kolibrios/programs/emulator/dgen-sdl-1.33/cyclone/OpLogic.cpp
turbocat ea1a60faa3 Upload DGEN port source
git-svn-id: svn://kolibrios.org@9837 a494cfbc-eb01-0410-851d-a64ba20cac60
2022-06-15 18:25:17 +00:00

715 lines
17 KiB
C++

// This file is part of the Cyclone 68000 Emulator
// Copyright (c) 2004,2011 FinalDave (emudave (at) gmail.com)
// Copyright (c) 2005-2011 Gražvydas "notaz" Ignotas (notasas (at) gmail.com)
// This code is licensed under the GNU General Public License version 2.0 and the MAME License.
// You can choose the license that has the most advantages for you.
// SVN repository can be found at http://code.google.com/p/cyclone68000/
#include "app.h"
// --------------------- Opcodes 0x0100+ ---------------------
// Emit a Btst (Register) opcode 0000nnn1 ttaaaaaa
int OpBtstReg(int op)
{
int use=0;
int type=0,sea=0,tea=0;
int size=0;
type=(op>>6)&3; // Btst/Bchg/Bclr/Bset
// Get source and target EA
sea=(op>>9)&7;
tea=op&0x003f;
if (tea<0x10) size=2; // For registers, 32-bits
if ((tea&0x38)==0x08) return 1; // movep
// See if we can do this opcode:
if (EaCanRead(tea,0)==0) return 1;
if (type>0)
{
if (EaCanWrite(tea)==0) return 1;
}
use=OpBase(op,size);
use&=~0x0e00; // Use same handler for all registers
if (op!=use) { OpUse(op,use); return 0; } // Use existing handler
OpStart(op,tea);
if(type==1||type==3) {
Cycles=8;
} else {
Cycles=type?8:4;
if(size>=2) Cycles+=2;
}
EaCalcReadNoSE(-1,11,sea,0,0x0e00);
EaCalcReadNoSE((type>0)?8:-1,0,tea,size,0x003f);
if (tea>=0x10)
ot(" and r11,r11,#7 ;@ mem - do mod 8\n"); // size always 0
else ot(" and r11,r11,#31 ;@ reg - do mod 32\n"); // size always 2
ot("\n");
ot(" mov r1,#1\n");
ot(" tst r0,r1,lsl r11 ;@ Do arithmetic\n");
ot(" bicne r10,r10,#0x40000000\n");
ot(" orreq r10,r10,#0x40000000 ;@ Get Z flag\n");
ot("\n");
if (type>0)
{
if (type==1) ot(" eor r1,r0,r1,lsl r11 ;@ Toggle bit\n");
if (type==2) ot(" bic r1,r0,r1,lsl r11 ;@ Clear bit\n");
if (type==3) ot(" orr r1,r0,r1,lsl r11 ;@ Set bit\n");
ot("\n");
EaWrite(8,1,tea,size,0x003f,0,0);
}
OpEnd(tea);
return 0;
}
// --------------------- Opcodes 0x0800+ ---------------------
// Emit a Btst/Bchg/Bclr/Bset (Immediate) opcode 00001000 ttaaaaaa nn
int OpBtstImm(int op)
{
int type=0,sea=0,tea=0;
int use=0;
int size=0;
type=(op>>6)&3;
// Get source and target EA
sea= 0x003c;
tea=op&0x003f;
if (tea<0x10) size=2; // For registers, 32-bits
// See if we can do this opcode:
if (EaCanRead(tea,0)==0||EaAn(tea)||tea==0x3c) return 1;
if (type>0)
{
if (EaCanWrite(tea)==0) return 1;
}
use=OpBase(op,size);
if (op!=use) { OpUse(op,use); return 0; } // Use existing handler
