From c2ff461ae8ac7c541904eab54f08c95fe8f3b644 Mon Sep 17 00:00:00 2001
From: EliseZeroTwo <mail@elise.moe>
Date: Sun, 28 Nov 2021 19:26:30 +0100
Subject: [PATCH] feat: push pop opcodes

---
 src/gameboy/cpu.rs                 |  8 ++++
 src/gameboy/cpu/load_store_move.rs | 66 ++++++++++++++++++++++++++----
 2 files changed, 66 insertions(+), 8 deletions(-)

diff --git a/src/gameboy/cpu.rs b/src/gameboy/cpu.rs
index 8cbf6a3..eff9468 100644
--- a/src/gameboy/cpu.rs
+++ b/src/gameboy/cpu.rs
@@ -239,9 +239,11 @@ pub fn tick_cpu(state: &mut Gameboy) {
 		0xAE => alu::xor_a_deref_hl,
 		0xAF => alu::xor_a_a,
 		0xC0 => flow::ret_nz,
+		0xC1 => load_store_move::pop_bc,
 		0xC2 => flow::jp_nz_u16,
 		0xC3 => flow::jp_u16,
 		0xC4 => flow::call_nz_u16,
+		0xC5 => load_store_move::push_bc,
 		0xC8 => flow::ret_z,
 		0xC9 => flow::ret,
 		0xCA => flow::jp_z_u16,
@@ -249,20 +251,26 @@ pub fn tick_cpu(state: &mut Gameboy) {
 		0xCC => flow::call_z_u16,
 		0xCD => flow::call_u16,
 		0xD0 => flow::ret_nc,
+		0xD1 => load_store_move::pop_de,
 		0xD2 => flow::jp_nc_u16,
 		0xD4 => flow::call_nc_u16,
+		0xD5 => load_store_move::push_de,
 		0xD8 => flow::ret_c,
 		0xD9 => flow::reti,
 		0xDA => flow::jp_c_u16,
 		0xDC => flow::call_c_u16,
 		0xDE => alu::sbc_a_imm_u8,
 		0xE0 => load_store_move::ldh_imm_u8_a,
+		0xE1 => load_store_move::pop_hl,
 		0xE2 => load_store_move::ldh_deref_c_a,
+		0xE5 => load_store_move::push_hl,
 		0xE9 => flow::jp_hl,
 		0xEA => load_store_move::ld_deref_imm_u16_a,
 		0xEE => alu::xor_a_imm_u8,
 		0xF0 => load_store_move::ldh_a_imm_u8,
+		0xF1 => load_store_move::pop_af,
 		0xF2 => load_store_move::ldh_a_deref_c,
+		0xF5 => load_store_move::push_af,
 		0xF9 => load_store_move::ld_sp_hl,
 		0xFA => load_store_move::ld_a_deref_imm_u16,
 		unknown => panic!("Unrecognized opcode: {:#X}\nRegisters: {:#?}", unknown, state.registers),
diff --git a/src/gameboy/cpu/load_store_move.rs b/src/gameboy/cpu/load_store_move.rs
index 956f1cb..614b955 100644
--- a/src/gameboy/cpu/load_store_move.rs
+++ b/src/gameboy/cpu/load_store_move.rs
@@ -381,7 +381,7 @@ pub fn ld_deref_imm_u16_a(state: &mut Gameboy) -> CycleResult {
 	}
 }
 
-macro_rules! define_ld_reg_imm_u8 {
+macro_rules! define_ld_deref_hl_reg {
 	($lreg:ident) => {
 		paste::paste! {
 			pub fn [<ld_deref_hl_ $lreg>](state: &mut Gameboy) -> CycleResult {
@@ -399,10 +399,60 @@ macro_rules! define_ld_reg_imm_u8 {
 	};
 }
 
-define_ld_reg_imm_u8!(b);
-define_ld_reg_imm_u8!(c);
-define_ld_reg_imm_u8!(d);
-define_ld_reg_imm_u8!(e);
-define_ld_reg_imm_u8!(h);
-define_ld_reg_imm_u8!(l);
-define_ld_reg_imm_u8!(a);
+define_ld_deref_hl_reg!(b);
+define_ld_deref_hl_reg!(c);
+define_ld_deref_hl_reg!(d);
+define_ld_deref_hl_reg!(e);
+define_ld_deref_hl_reg!(h);
+define_ld_deref_hl_reg!(l);
+define_ld_deref_hl_reg!(a);
+
+macro_rules! define_push_pop_reg {
+	($reg:ident) => {
+		paste::paste! {
+			pub fn [<push_ $reg>](state: &mut Gameboy) -> CycleResult {
+				match state.registers.cycle {
+					0 => CycleResult::NeedsMore,
+					1 => {
+						state.cpu_push_stack((state.registers.[<get_ $reg>]() >> 8) as u8);
+						CycleResult::NeedsMore
+					},
+					2 => {
+						state.cpu_push_stack(state.registers.[<get_ $reg>]() as u8);
+						state.registers.opcode_bytecount = Some(1);
+						CycleResult::NeedsMore
+					},
+					3 => CycleResult::Finished,
+					_ => unreachable!(),
+				}
+			}
+			
+			pub fn [<pop_ $reg>](state: &mut Gameboy) -> CycleResult {
+				match state.registers.cycle {
+					0 => {
+						state.cpu_pop_stack();
+						CycleResult::NeedsMore
+					},
+					1 => {
+						let lsb = state.registers.take_mem() as u16;
+						state.registers.set_hold(lsb);
+						state.cpu_pop_stack();
+						CycleResult::NeedsMore
+					},
+					2 => {
+						let val = (state.registers.take_mem() as u16) << 8 | state.registers.take_hold();
+						state.registers.[<set_ $reg>](val);
+						state.registers.opcode_bytecount = Some(1);
+						CycleResult::Finished
+					},
+					_ => unreachable!(),
+				}
+			}
+		}
+	};
+}
+
+define_push_pop_reg!(bc);
+define_push_pop_reg!(de);
+define_push_pop_reg!(hl);
+define_push_pop_reg!(af);
\ No newline at end of file