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[/] [eco32/] [trunk/] [sim/] [cpu.c] - Blame information for rev 25

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/*
 * cpu.c -- CPU simulation
 */
 
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <setjmp.h>
 
#include "common.h"
#include "console.h"
#include "error.h"
#include "except.h"
#include "instr.h"
#include "cpu.h"
#include "mmu.h"
#include "timer.h"
 
 
/**************************************************************/
 
 
#define RR(n)           r[n]
#define WR(n,d)         ((void) ((n) != 0 ? r[n] = (d) : (d)))
 
#define V               (psw & PSW_V)
#define UM              (psw & PSW_UM)
#define PUM             (psw & PSW_PUM)
#define OUM             (psw & PSW_OUM)
#define IE              (psw & PSW_IE)
#define PIE             (psw & PSW_PIE)
#define OIE             (psw & PSW_OIE)
 
 
/**************************************************************/
 
 
static Bool debugIRQ = false;   /* set to true if debugging IRQs */
 
static Word pc;                 /* program counter */
static Word psw;                /* processor status word */
static Word r[32];              /* general purpose registers */
 
static unsigned irqPending;     /* one bit for each pending IRQ */
 
static Bool breakSet;           /* breakpoint set if true */
static Word breakAddr;          /* if breakSet, this is where */
 
static Word total;              /* counts total number of instrs */
 
static Bool run;                /* CPU runs continuously if true */
 
static Word startAddr;          /* start of ROM (or start of RAM, */
                                /* in case a program was loaded) */
 
 
/**************************************************************/
 
 
static void handleInterrupts(void) {
  unsigned irqMask;
  unsigned irqSeen;
  int priority;
 
  /* handle exceptions and interrupts */
  if (irqPending == 0) {
    /* no exception or interrupt pending */
    return;
  }
  /* at least one exception or interrupt is pending */
  irqMask = ~PSW_IRQ_MASK | (psw & PSW_IRQ_MASK);
  if (debugIRQ) {
    cPrintf("**** IRQ  = 0x%08X ****\n", irqPending);
    cPrintf("**** MASK = 0x%08X ****\n", irqMask);
  }
  irqSeen = irqPending & irqMask;
  if (irqSeen == 0) {
    /* none that gets through */
    return;
  }
  /* determine the one with the highest priority */
  for (priority = 31; priority >= 0; priority--) {
    if ((irqSeen & ((unsigned) 1 << priority)) != 0) {
      /* highest priority among visible ones found */
      break;
    }
  }
  /* acknowledge exception, or interrupt if enabled */
  if (priority >= 16 || IE != 0) {
    if (priority >= 16) {
      /* clear corresponding bit in irqPending vector */
      /* only done for exceptions, since interrupts are level-sensitive */
      irqPending &= ~((unsigned) 1 << priority);
    }
    /* copy and reset interrupt enable bit in PSW */
    if (PIE != 0) {
      psw |= PSW_OIE;
    } else {
      psw &= ~PSW_OIE;
    }
    if (IE != 0) {
      psw |= PSW_PIE;
    } else {
      psw &= ~PSW_PIE;
    }
    psw &= ~PSW_IE;
    /* copy and reset user mode enable bit in PSW */
    if (PUM != 0) {
      psw |= PSW_OUM;
    } else {
      psw &= ~PSW_OUM;
    }
    if (UM != 0) {
      psw |= PSW_PUM;
    } else {
      psw &= ~PSW_PUM;
    }
    psw &= ~PSW_UM;
    /* reflect priority in PSW */
    psw &= ~PSW_PRIO_MASK;
    psw |= priority << PSW_PRIO_SHFT;
    /* save interrupt return address and start service routine */
    WR(30, pc);
    if (V == 0) {
      /* exceptions and interrupts are vectored to ROM */
      pc = 0xC0000000 | ROM_BASE;
    } else {
      /* exceptions and interrupts are vectored to RAM */
      pc = 0xC0000000;
    }
    if (priority == EXC_TLB_MISS &&
        (mmuGetBadAddr() & 0x80000000) == 0) {
      /* user TLB miss exception */
      pc |= 0x00000008;
    } else {
      /* any other exception or interrupt */
      pc |= 0x00000004;
    }
  }
}
 
 
static void execNextInstruction(void) {
  Word instr;
  Word next;
  int op, reg1, reg2, reg3;
  Half immed;
  Word offset;
  int scnt;
  Word smsk;
  Word aux;
 