OpStart(op,sea,tea);
ot("\n");
EaCalcReadNoSE(-1,0,sea,0,0);
ot(" mov r11,#1\n");
ot(" bic r10,r10,#0x40000000 ;@ Blank Z flag\n");
if (tea>=0x10)
ot(" and r0,r0,#7 ;@ mem - do mod 8\n"); // size always 0
else ot(" and r0,r0,#0x1F ;@ reg - do mod 32\n"); // size always 2
ot(" mov r11,r11,lsl r0 ;@ Make bit mask\n");
ot("\n");
if(type==1||type==3) {
Cycles=12;
} else {
Cycles=type?12:8;
if(size>=2) Cycles+=2;
}
EaCalcReadNoSE((type>0)?8:-1,0,tea,size,0x003f);
ot(" tst r0,r11 ;@ Do arithmetic\n");
ot(" orreq r10,r10,#0x40000000 ;@ Get Z flag\n");
ot("\n");
if (type>0)
{
if (type==1) ot(" eor r1,r0,r11 ;@ Toggle bit\n");
if (type==2) ot(" bic r1,r0,r11 ;@ Clear bit\n");
if (type==3) ot(" orr r1,r0,r11 ;@ Set bit\n");
ot("\n");
EaWrite(8, 1,tea,size,0x003f,0,0);
#if CYCLONE_FOR_GENESIS && !MEMHANDLERS_CHANGE_CYCLES
// this is a bit hacky (device handlers might modify cycles)
if (tea==0x38||tea==0x39)
ot(" ldr r5,[r7,#0x5c] ;@ Load Cycles\n");
#endif
}
OpEnd(sea,tea);
return 0;
}
// --------------------- Opcodes 0x4000+ ---------------------
int OpNeg(int op)
{
// 01000tt0 xxeeeeee (tt=negx/clr/neg/not, xx=size, eeeeee=EA)
int type=0,size=0,ea=0,use=0;
type=(op>>9)&3;
ea =op&0x003f;
size=(op>>6)&3; if (size>=3) return 1;
// See if we can do this opcode:
if (EaCanRead (ea,size)==0||EaAn(ea)) return 1;
if (EaCanWrite(ea )==0) return 1;
use=OpBase(op,size);
if (op!=use) { OpUse(op,use); return 0; } // Use existing handler
OpStart(op,ea); Cycles=size<2?4:6;
if(ea >= 0x10) Cycles*=2;
EaCalc (11,0x003f,ea,size,0,0);
if (type!=1) EaRead (11,0,ea,size,0x003f,0,0); // Don't need to read for 'clr' (or do we, for a dummy read?)
if (type==1) ot("\n");
if (type==0)
{
ot(";@ Negx:\n");
GetXBit(1);
if(size!=2) ot(" mov r0,r0,asl #%i\n",size?16:24);
ot(" rscs r1,r0,#0 ;@ do arithmetic\n");
ot(" orr r3,r10,#0xb0000000 ;@ for old Z\n");
OpGetFlags(1,1,0);
if(size!=2) {
ot(" movs r1,r1,asr #%i\n",size?16:24);
ot(" orreq r10,r10,#0x40000000 ;@ possily missed Z\n");
}
ot(" andeq r10,r10,r3 ;@ fix Z\n");
ot("\n");
}
if (type==1)
{
ot(";@ Clear:\n");
ot(" mov r1,#0\n");
ot(" mov r10,#0x40000000 ;@ NZCV=0100\n");
ot("\n");
}
if (type==2)
{
ot(";@ Neg:\n");
if(size!=2) ot(" mov r0,r0,asl #%i\n",size?16:24);
ot(" rsbs r1,r0,#0\n");
OpGetFlags(1,1);
if(size!=2) ot(" mov r1,r1,asr #%i\n",size?16:24);
ot("\n");
}
if (type==3)
{
ot(";@ Not:\n");
if(size!=2) {
ot(" mov r0,r0,asl #%i\n",size?16:24);
ot(" mvn r1,r0,asr #%i\n",size?16:24);
}
else
ot(" mvn r1,r0\n");
ot(" adds r1,r1,#0 ;@ Defines NZ, clears CV\n");
OpGetFlags(0,0);
ot("\n");
}
