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Split the 286/386 interpreter away from the 486+ one (the 286/386 interpreter does not use the pccache's, readlookup's, and writelookup's as the emulated CPU's are too slow for them to be required, and also has more accurate FPU timings), also added a LPT status read function for future-proofing.

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This commit is contained in:
OBattler
2023-08-08 19:39:52 +02:00
parent 5f72dc7d56
commit b1c5cbaf47
23 changed files with 3759 additions and 144 deletions
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103
src/cpu/386_common.c
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@@ -67,6 +67,38 @@ int soft_reset_mask = 0;
int smi_latched = 0;
int smm_in_hlt = 0, smi_block = 0;
int prefetch_prefixes = 0;
int tempc, oldcpl, optype, inttype, oddeven = 0;
int timetolive;
uint16_t oldcs;
uint32_t oldds, oldss, olddslimit, oldsslimit,
olddslimitw, oldsslimitw;
uint32_t oxpc;
uint32_t rmdat32;
uint32_t backupregs[16];
x86seg _oldds;
int opcode_length[256] = { 3, 3, 3, 3, 3, 3, 1, 1, 3, 3, 3, 3, 3, 3, 1, 3, /* 0x0x */
3, 3, 3, 3, 3, 3, 1, 1, 3, 3, 3, 3, 3, 3, 1, 1, /* 0x1x */
3, 3, 3, 3, 3, 3, 1, 1, 3, 3, 3, 3, 3, 3, 1, 1, /* 0x2x */
3, 3, 3, 3, 3, 3, 1, 1, 3, 3, 3, 3, 3, 3, 1, 1, /* 0x3x */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x4x */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x5x */
1, 1, 3, 3, 1, 1, 1, 1, 3, 3, 2, 3, 1, 1, 1, 1, /* 0x6x */
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, /* 0x7x */
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 0x8x */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, /* 0x9x */
3, 3, 3, 3, 1, 1, 1, 1, 2, 3, 1, 1, 1, 1, 1, 1, /* 0xax */
2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, /* 0xbx */
3, 3, 3, 1, 3, 3, 3, 3, 3, 1, 3, 1, 1, 2, 1, 1, /* 0xcx */
3, 3, 3, 3, 2, 2, 1, 1, 3, 3, 3, 3, 3, 3, 3, 3, /* 0xdx */
2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 2, 1, 1, 1, 1, /* 0xex */
1, 1, 1, 1, 1, 1, 3, 3, 1, 1, 1, 1, 1, 1, 3, 3 }; /* 0xfx */
uint32_t addr64, addr64_2;
uint32_t addr64a[8], addr64a_2[8];
@@ -321,6 +353,77 @@ x386_common_log(const char *fmt, ...)
# define x386_common_log(fmt, ...)
#endif
/*Prefetch emulation is a fairly simplistic model:
- All instruction bytes must be fetched before it starts.
- Cycles used for non-instruction memory accesses are counted and subtracted
from the total cycles taken
- Any remaining cycles are used to refill the prefetch queue.
Note that this is only used for 286 / 386 systems. It is disabled when the
internal cache on 486+ CPUs is enabled.
*/
static int prefetch_bytes = 0;
void
prefetch_run(int instr_cycles, int bytes, int modrm, int reads, int reads_l, int writes, int writes_l, int ea32)
{
int mem_cycles = reads * cpu_cycles_read + reads_l * cpu_cycles_read_l + writes * cpu_cycles_write + writes_l * cpu_cycles_write_l;
if (instr_cycles < mem_cycles)
instr_cycles = mem_cycles;
prefetch_bytes -= prefetch_prefixes;
prefetch_bytes -= bytes;
if (modrm != -1) {
if (ea32) {
if ((modrm & 7) == 4) {
if ((modrm & 0x700) == 0x500)
prefetch_bytes -= 5;
else if ((modrm & 0xc0) == 0x40)
prefetch_bytes -= 2;
else if ((modrm & 0xc0) == 0x80)
prefetch_bytes -= 5;
} else {
if ((modrm & 0xc7) == 0x05)
prefetch_bytes -= 4;
else if ((modrm & 0xc0) == 0x40)
prefetch_bytes--;
else if ((modrm & 0xc0) == 0x80)
prefetch_bytes -= 4;
}
} else {
if ((modrm & 0xc7) == 0x06)
prefetch_bytes -= 2;
else if ((modrm & 0xc0) != 0xc0)
prefetch_bytes -= ((modrm & 0xc0) >> 6);
}
}
/* Fill up prefetch queue */
while (prefetch_bytes < 0) {
prefetch_bytes += cpu_prefetch_width;
cycles -= cpu_prefetch_cycles;
}
/* Subtract cycles used for memory access by instruction */
instr_cycles -= mem_cycles;
while (instr_cycles >= cpu_prefetch_cycles) {
prefetch_bytes += cpu_prefetch_width;
instr_cycles -= cpu_prefetch_cycles;
}
prefetch_prefixes = 0;
if (prefetch_bytes > 16)
prefetch_bytes = 16;
}
void
prefetch_flush(void)
{
prefetch_bytes = 0;
}
static __inline void
set_stack32(int s)
{