  /* count the instruction */
  total++;
  /* fetch the instruction */
  instr = mmuReadWord(pc, UM);
  /* decode the instruction */
  op = (instr >> 26) & 0x3F;
  reg1 = (instr >> 21) & 0x1F;
  reg2 = (instr >> 16) & 0x1F;
  reg3 = (instr >> 11) & 0x1F;
  immed = instr & 0x0000FFFF;
  offset = instr & 0x03FFFFFF;
  next = pc + 4;
  /* execute the instruction */
  switch (op) {
    case OP_ADD:
      WR(reg3, (signed int) RR(reg1) + (signed int) RR(reg2));
      break;
    case OP_ADDI:
      WR(reg2, (signed int) RR(reg1) + (signed int) SEXT16(immed));
      break;
    case OP_SUB:
      WR(reg3, (signed int) RR(reg1) - (signed int) RR(reg2));
      break;
    case OP_SUBI:
      WR(reg2, (signed int) RR(reg1) - (signed int) SEXT16(immed));
      break;
    case OP_MUL:
      WR(reg3, (signed int) RR(reg1) * (signed int) RR(reg2));
      break;
    case OP_MULI:
      WR(reg2, (signed int) RR(reg1) * (signed int) SEXT16(immed));
      break;
    case OP_MULU:
      WR(reg3, RR(reg1) * RR(reg2));
      break;
    case OP_MULUI:
      WR(reg2, RR(reg1) * ZEXT16(immed));
      break;
    case OP_DIV:
      if (RR(reg2) == 0) {
        throwException(EXC_DIVIDE);
      }
      WR(reg3, (signed int) RR(reg1) / (signed int) RR(reg2));
      break;
    case OP_DIVI:
      if (SEXT16(immed) == 0) {
        throwException(EXC_DIVIDE);
      }
      WR(reg2, (signed int) RR(reg1) / (signed int) SEXT16(immed));
      break;
    case OP_DIVU:
      if (RR(reg2) == 0) {
        throwException(EXC_DIVIDE);
      }
      WR(reg3, RR(reg1) / RR(reg2));
      break;
    case OP_DIVUI:
      if (SEXT16(immed) == 0) {
        throwException(EXC_DIVIDE);
      }
      WR(reg2, RR(reg1) / ZEXT16(immed));
      break;
    case OP_REM:
      if (RR(reg2) == 0) {
        throwException(EXC_DIVIDE);
      }
      WR(reg3, (signed int) RR(reg1) % (signed int) RR(reg2));
      break;
    case OP_REMI:
      if (SEXT16(immed) == 0) {
        throwException(EXC_DIVIDE);
      }
      WR(reg2, (signed int) RR(reg1) % (signed int) SEXT16(immed));
      break;
    case OP_REMU:
      if (RR(reg2) == 0) {
        throwException(EXC_DIVIDE);
      }
      WR(reg3, RR(reg1) % RR(reg2));
      break;
    case OP_REMUI:
      if (SEXT16(immed) == 0) {
        throwException(EXC_DIVIDE);
      }
      WR(reg2, RR(reg1) % ZEXT16(immed));
      break;
    case OP_AND:
      WR(reg3, RR(reg1) & RR(reg2));
      break;
    case OP_ANDI:
      WR(reg2, RR(reg1) & ZEXT16(immed));
      break;
    case OP_OR:
      WR(reg3, RR(reg1) | RR(reg2));
      break;
    case OP_ORI:
      WR(reg2, RR(reg1) | ZEXT16(immed));
      break;
    case OP_XOR:
      WR(reg3, RR(reg1) ^ RR(reg2));
      break;
    case OP_XORI:
      WR(reg2, RR(reg1) ^ ZEXT16(immed));
      break;
    case OP_XNOR:
      WR(reg3, ~(RR(reg1) ^ RR(reg2)));
      break;
    case OP_XNORI:
      WR(reg2, ~(RR(reg1) ^ ZEXT16(immed)));
      break;
    case OP_SLL:
      scnt = RR(reg2) & 0x1F;
      WR(reg3, RR(reg1) << scnt);
      break;
    case OP_SLLI:
      scnt = immed & 0x1F;
      WR(reg2, RR(reg1) << scnt);
      break;
    case OP_SLR:
      scnt = RR(reg2) & 0x1F;
      WR(reg3, RR(reg1) >> scnt);
      break;
    case OP_SLRI:
      scnt = immed & 0x1F;
      WR(reg2, RR(reg1) >> scnt);
      break;
    case OP_SAR:
      scnt = RR(reg2) & 0x1F;
      smsk = (RR(reg1) & 0x80000000 ? ~(((Word) 0xFFFFFFFF) >> scnt) : 0);
      WR(reg3, smsk | (RR(reg1) >> scnt));
      break;
    case OP_SARI:
      scnt = immed & 0x1F;
      smsk = (RR(reg1) & 0x80000000 ? ~(((Word) 0xFFFFFFFF) >> scnt) : 0);
      WR(reg2, smsk | (RR(reg1) >> scnt));
      break;
    case OP_LDHI:
      WR(reg2, ZEXT16(immed) << 16);
      break;
    case OP_BEQ:
      if (RR(reg1) == RR(reg2)) {
        next += SEXT16(immed) << 2;
      }
      break;
    case OP_BNE:
      if (RR(reg1) != RR(reg2)) {
        next += SEXT16(immed) << 2;
      }
      break;
    case OP_BLE:
      if ((signed int) RR(reg1) <= (signed int) RR(reg2)) {
        next += SEXT16(immed) << 2;
      }
      break;
