Intravision/reactos
1
0
Fork 0
mirror of https://github.com/reactos/reactos.git synced 2024-10-02 15:34:13 +00:00
Code Issues Packages Projects Releases Wiki Activity

[FAST486]

Browse source 
Finish implementing FPU opcode 0xDB (FILD, FIST, FISTP, FLD, FSTP).


svn path=/trunk/; revision=65927
This commit is contained in:
Aleksandar Andrejevic 2015-01-01 04:25:09 +00:00
parent e274681598
commit d89cf74100
2 changed files with 236 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

238
reactos/lib/fast486/fpu.c
View file

@ -67,9 +67,105 @@ UnsignedMult128(ULONGLONG Multiplicand,
}
static VOID
Fast486FpuGetSingleReal(PFAST486_STATE State,
ULONG Value,
PFAST486_FPU_DATA_REG Result)
Fast486FpuFromInteger(PFAST486_STATE State,
LONGLONG Value,
PFAST486_FPU_DATA_REG Result)
{
ULONG ZeroCount;
Result->Sign = Result->Exponent = Result->Mantissa = 0;
if (Value == 0LL) return;
if (Value < 0LL)
{
Result->Sign = 1;
Value = -Value;
}
Result->Mantissa = (ULONGLONG)Value;
ZeroCount = CountLeadingZeros64(Result->Mantissa);
Result->Mantissa <<= ZeroCount;
Result->Exponent = FPU_REAL10_BIAS + 63 - ZeroCount;
}
static BOOLEAN
Fast486FpuToInteger(PFAST486_STATE State,
PFAST486_FPU_DATA_REG Value,
PLONGLONG Result)
{
ULONG Bits;
ULONGLONG Remainder;
SHORT UnbiasedExp = (SHORT)Value->Exponent - FPU_REAL10_BIAS;
if (FPU_IS_ZERO(Value))
{
Result = 0LL;
return TRUE;
}
if (FPU_IS_NAN(Value) || !FPU_IS_NORMALIZED(Value)
|| (UnbiasedExp < 0) || (UnbiasedExp > 63))
{
State->FpuStatus.Ie = TRUE;
return FALSE;
}
Bits = 63 - UnbiasedExp;
/* Calculate the result and the remainder */
*Result = (LONGLONG)(Value->Mantissa >> Bits);
Remainder = Value->Mantissa & ((1 << Bits) - 1);
/* The result must be positive here */
ASSERT(*Result >= 0LL);
switch (State->FpuControl.Rc)
{
case FPU_ROUND_NEAREST:
{
/* Check if the highest bit of the remainder is set */
if (Remainder & (1 << (Bits - 1)))
{
*Result++;
/* Check if all the other bits are clear */
if (!(Remainder & ((1 << (Bits - 1)) - 1)))
{
/* Round to even */
*Result &= ~1;
}
}
break;
}
case FPU_ROUND_DOWN:
{
if ((Remainder != 0ULL) && Value->Sign) *Result++;
break;
}
case FPU_ROUND_UP:
{
if ((Remainder != 0ULL) && !Value->Sign) *Result++;
break;
}
default:
{
/* Leave it truncated */
}
}
if (Value->Sign) *Result = -*Result;
return TRUE;
}
static VOID
Fast486FpuFromSingleReal(PFAST486_STATE State,
ULONG Value,
PFAST486_FPU_DATA_REG Result)
{
/* Extract the sign, exponent and mantissa */
Result->Sign = (UCHAR)(Value >> 31);
@ -88,9 +184,9 @@ Fast486FpuGetSingleReal(PFAST486_STATE State,
}
static VOID
Fast486FpuGetDoubleReal(PFAST486_STATE State,
ULONGLONG Value,
PFAST486_FPU_DATA_REG Result)
Fast486FpuFromDoubleReal(PFAST486_STATE State,
ULONGLONG Value,
PFAST486_FPU_DATA_REG Result)
{
/* Extract the sign, exponent and mantissa */
Result->Sign = (UCHAR)(Value >> 63);
