自学教程：C++ INDEXK函数代码示例

static const char* kname(Proto* p, int c){	if (ISK(c) && ttisstring(&p->k[INDEXK(c)]))		return svalue(&p->k[INDEXK(c)]);	else		return "?";}

static int do_getinstruction(lua_State *L)	/** getinstruction(f,i) */{ const Proto* f=Pget(L,1); int pc=luaL_checkinteger(L,2); if (pc<=0 || pc>f->sizecode || f->code==NULL) return 0; pc--; { const Instruction* code=f->code; Instruction i=code[pc]; OpCode o=GET_OPCODE(i); int a=GETARG_A(i); int b=GETARG_B(i); int c=GETARG_C(i); int ax=GETARG_Ax(i); int bx=GETARG_Bx(i); int sbx=GETARG_sBx(i); int line=getfuncline(f,pc); if (line>0) lua_pushinteger(L,line); else lua_pushnil(L); lua_pushstring(L,luaP_opnames[o]); switch (getOpMode(o)) {  case iABC:   lua_pushinteger(L,a);   if (getBMode(o)!=OpArgN) lua_pushinteger(L,ISK(b) ? (MYK(INDEXK(b))) : b);   else lua_pushnil(L);   if (getCMode(o)!=OpArgN) lua_pushinteger(L,ISK(c) ? (MYK(INDEXK(c))) : c);   else lua_pushnil(L);   break;  case iABx:   lua_pushinteger(L,a);   if (getBMode(o)==OpArgK) lua_pushinteger(L,MYK(bx)); else lua_pushinteger(L,bx);   lua_pushnil(L);   break;  case iAsBx:   lua_pushinteger(L,a);   lua_pushinteger(L,sbx);   lua_pushnil(L);   break;  case iAx:   lua_pushinteger(L,MYK(ax));   lua_pushnil(L);   lua_pushnil(L);   break; } switch (o) {   case OP_JMP:   case OP_FORLOOP:   case OP_FORPREP:   case OP_TFORLOOP:    lua_pop(L,1);    lua_pushinteger(L,sbx+pc+2);    break;   default:    break; } } return 5;}

/* local op, a, b, c, test = jit.util.bytecode(func, pc) */static int ju_bytecode(lua_State *L){    Proto *pt = check_LCL(L)->l.p;    int pc = luaL_checkint(L, 2);    if (pc >= 1 && pc <= pt->sizecode) {        Instruction ins = pt->code[pc-1];        OpCode op = GET_OPCODE(ins);        if (pc > 1 && (((int)OP_SETLIST) << POS_OP) ==                (pt->code[pc-2] & (MASK1(SIZE_OP,POS_OP) | MASK1(SIZE_C,POS_C)))) {            lua_pushstring(L, luaP_opnames[OP_SETLIST]);            lua_pushnumber(L, (lua_Number)ins);  /* Fake extended op. */            return 1;        }        if (op >= NUM_OPCODES) return 0;  /* Just in case. */        lua_pushstring(L, luaP_opnames[op]);        lua_pushinteger(L, GETARG_A(ins));        switch (getOpMode(op)) {        case iABC: {            int b = GETARG_B(ins), c = GETARG_C(ins);            switch (getBMode(op)) {            case OpArgN:                lua_pushnil(L);                break;            case OpArgK:                if (ISK(b)) b = -1-INDEXK(b);            case OpArgR:            case OpArgU:                lua_pushinteger(L, b);                break;            }            switch (getCMode(op)) {            case OpArgN:                lua_pushnil(L);                break;            case OpArgK:                if (ISK(c)) c = -1-INDEXK(c);            case OpArgR:            case OpArgU:                lua_pushinteger(L, c);                break;            }            lua_pushboolean(L, testTMode(op));            return 5;        }        case iABx: {            int bx = GETARG_Bx(ins);            lua_pushinteger(L, getBMode(op) == OpArgK ? -1-bx : bx);            return 3;        }        case iAsBx:            lua_pushinteger(L, GETARG_sBx(ins));            return 3;        }    }    return 0;}