    case OP_BLEU:
      if (RR(reg1) <= RR(reg2)) {
        next += SEXT16(immed) << 2;
      }
      break;
    case OP_BLT:
      if ((signed int) RR(reg1) < (signed int) RR(reg2)) {
        next += SEXT16(immed) << 2;
      }
      break;
    case OP_BLTU:
      if (RR(reg1) < RR(reg2)) {
        next += SEXT16(immed) << 2;
      }
      break;
    case OP_BGE:
      if ((signed int) RR(reg1) >= (signed int) RR(reg2)) {
        next += SEXT16(immed) << 2;
      }
      break;
    case OP_BGEU:
      if (RR(reg1) >= RR(reg2)) {
        next += SEXT16(immed) << 2;
      }
      break;
    case OP_BGT:
      if ((signed int) RR(reg1) > (signed int) RR(reg2)) {
        next += SEXT16(immed) << 2;
      }
      break;
    case OP_BGTU:
      if (RR(reg1) > RR(reg2)) {
        next += SEXT16(immed) << 2;
      }
      break;
    case OP_J:
      next += SEXT26(offset) << 2;
      break;
    case OP_JR:
      next = RR(reg1);
      break;
    case OP_JAL:
      WR(31, next);
      next += SEXT26(offset) << 2;
      break;
    case OP_JALR:
      aux = RR(reg1);
      WR(31, next);
      next = aux;
      break;
    case OP_TRAP:
      throwException(EXC_TRAP);
      break;
    case OP_RFX:
      if (UM != 0) {
        throwException(EXC_PRV_INSTRCT);
      }
      if (PIE != 0) {
        psw |= PSW_IE;
      } else {
        psw &= ~PSW_IE;
      }
      if (OIE != 0) {
        psw |= PSW_PIE;
      } else {
        psw &= ~PSW_PIE;
      }
      if (PUM != 0) {
        psw |= PSW_UM;
      } else {
        psw &= ~PSW_UM;
      }
      if (OUM != 0) {
        psw |= PSW_PUM;
      } else {
        psw &= ~PSW_PUM;
      }
      next = RR(30);
      break;
    case OP_LDW:
      WR(reg2, mmuReadWord(RR(reg1) + SEXT16(immed), UM));
      break;
    case OP_LDH:
      WR(reg2, (signed int) (signed short)
               mmuReadHalf(RR(reg1) + SEXT16(immed), UM));
      break;
    case OP_LDHU:
      WR(reg2, mmuReadHalf(RR(reg1) + SEXT16(immed), UM));
      break;
    case OP_LDB:
      WR(reg2, (signed int) (signed char)
               mmuReadByte(RR(reg1) + SEXT16(immed), UM));
      break;
    case OP_LDBU:
      WR(reg2, mmuReadByte(RR(reg1) + SEXT16(immed), UM));
      break;
    case OP_STW:
      mmuWriteWord(RR(reg1) + SEXT16(immed), RR(reg2), UM);
      break;
    case OP_STH:
      mmuWriteHalf(RR(reg1) + SEXT16(immed), RR(reg2), UM);
      break;
    case OP_STB:
      mmuWriteByte(RR(reg1) + SEXT16(immed), RR(reg2), UM);
      break;
    case OP_MVFS:
      switch (immed) {
        case 0:
          WR(reg2, psw);
          break;
        case 1:
          WR(reg2, mmuGetIndex());
          break;
        case 2:
          WR(reg2, mmuGetEntryHi());
          break;
        case 3:
          WR(reg2, mmuGetEntryLo());
          break;
        case 4:
          WR(reg2, mmuGetBadAddr());
          break;
        default:
          throwException(EXC_ILL_INSTRCT);
          break;
      }
      break;
    case OP_MVTS:
      if (UM != 0) {
        throwException(EXC_PRV_INSTRCT);
      }
      switch (immed) {
        case 0:
          psw = RR(reg2);
          break;
        case 1:
          mmuSetIndex(RR(reg2));
          break;
        case 2:
          mmuSetEntryHi(RR(reg2));
          break;
        case 3:
          mmuSetEntryLo(RR(reg2));
          break;
        case 4:
          mmuSetBadAddr(RR(reg2));
          break;
        default:
          throwException(EXC_ILL_INSTRCT);
          break;
      }
      break;
    case OP_TBS:
      if (UM != 0) {
        throwException(EXC_PRV_INSTRCT);
      }
      mmuTbs();
      break;
    case OP_TBWR:
      if (UM != 0) {
        throwException(EXC_PRV_INSTRCT);
      }
      mmuTbwr();
      break;
    case OP_TBRI:
      if (UM != 0) {
        throwException(EXC_PRV_INSTRCT);
      }
      mmuTbri();
      break;
    case OP_TBWI:
      if (UM != 0) {
        throwException(EXC_PRV_INSTRCT);
      }
      mmuTbwi();
      break;
    default:
      throwException(EXC_ILL_INSTRCT);
      break;
  }
  /* update PC */
  pc = next;
}
 
