mirror of
https://github.com/ksherlock/mpw.git
synced 2024-11-25 04:31:52 +00:00
579 lines
15 KiB
C
579 lines
15 KiB
C
/* @(#) $Id: CpuModule_Flags.c,v 1.3 2011-07-18 17:22:55 peschau Exp $ */
|
|
/*=========================================================================*/
|
|
/* Fellow */
|
|
/* 68000 flag and condition code handling */
|
|
/* */
|
|
/* Author: Petter Schau */
|
|
/* */
|
|
/* Copyright (C) 1991, 1992, 1996 Free Software Foundation, Inc. */
|
|
/* */
|
|
/* This program is free software; you can redistribute it and/or modify */
|
|
/* it under the terms of the GNU General Public License as published by */
|
|
/* the Free Software Foundation; either version 2, or (at your option) */
|
|
/* any later version. */
|
|
/* */
|
|
/* This program is distributed in the hope that it will be useful, */
|
|
/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
|
|
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
|
|
/* GNU General Public License for more details. */
|
|
/* */
|
|
/* You should have received a copy of the GNU General Public License */
|
|
/* along with this program; if not, write to the Free Software Foundation, */
|
|
/* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
|
|
/*=========================================================================*/
|
|
#include "defs.h"
|
|
#include "fellow.h"
|
|
#include "CpuModule.h"
|
|
#include "CpuModule_Internal.h"
|
|
|
|
|
|
/// Sets the Z flag for bit operations
|
|
void cpuSetZFlagBitOpsB(UBY res)
|
|
{
|
|
ULO flags = cpu_sr & 0xfffb;
|
|
if (res == 0) flags |= 4;
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// Sets the Z flag for bit operations
|
|
void cpuSetZFlagBitOpsL(ULO res)
|
|
{
|
|
ULO flags = cpu_sr & 0xfffb;
|
|
if (res == 0) flags |= 4;
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
// rm,dm,sm
|
|
ULO cpu_xnvc_flag_add_table[2][2][2] = { 0,0x11,0x11,0x13,0xa,8,8,0x19};
|
|
|
|
/// <summary>
|
|
/// Calculate XNVC flags of an add operation.
|
|
/// </summary>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="dm">The MSB of the destination source.</param>
|
|
/// <param name="sm">The MSB of the source.</param>
|
|
static ULO cpuMakeFlagXNVCAdd(BOOLE rm, BOOLE dm, BOOLE sm)
|
|
{
|
|
return cpu_xnvc_flag_add_table[rm][dm][sm];
|
|
}
|
|
|
|
// rm,dm,sm
|
|
ULO cpu_nvc_flag_add_table[2][2][2] = { 0,1,1,3,0xa,8,8,9};
|
|
|
|
/// <summary>
|
|
/// Calculate NVC flags of an add operation for instructions not setting X.
|
|
/// </summary>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="dm">The MSB of the destination source.</param>
|
|
/// <param name="sm">The MSB of the source.</param>
|
|
static ULO cpuMakeFlagNVCAdd(BOOLE rm, BOOLE dm, BOOLE sm)
|
|
{
|
|
return cpu_nvc_flag_add_table[rm][dm][sm];
|
|
}
|
|
|
|
// rm,dm,sm
|
|
ULO cpu_xnvc_flag_sub_table[2][2][2] = { 0,0x11,2,0,0x19,0x1b,8,0x19};
|
|
|
|
/// <summary>
|
|
/// Calculate XNVC flags of a sub operation.
|
|
/// </summary>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="dm">The MSB of the destination source.</param>
|
|
/// <param name="sm">The MSB of the source.</param>
|
|
static ULO cpuMakeFlagXNVCSub(BOOLE rm, BOOLE dm, BOOLE sm)
|
|
{
|
|
return cpu_xnvc_flag_sub_table[rm][dm][sm];
|
|
}
|
|
|
|
// rm,dm,sm
|
|
ULO cpu_nvc_flag_sub_table[2][2][2] = { 0,1,2,0,9,0xb,8,9};
|
|
|
|
/// <summary>
|
|
/// Calculate NVC flags of a sub operation for instructions not setting X.
