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Slight optimisation when DS/SS are 'flat' (base=0, limit=4G).

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This commit is contained in:
SarahW 2017-05-24 21:50:37 +01:00
commit 083ca3d4a2
10 changed files with 564 additions and 139 deletions
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28
src/x86_ops_misc.h
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@ -761,9 +761,17 @@ static int opLOADALL(uint32_t fetchdat)
ss = readmemw(0, 0x842) | (readmemb(0, 0x844) << 16);
_ss.access = readmemb(0, 0x845);
_ss.limit = readmemw(0, 0x846);
if (_ss.base == 0 && _ss.limit_low == 0 && _ss.limit_high == 0xffffffff)
cpu_cur_status |= CPU_STATUS_FLATSS;
else
cpu_cur_status &= ~CPU_STATUS_FLATSS;
ds = readmemw(0, 0x848) | (readmemb(0, 0x84A) << 16);
_ds.access = readmemb(0, 0x84B);
_ds.limit = readmemw(0, 0x84C);
if (_ds.base == 0 && _ds.limit_low == 0 && _ds.limit_high == 0xffffffff)
cpu_cur_status |= CPU_STATUS_FLATDS;
else
cpu_cur_status &= ~CPU_STATUS_FLATDS;
gdt.base = readmemw(0, 0x84E) | (readmemb(0, 0x850) << 16);
gdt.limit = readmemw(0, 0x852);
ldt.base = readmemw(0, 0x854) | (readmemb(0, 0x856) << 16);
@ -803,8 +811,28 @@ static void loadall_load_segment(uint32_t addr, x86seg *s)
if (s == &_cs) use32 = (segdat3 & 0x40) ? 0x300 : 0;
if (s == &_ss) stack32 = (segdat3 & 0x40) ? 1 : 0;
cpu_cur_status &= ~(CPU_STATUS_USE32 | CPU_STATUS_STACK32);
if (use32)
cpu_cur_status |= CPU_STATUS_USE32;
if (stack32)
cpu_cur_status |= CPU_STATUS_STACK32;
set_segment_limit(s, segdat3);
if (s == &_ds)
{
if (s->base == 0 && s->limit_low == 0 && s->limit_high == 0xffffffff)
cpu_cur_status |= CPU_STATUS_FLATDS;
else
cpu_cur_status &= ~CPU_STATUS_FLATDS;
}
if (s == &_ss)
{
if (s->base == 0 && s->limit_low == 0 && s->limit_high == 0xffffffff)
cpu_cur_status |= CPU_STATUS_FLATSS;
else
cpu_cur_status &= ~CPU_STATUS_FLATSS;
}
}
static int opLOADALL386(uint32_t fetchdat)