 
/**************************************************************/
 
 
Word cpuGetPC(void) {
  return pc;
}
 
 
void cpuSetPC(Word addr) {
  pc = addr;
}
 
 
Word cpuGetReg(int regnum) {
  return RR(regnum & 0x1F);
}
 
 
void cpuSetReg(int regnum, Word value) {
  WR(regnum & 0x1F, value);
}
 
 
Word cpuGetPSW(void) {
  return psw;
}
 
 
void cpuSetPSW(Word value) {
  psw = value;
}
 
 
Word cpuGetIRQ(void) {
  return irqPending;
}
 
 
Bool cpuTestBreak(void) {
  return breakSet;
}
 
 
Word cpuGetBreak(void) {
  return breakAddr;
}
 
 
void cpuSetBreak(Word addr) {
  breakAddr = addr;
  breakSet = true;
}
 
 
void cpuResetBreak(void) {
  breakSet = false;
}
 
 
Word cpuGetTotal(void) {
  return total;
}
 
 
void cpuStep(void) {
  jmp_buf myEnvironment;
  int exception;
 
  exception = setjmp(myEnvironment);
  if (exception == 0) {
    /* initialization */
    pushEnvironment(&myEnvironment);
    timerTick();
    execNextInstruction();
    handleInterrupts();
  } else {
    /* an exception was thrown */
    cpuSetInterrupt(exception);
    handleInterrupts();
  }
  popEnvironment();
}
 
 
void cpuRun(void) {
  jmp_buf myEnvironment;
  int exception;
 
  run = true;
  exception = setjmp(myEnvironment);
  if (exception == 0) {
    /* initialization */
    pushEnvironment(&myEnvironment);
  } else {
    /* an exception was thrown */
    cpuSetInterrupt(exception);
    handleInterrupts();
    if (breakSet && pc == breakAddr) {
      run = false;
    }
  }
  while (run) {
    timerTick();
    execNextInstruction();
    handleInterrupts();
    if (breakSet && pc == breakAddr) {
      run = false;
    }
  }
  popEnvironment();
}
 
 
void cpuHalt(void) {
  run = false;
}
 
 
void cpuSetInterrupt(int priority) {
  irqPending |= ((unsigned) 1 << priority);
}
 
 
void cpuResetInterrupt(int priority) {
  irqPending &= ~((unsigned) 1 << priority);
}
 
 
void cpuReset(void) {
  int i;
 
  cPrintf("Resetting CPU...\n");
  /* most registers are in a random state */
  for (i = 1; i < 32; i++) {
    r[i] = rand();
  }
  /* but not all */
  pc = startAddr;
  r[0] = 0;
  psw = 0;
  /* reset simulator control variables */
  irqPending = 0;
  total = 0;
}
 
 
void cpuInit(Word initialPC) {
  startAddr = initialPC;
  cpuReset();
}
 
 
void cpuExit(void) {
}

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Subversion Repositories eco32

