1 files changed, 47 insertions(+), 0 deletions(-)

M src/processor.rs

@@ 385,4 385,51 @@ mod tests {
         assert_eq!(processor.reg[2], i16::MIN as u16 + 4);
         assert_eq!(processor.reg[3], 5);
     }
+    #[test]
+    fn arithmetic_invert () {
+        let memory: &mut [u16] = &mut [0x0600, 3, 0x0608, 4, 0x0110, 0x0044, 0, 0];
+        let disk: &mut [u16] = &mut [0];
+        let vram: &mut [u16] = &mut [0];
+        let mut processor = new(memory, disk, vram);
+        loop {
+            if processor.run() {break};
+        }
+        assert_eq!(processor.reg[2], !7);
+    }
+    #[test]
+    fn sub () {
+        let memory: &mut [u16] = &mut [0x0600, 5, 0x0608, 3, 0x0101, 0x0044, 0, 0];
+        let disk: &mut [u16] = &mut [0];
+        let vram: &mut [u16] = &mut [0];
+        let mut processor = new(memory, disk, vram);
+        loop {
+            if processor.run() {break};
+        }
+        assert_eq!(processor.reg[2], 2);
+    }
+    #[test]
+    fn underflow () {
+        let memory: &mut [u16] = &mut [0x0600, 3, 0x0608, 5, 0x0141, 0x0044, 0xA618, 7, 0, 0];
+        let disk: &mut [u16] = &mut [0];
+        let vram: &mut [u16] = &mut [0];
+        let mut processor = new(memory, disk, vram);
+        loop {
+            if processor.run() {break};
+        }
+        assert_eq!(processor.reg[2], u16::MAX - 1);
+        assert_eq!(processor.reg[3], 7);
+    }
+    #[test]
+    fn signed_underflow () {
+        let memory: &mut [u16] = &mut [0x0600, 3, 0x0608, 5, 0x01C1, 0x0044, 0x0600, i16::MIN as u16, 0x01E1, 0x0046, 0xD620, 7, 0, 0];
+        let disk: &mut [u16] = &mut [0];
+        let vram: &mut [u16] = &mut [0];
+        let mut processor = new(memory, disk, vram);
+        loop {
+            if processor.run() {break};
+        }
+        assert_eq!(processor.reg[2], -2i16 as u16);
+        assert_eq!(processor.reg[3], i16::MAX as u16 - 4);
+        assert_eq!(processor.reg[4], 7);
+    }
 }