license info at top of Cyclone source files

[cyclone68000.git] / Cyclone / OpArith.cpp

\r
// This file is part of the Cyclone 68000 Emulator\r
\r
// This code is licensed under the GNU General Public License version 2.0 and the MAME License.\r
// You can choose the license that has the most advantages for you.\r
\r
// SVN repository can be found at http://code.google.com/p/cyclone68000/\r
\r
#include "app.h"\r
\r
// --------------------- Opcodes 0x0000+ ---------------------\r
// Emit an Ori/And/Sub/Add/Eor/Cmp Immediate opcode, 0000ttt0 00aaaaaa\r
int OpArith(int op)\r
{\r
  int type=0,size=0;\r
  int sea=0,tea=0;\r
  int use=0;\r
\r
  // Get source and target EA\r
  type=(op>>9)&7; if (type==4 || type>=7) return 1;\r
  size=(op>>6)&3; if (size>=3) return 1;\r
  sea=   0x003c;\r
  tea=op&0x003f;\r
\r
  // See if we can do this opcode:\r
  if (EaCanRead(tea,size)==0) return 1;\r
  if (type!=6 && EaCanWrite(tea)==0) return 1;\r
\r
  use=OpBase(op);\r
  if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r
\r
  OpStart(op); Cycles=4;\r
\r
  EaCalc(10,0x0000, sea,size);\r
  EaRead(10,    10, sea,size,1);\r
\r
  EaCalc(11,0x003f, tea,size);\r
  EaRead(11,     0, tea,size,1);\r
\r
  ot(";@ Do arithmetic:\n");\r
\r
  if (type==0) ot("  orr r1,r0,r10\n");\r
  if (type==1) ot("  and r1,r0,r10\n");\r
  if (type==2) ot("  subs r1,r0,r10 ;@ Defines NZCV\n");\r
  if (type==3) ot("  adds r1,r0,r10 ;@ Defines NZCV\n");\r
  if (type==5) ot("  eor r1,r0,r10\n");\r
  if (type==6) ot("  cmp r0,r10 ;@ Defines NZCV\n");\r
\r
  if (type<2 || type==5) ot("  adds r1,r1,#0 ;@ Defines NZ, clears CV\n"); // 0,1,5\r
\r
  if (type< 2) OpGetFlags(0,0); // Ori/And\r
  if (type==2) OpGetFlags(1,1); // Sub: Subtract/X-bit\r
  if (type==3) OpGetFlags(0,1); // Add: X-bit\r
  if (type==5) OpGetFlags(0,0); // Eor\r
  if (type==6) OpGetFlags(1,0); // Cmp: Subtract\r
  ot("\n");\r
\r
  if (type!=6)\r
  {\r
    EaWrite(11, 1, tea,size,1);\r
  }\r
\r
  // Correct cycles:\r
  if (type==6)\r
  {\r
    if (size>=2 && tea<0x10) Cycles+=2;\r
  }\r
  else\r
  {\r
    if (size>=2) Cycles+=4;\r
    if (tea>=0x10) Cycles+=4;\r
    if (Amatch && type==1 && size>=2 && tea<0x10) Cycles-=2;\r
  }\r
\r
  OpEnd();\r
\r
  return 0;\r
}\r
\r
// --------------------- Opcodes 0x5000+ ---------------------\r
int OpAddq(int op)\r
{\r
  // 0101nnnt xxeeeeee (nnn=#8,1-7 t=addq/subq xx=size, eeeeee=EA)\r
  int num=0,type=0,size=0,ea=0;\r
  int use=0;\r
  char count[16]="";\r
  int shift=0;\r
\r
  num =(op>>9)&7; if (num==0) num=8;\r
  type=(op>>8)&1;\r
  size=(op>>6)&3; if (size>=3) return 1;\r
  ea  = op&0x3f;\r
\r
  // See if we can do this opcode:\r
  if (EaCanRead (ea,size)==0) return 1;\r
  if (EaCanWrite(ea     )==0) return 1;\r
\r
  use=op; if (ea<0x38) use&=~7;\r