[/] [eco32/] [trunk/] [sim/] [cpu.c] - Blame information for rev 25

Line No.	Rev	Author	Line
1	8	hellwig	`/*`
2			`* cpu.c -- CPU simulation`
3			`*/`
4
5
6			`#include <stdio.h>`
7			`#include <stdlib.h>`
8			`#include <string.h>`
9			`#include <setjmp.h>`
10
11			`#include "common.h"`
12			`#include "console.h"`
13			`#include "error.h"`
14			`#include "except.h"`
15			`#include "instr.h"`
16			`#include "cpu.h"`
17			`#include "mmu.h"`
18			`#include "timer.h"`
19
20
21			`/**************************************************************/`
22
23
24			`#define RR(n) r[n]`
25			`#define WR(n,d) ((void) ((n) != 0 ? r[n] = (d) : (d)))`
26
27			`#define V (psw & PSW_V)`
28			`#define UM (psw & PSW_UM)`
29			`#define PUM (psw & PSW_PUM)`
30			`#define OUM (psw & PSW_OUM)`
31			`#define IE (psw & PSW_IE)`
32			`#define PIE (psw & PSW_PIE)`
33			`#define OIE (psw & PSW_OIE)`
34
35
36			`/**************************************************************/`
37
38
39			`static Bool debugIRQ = false; /* set to true if debugging IRQs */`
40
41			`static Word pc; /* program counter */`
42			`static Word psw; /* processor status word */`
43			`static Word r[32]; /* general purpose registers */`
44
45			`static unsigned irqPending; /* one bit for each pending IRQ */`
46
47			`static Bool breakSet; /* breakpoint set if true */`
48			`static Word breakAddr; /* if breakSet, this is where */`
49
50			`static Word total; /* counts total number of instrs */`
51
52			`static Bool run; /* CPU runs continuously if true */`
53
54			`static Word startAddr; /* start of ROM (or start of RAM, */`
55			`/* in case a program was loaded) */`
56
57
58			`/**************************************************************/`
59
60
61			`static void handleInterrupts(void) {`
62			`unsigned irqMask;`
63			`unsigned irqSeen;`
64			`int priority;`
65
66			`/* handle exceptions and interrupts */`
67			`if (irqPending == 0) {`
68			`/* no exception or interrupt pending */`
69			`return;`
70			`}`
71			`/* at least one exception or interrupt is pending */`
72			`irqMask = ~PSW_IRQ_MASK \| (psw & PSW_IRQ_MASK);`
73			`if (debugIRQ) {`
74			`cPrintf("** IRQ = 0x%08X **\n", irqPending);`
75			`cPrintf("** MASK = 0x%08X **\n", irqMask);`
76			`}`
77			`irqSeen = irqPending & irqMask;`
78			`if (irqSeen == 0) {`
79			`/* none that gets through */`
80			`return;`
81			`}`
82			`/* determine the one with the highest priority */`
83			`for (priority = 31; priority >= 0; priority--) {`
84			`if ((irqSeen & ((unsigned) 1 << priority)) != 0) {`
85			`/* highest priority among visible ones found */`
86			`break;`
87			`}`
88			`}`
89			`/* acknowledge exception, or interrupt if enabled */`
90			`if (priority >= 16 \|\| IE != 0) {`
91			`if (priority >= 16) {`
92			`/* clear corresponding bit in irqPending vector */`
93			`/* only done for exceptions, since interrupts are level-sensitive */`
94			`irqPending &= ~((unsigned) 1 << priority);`
95			`}`
96			`/* copy and reset interrupt enable bit in PSW */`
97			`if (PIE != 0) {`
98			`psw \|= PSW_OIE;`
99			`} else {`
100			`psw &= ~PSW_OIE;`
101			`}`
102			`if (IE != 0) {`
103			`psw \|= PSW_PIE;`
104			`} else {`
105			`psw &= ~PSW_PIE;`
106			`}`
107			`psw &= ~PSW_IE;`
108			`/* copy and reset user mode enable bit in PSW */`
109			`if (PUM != 0) {`
110			`psw \|= PSW_OUM;`
111			`} else {`
112			`psw &= ~PSW_OUM;`
113			`}`
114			`if (UM != 0) {`
115			`psw \|= PSW_PUM;`
116			`} else {`
117			`psw &= ~PSW_PUM;`
118			`}`
119			`psw &= ~PSW_UM;`
120			`/* reflect priority in PSW */`
121			`psw &= ~PSW_PRIO_MASK;`
122			`psw \|= priority << PSW_PRIO_SHFT;`
123			`/* save interrupt return address and start service routine */`
124			`WR(30, pc);`
125			`if (V == 0) {`
126			`/* exceptions and interrupts are vectored to ROM */`
127			`pc = 0xC0000000 \| ROM_BASE;`
128			`} else {`
129			`/* exceptions and interrupts are vectored to RAM */`
130			`pc = 0xC0000000;`
131			`}`
132			`if (priority == EXC_TLB_MISS &&`
133			`(mmuGetBadAddr() & 0x80000000) == 0) {`
134			`/* user TLB miss exception */`
135			`pc \|= 0x00000008;`
