misc fixes and tests (yes arith is broken)

itsvic-dev · May 3, 2024 · af9d49f · af9d49f
1 parent 1571d94
commit af9d49f
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Showing 10 changed files with 63 additions and 10 deletions.
diff --git a/example/asm/klaus-functional.asm b/example/asm/klaus-functional.asm
@@ -141,7 +141,7 @@ ram_top = -1
 
 ;disable test decimal mode ADC & SBC, 0=enable, 1=disable,
 ;2=disable including decimal flag in processor status
-disable_decimal = 0
+disable_decimal = 2
 
 ;macros for error & success traps to allow user modification
 ;example:

diff --git a/example/klaustest.cpp b/example/klaustest.cpp
@@ -43,9 +43,16 @@ int main(int argc, char **argv) {
   // override read PC with Klaus test start
   cpu.pc = 0x400;
 
+  uint16_t prevPc = 0;
+
   try {
     while (true) {
+      prevPc = cpu.pc;
       cpu.executeStep();
+      if (cpu.pc == prevPc) {
+        print("caught trap on PC ${:04x}\n", prevPc);
+        break;
+      }
     }
   } catch (...) {
     print("[warn] execution ended prematurely due to a v6502 error!!!\n");

diff --git a/src/opcodes/logic.cpp b/src/opcodes/logic.cpp
@@ -1,15 +1,16 @@
 #include "v6502/cpu.h"
 #include "v6502/opcodes.h"
+#include <cstdint>
 
 OPCODE(_and) {
   cpu->a = cpu->a & (cpu->fetchByteWithMode(mode));
   cpu->evaluateFlags(cpu->a);
 }
 
 OPCODE(bit) {
-  uint8_t result = cpu->a & (cpu->fetchByteWithMode(mode));
-  const uint8_t mask = (1 << 7) | (1 << 6);
-  cpu->status = (result & mask) | (cpu->status & ~mask);
+  uint8_t m = cpu->fetchByteWithMode(mode);
+  uint8_t result = cpu->a & m;
+  cpu->status = (cpu->status & ~(0b11 << 6)) | (m & (0b11 << 6));
   cpu->clearFlags(STATUS_ZERO);
   if (result == 0) {
     cpu->setFlags(STATUS_ZERO);

diff --git a/tests/instructions/arith/adc-80.cpp b/tests/instructions/arith/adc-80.cpp
@@ -0,0 +1,17 @@
+// does ADC #$01 work properly with A=0xFF?
+#include "testMain.h"
+#include "v6502/cpu.h"
+#include <cassert>
+
+TEST {
+  cpu->bus->write(0, 0x69); // nice
+  cpu->bus->write(1, 0x80);
+  cpu->reset();
+  cpu->executeStep();
+
+  assert(cpu->a == 0x80);
+  assert(FLAG_IS_SET(cpu->status, STATUS_NEGATIVE));
+  assert(FLAG_IS_CLEAR(cpu->status, STATUS_OVERFLOW));
+  assert(FLAG_IS_CLEAR(cpu->status, STATUS_ZERO));
+  assert(FLAG_IS_CLEAR(cpu->status, STATUS_CARRY));
+}
diff --git a/tests/bugs/cmp_immediate_3a_works.cpp → tests/instructions/arith/cmp-3a-3a.cpp b/tests/bugs/cmp_immediate_3a_works.cpp → tests/instructions/arith/cmp-3a-3a.cpp
diff --git a/tests/instructions/arith/sbc-1-02.cpp b/tests/instructions/arith/sbc-1-02.cpp
@@ -11,5 +11,8 @@ TEST {
   cpu->executeStep();
 
   assert(cpu->a == 0x00);
-  STATUS_ASSERT(STATUS_ZERO | STATUS_CARRY);
+  assert(FLAG_IS_CLEAR(cpu->status, STATUS_NEGATIVE));
+  assert(FLAG_IS_CLEAR(cpu->status, STATUS_OVERFLOW));
+  assert(FLAG_IS_SET(cpu->status, STATUS_ZERO));
+  assert(FLAG_IS_SET(cpu->status, STATUS_CARRY));
 }
diff --git a/tests/instructions/arith/sbc-1-80.cpp b/tests/instructions/arith/sbc-1-80.cpp
@@ -11,5 +11,8 @@ TEST {
   cpu->executeStep();
 