|
|
/// </summary>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="dm">The MSB of the destination source.</param>
|
|
/// <param name="sm">The MSB of the source.</param>
|
|
static ULO cpuMakeFlagNVCSub(BOOLE rm, BOOLE dm, BOOLE sm)
|
|
{
|
|
return cpu_nvc_flag_sub_table[rm][dm][sm];
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the X and C flags to the value f.
|
|
/// </summary>
|
|
/// <param name="f">The new state of the flags.</param>
|
|
void cpuSetFlagXC(BOOLE f)
|
|
{
|
|
cpu_sr = (cpu_sr & 0xffee) | ((f) ? 0x11 : 0);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the C flag to the value f.
|
|
/// </summary>
|
|
/// <param name="f">The new state of the flag.</param>
|
|
void cpuSetFlagC(BOOLE f)
|
|
{
|
|
cpu_sr = (cpu_sr & 0xfffe) | ((f) ? 1 : 0);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the V flag.
|
|
/// </summary>
|
|
/// <param name="f">The new state of the flag.</param>
|
|
void cpuSetFlagV(BOOLE f)
|
|
{
|
|
cpu_sr = (cpu_sr & 0xfffd) | ((f) ? 2 : 0);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Clear the V flag.
|
|
/// </summary>
|
|
static void cpuClearFlagV(void)
|
|
{
|
|
cpu_sr = cpu_sr & 0xfffd;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Get the V flag.
|
|
/// </summary>
|
|
BOOLE cpuGetFlagV(void)
|
|
{
|
|
return cpu_sr & 0x2;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the N flag.
|
|
/// </summary>
|
|
/// <param name="f">The new state of the flag.</param>
|
|
void cpuSetFlagN(BOOLE f)
|
|
{
|
|
cpu_sr = (cpu_sr & 0xfff7) | ((f) ? 8 : 0);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the Z flag.
|
|
/// </summary>
|
|
/// <param name="f">The new state of the flag.</param>
|
|
void cpuSetFlagZ(BOOLE f)
|
|
{
|
|
cpu_sr = (cpu_sr & 0xfffb) | ((f) ? 4 : 0);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Clear the Z flag.
|
|
/// </summary>
|
|
static void cpuClearFlagZ(void)
|
|
{
|
|
cpu_sr = cpu_sr & 0xfffb;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Get the Z flag.
|
|
/// </summary>
|
|
static BOOLE cpuGetFlagZ(void)
|
|
{
|
|
return cpu_sr & 0x4;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Get the X flag.
|
|
/// </summary>
|
|
BOOLE cpuGetFlagX(void)
|
|
{
|
|
return cpu_sr & 0x10;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags.
|
|
/// </summary>
|
|
void cpuSetFlags0100(void)
|
|
{
|
|
cpu_sr = (cpu_sr & 0xfff0) | 4;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Clear V and C.
|
|
/// </summary>
|
|
static void cpuClearFlagsVC(void)
|
|
{
|
|
cpu_sr = cpu_sr & 0xfffc;
|
|
}
|
|
|
|
UWO cpuGetZFlagB(UBY res) {return (UWO)((res) ? 0 : 4);}
|
|
UWO cpuGetZFlagW(UWO res) {return (UWO)((res) ? 0 : 4);}
|
|
UWO cpuGetZFlagL(ULO res) {return (UWO)((res) ? 0 : 4);}
|
|
|
|
UWO cpuGetNFlagB(UBY res) {return (UWO)((res & 0x80) >> 4);}
|
|
UWO cpuGetNFlagW(UWO res) {return (UWO)((res & 0x8000) >> 12);}
|
|
UWO cpuGetNFlagL(ULO res) {return (UWO)((res & 0x80000000) >> 28);}
|
|
|
|
/// <summary>
|
|
/// Set the flags NZVC.