136			`} else {`
137			`/* any other exception or interrupt */`
138			`pc \|= 0x00000004;`
139			`}`
140			`}`
141			`}`
142
143
144			`static void execNextInstruction(void) {`
145			`Word instr;`
146			`Word next;`
147			`int op, reg1, reg2, reg3;`
148			`Half immed;`
149			`Word offset;`
150			`int scnt;`
151			`Word smsk;`
152			`Word aux;`
153
154			`/* count the instruction */`
155			`total++;`
156			`/* fetch the instruction */`
157			`instr = mmuReadWord(pc, UM);`
158			`/* decode the instruction */`
159			`op = (instr >> 26) & 0x3F;`
160			`reg1 = (instr >> 21) & 0x1F;`
161			`reg2 = (instr >> 16) & 0x1F;`
162			`reg3 = (instr >> 11) & 0x1F;`
163			`immed = instr & 0x0000FFFF;`
164			`offset = instr & 0x03FFFFFF;`
165			`next = pc + 4;`
166			`/* execute the instruction */`
167			`switch (op) {`
168			`case OP_ADD:`
169			`WR(reg3, (signed int) RR(reg1) + (signed int) RR(reg2));`
170			`break;`
171			`case OP_ADDI:`
172			`WR(reg2, (signed int) RR(reg1) + (signed int) SEXT16(immed));`
173			`break;`
174			`case OP_SUB:`
175			`WR(reg3, (signed int) RR(reg1) - (signed int) RR(reg2));`
176			`break;`
177			`case OP_SUBI:`
178			`WR(reg2, (signed int) RR(reg1) - (signed int) SEXT16(immed));`
179			`break;`
180			`case OP_MUL:`
181			`WR(reg3, (signed int) RR(reg1) * (signed int) RR(reg2));`
182			`break;`
183			`case OP_MULI:`
184			`WR(reg2, (signed int) RR(reg1) * (signed int) SEXT16(immed));`
185			`break;`
186			`case OP_MULU:`
187			`WR(reg3, RR(reg1) * RR(reg2));`
188			`break;`
189			`case OP_MULUI:`
190			`WR(reg2, RR(reg1) * ZEXT16(immed));`
191			`break;`
192			`case OP_DIV:`
193			`if (RR(reg2) == 0) {`
194			`throwException(EXC_DIVIDE);`
195			`}`
196			`WR(reg3, (signed int) RR(reg1) / (signed int) RR(reg2));`
197			`break;`
198			`case OP_DIVI:`
199			`if (SEXT16(immed) == 0) {`
200			`throwException(EXC_DIVIDE);`
201			`}`
202			`WR(reg2, (signed int) RR(reg1) / (signed int) SEXT16(immed));`
203			`break;`
204			`case OP_DIVU:`
205			`if (RR(reg2) == 0) {`
206			`throwException(EXC_DIVIDE);`
207			`}`
208			`WR(reg3, RR(reg1) / RR(reg2));`
209			`break;`
210			`case OP_DIVUI:`
211			`if (SEXT16(immed) == 0) {`
212			`throwException(EXC_DIVIDE);`
213			`}`
214			`WR(reg2, RR(reg1) / ZEXT16(immed));`
215			`break;`
216			`case OP_REM:`
217			`if (RR(reg2) == 0) {`
218			`throwException(EXC_DIVIDE);`
219			`}`
220			`WR(reg3, (signed int) RR(reg1) % (signed int) RR(reg2));`
221			`break;`
222			`case OP_REMI:`
223			`if (SEXT16(immed) == 0) {`
224			`throwException(EXC_DIVIDE);`
225			`}`
226			`WR(reg2, (signed int) RR(reg1) % (signed int) SEXT16(immed));`
227			`break;`
228			`case OP_REMU:`
229			`if (RR(reg2) == 0) {`
230			`throwException(EXC_DIVIDE);`
231			`}`
232			`WR(reg3, RR(reg1) % RR(reg2));`
233			`break;`
234			`case OP_REMUI:`
235			`if (SEXT16(immed) == 0) {`
236			`throwException(EXC_DIVIDE);`
237			`}`
238			`WR(reg2, RR(reg1) % ZEXT16(immed));`
239			`break;`
240			`case OP_AND:`
241			`WR(reg3, RR(reg1) & RR(reg2));`
242			`break;`
243			`case OP_ANDI:`
244			`WR(reg2, RR(reg1) & ZEXT16(immed));`
245			`break;`
246			`case OP_OR:`
247			`WR(reg3, RR(reg1) \| RR(reg2));`
248			`break;`
249			`case OP_ORI:`
250			`WR(reg2, RR(reg1) \| ZEXT16(immed));`
251			`break;`
252			`case OP_XOR:`
253			`WR(reg3, RR(reg1) ^ RR(reg2));`
254			`break;`
255			`case OP_XORI:`
256			`WR(reg2, RR(reg1) ^ ZEXT16(immed));`
257			`break;`
258			`case OP_XNOR:`
259			`WR(reg3, ~(RR(reg1) ^ RR(reg2)));`
260			`break;`
261			`case OP_XNORI:`
262			`WR(reg2, ~(RR(reg1) ^ ZEXT16(immed)));`
263			`break;`
264			`case OP_SLL:`
265			`scnt = RR(reg2) & 0x1F;`
266			`WR(reg3, RR(reg1) << scnt);`
267			`break;`
268			`case OP_SLLI:`
269			`scnt = immed & 0x1F;`
270			`WR(reg2, RR(reg1) << scnt);`
271			`break;`
272			`case OP_SLR:`
273			`scnt = RR(reg2) & 0x1F;`
274			`WR(reg3, RR(reg1) >> scnt);`
275			`break;`
276			`case OP_SLRI:`
277			`scnt = immed & 0x1F;`
278			`WR(reg2, RR(reg1) >> scnt);`
279			`break;`
280			`case OP_SAR:`
281			`scnt = RR(reg2) & 0x1F;`
282			`smsk = (RR(reg1) & 0x80000000 ? ~(((Word) 0xFFFFFFFF) >> scnt) : 0);`