/* * This function must be called before all code loaded. */void kp_optimize_code(ktap_state *ks, int level, ktap_proto *f){	int i;	for (i = 0; i < f->sizecode; i++) {		int instr = f->code[i];		ktap_value *k = f->k;		if (GET_OPCODE(instr) == OP_GETTABUP) {			if ((GETARG_B(instr) == 0) && ISK(GETARG_C(instr))) {				ktap_value *field = k + INDEXK(GETARG_C(instr));				if (ttype(field) == KTAP_TSTRING) {					int index = cfunction_cache_getindex(ks,									field);					if (index == -1)						break;					SET_OPCODE(instr, OP_LOAD_GLOBAL);					SETARG_C(instr, index);					f->code[i] = instr;					break;				}			}		}	}	/* continue optimize sub functions */	for (i = 0; i < f->sizep; i++)		kp_optimize_code(ks, level + 1, f->p[i]);}

/** * Is the operand a reference to a short string constant? */static int isshortstr(FuncState *fs, int kk) {  if (ISK(kk)) {    Proto *f = fs->f;    kk = INDEXK(kk);    lua_assert(kk >= 0 && kk < f->sizek);    return ttisshrstring(&f->k[kk]);  }  return 0;}

static int checkArgMode (const Proto *pt, int r, enum OpArgMask mode) {  switch (mode) {    case OpArgN: check(r == 0); break;    case OpArgU: break;    case OpArgR: checkreg(pt, r); break;    case OpArgK:      check(ISK(r) ? INDEXK(r) < pt->sizek : r < pt->maxstacksize);      break;  }  return 1;}

void RaviCodeGenerator::emit_BITWISE_SHIFT_OP(RaviFunctionDef *def, OpCode op,                                              int A, int B, int C, int pc) {  bool traced = emit_debug_trace(def, op, pc);  emit_load_base(def);  llvm::Value *ra = emit_gep_register(def, A);  // If the RHS is a constant and we know that LHS is  // and integer then we can optimize the code generation  if (op == OP_RAVI_SHL_II && ISK(C)) {    lua_Integer y = def->p->k[INDEXK(C)].value_.i;    emit_bitwise_shiftl(def, ra, B, y);  } else if (op == OP_RAVI_SHR_II && ISK(C)) {    lua_Integer y = def->p->k[INDEXK(C)].value_.i;    emit_bitwise_shiftl(def, ra, B, -y);  } else {    // RHS is not a constant    llvm::Value *rc = emit_gep_register_or_constant(def, C);    llvm::Value *rb = emit_gep_register_or_constant(def, B);    // Since the Lua OP_SHL and OP_SHR bytecodes    // could invoke metamethods we need to set    // 'savedpc'    switch (op) {    case OP_SHL:      if (!traced) emit_update_savedpc(def, pc);    case OP_RAVI_SHL_II:      CreateCall4(def->builder, def->raviV_op_shlF, def->L, ra, rb, rc);      break;    case OP_SHR:      if (!traced) emit_update_savedpc(def, pc);    case OP_RAVI_SHR_II:      CreateCall4(def->builder, def->raviV_op_shrF, def->L, ra, rb, rc);      break;    default:      fprintf(stderr, "unexpected value of opcode %d/n", (int)op);      abort();    }  }}

/*** find a "name" for the RK value 'c'*/static void kname (Proto *p, int pc, int c, const char **name) {	if (ISK(c)) {  /* is 'c' a constant? */	TValue *kvalue = &p->k[INDEXK(c)];	if (ttisstring(kvalue)) {  /* literal constant? */		*name = svalue(kvalue);  /* it is its own name */		return;	}	/* else no reasonable name found */	}	else {  /* 'c' is a register */	const char *what = getobjname(p, pc, c, name); /* search for 'c' */	if (what && *what == 'c') {  /* found a constant name? */		return;  /* 'name' already filled */	}	/* else no reasonable name found */	}	*name = "?";  /* no reasonable name found */}

