lsnes/snes/smp/core/opcode_misc.cpp
2013-05-03 17:47:19 +03:00

148 lines
2.6 KiB
C++
Executable file

#ifdef SMPCORE_CPP
void SMPcore::op_nop() {
op_io();
}
void SMPcore::op_wait() {
while(true) {
op_io();
op_io();
}
}
void SMPcore::op_xcn() {
op_io();
op_io();
op_io();
op_io();
regs.a = (regs.a >> 4) | (regs.a << 4);
regs.p.n = (regs.a & 0x80);
regs.p.z = (regs.a == 0);
}
void SMPcore::op_daa() {
op_io();
op_io();
if(regs.p.c || (regs.a) > 0x99) {
regs.a += 0x60;
regs.p.c = 1;
}
if(regs.p.h || (regs.a & 15) > 0x09) {
regs.a += 0x06;
}
regs.p.n = (regs.a & 0x80);
regs.p.z = (regs.a == 0);
}
void SMPcore::op_das() {
op_io();
op_io();
if(!regs.p.c || (regs.a) > 0x99) {
regs.a -= 0x60;
regs.p.c = 0;
}
if(!regs.p.h || (regs.a & 15) > 0x09) {
regs.a -= 0x06;
}
regs.p.n = (regs.a & 0x80);
regs.p.z = (regs.a == 0);
}
template<int mask, int value> void SMPcore::op_setbit() {
op_io();
regs.p = (regs.p & ~mask) | value;
}
void SMPcore::op_notc() {
op_io();
op_io();
regs.p.c = !regs.p.c;
}
template<int value> void SMPcore::op_seti() {
op_io();
op_io();
regs.p.i = value;
}
template<int op, int value> void SMPcore::op_setbit_dp() {
dp = op_readpc();
rd = op_readdp(dp);
rd = (op ? rd | value : rd & ~value);
op_writedp(dp, rd);
}
template<int n> void SMPcore::op_push_reg() {
op_io();
op_io();
op_writesp(regs.r[n]);
}
void SMPcore::op_push_p() {
op_io();
op_io();
op_writesp(regs.p);
}
template<int n> void SMPcore::op_pop_reg() {
op_io();
op_io();
regs.r[n] = op_readsp();
}
void SMPcore::op_pop_p() {
op_io();
op_io();
regs.p = op_readsp();
}
void SMPcore::op_mul_ya() {
op_io();
op_io();
op_io();
op_io();
op_io();
op_io();
op_io();
op_io();
ya = regs.y * regs.a;
regs.a = ya;
regs.y = ya >> 8;
//result is set based on y (high-byte) only
regs.p.n = (regs.y & 0x80);
regs.p.z = (regs.y == 0);
}
void SMPcore::op_div_ya_x() {
op_io();
op_io();
op_io();
op_io();
op_io();
op_io();
op_io();
op_io();
op_io();
op_io();
op_io();
ya = regs.ya;
//overflow set if quotient >= 256
regs.p.v = (regs.y >= regs.x);
regs.p.h = ((regs.y & 15) >= (regs.x & 15));
if(regs.y < (regs.x << 1)) {
//if quotient is <= 511 (will fit into 9-bit result)
regs.a = ya / regs.x;
regs.y = ya % regs.x;
} else {
//otherwise, the quotient won't fit into regs.p.v + regs.a
//this emulates the odd behavior of the S-SMP in this case
regs.a = 255 - (ya - (regs.x << 9)) / (256 - regs.x);
regs.y = regs.x + (ya - (regs.x << 9)) % (256 - regs.x);
}
//result is set based on a (quotient) only
regs.p.n = (regs.a & 0x80);
regs.p.z = (regs.a == 0);
}
#endif