283			`WR(reg3, smsk \| (RR(reg1) >> scnt));`
284			`break;`
285			`case OP_SARI:`
286			`scnt = immed & 0x1F;`
287			`smsk = (RR(reg1) & 0x80000000 ? ~(((Word) 0xFFFFFFFF) >> scnt) : 0);`
288			`WR(reg2, smsk \| (RR(reg1) >> scnt));`
289			`break;`
290			`case OP_LDHI:`
291			`WR(reg2, ZEXT16(immed) << 16);`
292			`break;`
293			`case OP_BEQ:`
294			`if (RR(reg1) == RR(reg2)) {`
295			`next += SEXT16(immed) << 2;`
296			`}`
297			`break;`
298			`case OP_BNE:`
299			`if (RR(reg1) != RR(reg2)) {`
300			`next += SEXT16(immed) << 2;`
301			`}`
302			`break;`
303			`case OP_BLE:`
304			`if ((signed int) RR(reg1) <= (signed int) RR(reg2)) {`
305			`next += SEXT16(immed) << 2;`
306			`}`
307			`break;`
308			`case OP_BLEU:`
309			`if (RR(reg1) <= RR(reg2)) {`
310			`next += SEXT16(immed) << 2;`
311			`}`
312			`break;`
313			`case OP_BLT:`
314			`if ((signed int) RR(reg1) < (signed int) RR(reg2)) {`
315			`next += SEXT16(immed) << 2;`
316			`}`
317			`break;`
318			`case OP_BLTU:`
319			`if (RR(reg1) < RR(reg2)) {`
320			`next += SEXT16(immed) << 2;`
321			`}`
322			`break;`
323			`case OP_BGE:`
324			`if ((signed int) RR(reg1) >= (signed int) RR(reg2)) {`
325			`next += SEXT16(immed) << 2;`
326			`}`
327			`break;`
328			`case OP_BGEU:`
329			`if (RR(reg1) >= RR(reg2)) {`
330			`next += SEXT16(immed) << 2;`
331			`}`
332			`break;`
333			`case OP_BGT:`
334			`if ((signed int) RR(reg1) > (signed int) RR(reg2)) {`
335			`next += SEXT16(immed) << 2;`
336			`}`
337			`break;`
338			`case OP_BGTU:`
339			`if (RR(reg1) > RR(reg2)) {`
340			`next += SEXT16(immed) << 2;`
341			`}`
342			`break;`
343			`case OP_J:`
344			`next += SEXT26(offset) << 2;`
345			`break;`
346			`case OP_JR:`
347			`next = RR(reg1);`
348			`break;`
349			`case OP_JAL:`
350			`WR(31, next);`
351			`next += SEXT26(offset) << 2;`
352			`break;`
353			`case OP_JALR:`
354			`aux = RR(reg1);`
355			`WR(31, next);`
356			`next = aux;`
357			`break;`
358			`case OP_TRAP:`
359			`throwException(EXC_TRAP);`
360			`break;`
361			`case OP_RFX:`
362			`if (UM != 0) {`
363			`throwException(EXC_PRV_INSTRCT);`
364			`}`
365			`if (PIE != 0) {`
366			`psw \|= PSW_IE;`
367			`} else {`
368			`psw &= ~PSW_IE;`
369			`}`
370			`if (OIE != 0) {`
371			`psw \|= PSW_PIE;`
372			`} else {`
373			`psw &= ~PSW_PIE;`
374			`}`
375			`if (PUM != 0) {`
376			`psw \|= PSW_UM;`
377			`} else {`
378			`psw &= ~PSW_UM;`
379			`}`
380			`if (OUM != 0) {`
381			`psw \|= PSW_PUM;`
382			`} else {`
383			`psw &= ~PSW_PUM;`
384			`}`
385			`next = RR(30);`
386			`break;`
387			`case OP_LDW:`
388			`WR(reg2, mmuReadWord(RR(reg1) + SEXT16(immed), UM));`
389			`break;`
390			`case OP_LDH:`
391			`WR(reg2, (signed int) (signed short)`
392			`mmuReadHalf(RR(reg1) + SEXT16(immed), UM));`
393			`break;`
394			`case OP_LDHU:`
395			`WR(reg2, mmuReadHalf(RR(reg1) + SEXT16(immed), UM));`
396			`break;`
397			`case OP_LDB:`
398			`WR(reg2, (signed int) (signed char)`
399			`mmuReadByte(RR(reg1) + SEXT16(immed), UM));`
400			`break;`
401			`case OP_LDBU:`
402			`WR(reg2, mmuReadByte(RR(reg1) + SEXT16(immed), UM));`
403			`break;`
404			`case OP_STW:`
405			`mmuWriteWord(RR(reg1) + SEXT16(immed), RR(reg2), UM);`
406			`break;`
407			`case OP_STH:`
408			`mmuWriteHalf(RR(reg1) + SEXT16(immed), RR(reg2), UM);`
409			`break;`
410			`case OP_STB:`
411			`mmuWriteByte(RR(reg1) + SEXT16(immed), RR(reg2), UM);`
412			`break;`
413			`case OP_MVFS:`
414			`switch (immed) {`
415			`case 0:`
416			`WR(reg2, psw);`
417			`break;`
418			`case 1:`
419			`WR(reg2, mmuGetIndex());`
420			`break;`
421			`case 2:`
422			`WR(reg2, mmuGetEntryHi());`
423			`break;`
424			`case 3:`
425			`WR(reg2, mmuGetEntryLo());`
426			`break;`
427			`case 4:`
428			`WR(reg2, mmuGetBadAddr());`
429			`break;`
430			`default:`
431			`throwException(EXC_ILL_INSTRCT);`
432			`break;`
433			`}`
434			`break;`
435			`case OP_MVTS:`
436			`if (UM != 0) {`
437			`throwException(EXC_PRV_INSTRCT);`
438			`}`
439			`switch (immed) {`
440			`case 0:`
441			`psw = RR(reg2);`
442			`break;`
443			`case 1:`
