Files
86Box/src/cpu/x86_ops_bcd.h
2023-08-11 19:11:32 -04:00

137 lines
3.1 KiB
C

static int
opAAA(uint32_t fetchdat)
{
flags_rebuild();
if ((cpu_state.flags & A_FLAG) || ((AL & 0xF) > 9)) {
/* On 286, it's indeed AX - behavior difference from 808x. */
AX += 6;
AH++;
cpu_state.flags |= (A_FLAG | C_FLAG);
} else
cpu_state.flags &= ~(A_FLAG | C_FLAG);
AL &= 0xF;
CLOCK_CYCLES(is486 ? 3 : 4);
PREFETCH_RUN(is486 ? 3 : 4, 1, -1, 0, 0, 0, 0, 0);
return 0;
}
static int
opAAD(uint32_t fetchdat)
{
int base = getbytef();
if (!cpu_isintel)
base = 10;
AL = (AH * base) + AL;
AH = 0;
setznp16(AX);
CLOCK_CYCLES((is486) ? 14 : 19);
PREFETCH_RUN(is486 ? 14 : 19, 2, -1, 0, 0, 0, 0, 0);
return 0;
}
static int
opAAM(uint32_t fetchdat)
{
int base = getbytef();
if (!base || !cpu_isintel)
base = 10;
AH = AL / base;
AL %= base;
setznp16(AX);
CLOCK_CYCLES((is486) ? 15 : 17);
PREFETCH_RUN(is486 ? 15 : 17, 2, -1, 0, 0, 0, 0, 0);
return 0;
}
static int
opAAS(uint32_t fetchdat)
{
flags_rebuild();
if ((cpu_state.flags & A_FLAG) || ((AL & 0xF) > 9)) {
/* On 286, it's indeed AX - behavior difference from 808x. */
AX -= 6;
AH--;
cpu_state.flags |= (A_FLAG | C_FLAG);
} else
cpu_state.flags &= ~(A_FLAG | C_FLAG);
AL &= 0xF;
CLOCK_CYCLES(is486 ? 3 : 4);
PREFETCH_RUN(is486 ? 3 : 4, 1, -1, 0, 0, 0, 0, 0);
return 0;
}
static int
opDAA(uint32_t fetchdat)
{
uint16_t tempw;
uint16_t old_AL;
uint16_t old_CF;
flags_rebuild();
old_AL = AL;
old_CF = cpu_state.flags & C_FLAG;
cpu_state.flags &= ~C_FLAG;
if (((AL & 0xf) > 9) || (cpu_state.flags & A_FLAG)) {
int tempi = ((uint16_t) AL) + 6;
AL += 6;
if (old_CF || (tempi & 0x100))
cpu_state.flags |= C_FLAG;
cpu_state.flags |= A_FLAG;
} else
cpu_state.flags &= ~A_FLAG;
if ((old_AL > 0x99) || old_CF) {
AL += 0x60;
cpu_state.flags |= C_FLAG;
} else
cpu_state.flags &= ~C_FLAG;
tempw = cpu_state.flags & (C_FLAG | A_FLAG);
setznp8(AL);
flags_rebuild();
cpu_state.flags = (cpu_state.flags & ~(C_FLAG | A_FLAG)) | tempw;
CLOCK_CYCLES(4);
PREFETCH_RUN(4, 1, -1, 0, 0, 0, 0, 0);
return 0;
}
static int
opDAS(uint32_t fetchdat)
{
uint16_t tempw;
uint16_t old_AL;
uint16_t old_CF;
flags_rebuild();
old_AL = AL;
old_CF = cpu_state.flags & C_FLAG;
cpu_state.flags &= ~C_FLAG;
if (((AL & 0xf) > 9) || (cpu_state.flags & A_FLAG)) {
int tempi = ((uint16_t) AL) - 6;
AL -= 6;
if (old_CF || (tempi & 0x100))
cpu_state.flags |= C_FLAG;
cpu_state.flags |= A_FLAG;
} else
cpu_state.flags &= ~A_FLAG;
if ((old_AL > 0x99) || old_CF) {
AL -= 0x60;
cpu_state.flags |= C_FLAG;
}
tempw = cpu_state.flags & (C_FLAG | A_FLAG);
setznp8(AL);
flags_rebuild();
cpu_state.flags = (cpu_state.flags & ~(C_FLAG | A_FLAG)) | tempw;
CLOCK_CYCLES(4);
PREFETCH_RUN(4, 1, -1, 0, 0, 0, 0, 0);
return 0;
}