  if ((ea&0x38)==0x08) { size=2; use&=~0xc0; } // Every addq #n,An is 32-bit\r
\r
  if (num!=8) use|=0x0e00; // If num is not 8, use same handler\r
  if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r
\r
  OpStart(op);\r
  Cycles=ea<8?4:8;\r
  if (size>=2 && ea!=8) Cycles+=4;\r
\r
  EaCalc(10,0x003f, ea,size);\r
  EaRead(10,     0, ea,size,1);\r
\r
  shift=32-(8<<size);\r
\r
  if (num!=8)\r
  {\r
    int lsr=9-shift;\r
\r
    if (lsr>=0) ot("  mov r2,r8,lsr #%d ;@ Get quick value\n", lsr);\r
    else        ot("  mov r2,r8,lsl #%d ;@ Get quick value\n",-lsr);\r
\r
    ot("  and r2,r2,#0x%.4x\n",7<<shift);\r
    ot("\n");\r
    strcpy(count,"r2");\r
  }\r
\r
  if (num==8) sprintf(count,"#0x%.4x",8<<shift);\r
\r
  if (type==0) ot("  adds r1,r0,%s\n",count);\r
  if (type==1) ot("  subs r1,r0,%s\n",count);\r
\r
  if ((ea&0x38)!=0x08) OpGetFlags(type,1);\r
  ot("\n");\r
\r
  EaWrite(10,     1, ea,size,1);\r
\r
  OpEnd();\r
\r
  return 0;\r
}\r
\r
// --------------------- Opcodes 0x8000+ ---------------------\r
// 1t0tnnnd xxeeeeee (tt=type:or/sub/and/add xx=size, eeeeee=EA)\r
int OpArithReg(int op)\r
{\r
  int use=0;\r
  int type=0,size=0,dir=0,rea=0,ea=0;\r
\r
  type=(op>>12)&5;\r
  rea =(op>> 9)&7;\r
  dir =(op>> 8)&1;\r
  size=(op>> 6)&3; if (size>=3) return 1;\r
  ea  = op&0x3f;\r
\r
  if (dir && ea<0x10) return 1; // addx/subx opcode\r
\r
  // See if we can do this opcode:\r
  if (dir==0 && EaCanWrite(rea)==0) return 1;\r
  if (dir    && EaCanWrite( ea)==0) return 1;\r
\r
  use=OpBase(op);\r
  use&=~0x0e00; // Use same opcode for Dn\r
  if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r
\r
  OpStart(op); Cycles=4;\r
\r
  ot(";@ Get r10=EA r11=EA value\n");\r
  EaCalc(10,0x003f, ea,size);\r
  EaRead(10,    11, ea,size,1);\r
  ot(";@ Get r0=Register r1=Register value\n");\r
  EaCalc( 0,0x0e00,rea,size);\r
  EaRead( 0,     1,rea,size,1);\r
\r
  ot(";@ Do arithmetic:\n");\r
  if (type==0) ot("  orr  ");\r
  if (type==1) ot("  subs ");\r
  if (type==4) ot("  and  ");\r
  if (type==5) ot("  adds ");\r
  if (dir) ot("r1,r11,r1\n");\r
  else     ot("r1,r1,r11\n");\r
\r
  if ((type&1)==0) ot("  adds r1,r1,#0 ;@ Defines NZ, clears CV\n");\r
\r
  OpGetFlags(type==1,type&1); // 1==subtract\r
  ot("\n");\r
\r
  ot(";@ Save result:\n");\r
  if (dir) EaWrite(10, 1, ea,size,1);\r
  else     EaWrite( 0, 1,rea,size,1);\r
\r
  if (size==1 && ea>=0x10) Cycles+=4;\r
  if (size>=2) { if (ea<0x10) Cycles+=4; else Cycles+=2; }\r
\r
  OpEnd();\r
\r
  return 0;\r
}\r
\r
// --------------------- Opcodes 0x80c0+ ---------------------\r
int OpMul(int op)\r
{\r
  // Div/Mul: 1m00nnns 11eeeeee (m=Mul, nnn=Register Dn, s=signed, eeeeee=EA)\r
  int type=0,rea=0,sign=0,ea=0;\r
  int use=0;\r
\r
  type=(op>>14)&1; // div/mul\r
  rea =(op>> 9)&7;\r