@ -347,7 +443,7 @@ FAST486_OPCODE_HANDLER(Fast486FpuOpcodeD8DC)
return;
}
Fast486FpuGetDoubleReal(State, Value, &MemoryData);
Fast486FpuFromDoubleReal(State, Value, &MemoryData);
}
else
{
@ -359,7 +455,7 @@ FAST486_OPCODE_HANDLER(Fast486FpuOpcodeD8DC)
return;
}
Fast486FpuGetSingleReal(State, Value, &MemoryData);
Fast486FpuFromSingleReal(State, Value, &MemoryData);
}
SourceOperand = &MemoryData;
@ -509,8 +605,130 @@ FAST486_OPCODE_HANDLER(Fast486FpuOpcodeDB)
if (ModRegRm.Memory)
{
// TODO: NOT IMPLEMENTED
UNIMPLEMENTED;
switch (ModRegRm.Register)
{
/* FILD */
case 0:
{
LONG Value;
FAST486_FPU_DATA_REG Temp;
if (!Fast486ReadModrmDwordOperands(State, &ModRegRm, NULL, (PULONG)&Value))
{
/* Exception occurred */
return;
}
Fast486FpuFromInteger(State, (LONGLONG)Value, &Temp);
Fast486FpuPush(State, &Temp);
break;
}
/* FIST */
case 2:
/* FISTP */
case 3:
{
LONGLONG Temp;
if ((FPU_GET_TAG(0) == FPU_TAG_EMPTY) || (FPU_GET_TAG(0) == FPU_TAG_SPECIAL))
{
/* Fail */
State->FpuStatus.Ie = TRUE;
return;
}
if (!Fast486FpuToInteger(State, &FPU_ST(0), &Temp))
{
/* Exception occurred */
return;
}
/* Check if it can fit in a signed 32-bit integer */
if ((((ULONGLONG)Temp >> 31) + 1ULL) > 1ULL)
{
State->FpuStatus.Ie = TRUE;
return;
}
if (!Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, (ULONG)((LONG)Temp)))
{
/* Exception occurred */
return;
}
if (ModRegRm.Register == 3)
{
/* Pop the FPU stack too */
Fast486FpuPop(State);
}
break;
}
/* FLD */
case 5:
{
FAST486_FPU_DATA_REG Value;
UCHAR Buffer[10];
if (!Fast486ReadMemory(State,
(State->PrefixFlags & FAST486_PREFIX_SEG)
? State->SegmentOverride : FAST486_REG_DS,
ModRegRm.MemoryAddress,
FALSE,
Buffer,
sizeof(Buffer)))
{
/* Exception occurred */
return;
}
Value.Mantissa = *((PULONGLONG)Buffer);
Value.Exponent = *((PUSHORT)&Buffer[8]) & (FPU_MAX_EXPONENT + 1);
Value.Sign = *((PUCHAR)&Buffer[9]) >> 7;
Fast486FpuPush(State, &Value);
break;
}
/* FSTP */
case 7:
{
UCHAR Buffer[10];
if ((FPU_GET_TAG(0) == FPU_TAG_EMPTY) || (FPU_GET_TAG(0) == FPU_TAG_SPECIAL))
{
/* Fail */
State->FpuStatus.Ie = TRUE;
return;
}
*((PULONGLONG)Buffer) = FPU_ST(0).Mantissa;
*((PUSHORT)&Buffer[sizeof(ULONGLONG)]) = FPU_ST(0).Exponent | (FPU_ST(0).Sign ? 0x8000 : 0);
if (!Fast486WriteMemory(State,
(State->PrefixFlags & FAST486_PREFIX_SEG)
? State->SegmentOverride : FAST486_REG_DS,
ModRegRm.MemoryAddress,
Buffer,
sizeof(Buffer)))
{
/* Exception occurred */
return;
}
Fast486FpuPop(State);
break;
}
/* Invalid */
default:
{
Fast486Exception(State, FAST486_EXCEPTION_UD);
}
}
}
else
{

8
reactos/lib/fast486/fpu.h
View file

@ -68,6 +68,14 @@ enum
FPU_TAG_EMPTY = 3
};
enum
{
FPU_ROUND_NEAREST = 0,
FPU_ROUND_DOWN = 1,
FPU_ROUND_UP = 2,
FPU_ROUND_TRUNCATE = 3
};
FAST486_OPCODE_HANDLER(Fast486FpuOpcodeD8DC);
FAST486_OPCODE_HANDLER(Fast486FpuOpcodeD9);
FAST486_OPCODE_HANDLER(Fast486FpuOpcodeDA);