/resources/cpu.js

@@ -1621,13 +1621,14 @@ var EOR_const = {
     if(cpu.p.e||cpu.p.m) {
       cpu.r.a ^= bytes[0];
       cpu.p.n = cpu.r.a >> 7;
+      cpu_lib.r.p.check_z(cpu, cpu.r.a & 0xff);
     } else {
       cpu.cycle_count++;
       cpu.r.a ^= (bytes[1]<<8)|bytes[0];
       cpu.p.n = cpu.r.a >> 15;
+      cpu_lib.r.p.check_z(cpu, cpu.r.a);
     }
 
-    cpu_lib.r.p.check_z(cpu, cpu.r.a);
   }
 };
 
@@ -1690,14 +1691,14 @@ var ORA_const= {
     if(cpu.p.e||cpu.p.m) {
       cpu.r.a |= bytes[0];
       cpu.p.n = cpu.r.a >> 7;
+      cpu_lib.r.p.check_z(cpu, cpu.r.a & 0xff);
     } else {
       cpu.cycle_count++;
 
       cpu.r.a |= (bytes[1]<<8)|bytes[0];
       cpu.p.n = cpu.r.a >> 15;
+      cpu_lib.r.p.check_z(cpu, cpu.r.a);
     }
-
-    cpu_lib.r.p.check_z(cpu, cpu.r.a);
   }
 };
 
@@ -1758,16 +1759,16 @@ var AND_const= {
     cpu.cycle_count+=2;
 
     if(cpu.p.e||cpu.p.m) {
-      cpu.r.a &= bytes[0];
+      cpu.r.a = cpu.r.a & 0xff00 | cpu.r.a & 0xff & bytes[0];
       cpu.p.n = cpu.r.a >> 7;
+      cpu_lib.r.p.check_z(cpu, cpu.r.a & 0xff);
     } else {
       cpu.cycle_count++;
 
       cpu.r.a &= (bytes[1]<<8)|bytes[0];
       cpu.p.n = cpu.r.a >> 15;
+      cpu_lib.r.p.check_z(cpu, cpu.r.a);
     }
-
-    cpu_lib.r.p.check_z(cpu, cpu.r.a);
   }
 };
 
@@ -1829,7 +1830,7 @@ var CPX_const= {
 
     var result;
     if(cpu.p.e||cpu.p.x) {
-      result = cpu.r.x - bytes[0];
+      result = (cpu.r.x & 0xff) - bytes[0];
       if(result<0) {
         cpu.p.c = 0;
         result = 0x100 + result;
@@ -1878,7 +1879,7 @@ var CPY_const= {
 
     var result;
     if(cpu.p.e||cpu.p.x) {
-      result = cpu.r.y - bytes[0];
+      result = (cpu.r.y & 0xff) - bytes[0];
       if(result<0) {
         cpu.p.c = 0;
         result = 0x100 + result;
@@ -1926,7 +1927,7 @@ var CMP_const= {
 
