From a1aeda38f503d87b2d1af493901475caa0350a83 Mon Sep 17 00:00:00 2001
From: Franco Colmenarez <info@francoacg.com>
Date: Tue, 26 Dec 2023 20:24:47 -0500
Subject: [PATCH] asl

---
 snes-core/src/cpu/instructionstemp/asl.rs | 102 ++++++++++++++++++++++
 snes-core/src/cpu/instructionstemp/mod.rs |   1 +
 2 files changed, 103 insertions(+)
 create mode 100644 snes-core/src/cpu/instructionstemp/asl.rs

diff --git a/snes-core/src/cpu/instructionstemp/asl.rs b/snes-core/src/cpu/instructionstemp/asl.rs
new file mode 100644
index 0000000..642d5d6
--- /dev/null
+++ b/snes-core/src/cpu/instructionstemp/asl.rs
@@ -0,0 +1,102 @@
+use crate::{cpu::{bus::Bus, registers::Registers}, utils::{alu, addressing::AddressingMode}};
+
+use crate::cpu::cycles;
+use super::{CPUInstruction, Decode};
+
+pub const OPCODE: u8 = 0x0A;
+
+fn mnemonic_8bit(registers: &Registers, bus: &Bus) -> String {
+    let next_byte = bus.read_external(registers.get_pc_address() + 1);
+    format!("{:02X} {:02X} __ __ | ASL #${:02X}", OPCODE, next_byte, next_byte)
+}
+
+fn mnemonic_16bit(registers: &Registers, bus: &Bus) -> String {
+    let next_byte = bus.read_external(registers.get_pc_address() + 1);
+    let next_second_byte = bus.read_external(registers.get_pc_address() + 2);
+    let word = (next_byte as u16) | ((next_byte as u16) << 8);
+    format!("{:02X} {:02X} {:02X} __ | AND #${:04X}", OPCODE, next_byte, next_second_byte, word)
+}
+
+pub struct ASL8 {}
+
+impl CPUInstruction for ASL8 {
+    fn execute(&self, registers: &mut Registers, _bus: &mut Bus, addressing_mode: AddressingMode) {
+        let (result, affected_flags) = alu::asl(
+            registers.a as u8,
+        );
+        registers.set_low_a(result);
+        registers.set_flags(&affected_flags);
+        let (bytes, cycles) = cycles::increment_cycles_bitwise(&registers, addressing_mode);
+        registers.increment_pc(bytes); registers.cycles += cycles;
+    }
+}
+
+impl Decode for ASL8 {
+    fn mnemonic(&self, registers: &Registers, bus: &Bus) -> String {
+        mnemonic_8bit(registers, bus)
+    }
+}
+
+pub struct ASL16 {}
+
+impl CPUInstruction for ASL16 {
+    fn execute(&self, registers: &mut Registers, _bus: &mut Bus, addressing_mode: AddressingMode) {
+        let (result, affected_flags) = alu::asl(
+            registers.a,
+        );
+        registers.a = result;
+        registers.set_flags(&affected_flags);
+        let (bytes, cycles) = cycles::increment_cycles_bitwise(&registers, addressing_mode);
+        registers.increment_pc(bytes); registers.cycles += cycles;
+    }
+}
+
+impl Decode for ASL16 {
+    fn mnemonic(&self, registers: &Registers, bus: &Bus) -> String {
+        mnemonic_16bit(registers, bus)
+    }
+}
+
+
+#[cfg(test)]
+mod cpu_instructions_tests {
+    use super::*;
+
+    #[test]
+    fn test_asl_8bit() {
+        let mut registers = Registers::new();
+        let mut bus = Bus::new();
+        registers.emulation_mode = false;
+        registers.a   = 0b01010000;
+        registers.pbr = 0x00;
+        registers.pc  = 0x0000;
+        registers.set_memory_select_flag(true);
+        let instruction = ASL8{};
+        instruction.execute(&mut registers, &mut bus, AddressingMode::Immediate);
+        assert_eq!(registers.a, 0b10100000);
+        assert_eq!(registers.pc, 0x02);
+        assert_eq!(registers.cycles, 2);
+        assert!(!registers.get_carry_flag());
+        assert!(!registers.get_zero_flag());
+        assert!(registers.get_negative_flag());
+    }
+
+    #[test]
+    fn test_asl_16bit() {
+        let mut registers = Registers::new();
+        let mut bus = Bus::new();
+        registers.emulation_mode = false;
+        registers.a   = 0b01010000_00000000;
+        registers.pbr = 0x00;
+        registers.pc  = 0x0000;
+        registers.set_memory_select_flag(false);
+        let instruction = ASL16{};
+        instruction.execute(&mut registers, &mut bus, AddressingMode::Immediate);
+        assert_eq!(registers.a, 0b10100000_00000000);
+        assert_eq!(registers.pc, 0x03);
+        assert_eq!(registers.cycles, 3);
+        assert!(!registers.get_carry_flag());
+        assert!(!registers.get_zero_flag());
+        assert!(registers.get_negative_flag());
+    }
+}
diff --git a/snes-core/src/cpu/instructionstemp/mod.rs b/snes-core/src/cpu/instructionstemp/mod.rs
index 7dc353d..2364c1c 100644
--- a/snes-core/src/cpu/instructionstemp/mod.rs
+++ b/snes-core/src/cpu/instructionstemp/mod.rs
@@ -4,6 +4,7 @@ use crate::utils::addressing::AddressingMode;
 
 pub mod adc;
 pub mod and;
+pub mod asl;
 
 pub trait CPUInstruction {
     fn execute(&self, registers: &mut Registers, bus: &mut Bus, addressing_mode: AddressingMode);