   assert(cpu->a == 0x7E);
-  STATUS_ASSERT(STATUS_OVERFLOW | STATUS_CARRY);
+  assert(FLAG_IS_CLEAR(cpu->status, STATUS_NEGATIVE));
+  assert(FLAG_IS_SET(cpu->status, STATUS_OVERFLOW));
+  assert(FLAG_IS_CLEAR(cpu->status, STATUS_ZERO));
+  assert(FLAG_IS_SET(cpu->status, STATUS_CARRY));
 }
diff --git a/tests/instructions/arith/sbc-1.cpp b/tests/instructions/arith/sbc-1.cpp
@@ -1,5 +1,6 @@
 #include "testMain.h"
 #include "v6502/cpu.h"
+#include <cassert>
 
 TEST {
   // SBC #$01
@@ -9,5 +10,8 @@ TEST {
   cpu->executeStep();
 
   assert(cpu->a == 0xFE);
-  STATUS_ASSERT(STATUS_NEGATIVE);
+  assert(FLAG_IS_SET(cpu->status, STATUS_NEGATIVE));
+  assert(FLAG_IS_CLEAR(cpu->status, STATUS_OVERFLOW));
+  assert(FLAG_IS_CLEAR(cpu->status, STATUS_ZERO));
+  assert(FLAG_IS_CLEAR(cpu->status, STATUS_CARRY));
 }
diff --git a/tests/instructions/arith/sbc-fe-7f.cpp b/tests/instructions/arith/sbc-fe-7f.cpp
@@ -0,0 +1,18 @@
+#include "testMain.h"
+#include "v6502/cpu.h"
+
+TEST {
+  cpu->a = 0x7F;
+
+  // SBC #$FE
+  cpu->bus->write(0, 0xE9);
+  cpu->bus->write(1, 0xFE);
+  cpu->reset();
+  cpu->executeStep();
+
+  assert(cpu->a == 0x80);
+  assert(FLAG_IS_SET(cpu->status, STATUS_NEGATIVE));
+  assert(FLAG_IS_SET(cpu->status, STATUS_OVERFLOW));
+  assert(FLAG_IS_CLEAR(cpu->status, STATUS_ZERO));
+  assert(FLAG_IS_CLEAR(cpu->status, STATUS_CARRY));
+}
diff --git a/tests/meson.build b/tests/meson.build
@@ -17,9 +17,12 @@ tests = {
     'instructions(arith) - ADC #$01': 'instructions/arith/adc-1.cpp',
     'instructions(arith) - ADC #$01 with A=$FF': 'instructions/arith/adc-1-ff.cpp',
     'instructions(arith) - ADC #$01 with A=$7F': 'instructions/arith/adc-1-7f.cpp',
+    'instructions(arith) - ADC #$80': 'instructions/arith/adc-80.cpp',
+    'instructions(arith) - CMP #$3A with A=$3A': 'instructions/arith/cmp-3a-3a.cpp',
     'instructions(arith) - SBC #$01': 'instructions/arith/sbc-1.cpp',
     'instructions(arith) - SBC #$01 with A=$02': 'instructions/arith/sbc-1-02.cpp',
     'instructions(arith) - SBC #$01 with A=$80': 'instructions/arith/sbc-1-80.cpp',
+    'instructions(arith) - SBC #$FE with A=$7F': 'instructions/arith/sbc-fe-7f.cpp',
 
     'instructions(branch) - BCC with clear carry': 'instructions/branch/bcc-clear.cpp',
     'instructions(branch) - BCC with set carry': 'instructions/branch/bcc-set.cpp',
@@ -40,9 +43,6 @@ tests = {
 
     'instructions(shift) - ASL A with A=$80': 'instructions/shift/asl-a-80.cpp',
     'instructions(shift) - ROL A with set carry': 'instructions/shift/rol-sec.cpp',
-
-    # old bugs
-    'old bugs - does CMP #$3A with A=$3A work correctly?': 'bugs/cmp_immediate_3a_works.cpp',
 }
 
 foreach name, sources : tests