INLINE void saturn_exchange_pc(int reg)
{
int temp=saturn.pc;
saturn.pc=S64_READ_A(reg);
change_pc(saturn.pc);
S64_WRITE_A(reg, temp);
}
static void saturn_instruction(void)
{
int reg, adr;
switch(READ_OP()) {
case 0:
switch(READ_OP()) {
case 0: saturn_return_xm_set();break;
case 1: saturn_return(1);break;
case 2: saturn_return_carry_set();break;
case 3: saturn_return_carry_clear();break;
case 4: saturn_sethex();break;
case 5: saturn_setdec();break;
case 6: saturn_push_c();break;
case 7: saturn_pop_c();break;
case 8: saturn_clear_st();break;
case 9: saturn_st_to_c();break;
case 0xa: saturn_c_to_st();break;
case 0xb: saturn_exchange_c_st();break;
case 0xc:
saturn_inc_p();
break;
case 0xd:
saturn_dec_p();
break;
case 0xf: saturn_return_interrupt();break;
case 0xe:
saturn_instruction_0e();
break;
}
break;
case 1:
saturn_instruction_1();
break;
case 2:
saturn_load_p();
break;
case 3: saturn_load_reg(C);break; /* lc */
case 4:
adr=READ_OP_DIS8();
if (adr==0) {
saturn_return(saturn.carry);
} else {
saturn_jump((saturn.pc+adr-2)&0xfffff, saturn.carry);
}
break;
case 5:
adr=READ_OP_DIS8();
if (adr==0) {
saturn_return(!saturn.carry);
} else {
saturn_jump((saturn.pc+adr-2)&0xfffff,!saturn.carry);
}
break;
case 6:
adr=READ_OP_DIS12();
saturn_jump((saturn.pc+adr-3)&0xfffff,1); break;
case 7:
adr=READ_OP_DIS12();
saturn_call((adr+saturn.pc)&0xfffff); break;
case 8:
saturn_instruction_8();
break;
case 9:
saturn_instruction_9();
break;
case 0xa:
saturn_instruction_a();
break;
case 0xb:
saturn_instruction_b();
break;
case 0xc:
switch (reg=READ_OP()) {
case 0: case 1: case 2: case 3:
case 8: case 9: case 0xa: case 0xb:
saturn_add(add_left[reg], BEGIN_A, COUNT_A, add_right[reg]);
break;
case 4: case 5: case 6: case 7:
saturn_shift_left(A+(reg&3), BEGIN_A, COUNT_A);
break;
case 0xc: case 0xd: case 0xe: case 0xf:
saturn_decrement(A+(reg&3), BEGIN_A, COUNT_A);
break;
}
break;
case 0xd:
switch(reg=READ_OP()) {
case 0: case 1: case 2: case 3:
saturn_clear(A+reg, BEGIN_A, COUNT_A);
break; /* a=0 a */
case 4: case 5: case 6: case 7:
case 8: case 9: case 0xa: case 0xb:
saturn_copy(reg_right[reg&7], BEGIN_A, COUNT_A, reg_left[reg&7]); /*correct */
break; /* a=b a */
case 0xc: case 0xd: case 0xe: case 0xf:
saturn_exchange(reg_left[reg&3], BEGIN_A, COUNT_A, reg_right[reg&3]);
break; /* abex a */
}
break;
case 0xe:
switch(reg=READ_OP()) {
case 0: case 1: case 2: case 3:
case 8: case 9: case 0xa: case 0xb:
saturn_sub(sub_left[reg], BEGIN_A, COUNT_A, S64_READ_A(sub_right[reg]));
break;
case 4: case 5: case 6: case 7:
saturn_increment(A+(reg&3), BEGIN_A, COUNT_A);
break; /* a=a+1 a */
case 0xc: case 0xd: case 0xe: case 0xf:
saturn_sub2(sub_left[reg], BEGIN_A, COUNT_A, S64_READ_A(sub_right[reg]));
break;
}
break;
case 0xf:
switch(reg=READ_OP()) {
case 0: case 1: case 2: case 3:
saturn_shift_nibble_left(A+reg,BEGIN_A, COUNT_A);
break; /* asl a */
case 4: case 5: case 6: case 7:
saturn_shift_nibble_right(A+(reg&3),BEGIN_A, COUNT_A);
break; /* asr a */
case 8: case 9: case 0xa: case 0xb:
saturn_invert(A+(reg&3),BEGIN_A, COUNT_A);
break; /* A=-A a */
case 0xc: case 0xd: case 0xe: case 0xf:
saturn_negate(A+(reg&3),BEGIN_A, COUNT_A);
break; /* A=-A-1 a */
}
break;
}
}
INLINE void saturn_exchange_adr_reg(int adr, int reg)
{
int temp=saturn.d[adr];
saturn.d[adr]=S64_READ_A(reg);
S64_WRITE_A(reg,temp);
}
INLINE void saturn_reg_to_adr(int reg, int adr)
{
saturn.d[adr]=S64_READ_A(reg);
}
INLINE void saturn_load_pc(int reg)
{
saturn.pc=S64_READ_A(reg);
change_pc(saturn.pc);
}
INLINE void saturn_indirect_jump(int reg)
{
saturn.pc=READ_20(S64_READ_A(reg));
change_pc(saturn.pc);
}
INLINE void saturn_push_c(void)
{
saturn_push(S64_READ_A(C));
}
INLINE void saturn_ca_p_1(void)
{
int a=S64_READ_A(C)+1+saturn.p;
saturn.carry=a>=0x100000;
S64_WRITE_A(C,a&0xfffff);
}
INLINE void saturn_mem_unconfig(void)
{
if (saturn.config->unconfig) saturn.config->unconfig(S64_READ_A(C));
}