  sign=(op>> 8)&1;\r
  ea  = op&0x3f;\r
\r
  // See if we can do this opcode:\r
  if (EaCanRead(ea,1)==0) return 1;\r
\r
  use=OpBase(op);\r
  use&=~0x0e00; // Use same for all registers\r
  if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r
\r
  OpStart(op); Cycles=type?70:133;\r
\r
  EaCalc(10,0x003f, ea, 1);\r
  EaRead(10,    10, ea, 1);\r
\r
  EaCalc (0,0x0e00,rea, 2);\r
  EaRead (0,     2,rea, 2);\r
\r
  if (type==0)\r
  {\r
    ot("  cmp r10,#0\n");\r
    ot("  moveq r10,#1 ;@ Divide by zero\n");\r
    ot("\n");\r
    \r
    if (sign)\r
    {\r
      ot("  mov r11,#0 ;@ r11 = 1 if the result is negative\n");\r
      ot("  eorlt r11,r11,#1\n");\r
      ot("  rsblt r10,r10,#0 ;@ Make r10 positive\n");\r
      ot("\n");\r
      ot("  cmp r2,#0\n");\r
      ot("  eorlt r11,r11,#1\n");\r
      ot("  rsblt r2,r2,#0 ;@ Make r2 positive\n");\r
      ot("\n");\r
    }\r
\r
    ot(";@ Divide r2 by r10\n");\r
    ot("  mov r3,#0\n");\r
    ot("  mov r1,r10\n");\r
    ot("\n");\r
    ot(";@ Shift up divisor till it's just less than numerator\n");\r
    ot("Shift%.4x%s\n",op,ms?"":":");\r
    ot("  cmp r1,r2,lsr #1\n");\r
    ot("  movls r1,r1,lsl #1\n");\r
    ot("  bcc Shift%.4x\n",op);\r
    ot("\n");\r
\r
    ot("Divide%.4x%s\n",op,ms?"":":");\r
    ot("  cmp r2,r1\n");\r
    ot("  adc r3,r3,r3 ;@ Double r3 and add 1 if carry set\n");\r
    ot("  subcs r2,r2,r1\n");\r
    ot("  teq r1,r10\n");\r
    ot("  movne r1,r1,lsr #1\n");\r
    ot("  bne Divide%.4x\n",op);\r
    ot("\n");\r
\r
    if (sign)\r
    {\r
      ot("  tst r11,r11\n");\r
      ot("  rsbne r3,r3,#0 ;@ Negate if result is negative\n");\r
    }\r
\r
    ot("  mov r11,r2 ;@ Remainder\n");\r
\r
    ot("  adds r1,r3,#0 ;@ Defines NZ, clears CV\n");\r
    OpGetFlags(0,0);\r
\r
    ot("  mov r1,r1,lsl #16 ;@ Clip to 16-bits\n");\r
    ot("  mov r1,r1,lsr #16\n");\r
    ot("  orr r1,r1,r11,lsl #16 ;@ Insert remainder\n");\r
  }\r
\r
  if (type==1)\r
  {\r
    char *shift="asr";\r
\r
    ot(";@ Get 16-bit signs right:\n");\r
    if (sign==0) { ot("  mov r10,r10,lsl #16\n"); shift="lsr"; }\r
    ot("  mov r2,r2,lsl #16\n");\r
\r
    if (sign==0) ot("  mov r10,r10,lsr #16\n");\r
    ot("  mov r2,r2,%s #16\n",shift);\r
    ot("\n");\r
\r
    ot("  mul r1,r2,r10\n");\r
    ot("  adds r1,r1,#0 ;@ Defines NZ, clears CV\n");\r
    OpGetFlags(0,0);\r
\r
    if (Amatch && ea==0x3c) Cycles-=4;\r
  }\r
  ot("\n");\r
\r
  EaWrite(0,     1,rea, 2);\r
\r
\r
  OpEnd();\r
\r
  return 0;\r
}\r
\r
// Get X Bit into carry - trashes r2\r
static int GetXBit(int subtract)\r
{\r
  ot(";@ Get X bit:\n");\r
  ot("  ldrb r2,[r7,#0x45]\n");\r
  if (subtract) ot("  mvn r2,r2,lsl #28 ;@ Invert it\n");\r
  else          ot("  mov r2,r2,lsl #28\n");\r
  ot("  msr cpsr_flg,r2 ;@ Get into Carry\n");\r