if (type==1) eawrite_check_addrerr=1;
EaWrite(11, 1,ea,size,0x003f,0,0);
OpEnd(ea);
return 0;
}
// --------------------- Opcodes 0x4840+ ---------------------
// Swap, 01001000 01000nnn swap Dn
int OpSwap(int op)
{
int ea=0,use=0;
ea=op&7;
use=op&~0x0007; // Use same opcode for all An
if (op!=use) { OpUse(op,use); return 0; } // Use existing handler
OpStart(op); Cycles=4;
EaCalc (11,0x0007,ea,2,1);
EaRead (11, 0,ea,2,0x0007,1);
ot(" mov r1,r0,ror #16\n");
ot(" adds r1,r1,#0 ;@ Defines NZ, clears CV\n");
OpGetFlags(0,0);
EaWrite(11, 1,8,2,0x0007,1);
OpEnd();
return 0;
}
// --------------------- Opcodes 0x4a00+ ---------------------
// Emit a Tst opcode, 01001010 xxeeeeee
int OpTst(int op)
{
int sea=0;
int size=0,use=0;
sea=op&0x003f;
size=(op>>6)&3; if (size>=3) return 1;
// See if we can do this opcode:
if (EaCanWrite(sea)==0||EaAn(sea)) return 1;
use=OpBase(op,size);
if (op!=use) { OpUse(op,use); return 0; } // Use existing handler
OpStart(op,sea); Cycles=4;
EaCalc ( 0,0x003f,sea,size,1);
EaRead ( 0, 0,sea,size,0x003f,1);
ot(" adds r0,r0,#0 ;@ Defines NZ, clears CV\n");
ot(" mrs r10,cpsr ;@ r10=flags\n");
ot("\n");
OpEnd(sea);
return 0;
}
// --------------------- Opcodes 0x4880+ ---------------------
// Emit an Ext opcode, 01001000 1x000nnn
int OpExt(int op)
{
int ea=0;
int size=0,use=0;
int shift=0;
ea=op&0x0007;
size=(op>>6)&1;
shift=32-(8<<size);
use=OpBase(op,size);
if (op!=use) { OpUse(op,use); return 0; } // Use existing handler
OpStart(op); Cycles=4;
EaCalc (11,0x0007,ea,size+1,0,0);
EaRead (11, 0,ea,size+1,0x0007,0,0);
ot(" mov r0,r0,asl #%d\n",shift);
ot(" adds r0,r0,#0 ;@ Defines NZ, clears CV\n");
ot(" mrs r10,cpsr ;@ r10=flags\n");
ot(" mov r1,r0,asr #%d\n",shift);
ot("\n");
EaWrite(11, 1,ea,size+1,0x0007,0,0);
OpEnd();
return 0;
}
// --------------------- Opcodes 0x50c0+ ---------------------
// Emit a Set cc opcode, 0101cccc 11eeeeee
int OpSet(int op)
{
int cc=0,ea=0;
int size=0,use=0,changed_cycles=0;
static const char * const cond[16]=
{
"al","", "hi","ls","cc","cs","ne","eq",
"vc","vs","pl","mi","ge","lt","gt","le"
};
cc=(op>>8)&15;
ea=op&0x003f;
if ((ea&0x38)==0x08) return 1; // dbra, not scc
// See if we can do this opcode:
if (EaCanWrite(ea)==0) return 1;
use=OpBase(op,size);
if (op!=use) { OpUse(op,use); return 0; } // Use existing handler
changed_cycles=ea<8 && cc>=2;
OpStart(op,ea,0,changed_cycles); Cycles=8;
if (ea<8) Cycles=4;
if (cc)
ot(" mov r1,#0\n");
switch (cc)
{
case 0: // T
ot(" mvn r1,#0\n");
if (ea<8) Cycles+=2;
break;
case 1: // F
break;
case 2: // hi
ot(" tst r10,#0x60000000 ;@ hi: !C && !Z\n");