/*** find a "name" for the RK value 'c'*/void kname2 (LuaProto *p, int pc, int c, std::string& name) {  if (ISK(c)) {  /* is 'c' a constant? */    LuaValue *kvalue = &p->constants[INDEXK(c)];    if (kvalue->isString()) {  /* literal constant? */      name = kvalue->getString()->c_str();  /* it is its own name */      return;    }    /* else no reasonable name found */  }  else {  /* 'c' is a register */    const char *what = getobjname2(p, pc, c, name); /* search for 'c' */    if (what && *what == 'c') {  /* found a constant name? */      return;  /* 'name' already filled */    }    /* else no reasonable name found */  }  name = "?";  /* no reasonable name found */}

static void PrintCode(const Proto* f){ const Instruction* code=f->code; int pc,n=f->sizecode; for (pc=0; pc<n; pc++) {  Instruction i=code[pc];  OpCode o=GET_OPCODE(i);  int a=GETARG_A(i);  int b=GETARG_B(i);  int c=GETARG_C(i);  int ax=GETARG_Ax(i);  int bx=GETARG_Bx(i);  int sbx=GETARG_sBx(i);  int line=getfuncline(f,pc);  printf("/t%d/t",pc+1);  if (line>0) printf("[%d]/t",line); else printf("[-]/t");  printf("%-9s/t",luaP_opnames[o]);  switch (getOpMode(o))  {   case iABC:    printf("%d",a);    if (getBMode(o)!=OpArgN) printf(" %d",ISK(b) ? (MYK(INDEXK(b))) : b);    if (getCMode(o)!=OpArgN) printf(" %d",ISK(c) ? (MYK(INDEXK(c))) : c);    break;   case iABx:    printf("%d",a);    if (getBMode(o)==OpArgK) printf(" %d",MYK(bx));    if (getBMode(o)==OpArgU) printf(" %d",bx);    break;   case iAsBx:    printf("%d %d",a,sbx);    break;   case iAx:    printf("%d",MYK(ax));    break;  }  switch (o)  {   case OP_LOADK:    printf("/t; "); PrintConstant(f,bx);    break;   case OP_GETUPVAL:   case OP_SETUPVAL:    printf("/t; %s",UPVALNAME(b));    break;   case OP_GETTABUP:    printf("/t; %s",UPVALNAME(b));    if (ISK(c)) { printf(" "); PrintConstant(f,INDEXK(c)); }    break;   case OP_SETTABUP:    printf("/t; %s",UPVALNAME(a));    if (ISK(b)) { printf(" "); PrintConstant(f,INDEXK(b)); }    if (ISK(c)) { printf(" "); PrintConstant(f,INDEXK(c)); }    break;   case OP_GETTABLE:   case OP_SELF:    if (ISK(c)) { printf("/t; "); PrintConstant(f,INDEXK(c)); }    break;   case OP_SETTABLE:   case OP_ADD:   case OP_SUB:   case OP_MUL:   case OP_POW:   case OP_DIV:   case OP_IDIV:   case OP_BAND:   case OP_BOR:   case OP_BXOR:   case OP_SHL:   case OP_SHR:   case OP_EQ:   case OP_LT:   case OP_LE:    if (ISK(b) || ISK(c))    {     printf("/t; ");     if (ISK(b)) PrintConstant(f,INDEXK(b)); else printf("-");     printf(" ");     if (ISK(c)) PrintConstant(f,INDEXK(c)); else printf("-");    }    break;   case OP_JMP:   case OP_FORLOOP:   case OP_FORPREP:   case OP_TFORLOOP:    printf("/t; to %d",sbx+pc+2);    break;   case OP_CLOSURE:    printf("/t; %p",VOID(f->p[bx]));    break;   case OP_SETLIST:    if (c==0) printf("/t; %d",(int)code[++pc]); else printf("/t; %d",c);    break;   case OP_EXTRAARG:    printf("/t; "); PrintConstant(f,ax);    break;   default:    break;  }//.........这里部分代码省略.........

