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Fixed lazy V flag on SHL/SHR/SAR - IBM AT & Acer 386 BIOSes work again.

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This commit is contained in:
TomW 2013-11-15 19:55:22 +00:00
commit 6c7b746bf9
2 changed files with 351 additions and 276 deletions
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78
src/x86_flags.h
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@ -12,7 +12,19 @@ enum
FLAGS_SUB8,
FLAGS_SUB16,
FLAGS_SUB32
FLAGS_SUB32,
FLAGS_SHL8,
FLAGS_SHL16,
FLAGS_SHL32,
FLAGS_SHR8,
FLAGS_SHR16,
FLAGS_SHR32,
FLAGS_SAR8,
FLAGS_SAR16,
FLAGS_SAR32,
};
static int flags_op;
@ -32,6 +44,15 @@ static inline int ZF_SET()
case FLAGS_SUB8:
case FLAGS_SUB16:
case FLAGS_SUB32:
case FLAGS_SHL8:
case FLAGS_SHL16:
case FLAGS_SHL32:
case FLAGS_SHR8:
case FLAGS_SHR16:
case FLAGS_SHR32:
case FLAGS_SAR8:
case FLAGS_SAR16:
case FLAGS_SAR32:
return !flags_res;
case FLAGS_UNKNOWN:
@ -46,16 +67,25 @@ static inline int NF_SET()
case FLAGS_ZN8:
case FLAGS_ADD8:
case FLAGS_SUB8:
case FLAGS_SHL8:
case FLAGS_SHR8:
case FLAGS_SAR8:
return flags_res & 0x80;
case FLAGS_ZN16:
case FLAGS_ADD16:
case FLAGS_SUB16:
case FLAGS_SHL16:
case FLAGS_SHR16:
case FLAGS_SAR16:
return flags_res & 0x8000;
case FLAGS_ZN32:
case FLAGS_ADD32:
case FLAGS_SUB32:
case FLAGS_SHL32:
case FLAGS_SHR32:
case FLAGS_SAR32:
return flags_res & 0x80000000;
case FLAGS_UNKNOWN:
@ -76,6 +106,15 @@ static inline int PF_SET()
case FLAGS_SUB8:
case FLAGS_SUB16:
case FLAGS_SUB32:
case FLAGS_SHL8:
case FLAGS_SHL16:
case FLAGS_SHL32:
case FLAGS_SHR8:
case FLAGS_SHR16:
case FLAGS_SHR32:
case FLAGS_SAR8:
case FLAGS_SAR16:
case FLAGS_SAR32:
return znptable8[flags_res & 0xff] & P_FLAG;
case FLAGS_UNKNOWN:
@ -87,9 +126,12 @@ static inline int VF_SET()
{
switch (flags_op)
{
case FLAGS_ZN8:
case FLAGS_ZN8:
case FLAGS_ZN16:
case FLAGS_ZN32:
case FLAGS_SAR8:
case FLAGS_SAR16:
case FLAGS_SAR32:
return 0;
case FLAGS_ADD8:
@ -105,7 +147,21 @@ static inline int VF_SET()
return ((flags_op1 ^ flags_op2) & (flags_op1 ^ flags_res) & 0x8000);
case FLAGS_SUB32:
return ((flags_op1 ^ flags_op2) & (flags_op1 ^ flags_res) & 0x80000000);
case FLAGS_SHL8:
return (((flags_op1 << flags_op2) ^ (flags_op1 << (flags_op2 - 1))) & 0x80);
case FLAGS_SHL16:
return (((flags_op1 << flags_op2) ^ (flags_op1 << (flags_op2 - 1))) & 0x8000);
case FLAGS_SHL32:
return (((flags_op1 << flags_op2) ^ (flags_op1 << (flags_op2 - 1))) & 0x80000000);
case FLAGS_SHR8:
return ((flags_op2 == 1) && (flags_op1 & 0x80));
case FLAGS_SHR16:
return ((flags_op2 == 1) && (flags_op1 & 0x8000));
case FLAGS_SHR32:
return ((flags_op2 == 1) && (flags_op1 & 0x80000000));
case FLAGS_UNKNOWN:
return flags & V_FLAG;
}
@ -118,6 +174,15 @@ static inline int AF_SET()
case FLAGS_ZN8:
case FLAGS_ZN16:
case FLAGS_ZN32:
case FLAGS_SHL8:
case FLAGS_SHL16:
case FLAGS_SHL32:
case FLAGS_SHR8:
case FLAGS_SHR16:
case FLAGS_SHR32:
case FLAGS_SAR8:
case FLAGS_SAR16:
case FLAGS_SAR32:
return 0;
case FLAGS_ADD8:
@ -214,6 +279,13 @@ static inline void setznp32(uint32_t val)
flags &= ~C_FLAG;
}
#define set_flags_shift(op, orig, shift, res) \
flags_op = op; \
flags_res = res; \
flags_op1 = orig; \
flags_op2 = shift; \
flags &= ~C_FLAG;
static inline void setadd8(uint8_t a, uint8_t b)
{
flags_op1 = a;