|
|
/// </summary>
|
|
/// <param name="z">The Z flag.</param>
|
|
/// <param name="n">The N flag.</param>
|
|
/// <param name="v">The V flag.</param>
|
|
/// <param name="c">The C flag.</param>
|
|
void cpuSetFlagsNZVC(BOOLE z, BOOLE n, BOOLE v, BOOLE c)
|
|
{
|
|
ULO flags = cpu_sr & 0xfff0;
|
|
if (n) flags |= 8;
|
|
else if (z) flags |= 4;
|
|
if (v) flags |= 2;
|
|
if (c) flags |= 1;
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags VC.
|
|
/// </summary>
|
|
/// <param name="v">The V flag.</param>
|
|
/// <param name="c">The C flag.</param>
|
|
void cpuSetFlagsVC(BOOLE v, BOOLE c)
|
|
{
|
|
ULO flags = cpu_sr & 0xfffc;
|
|
if (v) flags |= 2;
|
|
if (c) flags |= 1;
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags (all) of an add operation.
|
|
/// </summary>
|
|
/// <param name="z">The Z flag.</param>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="dm">The MSB of the destination source.</param>
|
|
/// <param name="sm">The MSB of the source.</param>
|
|
void cpuSetFlagsAdd(BOOLE z, BOOLE rm, BOOLE dm, BOOLE sm)
|
|
{
|
|
ULO flags = cpu_sr & 0xffe0;
|
|
if (z) flags |= 4;
|
|
flags |= cpuMakeFlagXNVCAdd(rm, dm, sm);
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags (all) of a sub operation.
|
|
/// </summary>
|
|
/// <param name="z">The Z flag.</param>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="dm">The MSB of the destination source.</param>
|
|
/// <param name="sm">The MSB of the source.</param>
|
|
void cpuSetFlagsSub(BOOLE z, BOOLE rm, BOOLE dm, BOOLE sm)
|
|
{
|
|
ULO flags = cpu_sr & 0xffe0;
|
|
if (z) flags |= 4;
|
|
flags |= cpuMakeFlagXNVCSub(rm, dm, sm);
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags (all) of an addx operation.
|
|
/// </summary>
|
|
/// <param name="z">The Z flag.</param>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="dm">The MSB of the destination source.</param>
|
|
/// <param name="sm">The MSB of the source.</param>
|
|
void cpuSetFlagsAddX(BOOLE z, BOOLE rm, BOOLE dm, BOOLE sm)
|
|
{
|
|
ULO flags = cpu_sr & ((z) ? 0xffe4 : 0xffe0); // Clear z if result is non-zero
|
|
flags |= cpuMakeFlagXNVCAdd(rm, dm, sm);
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags (all) of a subx operation.
|
|
/// </summary>
|
|
/// <param name="z">The Z flag.</param>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="dm">The MSB of the destination source.</param>
|
|
/// <param name="sm">The MSB of the source.</param>
|
|
void cpuSetFlagsSubX(BOOLE z, BOOLE rm, BOOLE dm, BOOLE sm)
|
|
{
|
|
ULO flags = cpu_sr & ((z) ? 0xffe4 : 0xffe0); // Clear z if result is non-zero
|
|
flags |= cpuMakeFlagXNVCSub(rm, dm, sm);
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags (all) of a neg operation.
|
|
/// </summary>
|
|
/// <param name="z">The Z flag.</param>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="dm">The MSB of the destination source.</param>
|
|
void cpuSetFlagsNeg(BOOLE z, BOOLE rm, BOOLE dm)
|
|
{
|
|
ULO flags = cpu_sr & 0xffe0;
|
|
if (z) flags |= 4;
|
|
else
|
|
{
|
|
flags |= 0x11; // set XC if result is non-zero
|
|
if (rm)
|
|
{
|
|
flags |= 8;
|
|
if (dm) flags |= 2; // V
|
|
}
|
|
}
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags (all) of a negx operation.