     var result;
     if(cpu.p.e||cpu.p.m) {
-      result = cpu.r.a - bytes[0];
+      result = (cpu.r.a & 0xff) - bytes[0];
       if(result<0) {
         cpu.p.c = 0;
         result = 0x100 + result;
@@ -2433,21 +2434,16 @@ var TYA = {
   execute:function(cpu) {
     cpu.cycle_count+=2;
     if(cpu.p.e||cpu.p.m) {
-      if(cpu.p.e||cpu.p.x) {
-        // 8-bit index register to 8-bit accumulator.
-        cpu.r.a = cpu.r.y;
-      } else {
-        // 16-bit index register to 8-bit accumulator.
-        cpu.r.a = cpu.r.y & 0x00ff;
-      }
+      // 8-bit accumulator.
+      cpu.r.a = cpu.r.a & 0xff00 | cpu.r.y & 0x00ff;
       cpu.p.n = cpu.r.a >> 7;
+      cpu_lib.r.p.check_z(cpu, cpu.r.a & 0xff);
     } else {
-      // 8-bit index register to 16-bit accumulator.
-      // 16-bit index register to 16-bit accumulator.
+      // 16-bit accumulator.
       cpu.r.a = cpu.r.y;
       cpu.p.n = cpu.r.a >> 15;
+      cpu_lib.r.p.check_z(cpu, cpu.r.a);
     }
-    cpu_lib.r.p.check_z(cpu, cpu.r.a);
     cpu.instruction_history += " TYA";
     cpu.instruction_details += "<br />Transfer Y Register to Accumulator";
   }
@@ -2496,21 +2492,16 @@ var TXA = {
   execute:function(cpu) {
     cpu.cycle_count+=2;
     if(cpu.p.e||cpu.p.m) {
-      if(cpu.p.e||cpu.p.x) {
-        // 8-bit index register to 8-bit accumulator.
-        cpu.r.a = cpu.r.x;
-      } else {
-        // 16-bit index register to 8-bit accumulator.
-        cpu.r.a = cpu.r.x & 0x00ff;
-      }
+      // 8-bit accumulator.
+      cpu.r.a = cpu.r.a & 0xff00 | cpu.r.x & 0x00ff;
       cpu.p.n = cpu.r.a >> 7;
+      cpu_lib.r.p.check_z(cpu, cpu.r.a & 0xff);
     } else {
-      // 8-bit index register to 16-bit accumulator.
-      // 16-bit index register to 16-bit accumulator.
+      // 16-bit accumulator.
       cpu.r.a = cpu.r.x;
       cpu.p.n = cpu.r.a >> 15;
+      cpu_lib.r.p.check_z(cpu, cpu.r.a);
     }
-    cpu_lib.r.p.check_z(cpu, cpu.r.a);
     cpu.instruction_history += " TXA";
     cpu.instruction_details += "<br />Transfer X Register to Accumulator";
   }
@@ -3336,15 +3327,16 @@ var LDA_const= {
     cpu.cycle_count+=2;
 
     if(cpu.p.e||cpu.p.m) {
-      cpu.r.a = bytes[0];
+      cpu.r.a = cpu.r.a & 0xff00 | bytes[0];
       cpu.p.n = cpu.r.a >> 7;
+      cpu_lib.r.p.check_z(cpu, cpu.r.a & 0xff);
     } else {
       cpu.cycle_count++;
 
       cpu.r.a = (bytes[1]<<8)|bytes[0];
       cpu.p.n = cpu.r.a >> 15;
+      cpu_lib.r.p.check_z(cpu, cpu.r.a);
     }
-    cpu_lib.r.p.check_z(cpu, cpu.r.a);
   }
 };
 

src/test/scala/millfork/test/ComparisonSuite.scala

@@ -561,6 +561,8 @@ class ComparisonSuite extends FunSuite with Matchers with AppendedClues {
         |  noinline word id(word x) = x
         |""".stripMargin
     EmuCrossPlatformBenchmarkRun(Cpu.Mos, Cpu.Sixteen, Cpu.Z80, Cpu.Intel8080, Cpu.Sharp, Cpu.Motorola6809)(code) {m =>
+      // TODO: for some reason this still fails on 65816
+      // the main suspect is a bug in the emulator
       m.readByte(0xc000) should equal (code.count(_ == '↑'))
     }
   }

src/test/scala/millfork/test/EmulatorCorrectnessSuite.scala

@@ -0,0 +1,28 @@
+package millfork.test
+
+import millfork.test.emu.EmuUnoptimizedNative65816Run
+import org.scalatest.{AppendedClues, FunSuite, Matchers}
+
+/**
+  * @author Karol Stasiak
+  */
+class EmulatorCorrectnessSuite extends FunSuite with Matchers with AppendedClues {
+
+  test("TXA should not clobber AH") {
+    val m = EmuUnoptimizedNative65816Run(
+      """
+        |
+        |asm void main() {
+        |  SEP #$30
+        |  LDA #1
+        |  XBA
+        |  LDX #3
+        |  TXA
+        |  REP #$30
+        |  STA $700
+        |  RTS
+        |}
+        |""".stripMargin)
+    m.readWord(0x700) should equal(0x103)
+  }
+}