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// license:BSD-3-Clause
// copyright-holders:Nathan Woods
/*********************************************************************
m6809inl.h
Portable 6809 emulator - Inline functions for the purposes of
optimization
**********************************************************************/
#include "m6809.h"
//-------------------------------------------------
// rotate_right
//-------------------------------------------------
template<class T>
inline ATTR_FORCE_INLINE T m6809_base_device::rotate_right(T value)
{
bool new_carry = (value & 1) ? true : false;
value = value >> 1;
T high_bit = ((T) 1) << (sizeof(T) * 8 - 1);
if (m_cc & CC_C)
value |= high_bit;
else
value &= ~high_bit;
if (new_carry)
m_cc |= CC_C;
else
m_cc &= ~CC_C;
return value;
}
//-------------------------------------------------
// rotate_left
//-------------------------------------------------
template<class T>
inline ATTR_FORCE_INLINE UINT32 m6809_base_device::rotate_left(T value)
{
T high_bit = ((T) 1) << (sizeof(T) * 8 - 1);
bool new_carry = (value & high_bit) ? true : false;
UINT32 new_value = value;
new_value <<= 1;
if (m_cc & CC_C)
new_value |= 1;
else
new_value &= ~1;
if (new_carry)
m_cc |= CC_C;
else
m_cc &= ~CC_C;
return new_value;
}
//-------------------------------------------------
// read_operand
//-------------------------------------------------
inline ATTR_FORCE_INLINE UINT8 m6809_base_device::read_operand()
{
switch(m_addressing_mode)
{
case ADDRESSING_MODE_EA: return read_memory(m_ea.w);
case ADDRESSING_MODE_IMMEDIATE: return read_opcode_arg();
case ADDRESSING_MODE_REGISTER_A: return m_q.r.a;
case ADDRESSING_MODE_REGISTER_B: return m_q.r.b;
default: fatalerror("Unexpected"); return 0x00;
}
}
//-------------------------------------------------
// read_operand
//-------------------------------------------------
inline ATTR_FORCE_INLINE UINT8 m6809_base_device::read_operand(int ordinal)
{
switch(m_addressing_mode)
{
case ADDRESSING_MODE_EA: return read_memory(m_ea.w + ordinal);
case ADDRESSING_MODE_IMMEDIATE: return read_opcode_arg();
default: fatalerror("Unexpected"); return 0x00;
}
}
//-------------------------------------------------
// write_operand
//-------------------------------------------------
inline ATTR_FORCE_INLINE void m6809_base_device::write_operand(UINT8 data)
{
switch(m_addressing_mode)
{
case ADDRESSING_MODE_IMMEDIATE: /* do nothing */ break;
case ADDRESSING_MODE_EA: write_memory(m_ea.w, data); break;
case ADDRESSING_MODE_REGISTER_A: m_q.r.a = data; break;
case ADDRESSING_MODE_REGISTER_B: m_q.r.b = data; break;
default: fatalerror("Unexpected"); break;
}
}
//-------------------------------------------------
// write_operand
//-------------------------------------------------
inline ATTR_FORCE_INLINE void m6809_base_device::write_operand(int ordinal, UINT8 data)
{
switch(m_addressing_mode)
{
case ADDRESSING_MODE_IMMEDIATE: /* do nothing */ break;
case ADDRESSING_MODE_EA: write_memory(m_ea.w + ordinal, data); break;
default: fatalerror("Unexpected"); break;
}
}
//-------------------------------------------------
// daa - decimal arithmetic adjustment instruction
//-------------------------------------------------
inline ATTR_FORCE_INLINE void m6809_base_device::daa()
{
UINT16 t, cf = 0;
UINT8 msn = m_q.r.a & 0xF0;
UINT8 lsn = m_q.r.a & 0x0F;
// compute the carry
if (lsn > 0x09 || m_cc & CC_H) cf |= 0x06;
if (msn > 0x80 && lsn > 0x09 ) cf |= 0x60;
if (msn > 0x90 || m_cc & CC_C) cf |= 0x60;
// calculate the result
t = m_q.r.a + cf;
m_cc &= ~CC_V;
if (t & 0x0100) // keep carry from previous operation
m_cc |= CC_C;
// and put it back into A
m_q.r.a = set_flags(CC_NZ, (UINT8) t);
}
//-------------------------------------------------
// mul
//-------------------------------------------------
inline ATTR_FORCE_INLINE void m6809_base_device::mul()
{
// perform multiply
UINT16 result = ((UINT16) m_q.r.a) * ((UINT16) m_q.r.b);
// set result and Z flag
m_q.r.d = set_flags(CC_Z, result);
// set C flag
if (m_q.r.d & 0x0080)
m_cc |= CC_C;
else
m_cc &= ~CC_C;
}
//-------------------------------------------------
// ireg
//-------------------------------------------------
inline ATTR_FORCE_INLINE UINT16 &m6809_base_device::ireg()
{
switch(m_opcode & 0x60)
{
case 0x00: return m_x.w;
case 0x20: return m_y.w;
case 0x40: return m_u.w;
case 0x60: return m_s.w;
default:
fatalerror("Unexpected");
return m_x.w;
}
}
//-------------------------------------------------
// set_flags
//-------------------------------------------------
template<class T>
inline T m6809_base_device::set_flags(UINT8 mask, T a, T b, UINT32 r)
{
T hi_bit = (T) (1 << (sizeof(T) * 8 - 1));
m_cc &= ~mask;
if (mask & CC_H)
m_cc |= ((a ^ b ^ r) & 0x10) ? CC_H : 0;
if (mask & CC_N)
m_cc |= (r & hi_bit) ? CC_N : 0;
if (mask & CC_Z)
m_cc |= (((T)r) == 0) ? CC_Z : 0;
if (mask & CC_V)
m_cc |= ((a ^ b ^ r ^ (r >> 1)) & hi_bit) ? CC_V : 0;
if (mask & CC_C)
m_cc |= (r & (hi_bit << 1)) ? CC_C : 0;
return (T) r;
}
//-------------------------------------------------
// set_flags
//-------------------------------------------------
template<class T>
inline T m6809_base_device::set_flags(UINT8 mask, T r)
{
return set_flags(mask, (T)0, r, r);
}
//-------------------------------------------------
// eat_remaining
//-------------------------------------------------
inline void m6809_base_device::eat_remaining()
{
// we do this in order to be nice to people debugging
UINT16 real_pc = m_pc.w;
eat(m_icount);
m_pc.w = m_ppc.w;
debugger_instruction_hook(this, m_pc.w);
m_pc.w = real_pc;
}
//-------------------------------------------------
// is_register_addressing_mode
//-------------------------------------------------
inline bool m6809_base_device::is_register_addressing_mode()
{
return (m_addressing_mode != ADDRESSING_MODE_IMMEDIATE)
&& (m_addressing_mode != ADDRESSING_MODE_EA);
}
//-------------------------------------------------
// get_pending_interrupt
//-------------------------------------------------
inline UINT16 m6809_base_device::get_pending_interrupt()
{
if (m_nmi_asserted)
return VECTOR_NMI;
else if (!(m_cc & CC_F) && m_firq_line)
return VECTOR_FIRQ;
else if (!(m_cc & CC_I) && m_irq_line)
return VECTOR_IRQ;
else
return 0;
}
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