|
|
/// </summary>
|
|
/// <param name="z">The Z flag.</param>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="dm">The MSB of the destination source.</param>
|
|
void cpuSetFlagsNegx(BOOLE z, BOOLE rm, BOOLE dm)
|
|
{
|
|
ULO flags = cpu_sr & ((z) ? 0xffe4 : 0xffe0); // Clear z if result is non-zero
|
|
if (dm || rm)
|
|
{
|
|
flags |= 0x11; // XC
|
|
if (rm)
|
|
{
|
|
flags |= 8;
|
|
if (dm) flags |= 2; // V
|
|
}
|
|
}
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags (all) of a cmp operation. (Same as sub, but no X.)
|
|
/// </summary>
|
|
/// <param name="z">The Z flag.</param>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="dm">The MSB of the destination source.</param>
|
|
/// <param name="sm">The MSB of the source.</param>
|
|
void cpuSetFlagsCmp(BOOLE z, BOOLE rm, BOOLE dm, BOOLE sm)
|
|
{
|
|
ULO flags = cpu_sr & 0xfff0;
|
|
if (z) flags |= 4;
|
|
flags |= cpuMakeFlagNVCSub(rm, dm, sm);
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags of a 0 shift count operation.
|
|
/// </summary>
|
|
/// <param name="z">The Z flag.</param>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
void cpuSetFlagsShiftZero(BOOLE z, BOOLE rm)
|
|
{
|
|
ULO flags = cpu_sr & 0xfff0; // Always clearing the VC flag
|
|
if (rm) flags |= 8;
|
|
else if (z) flags |= 4;
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags of a shift operation.
|
|
/// </summary>
|
|
/// <param name="z">The Z flag.</param>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="c">The carry of the result.</param>
|
|
/// <param name="c">The overflow of the result.</param>
|
|
void cpuSetFlagsShift(BOOLE z, BOOLE rm, BOOLE c, BOOLE v)
|
|
{
|
|
ULO flags = cpu_sr & 0xffe0;
|
|
if (rm) flags |= 8;
|
|
else if (z) flags |= 4;
|
|
if (v) flags |= 2;
|
|
if (c) flags |= 0x11;
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags of a rotate operation.
|
|
/// </summary>
|
|
/// <param name="z">The Z flag.</param>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="c">The carry of the result.</param>
|
|
void cpuSetFlagsRotate(BOOLE z, BOOLE rm, BOOLE c)
|
|
{
|
|
ULO flags = cpu_sr & 0xfff0; // Always clearing the V flag
|
|
|
|
if (rm) flags |= 8;
|
|
else if (z) flags |= 4;
|
|
if (c) flags |= 1;
|
|
|
|
cpu_sr = flags;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags of a rotate with x operation.
|
|
/// </summary>
|
|
/// <param name="z">The Z flag.</param>
|
|
/// <param name="rm">The MSB of the result.</param>
|
|
/// <param name="c">The extend bit and carry of the result.</param>
|
|
void cpuSetFlagsRotateX(UWO z, UWO rm, UWO x)
|
|
{
|
|
cpu_sr = (cpu_sr & 0xffe0) | z | rm | x;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags (ZN00).
|
|
/// </summary>
|
|
void cpuSetFlagsNZ00NewB(UBY res)
|
|
{
|
|
ULO flag = cpu_sr & 0xfff0;
|
|
if (res & 0x80) flag |= 0x8;
|
|
else if (res == 0) flag |= 0x4;
|
|
cpu_sr = flag;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags (ZN00).
|
|
/// </summary>
|
|
void cpuSetFlagsNZ00NewW(UWO res)
|
|
{
|
|
ULO flag = cpu_sr & 0xfff0;
|
|
if (res & 0x8000) flag |= 0x8;
|
|
else if (res == 0) flag |= 0x4;
|
|
cpu_sr = flag;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags (ZN00).
|
|
/// </summary>
|
|
void cpuSetFlagsNZ00NewL(ULO res)
|
|
{
|
|
ULO flag = cpu_sr & 0xfff0;
|
|
if (res & 0x80000000) flag |= 0x8;
|
|
else if (res == 0) flag |= 0x4;
|
|
cpu_sr = flag;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the flags (ZN00).