  ot("\n");\r
  return 0;\r
}\r
\r
// --------------------- Opcodes 0x8100+ ---------------------\r
// 1t00ddd1 0000asss - sbcd/abcd Ds,Dd or -(As),-(Ad)\r
int OpAbcd(int op)\r
{\r
  int use=0;\r
  int type=0,sea=0,addr=0,dea=0;\r
  \r
  type=(op>>14)&1;\r
  dea =(op>> 9)&7;\r
  addr=(op>> 3)&1;\r
  sea = op     &7;\r
\r
  if (addr) { sea|=0x20; dea|=0x20; }\r
\r
  use=op&~0x0e07; // Use same opcode for all registers\r
  if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r
\r
  OpStart(op); Cycles=6;\r
\r
  EaCalc( 0,0x0007, sea,0);\r
  EaRead( 0,    10, sea,0,1);\r
  EaCalc(11,0x0e00, dea,0);\r
  EaRead(11,     1, dea,0,1);\r
\r
  ot("  ldrb r2,[r7,#0x45] ;@ Get X bit\n");\r
  ot("  tst r2,#2\n");\r
  ot("  addne r10,r10,#0x01000000 ;@ Add carry bit\n");\r
\r
  if (type)\r
  {\r
    ot(";@ Add units into r2:\n");\r
    ot("  and r2,r1, #0x0f000000\n");\r
    ot("  and r0,r10,#0x0f000000\n");\r
    ot("  add r2,r2,r0\n");\r
    ot("  cmp r2,#0x0a000000\n");\r
    ot("  addpl r1,r1,#0x06000000 ;@ Decimal adjust units\n");\r
    ot("  add r1,r1,r10 ;@ Add BCD\n");\r
    ot("  mov r0,r1,lsr #24\n");\r
    ot("  cmp r0,#0xa0\n");\r
    ot("  addpl r1,r1,#0x60000000 ;@ Decimal adjust tens\n");\r
    OpGetFlags(0,1);\r
  }\r
  else\r
  {\r
    ot(";@ Sub units into r2:\n");\r
    ot("  and r2,r1, #0x0f000000\n");\r
    ot("  and r0,r10,#0x0f000000\n");\r
    ot("  subs r2,r2,r0\n");\r
    ot("  submi r1,r1,#0x06000000 ;@ Decimal adjust units\n");\r
    ot("  subs r1,r1,r10 ;@ Subtract BCD\n");\r
    ot("  submis r1,r1,#0x60000000 ;@ Decimal adjust tens\n");\r
    OpGetFlags(1,1);\r
  }\r
  ot("\n");\r
\r
  EaWrite(11,     1, dea,0,1);\r
\r
  OpEnd();\r
\r
  return 0;\r
}\r
\r
// --------------------- Opcodes 0x90c0+ ---------------------\r
// Suba/Cmpa/Adda 1tt1nnnx 11eeeeee (tt=type, x=size, eeeeee=Source EA)\r
int OpAritha(int op)\r
{\r
  int use=0;\r
  int type=0,size=0,sea=0,dea=0;\r
\r
  // Suba/Cmpa/Adda/(invalid):\r
  type=(op>>13)&3; if (type>=3) return 1;\r
\r
  size=(op>>8)&1; size++;\r
  dea=(op>>9)&7; dea|=8; // Dest=An\r
  sea=op&0x003f; // Source\r
\r
  // See if we can do this opcode:\r
  if (EaCanRead(sea,size)==0) return 1;\r
\r
  use=OpBase(op);\r
  use&=~0x0e00; // Use same opcode for An\r
  if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r
\r
  OpStart(op); Cycles=4;\r
  EaCalc ( 0,0x003f, sea,size);\r
  EaRead ( 0,    10, sea,size);\r
\r
  EaCalc ( 0,0x0e00, dea,2);\r
  EaRead ( 0,     1, dea,2);\r
\r
  if (type==0) ot("  sub r1,r1,r10\n");\r
  if (type==1) ot("  cmp r1,r10 ;@ Defines NZCV\n");\r
  if (type==1) OpGetFlags(1,0); // Get Cmp flags\r
  if (type==2) ot("  add r1,r1,r10\n");\r
  ot("\n");\r
  \r
  EaWrite( 0,     1, dea,2);\r
\r
  if (Amatch && sea==0x3c) Cycles-=size<2?4:8; // Correct?\r
