bsnes/higan/processor/spc700/algorithms.cpp

131 lines
2.2 KiB
C++

auto SPC700::algorithmADC(uint8 x, uint8 y) -> uint8 {
int z = x + y + CF;
CF = z > 0xff;
ZF = (uint8)z == 0;
HF = (x ^ y ^ z) & 0x10;
VF = ~(x ^ y) & (x ^ z) & 0x80;
NF = z & 0x80;
return z;
}
auto SPC700::algorithmAND(uint8 x, uint8 y) -> uint8 {
x &= y;
ZF = x == 0;
NF = x & 0x80;
return x;
}
auto SPC700::algorithmASL(uint8 x) -> uint8 {
CF = x & 0x80;
x <<= 1;
ZF = x == 0;
NF = x & 0x80;
return x;
}
auto SPC700::algorithmCMP(uint8 x, uint8 y) -> uint8 {
int z = x - y;
CF = z >= 0;
ZF = (uint8)z == 0;
NF = z & 0x80;
return x;
}
auto SPC700::algorithmDEC(uint8 x) -> uint8 {
x--;
ZF = x == 0;
NF = x & 0x80;
return x;
}
auto SPC700::algorithmEOR(uint8 x, uint8 y) -> uint8 {
x ^= y;
ZF = x == 0;
NF = x & 0x80;
return x;
}
auto SPC700::algorithmINC(uint8 x) -> uint8 {
x++;
ZF = x == 0;
NF = x & 0x80;
return x;
}
auto SPC700::algorithmLD(uint8 x, uint8 y) -> uint8 {
ZF = y == 0;
NF = y & 0x80;
return y;
}
auto SPC700::algorithmLSR(uint8 x) -> uint8 {
CF = x & 0x01;
x >>= 1;
ZF = x == 0;
NF = x & 0x80;
return x;
}
auto SPC700::algorithmOR(uint8 x, uint8 y) -> uint8 {
x |= y;
ZF = x == 0;
NF = x & 0x80;
return x;
}
auto SPC700::algorithmROL(uint8 x) -> uint8 {
bool carry = CF;
CF = x & 0x80;
x = x << 1 | carry;
ZF = x == 0;
NF = x & 0x80;
return x;
}
auto SPC700::algorithmROR(uint8 x) -> uint8 {
bool carry = CF;
CF = x & 0x01;
x = carry << 7 | x >> 1;
ZF = x == 0;
NF = x & 0x80;
return x;
}
auto SPC700::algorithmSBC(uint8 x, uint8 y) -> uint8 {
return algorithmADC(x, ~y);
}
//
auto SPC700::algorithmADW(uint16 x, uint16 y) -> uint16 {
uint16 z;
CF = 0;
z = algorithmADC(x, y);
z |= algorithmADC(x >> 8, y >> 8) << 8;
ZF = z == 0;
return z;
}
auto SPC700::algorithmCPW(uint16 x, uint16 y) -> uint16 {
int z = x - y;
CF = z >= 0;
ZF = (uint16)z == 0;
NF = z & 0x8000;
return x;
}
auto SPC700::algorithmLDW(uint16 x, uint16 y) -> uint16 {
ZF = y == 0;
NF = y & 0x8000;
return y;
}
auto SPC700::algorithmSBW(uint16 x, uint16 y) -> uint16 {
uint16 z;
CF = 1;
z = algorithmSBC(x, y);
z |= algorithmSBC(x >> 8, y >> 8) << 8;
ZF = z == 0;
return z;
}