From 827167683b9bbcf99afad5b85c5c3cbb51890f2d Mon Sep 17 00:00:00 2001
From: hap <happppp@users.noreply.github.com>
Date: Sun, 8 Jan 2023 18:51:47 +0100
Subject: pic16c5x: no need for m_old_data class variable

---
 src/devices/cpu/pic16c5x/pic16c5x.cpp | 63 ++++++++++++++---------------------
 src/devices/cpu/pic16c5x/pic16c5x.h   |  7 ++--
 2 files changed, 27 insertions(+), 43 deletions(-)

diff --git a/src/devices/cpu/pic16c5x/pic16c5x.cpp b/src/devices/cpu/pic16c5x/pic16c5x.cpp
index 7f9757ab436..05aa42eca34 100644
--- a/src/devices/cpu/pic16c5x/pic16c5x.cpp
+++ b/src/devices/cpu/pic16c5x/pic16c5x.cpp
@@ -309,44 +309,35 @@ void pic16c5x_device::calc_zero_flag()
 		CLR(STATUS, Z_FLAG);
 }
 
-void pic16c5x_device::CALCULATE_ADD_CARRY()
+void pic16c5x_device::calc_add_flags(u8 augend)
 {
-	if (m_old_data > m_ALU) {
+	calc_zero_flag();
+
+	if (augend > m_ALU)
 		SET(STATUS, C_FLAG);
-	}
-	else {
+	else
 		CLR(STATUS, C_FLAG);
-	}
-}
 
-void pic16c5x_device::CALCULATE_ADD_DIGITCARRY()
-{
-	if ((m_old_data & 0x0f) > (m_ALU & 0x0f)) {
+	if ((augend & 0x0f) > (m_ALU & 0x0f))
 		SET(STATUS, DC_FLAG);
-	}
-	else {
+	else
 		CLR(STATUS, DC_FLAG);
-	}
+
 }
 
-void pic16c5x_device::CALCULATE_SUB_CARRY()
+void pic16c5x_device::calc_sub_flags(u8 minuend)
 {
-	if (m_old_data < m_ALU) {
+	calc_zero_flag();
+
+	if (minuend < m_ALU)
 		CLR(STATUS, C_FLAG);
-	}
-	else {
+	else
 		SET(STATUS, C_FLAG);
-	}
-}
 
-void pic16c5x_device::CALCULATE_SUB_DIGITCARRY()
-{
-	if ((m_old_data & 0x0f) < (m_ALU & 0x0f)) {
+	if ((minuend & 0x0f) < (m_ALU & 0x0f))
 		CLR(STATUS, DC_FLAG);
-	}
-	else {
+	else
 		SET(STATUS, DC_FLAG);
-	}
 }
 
 
@@ -573,12 +564,10 @@ void pic16c5x_device::illegal()
 
 void pic16c5x_device::addwf()
 {
-	m_old_data = get_regfile(ADDR);
-	m_ALU = m_old_data + m_W;
+	u8 augend = get_regfile(ADDR);
+	m_ALU = augend + m_W;
 	store_result(ADDR, m_ALU);
-	calc_zero_flag();
-	CALCULATE_ADD_CARRY();
-	CALCULATE_ADD_DIGITCARRY();
+	calc_add_flags(augend);
 }
 
 void pic16c5x_device::andwf()
@@ -747,12 +736,12 @@ void pic16c5x_device::retlw()
 void pic16c5x_device::rlf()
 {
 	m_ALU = get_regfile(ADDR);
-	u8 bit7 = m_ALU & 0x80;
+	int carry = BIT(m_ALU, 7);
 	m_ALU <<= 1;
 	if (STATUS & C_FLAG) m_ALU |= 1;
 	store_result(ADDR, m_ALU);
 
-	if (bit7)
+	if (carry)
 		SET(STATUS, C_FLAG);
 	else
 		CLR(STATUS, C_FLAG);
@@ -761,12 +750,12 @@ void pic16c5x_device::rlf()
 void pic16c5x_device::rrf()
 {
 	m_ALU = get_regfile(ADDR);
-	u8 bit0 = m_ALU & 1;
+	int carry = BIT(m_ALU, 0);
 	m_ALU >>= 1;
 	if (STATUS & C_FLAG) m_ALU |= 0x80;
 	store_result(ADDR, m_ALU);
 
-	if (bit0)
+	if (carry)
 		SET(STATUS, C_FLAG);
 	else
 		CLR(STATUS, C_FLAG);
@@ -782,12 +771,10 @@ void pic16c5x_device::sleepic()
 
 void pic16c5x_device::subwf()
 {
-	m_old_data = get_regfile(ADDR);
-	m_ALU = m_old_data - m_W;
+	u8 minuend = get_regfile(ADDR);
+	m_ALU = minuend - m_W;
 	store_result(ADDR, m_ALU);
-	calc_zero_flag();
-	CALCULATE_SUB_CARRY();
-	CALCULATE_SUB_DIGITCARRY();
+	calc_sub_flags(minuend);
 }
 
 void pic16c5x_device::swapf()
diff --git a/src/devices/cpu/pic16c5x/pic16c5x.h b/src/devices/cpu/pic16c5x/pic16c5x.h
index 3dd2aca758a..171890538a1 100644
--- a/src/devices/cpu/pic16c5x/pic16c5x.h
+++ b/src/devices/cpu/pic16c5x/pic16c5x.h
@@ -140,7 +140,6 @@ private:
 	u16       m_temp_config;
 	int       m_rtcc;
 	int       m_count_cycles;
-	u8        m_old_data;
 	u8        m_data_mask;
 	u16       m_program_mask;
 	u8        m_status_mask;
@@ -174,10 +173,8 @@ private:
 
 	void update_internalram_ptr();
 	void calc_zero_flag();
-	void CALCULATE_ADD_CARRY();
-	void CALCULATE_ADD_DIGITCARRY();
-	void CALCULATE_SUB_CARRY();
-	void CALCULATE_SUB_DIGITCARRY();
+	void calc_add_flags(u8 augend);
+	void calc_sub_flags(u8 minuend);
 	u16 pop_stack();
 	void push_stack(u16 data);
 	void set_pc(offs_t addr);
-- 
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