static void PrintCode(const Proto* f){ const Instruction* code=f->code; int pc,n=f->sizecode; for (pc=0; pc<n; pc++) {  Instruction i=code[pc];  OpCode o=GET_OPCODE(i);  int a=GETARG_A(i);  int b=GETARG_B(i);  int c=GETARG_C(i);  int bx=GETARG_Bx(i);  int sbx=GETARG_sBx(i);  int line=getline(f,pc);  printf("/t%d/t",pc+1);  if (line>0) printf("[%d]/t",line); else printf("[-]/t");  printf("%-9s/t",luaP_opnames[o]);  switch (getOpMode(o))  {   case iABC:    printf("%d",a);    if (getBMode(o)!=OpArgN) printf(" %d",ISK(b) ? (-1-INDEXK(b)) : b);    if (getCMode(o)!=OpArgN) printf(" %d",ISK(c) ? (-1-INDEXK(c)) : c);    break;   case iABx:    if (getBMode(o)==OpArgK) printf("%d %d",a,-1-bx); else printf("%d %d",a,bx);    break;   case iAsBx:    if (o==OP_JMP) printf("%d",sbx); else printf("%d %d",a,sbx);    break;  }  switch (o)  {   case OP_LOADK:    printf("/t; "); PrintConstant(f,bx);    break;   case OP_GETUPVAL:   case OP_SETUPVAL:    printf("/t; %s", (f->sizeupvalues>0) ? getstr(f->upvalues[b]) : "-");    break;   case OP_GETGLOBAL:   case OP_SETGLOBAL:    printf("/t; %s",svalue(&f->k[bx]));    break;   case OP_GETTABLE:   case OP_SELF:    if (ISK(c)) { printf("/t; "); PrintConstant(f,INDEXK(c)); }    break;   case OP_SETTABLE:   case OP_ADD:   case OP_SUB:   case OP_MUL:   case OP_DIV:   case OP_POW:   case OP_EQ:   case OP_LT:   case OP_LE:    if (ISK(b) || ISK(c))    {     printf("/t; ");     if (ISK(b)) PrintConstant(f,INDEXK(b)); else printf("-");     printf(" ");     if (ISK(c)) PrintConstant(f,INDEXK(c)); else printf("-");    }    break;   case OP_JMP:   case OP_FORLOOP:   case OP_FORPREP:    printf("/t; to %d",sbx+pc+2);    break;   case OP_CLOSURE:    printf("/t; %p",VOID(f->p[bx]));    break;   case OP_SETLIST:    if (c==0) printf("/t; %d",(int)code[++pc]);    else printf("/t; %d",c);    break;   default:    break;  }  printf("/n"); }}

const char* raviP_instruction_to_str(char *buf, size_t n, Instruction i) {  OpCode o = GET_OPCODE(i);  int a = GETARG_A(i);  int b = GETARG_B(i);  int c = GETARG_C(i);  int ax = GETARG_Ax(i);  int bx = GETARG_Bx(i);  int sbx = GETARG_sBx(i);  snprintf(buf, n, "%s ", luaP_opnames[o]);  switch (getOpMode(o)) {  case iABC:    snprintf(buf+strlen(buf), n-strlen(buf), "A=%d", a);    if (getBMode(o) != OpArgN)      snprintf(buf + strlen(buf), n - strlen(buf), " B=%d", (getBMode(o) == OpArgK && ISK(b)) ? (MYK(INDEXK(b))) : b);    if (getCMode(o) != OpArgN)      snprintf(buf + strlen(buf), n - strlen(buf), " C=%d", (getCMode(o) == OpArgK && ISK(c)) ? (MYK(INDEXK(c))) : c);    break;  case iABx:    snprintf(buf + strlen(buf), n - strlen(buf), "A=%d", a);    if (getBMode(o) == OpArgK)      snprintf(buf + strlen(buf), n - strlen(buf), " Bx=%d", MYK(bx));    if (getBMode(o) == OpArgU)      snprintf(buf + strlen(buf), n - strlen(buf), " Bx=%d", bx);    break;  case iAsBx:    snprintf(buf + strlen(buf), n - strlen(buf), "As=%d Bx=%d", a, sbx);    break;  case iAx:    snprintf(buf + strlen(buf), n - strlen(buf), "Ax=%d", MYK(ax));    break;  }  return buf;}