ot(" mvneq r1,r1\n");
if (ea<8) ot(" subeq r5,r5,#2 ;@ Extra cycles\n");
break;
case 3: // ls
ot(" tst r10,#0x60000000 ;@ ls: C || Z\n");
ot(" mvnne r1,r1\n");
if (ea<8) ot(" subne r5,r5,#2 ;@ Extra cycles\n");
break;
default:
ot(";@ Is the condition true?\n");
ot(" msr cpsr_flg,r10 ;@ ARM flags = 68000 flags\n");
ot(" mvn%s r1,r1\n",cond[cc]);
if (ea<8) ot(" sub%s r5,r5,#2 ;@ Extra cycles\n",cond[cc]);
break;
}
ot("\n");
eawrite_check_addrerr=1;
EaCalc (0,0x003f, ea,size,0,0);
EaWrite(0, 1, ea,size,0x003f,0,0);
opend_op_changes_cycles=changed_cycles;
OpEnd(ea,0);
return 0;
}
// Emit a Asr/Lsr/Roxr/Ror opcode
static int EmitAsr(int op,int type,int dir,int count,int size,int usereg)
{
char pct[8]=""; // count
int shift=32-(8<<size);
if (count>=1) sprintf(pct,"#%d",count); // Fixed count
if (usereg)
{
ot(";@ Use Dn for count:\n");
ot(" and r2,r8,#0x0e00\n");
ot(" ldr r2,[r7,r2,lsr #7]\n");
ot(" and r2,r2,#63\n");
ot("\n");
strcpy(pct,"r2");
}
else if (count<0)
{
ot(" mov r2,r8,lsr #9 ;@ Get 'n'\n");
ot(" and r2,r2,#7\n\n"); strcpy(pct,"r2");
}
// Take 2*n cycles:
if (count<0) ot(" sub r5,r5,r2,asl #1 ;@ Take 2*n cycles\n\n");
else Cycles+=count<<1;
if (type<2)
{
// Asr/Lsr
if (dir==0 && size<2)
{
ot(";@ For shift right, use loworder bits for the operation:\n");
ot(" mov r0,r0,%s #%d\n",type?"lsr":"asr",32-(8<<size));
ot("\n");
}
if (type==0 && dir) ot(" adds r3,r0,#0 ;@ save old value for V flag calculation, also clear V\n");
ot(";@ Shift register:\n");
if (type==0) ot(" movs r0,r0,%s %s\n",dir?"asl":"asr",pct);
if (type==1) ot(" movs r0,r0,%s %s\n",dir?"lsl":"lsr",pct);
OpGetFlags(0,0);
if (usereg) { // store X only if count is not 0
ot(" cmp %s,#0 ;@ shifting by 0?\n",pct);
ot(" biceq r10,r10,#0x20000000 ;@ if so, clear carry\n");
ot(" strne r10,[r7,#0x4c] ;@ else Save X bit\n");
} else {
// count will never be 0 if we use immediate
ot(" str r10,[r7,#0x4c] ;@ Save X bit\n");
}
ot("\n");
if (dir==0 && size<2)
{
ot(";@ restore after right shift:\n");
ot(" movs r0,r0,lsl #%d\n",32-(8<<size));
if (type)
ot(" orrmi r10,r10,#0x80000000 ;@ Potentially missed N flag\n");
ot("\n");
}
if (type==0 && dir) {
ot(";@ calculate V flag (set if sign bit changes at anytime):\n");
ot(" mov r1,#0x80000000\n");
ot(" ands r3,r3,r1,asr %s\n", pct);
ot(" cmpne r3,r1,asr %s\n", pct);
ot(" eoreq r1,r0,r3\n"); // above check doesn't catch (-1)<<(32+), so we need this
ot(" tsteq r1,#0x80000000\n");
ot(" orrne r10,r10,#0x10000000\n");
ot("\n");
}
}
// --------------------------------------
if (type==2)
{
int wide=8<<size;
// Roxr
if(count == 1)
{
if(dir==0) {
if(size!=2) {
