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SBC opcodes

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FranLMSP
2022-11-20 12:11:36 -05:00
parent f8a6872b8c
commit 4ddc3b3aa7
2 changed files with 69 additions and 22 deletions
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snes-core/src/utils/alu.rs
+14 -14
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@@ -68,7 +68,7 @@ pub fn adc16bcd(target: u16, value: u16, carry: bool) -> (u16, bool, bool, bool)
(result, is_carry, is_negative, is_zero)
}
pub fn dec8bin(target: u8, value: u8, carry: bool) -> (u8, bool, bool, bool) {
pub fn sbc8bin(target: u8, value: u8, carry: bool) -> (u8, bool, bool, bool) {
let is_carry = match target.checked_sub(value) {
None => true,
Some(res) => match res.checked_sub(carry as u8) {
@@ -84,7 +84,7 @@ pub fn dec8bin(target: u8, value: u8, carry: bool) -> (u8, bool, bool, bool) {
(result, is_carry, is_negative, is_zero)
}
pub fn dec16bin(target: u16, value: u16, carry: bool) -> (u16, bool, bool, bool) {
pub fn sbc16bin(target: u16, value: u16, carry: bool) -> (u16, bool, bool, bool) {
let is_carry = match target.checked_sub(value) {
None => true,
Some(res) => match res.checked_sub(carry as u16) {
@@ -100,7 +100,7 @@ pub fn dec16bin(target: u16, value: u16, carry: bool) -> (u16, bool, bool, bool)
(result, is_carry, is_negative, is_zero)
}
pub fn dec8bcd(target: u8, value: u8, carry: bool) -> (u8, bool, bool, bool) {
pub fn sbc8bcd(target: u8, value: u8, carry: bool) -> (u8, bool, bool, bool) {
let mut is_carry = carry;
let target = target as u16;
let value = !(value as u16);
@@ -120,7 +120,7 @@ pub fn dec8bcd(target: u8, value: u8, carry: bool) -> (u8, bool, bool, bool) {
(result, is_carry, is_negative, is_zero)
}
pub fn dec16bcd(target: u16, value: u16, carry: bool) -> (u16, bool, bool, bool) {
pub fn sbc16bcd(target: u16, value: u16, carry: bool) -> (u16, bool, bool, bool) {
let mut is_carry = carry;
let target = target as u32;
let value = !(value as u32);
@@ -307,19 +307,19 @@ mod alu_tests {
#[test]
fn test_dec8bin() {
let (result, carry, negative, zero) = dec8bin(1, 1, false);
let (result, carry, negative, zero) = sbc8bin(1, 1, false);
assert_eq!(result, 0);
assert_eq!(carry, false);
assert_eq!(negative, false);
assert_eq!(zero, true);
let (result, carry, negative, zero) = dec8bin(0, 1, false);
let (result, carry, negative, zero) = sbc8bin(0, 1, false);
assert_eq!(result, 0b11111111);
assert_eq!(carry, true);
assert_eq!(negative, true);
assert_eq!(zero, false);
let (result, carry, negative, zero) = dec8bin(0, 1, true);
let (result, carry, negative, zero) = sbc8bin(0, 1, true);
assert_eq!(result, 0b11111110);
assert_eq!(carry, true);
assert_eq!(negative, true);
@@ -328,19 +328,19 @@ mod alu_tests {
#[test]
fn test_dec16bin() {
let (result, carry, negative, zero) = dec16bin(1, 1, false);
let (result, carry, negative, zero) = sbc16bin(1, 1, false);
assert_eq!(result, 0);
assert_eq!(carry, false);
assert_eq!(negative, false);
assert_eq!(zero, true);
let (result, carry, negative, zero) = dec16bin(0, 1, false);
let (result, carry, negative, zero) = sbc16bin(0, 1, false);
assert_eq!(result, 0b11111111_11111111);
assert_eq!(carry, true);
assert_eq!(negative, true);
assert_eq!(zero, false);
let (result, carry, negative, zero) = dec16bin(0, 1, true);
let (result, carry, negative, zero) = sbc16bin(0, 1, true);
assert_eq!(result, 0b11111111_11111110);
assert_eq!(carry, true);
assert_eq!(negative, true);
@@ -349,13 +349,13 @@ mod alu_tests {
#[test]
fn test_dec8bcd() {
let (result, carry, negative, zero) = dec8bcd(0x49, 0x48, false);
let (result, carry, negative, zero) = sbc8bcd(0x49, 0x48, false);
assert_eq!(result, 0x00);
assert_eq!(carry, true);
assert_eq!(negative, false);
assert_eq!(zero, true);
let (result, carry, negative, zero) = dec8bcd(0x49, 0x50, true);
let (result, carry, negative, zero) = sbc8bcd(0x49, 0x50, true);
assert_eq!(result, 0x99);
assert_eq!(carry, false);
assert_eq!(negative, true);
@@ -364,13 +364,13 @@ mod alu_tests {
#[test]
fn test_dec16bcd() {
let (result, carry, negative, zero) = dec16bcd(0x4999, 0x4998, false);
let (result, carry, negative, zero) = sbc16bcd(0x4999, 0x4998, false);
assert_eq!(result, 0x0000);
assert_eq!(carry, true);
assert_eq!(negative, false);
assert_eq!(zero, true);
let (result, carry, negative, zero) = dec16bcd(0x4999, 0x5000, true);
let (result, carry, negative, zero) = sbc16bcd(0x4999, 0x5000, true);
assert_eq!(result, 0x9999);
assert_eq!(carry, false);
assert_eq!(negative, true);