444			`mmuSetIndex(RR(reg2));`
445			`break;`
446			`case 2:`
447			`mmuSetEntryHi(RR(reg2));`
448			`break;`
449			`case 3:`
450			`mmuSetEntryLo(RR(reg2));`
451			`break;`
452			`case 4:`
453			`mmuSetBadAddr(RR(reg2));`
454			`break;`
455			`default:`
456			`throwException(EXC_ILL_INSTRCT);`
457			`break;`
458			`}`
459			`break;`
460			`case OP_TBS:`
461			`if (UM != 0) {`
462			`throwException(EXC_PRV_INSTRCT);`
463			`}`
464			`mmuTbs();`
465			`break;`
466			`case OP_TBWR:`
467			`if (UM != 0) {`
468			`throwException(EXC_PRV_INSTRCT);`
469			`}`
470			`mmuTbwr();`
471			`break;`
472			`case OP_TBRI:`
473			`if (UM != 0) {`
474			`throwException(EXC_PRV_INSTRCT);`
475			`}`
476			`mmuTbri();`
477			`break;`
478			`case OP_TBWI:`
479			`if (UM != 0) {`
480			`throwException(EXC_PRV_INSTRCT);`
481			`}`
482			`mmuTbwi();`
483			`break;`
484			`default:`
485			`throwException(EXC_ILL_INSTRCT);`
486			`break;`
487			`}`
488			`/* update PC */`
489			`pc = next;`
490			`}`
491
492
493			`/**************************************************************/`
494
495
496			`Word cpuGetPC(void) {`
497			`return pc;`
498			`}`
499
500
501			`void cpuSetPC(Word addr) {`
502			`pc = addr;`
503			`}`
504
505
506			`Word cpuGetReg(int regnum) {`
507			`return RR(regnum & 0x1F);`
508			`}`
509
510
511			`void cpuSetReg(int regnum, Word value) {`
512			`WR(regnum & 0x1F, value);`
513			`}`
514
515
516			`Word cpuGetPSW(void) {`
517			`return psw;`
518			`}`
519
520
521			`void cpuSetPSW(Word value) {`
522			`psw = value;`
523			`}`
524
525
526			`Word cpuGetIRQ(void) {`
527			`return irqPending;`
528			`}`
529
530
531			`Bool cpuTestBreak(void) {`
532			`return breakSet;`
533			`}`
534
535
536			`Word cpuGetBreak(void) {`
537			`return breakAddr;`
538			`}`
539
540
541			`void cpuSetBreak(Word addr) {`
542			`breakAddr = addr;`
543			`breakSet = true;`
544			`}`
545
546
547			`void cpuResetBreak(void) {`
548			`breakSet = false;`
549			`}`
550
551
552			`Word cpuGetTotal(void) {`
553			`return total;`
554			`}`
555
556
557			`void cpuStep(void) {`
558			`jmp_buf myEnvironment;`
559			`int exception;`
560
561			`exception = setjmp(myEnvironment);`
562			`if (exception == 0) {`
563			`/* initialization */`
564			`pushEnvironment(&myEnvironment);`
565	25	hellwig	`timerTick();`
566	8	hellwig	`execNextInstruction();`
567			`handleInterrupts();`
568			`} else {`
569			`/* an exception was thrown */`
570			`cpuSetInterrupt(exception);`
571			`handleInterrupts();`
572			`}`
573			`popEnvironment();`
574			`}`
575
576
577			`void cpuRun(void) {`
578			`jmp_buf myEnvironment;`
579			`int exception;`
580
581			`run = true;`
582			`exception = setjmp(myEnvironment);`
583			`if (exception == 0) {`
584			`/* initialization */`
585			`pushEnvironment(&myEnvironment);`
586			`} else {`
587			`/* an exception was thrown */`
588			`cpuSetInterrupt(exception);`
589			`handleInterrupts();`
590			`if (breakSet && pc == breakAddr) {`
591			`run = false;`
592			`}`
593			`}`
594			`while (run) {`
595	25	hellwig	`timerTick();`
596	8	hellwig	`execNextInstruction();`
597			`handleInterrupts();`
598			`if (breakSet && pc == breakAddr) {`
599			`run = false;`
600			`}`
601			`}`
602			`popEnvironment();`
603			`}`
604
605
606			`void cpuHalt(void) {`
607			`run = false;`
608			`}`
609
610
611			`void cpuSetInterrupt(int priority) {`
612			`irqPending \|= ((unsigned) 1 << priority);`
613			`}`
614
615
616			`void cpuResetInterrupt(int priority) {`
617			`irqPending &= ~((unsigned) 1 << priority);`
618			`}`
619
620
621			`void cpuReset(void) {`
622			`int i;`
623
624			`cPrintf("Resetting CPU...\n");`
625			`/* most registers are in a random state */`
626			`for (i = 1; i < 32; i++) {`
627			`r[i] = rand();`
628			`}`
629			`/* but not all */`
630			`pc = startAddr;`
631			`r[0] = 0;`
632			`psw = 0;`
633			`/* reset simulator control variables */`
634			`irqPending = 0;`
635			`total = 0;`
636			`}`
637
638
639			`void cpuInit(Word initialPC) {`
640			`startAddr = initialPC;`
641			`cpuReset();`
642			`}`
643
644
645			`void cpuExit(void) {`
646			`}`