ot(" orr r0,r0,r0,lsr #%i\n", size?16:24);
ot(" bic r0,r0,#0x%x\n", 1<<(32-wide));
}
GetXBit(0);
ot(" movs r0,r0,rrx\n");
OpGetFlags(0,1);
} else {
ot(" ldr r3,[r7,#0x4c]\n");
ot(" movs r0,r0,lsl #1\n");
OpGetFlags(0,1);
ot(" tst r3,#0x20000000\n");
ot(" orrne r0,r0,#0x%x\n", 1<<(32-wide));
ot(" bicne r10,r10,#0x40000000 ;@ clear Z in case it got there\n");
}
ot(" bic r10,r10,#0x10000000 ;@ make suve V is clear\n");
return 0;
}
if (usereg)
{
if (size==2)
{
ot(" subs r2,r2,#33\n");
ot(" addmis r2,r2,#33 ;@ Now r2=0-%d\n",wide);
}
else
{
ot(";@ Reduce r2 until <0:\n");
ot("Reduce_%.4x%s\n",op,ms?"":":");
ot(" subs r2,r2,#%d\n",wide+1);
ot(" bpl Reduce_%.4x\n",op);
ot(" adds r2,r2,#%d ;@ Now r2=0-%d\n",wide+1,wide);
}
ot(" beq norotx_%.4x\n",op);
ot("\n");
}
if (usereg||count < 0)
{
if (dir) ot(" rsb r2,r2,#%d ;@ Reverse direction\n",wide+1);
}
else
{
if (dir) ot(" mov r2,#%d ;@ Reversed\n",wide+1-count);
else ot(" mov r2,#%d\n",count);
}
if (shift) ot(" mov r0,r0,lsr #%d ;@ Shift down\n",shift);
ot("\n");
ot(";@ First get X bit (middle):\n");
ot(" ldr r3,[r7,#0x4c]\n");
ot(" rsb r1,r2,#%d\n",wide);
ot(" and r3,r3,#0x20000000\n");
ot(" mov r3,r3,lsr #29\n");
ot(" mov r3,r3,lsl r1\n");
ot(";@ Rotate bits:\n");
ot(" orr r3,r3,r0,lsr r2 ;@ Orr right part\n");
ot(" rsbs r2,r2,#%d ;@ should also clear ARM V\n",wide+1);
ot(" orrs r0,r3,r0,lsl r2 ;@ Orr left part, set flags\n");
ot("\n");
if (shift) ot(" movs r0,r0,lsl #%d ;@ Shift up and get correct NC flags\n",shift);
OpGetFlags(0,!usereg);
if (usereg) { // store X only if count is not 0
ot(" str r10,[r7,#0x4c] ;@ if not 0, Save X bit\n");
ot(" b nozerox%.4x\n",op);
ot("norotx_%.4x%s\n",op,ms?"":":");
ot(" ldr r2,[r7,#0x4c]\n");
ot(" adds r0,r0,#0 ;@ Defines NZ, clears CV\n");
OpGetFlags(0,0);
ot(" and r2,r2,#0x20000000\n");
ot(" orr r10,r10,r2 ;@ C = old_X\n");
ot("nozerox%.4x%s\n",op,ms?"":":");
}
ot("\n");
}
// --------------------------------------
if (type==3)
{
// Ror
if (size<2)
{
ot(";@ Mirror value in whole 32 bits:\n");
if (size<=0) ot(" orr r0,r0,r0,lsr #8\n");
if (size<=1) ot(" orr r0,r0,r0,lsr #16\n");
ot("\n");
}
ot(";@ Rotate register:\n");
if (!dir) ot(" adds r0,r0,#0 ;@ first clear V and C\n"); // ARM does not clear C if rot count is 0
if (count<0)
{
if (dir) ot(" rsb %s,%s,#32\n",pct,pct);
ot(" movs r0,r0,ror %s\n",pct);
}
else
{
int ror=count;
if (dir) ror=32-ror;
if (ror&31) ot(" movs r0,r0,ror #%d\n",ror);
}
OpGetFlags(0,0);
if (dir)
{
ot(" bic r10,r10,#0x30000000 ;@ clear CV\n");
ot(";@ Get carry bit from bit 0:\n");
if (usereg)
{
ot(" cmp %s,#32 ;@ rotating by 0?\n",pct);
