From b6f9557d115ec64bdea9c515f96d3308d10c1fd0 Mon Sep 17 00:00:00 2001
From: Max Regan <mgregan2@gmail.com>
Date: Fri, 7 Apr 2017 16:35:21 -0700
Subject: [PATCH] cpu: cleanup to use named registers

Since we have direct access to registers via name by "cpu->a" and the
like. Use that notation in a few more places since it is far more concise.

Signed-off-by: Max Regan <mgregan2@gmail.com>
---
 src/cpu.c | 56 ++++++++++++++++++-------------------------------------
 1 file changed, 18 insertions(+), 38 deletions(-)

diff --git a/src/cpu.c b/src/cpu.c
index 671cb40..9a7e579 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -492,11 +492,7 @@ static void _push_stack_16(struct lr35902_state *cpu, uint16_t val)
 
 static uint8_t _pop_stack_8(struct lr35902_state *cpu)
 {
-	uint8_t ret;
-	cpu->sp++;
-	ret = cpu->mem_read(cpu, cpu->sp);
-	lr35902_set_reg_16(cpu, LR35902_REG_SP, cpu->sp);
-	return ret;
+	return cpu->mem_read(cpu, cpu->sp++);
 }
 
 static uint16_t _pop_stack_16(struct lr35902_state *cpu)
@@ -597,9 +593,8 @@ static void ld(struct lr35902_state *cpu, uint8_t instr)
 
 static void ld_deref(struct lr35902_state *cpu, uint8_t instr)
 {
-	uint8_t val;
 	int incr = 0;
-	uint16_t hl_val;
+	uint8_t val;
 
 	switch(instr) {
 		/** Copy to Registers **/
@@ -613,17 +608,16 @@ static void ld_deref(struct lr35902_state *cpu, uint8_t instr)
 		incr = 1;
 		/* Intentional fall-through */
 	case 0x3A:
-		hl_val = lr35902_get_reg_16(cpu, LR35902_REG_HL);
-		val = cpu->mem_read(cpu, hl_val);
-		lr35902_set_reg_8(cpu, LR35902_REG_A, val);
+		val = cpu->mem_read(cpu, cpu->hl);
+		cpu->a = val;
 
 		if (incr) {
-			hl_val++;
+		    cpu->hl++;
 		} else {
-			hl_val--;
+		    cpu->hl--;
 		}
 
-		lr35902_set_reg_16(cpu, LR35902_REG_HL, hl_val);
+		lr35902_set_reg_16(cpu, LR35902_REG_HL, cpu->hl);
 		break;
 
 		/** Copy to memory **/
@@ -631,17 +625,14 @@ static void ld_deref(struct lr35902_state *cpu, uint8_t instr)
 		incr = 1;
 		/* Intentional fall-through */
 	case 0x32:
-		hl_val = cpu->hl;
-		val = cpu->a;
-		cpu->mem_write(cpu, hl_val, val);
+		cpu->mem_write(cpu, cpu->hl, cpu->a);
 
 		if (incr) {
-			hl_val++;
+			cpu->hl++;
 		} else {
-			hl_val--;
+			cpu->hl--;
 		}
 
-		cpu->hl = hl_val;
 		break;
 	case 0x12:
 		cpu->mem_write(cpu, cpu->de, cpu->a);
@@ -657,7 +648,7 @@ static void ld_deref(struct lr35902_state *cpu, uint8_t instr)
 
 static void ld_into_deref(struct lr35902_state *cpu, uint8_t instr)
 {
-	uint8_t reg, a;
+	uint8_t reg;
 	uint16_t addr;
 
 	switch (instr) {
@@ -669,18 +660,15 @@ static void ld_into_deref(struct lr35902_state *cpu, uint8_t instr)
 		return;
 	}
 
-	a = lr35902_get_reg_8(cpu, LR35902_REG_A);
 	addr = lr35902_get_reg_16(cpu, reg);
-	cpu->mem_write(cpu, addr, a);
+	cpu->mem_write(cpu, addr, cpu->a);
 }
 
 static void ld_d8(struct lr35902_state *cpu, uint8_t instr)
 {
 	uint8_t reg = (instr >> 3) & 0x7;
-	uint8_t val;
-	_incr_pc(cpu);
-	val = cpu->mem_read(cpu, lr35902_get_reg_16(cpu, LR35902_REG_PC));
-	_set_reg_8(cpu, reg, val);
+	++cpu->pc;
+	_set_reg_8(cpu, reg, cpu->mem_read(cpu, cpu->pc));
 }
 
 static void ld_d16(struct lr35902_state *cpu, uint8_t instr)
@@ -723,22 +711,19 @@ static void ld_a16(struct lr35902_state *cpu, uint8_t instr)
 
 static void ld_c_offset(struct lr35902_state *cpu, uint8_t instr)
 {
-	uint8_t val = 0;
 	uint16_t addr = 0;
 
-	addr = lr35902_get_reg_8(cpu, LR35902_REG_C);
+	addr = cpu->c;
 	addr |= 0xff00;
 
 	switch (instr) {
 	case 0xf2:
 		//LD A, ($FF00 + C)
-		val = cpu->mem_read(cpu,  addr);
-		lr35902_set_reg_8(cpu, LR35902_REG_A, val);
+		cpu->a = cpu->mem_read(cpu, addr);
 		break;
 	case 0xe2:
 		//LD ($FF00 + C), A
-		val = lr35902_get_reg_8(cpu, LR35902_REG_A);
-		cpu->mem_write(cpu, addr, val);
+		cpu->mem_write(cpu, addr, cpu->a);
 		break;
 	default:
 		ASSERT(0);
@@ -749,12 +734,7 @@ static void ld_c_offset(struct lr35902_state *cpu, uint8_t instr)
 
 static void ld_hl_d16(struct lr35902_state *cpu, uint8_t inst)
 {
-	uint16_t addr = lr35902_get_reg_16(cpu, LR35902_REG_HL);
-	uint8_t val = cpu->mem_read(cpu, addr);
-
-	_set_reg_8(cpu, LR35902_REG_A, val);
-	addr++;
-	lr35902_set_reg_16(cpu, LR35902_REG_HL, addr);
+	cpu->a = cpu->mem_read(cpu, cpu->hl++);
 }