|
|
/// </summary>
|
|
void cpuSetFlagsNZ00New64(LLO res)
|
|
{
|
|
ULO flag = cpu_sr & 0xfff0;
|
|
if (res < 0) flag |= 0x8;
|
|
else if (res == 0) flag |= 0x4;
|
|
cpu_sr = flag;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the 4 flags absolute.
|
|
/// </summary>
|
|
/// <param name="f">flags</param>
|
|
void cpuSetFlagsAbs(UWO f)
|
|
{
|
|
cpu_sr = (cpu_sr & 0xfff0) | f;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Calculates the values for the condition codes.
|
|
/// </summary>
|
|
/// <returns>TRUE or FALSE</returns>
|
|
BOOLE cpuCalculateConditionCode0(void)
|
|
{
|
|
return TRUE;
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode1(void)
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode2(void)
|
|
{
|
|
return !(cpu_sr & 5); // HI - !C && !Z
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode3(void)
|
|
{
|
|
return cpu_sr & 5; // LS - C || Z
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode4(void)
|
|
{
|
|
return (~cpu_sr) & 1; // CC - !C
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode5(void)
|
|
{
|
|
return cpu_sr & 1; // CS - C
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode6(void)
|
|
{
|
|
return (~cpu_sr) & 4; // NE - !Z
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode7(void)
|
|
{
|
|
return cpu_sr & 4; // EQ - Z
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode8(void)
|
|
{
|
|
return (~cpu_sr) & 2; // VC - !V
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode9(void)
|
|
{
|
|
return cpu_sr & 2; // VS - V
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode10(void)
|
|
{
|
|
return (~cpu_sr) & 8; // PL - !N
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode11(void)
|
|
{
|
|
return cpu_sr & 8; // MI - N
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode12(void)
|
|
{
|
|
ULO tmp = cpu_sr & 0xa;
|
|
return (tmp == 0xa) || (tmp == 0); // GE - (N && V) || (!N && !V)
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode13(void)
|
|
{
|
|
ULO tmp = cpu_sr & 0xa;
|
|
return (tmp == 0x8) || (tmp == 0x2); // LT - (N && !V) || (!N && V)
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode14(void)
|
|
{
|
|
ULO tmp = cpu_sr & 0xa;
|
|
return (!(cpu_sr & 0x4)) && ((tmp == 0xa) || (tmp == 0)); // GT - (N && V && !Z) || (!N && !V && !Z)
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode15(void)
|
|
{
|
|
ULO tmp = cpu_sr & 0xa;
|
|
return (cpu_sr & 0x4) || (tmp == 0x8) || (tmp == 2);// LE - Z || (N && !V) || (!N && V)
|
|
}
|
|
|
|
BOOLE cpuCalculateConditionCode(ULO cc)
|
|
{
|
|
switch (cc & 0xf)
|
|
{
|
|
case 0: return cpuCalculateConditionCode0();
|
|
case 1: return cpuCalculateConditionCode1();
|
|
case 2: return cpuCalculateConditionCode2();
|
|
case 3: return cpuCalculateConditionCode3();
|
|
case 4: return cpuCalculateConditionCode4();
|
|
case 5: return cpuCalculateConditionCode5();
|
|
case 6: return cpuCalculateConditionCode6();
|
|
case 7: return cpuCalculateConditionCode7();
|
|
case 8: return cpuCalculateConditionCode8();
|
|
case 9: return cpuCalculateConditionCode9();
|
|
case 10: return cpuCalculateConditionCode10();
|
|
case 11: return cpuCalculateConditionCode11();
|
|
case 12: return cpuCalculateConditionCode12();
|
|
case 13: return cpuCalculateConditionCode13();
|
|
case 14: return cpuCalculateConditionCode14();
|
|
case 15: return cpuCalculateConditionCode15();
|
|
}
|
|
return FALSE;
|
|
}
|