alu 8 and 16 bit bin add

snes-core/src/lib.rs

@@ -1,2 +1,3 @@
 pub mod cpu;
 pub mod bus;
+pub mod utils;

snes-core/src/utils/alu.rs

@@ -0,0 +1,110 @@
+pub fn adc8bin(target: u8, value: u8, carry: bool) -> (u8, bool, bool, bool) {
+    let is_carry = match target.checked_add(value) {
+        None => true,
+        Some(res) => match res.checked_add(carry as u8) {
+            None => true,
+            Some(_) => false,
+        },
+    };
+    let result = target
+        .wrapping_add(value)
+        .wrapping_add(carry as u8);
+    let is_negative = (result >> 7) == 1;
+    let is_zero = result == 0;
+    (result, is_carry, is_negative, is_zero)
+}
+
+pub fn adc16bin(target: u16, value: u16, carry: bool) -> (u16, bool, bool, bool) {
+    let is_carry = match target.checked_add(value) {
+        None => true,
+        Some(res) => match res.checked_add(carry as u16) {
+            None => true,
+            Some(_) => false,
+        },
+    };
+    let result = target
+        .wrapping_add(value)
+        .wrapping_add(carry as u16);
+    let is_negative = (result >> 15) == 1;
+    let is_zero = result == 0;
+    (result, is_carry, is_negative, is_zero)
+}
+
+pub fn adc8bcd() {
+}
+
+pub fn adc16bcd() {
+}
+
+
+
+#[cfg(test)]
+mod alu_tests {
+    use super::*;
+
+    #[test]
+    fn test_adc8bin() {
+        let (result, carry, negative, zero) = adc8bin(0, 0, false);
+        assert_eq!(result, 0);
+        assert_eq!(carry, false);
+        assert_eq!(negative, false);
+        assert_eq!(zero, true);
+
+        let (result, carry, negative, zero) = adc8bin(0, 50, false);
+        assert_eq!(result, 50);
+        assert_eq!(carry, false);
+        assert_eq!(negative, false);
+        assert_eq!(zero, false);
+
+        let (result, carry, negative, zero) = adc8bin(200, 155, false);
+        assert_eq!(result, 99);
+        assert_eq!(carry, true);
+        assert_eq!(negative, false);
+        assert_eq!(zero, false);
+
+        let (result, carry, negative, zero) = adc8bin(200, 155, true);
+        assert_eq!(result, 100);
+        assert_eq!(carry, true);
+        assert_eq!(negative, false);
+        assert_eq!(zero, false);
+
+        let (result, carry, negative, zero) = adc8bin(200, 54, true);
+        assert_eq!(result, 255);
+        assert_eq!(carry, false);
+        assert_eq!(negative, true);
+        assert_eq!(zero, false);
+    }
+
+    #[test]
+    fn test_adc16bin() {
+        let (result, carry, negative, zero) = adc16bin(0, 0, false);
+        assert_eq!(result, 0);
+        assert_eq!(carry, false);
+        assert_eq!(negative, false);
+        assert_eq!(zero, true);
+
+        let (result, carry, negative, zero) = adc16bin(0, 50, false);
+        assert_eq!(result, 50);
+        assert_eq!(carry, false);
+        assert_eq!(negative, false);
+        assert_eq!(zero, false);
+
+        let (result, carry, negative, zero) = adc16bin(65530, 10, false);
+        assert_eq!(result, 4);
+        assert_eq!(carry, true);
+        assert_eq!(negative, false);
+        assert_eq!(zero, false);
+
+        let (result, carry, negative, zero) = adc16bin(65530, 10, true);
+        assert_eq!(result, 5);
+        assert_eq!(carry, true);
+        assert_eq!(negative, false);
+        assert_eq!(zero, false);
+
+        let (result, carry, negative, zero) = adc16bin(65530, 4, true);
+        assert_eq!(result, 65535);
+        assert_eq!(carry, false);
+        assert_eq!(negative, true);
+        assert_eq!(zero, false);
+    }
+}

snes-core/src/utils/mod.rs

@@ -0,0 +1 @@
+pub mod alu;