ot(" tstne r0,#1 ;@ no, check bit 0\n");
}
else
ot(" tst r0,#1\n");
ot(" orrne r10,r10,#0x20000000\n");
}
ot("\n");
}
// --------------------------------------
return 0;
}
// Emit a Asr/Lsr/Roxr/Ror opcode - 1110cccd xxuttnnn
// (ccc=count, d=direction(r,l) xx=size extension, u=use reg for count, tt=type, nnn=register Dn)
int OpAsr(int op)
{
int ea=0,use=0;
int count=0,dir=0;
int size=0,usereg=0,type=0;
count =(op>>9)&7;
dir =(op>>8)&1;
size =(op>>6)&3;
if (size>=3) return 1; // use OpAsrEa()
usereg=(op>>5)&1;
type =(op>>3)&3;
if (usereg==0) count=((count-1)&7)+1; // because ccc=000 means 8
// Use the same opcode for target registers:
use=op&~0x0007;
// As long as count is not 8, use the same opcode for all shift counts:
if (usereg==0 && count!=8 && !(count==1&&type==2)) { use|=0x0e00; count=-1; }
if (usereg) { use&=~0x0e00; count=-1; } // Use same opcode for all Dn
if (op!=use) { OpUse(op,use); return 0; } // Use existing handler
OpStart(op,ea,0,count<0); Cycles=size<2?6:8;
EaCalc(11,0x0007, ea,size,1);
EaRead(11, 0, ea,size,0x0007,1);
EmitAsr(op,type,dir,count, size,usereg);
EaWrite(11, 0, ea,size,0x0007,1);
opend_op_changes_cycles = (count<0);
OpEnd(ea,0);
return 0;
}
// Asr/Lsr/Roxr/Ror etc EA - 11100ttd 11eeeeee
int OpAsrEa(int op)
{
int use=0,type=0,dir=0,ea=0,size=1;
type=(op>>9)&3;
dir =(op>>8)&1;
ea = op&0x3f;
if (ea<0x10) return 1;
// See if we can do this opcode:
if (EaCanRead(ea,0)==0) return 1;
if (EaCanWrite(ea)==0) return 1;
use=OpBase(op,size);
if (op!=use) { OpUse(op,use); return 0; } // Use existing handler
OpStart(op,ea); Cycles=6; // EmitAsr() will add 2
EaCalc (11,0x003f,ea,size,1);
EaRead (11, 0,ea,size,0x003f,1);
EmitAsr(op,type,dir,1,size,0);
EaWrite(11, 0,ea,size,0x003f,1);
OpEnd(ea);
return 0;
}
int OpTas(int op, int gen_special)
{
int ea=0;
int use=0;
ea=op&0x003f;
// See if we can do this opcode:
if (EaCanWrite(ea)==0 || EaAn(ea)) return 1;
use=OpBase(op,0);
if (op!=use) { OpUse(op,use); return 0; } // Use existing handler
if (!gen_special) OpStart(op,ea);
else
ot("Op%.4x_%s\n", op, ms?"":":");
Cycles=4;
if(ea>=8) Cycles+=10;
EaCalc (11,0x003f,ea,0,1);
EaRead (11, 1,ea,0,0x003f,1);
ot(" adds r1,r1,#0 ;@ Defines NZ, clears CV\n");
OpGetFlags(0,0);
ot("\n");
#if CYCLONE_FOR_GENESIS
// the original Sega hardware ignores write-back phase (to memory only)
if (ea < 0x10 || gen_special) {
#endif
ot(" orr r1,r1,#0x80000000 ;@ set bit7\n");
EaWrite(11, 1,ea,0,0x003f,1);
#if CYCLONE_FOR_GENESIS
}
#endif
OpEnd(ea);
#if (CYCLONE_FOR_GENESIS == 2)
if (!gen_special && ea >= 0x10) {
OpTas(op, 1);
}
#endif
return 0;
}