  if (size>=2) { if (sea<0x10) Cycles+=4; else Cycles+=2; }\r
\r
  OpEnd();\r
\r
  return 0;\r
}\r
\r
// --------------------- Opcodes 0x9100+ ---------------------\r
// Emit a Subx/Addx opcode, 1t01ddd1 zz000sss addx.z Ds,Dd\r
int OpAddx(int op)\r
{\r
  int use=0;\r
  int type=0,size=0,dea=0,sea=0;\r
\r
  type=(op>>12)&5;\r
  dea =(op>> 9)&7;\r
  size=(op>> 6)&3; if (size>=3) return 1;\r
  sea = op&0x3f;\r
\r
  // See if we can do this opcode:\r
  if (EaCanRead(sea,size)==0) return 1;\r
  if (EaCanWrite(dea)==0) return 1;\r
\r
  use=OpBase(op);\r
  use&=~0x0e00; // Use same opcode for Dn\r
  if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r
\r
  OpStart(op); Cycles=8;\r
\r
  ot(";@ Get r10=EA r11=EA value\n");\r
  EaCalc( 0,0x003f,sea,size);\r
  EaRead( 0,    11,sea,size,1);\r
  ot(";@ Get r0=Register r1=Register value\n");\r
  EaCalc( 0,0x0e00,dea,size);\r
  EaRead( 0,     1,dea,size,1);\r
\r
  ot(";@ Do arithmetic:\n");\r
  GetXBit(type==1);\r
\r
  if (type==5 && size<2)\r
  {\r
    ot(";@ Make sure the carry bit will tip the balance:\n");\r
    if (size==0) ot("  ldr r2,=0x00ffffff\n");\r
    else         ot("  ldr r2,=0x0000ffff\n");\r
    ot("  orr r11,r11,r2\n");\r
    ot("\n");\r
  }\r
\r
  if (type==1) ot("  sbcs r1,r1,r11\n");\r
  if (type==5) ot("  adcs r1,r1,r11\n");\r
  OpGetFlags(type==1,1); // subtract\r
  ot("\n");\r
\r
  ot(";@ Save result:\n");\r
  EaWrite( 0, 1, dea,size,1);\r
\r
  OpEnd();\r
\r
  return 0;\r
}\r
\r
// --------------------- Opcodes 0xb000+ ---------------------\r
// Emit a Cmp/Eor opcode, 1011rrrt xxeeeeee (rrr=Dn, t=cmp/eor, xx=size extension, eeeeee=ea)\r
int OpCmpEor(int op)\r
{\r
  int rea=0,eor=0;\r
  int size=0,ea=0,use=0;\r
\r
  // Get EA and register EA\r
  rea=(op>>9)&7;\r
  eor=(op>>8)&1;\r
  size=(op>>6)&3; if (size>=3) return 1;\r
  ea=op&0x3f;\r
\r
  // See if we can do this opcode:\r
  if (EaCanRead(ea,size)==0) return 1;\r
  if (eor && EaCanWrite(ea)==0) return 1;\r
\r
  use=OpBase(op);\r
  use&=~0x0e00; // Use 1 handler for register d0-7\r
  if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r
\r
  OpStart(op); Cycles=eor?8:4;\r
\r
  ot(";@ Get EA into r10 and value into r0:\n");\r
  EaCalc (10,0x003f,  ea,size);\r
  EaRead (10,     0,  ea,size,1);\r
\r
  ot(";@ Get register operand into r1:\n");\r
  EaCalc (1 ,0x0e00, rea,size);\r
  EaRead (1,      1, rea,size,1);\r
\r
  ot(";@ Do arithmetic:\n");\r
  if (eor==0) ot("  cmp r1,r0\n");\r
  if (eor)\r
  {\r
    ot("  eor r1,r0,r1\n");\r
    ot("  adds r1,r1,#0 ;@ Defines NZ, clears CV\n");\r
  }\r
\r
  OpGetFlags(eor==0,0); // Cmp like subtract\r
  ot("\n");\r
\r
  if (size>=2) Cycles+=4; // Correct?\r
  if (ea==0x3c) Cycles-=4;\r
\r
  if (eor) EaWrite(10, 1,ea,size,1);\r
\r
  OpEnd();\r
  return 0;\r
}\r
\r