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[FAST486]

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Implement F2XM1 using a Maclaurin series.


svn path=/trunk/; revision=67814
This commit is contained in:
Aleksandar Andrejevic 2015-05-17 16:21:29 +00:00
parent ade7bb8278
commit abd0364559
2 changed files with 126 additions and 25 deletions
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149
reactos/lib/fast486/fpu.c
View file

@ -53,6 +53,30 @@ static const FAST486_FPU_DATA_REG FpuLgTwo = {0x9A209A84FBCFF798ULL, FPU_REAL10_
/* ln(2) */
static const FAST486_FPU_DATA_REG FpuLnTwo = {0xB17217F7D1CF79ABULL, FPU_REAL10_BIAS - 1, FALSE};
static const FAST486_FPU_DATA_REG FpuInverseNumber[INVERSE_NUMBERS_COUNT] =
{
{0x8000000000000000ULL, FPU_REAL10_BIAS, FALSE}, /* 1 / 1 */
{0x8000000000000000ULL, FPU_REAL10_BIAS - 1, FALSE}, /* 1 / 2 */
{0xAAAAAAAAAAAAAAABULL, FPU_REAL10_BIAS - 2, FALSE}, /* 1 / 3 */
{0x8000000000000000ULL, FPU_REAL10_BIAS - 2, FALSE}, /* 1 / 4 */
{0xCCCCCCCCCCCCCCCDULL, FPU_REAL10_BIAS - 3, FALSE}, /* 1 / 5 */
{0xAAAAAAAAAAAAAAAAULL, FPU_REAL10_BIAS - 3, FALSE}, /* 1 / 6 */
{0x9249249249249249ULL, FPU_REAL10_BIAS - 3, FALSE}, /* 1 / 7 */
{0x8000000000000000ULL, FPU_REAL10_BIAS - 3, FALSE}, /* 1 / 8 */
{0xE38E38E38E38E38EULL, FPU_REAL10_BIAS - 4, FALSE}, /* 1 / 9 */
{0xCCCCCCCCCCCCCCCDULL, FPU_REAL10_BIAS - 4, FALSE}, /* 1 / 10 */
{0xBA2E8BA2E8BA2E8CULL, FPU_REAL10_BIAS - 4, FALSE}, /* 1 / 11 */
{0xAAAAAAAAAAAAAAABULL, FPU_REAL10_BIAS - 4, FALSE}, /* 1 / 12 */
{0x9D89D89D89D89D8AULL, FPU_REAL10_BIAS - 4, FALSE}, /* 1 / 13 */
{0x9249249249249249ULL, FPU_REAL10_BIAS - 4, FALSE}, /* 1 / 14 */
{0x8888888888888889ULL, FPU_REAL10_BIAS - 4, FALSE}, /* 1 / 15 */
{0x8000000000000000ULL, FPU_REAL10_BIAS - 4, FALSE}, /* 1 / 16 */
{0xF0F0F0F0F0F0F0F0ULL, FPU_REAL10_BIAS - 5, FALSE}, /* 1 / 17 */
{0xE38E38E38E38E38EULL, FPU_REAL10_BIAS - 5, FALSE}, /* 1 / 18 */
{0xD79435E50D79435EULL, FPU_REAL10_BIAS - 5, FALSE}, /* 1 / 19 */
{0xCCCCCCCCCCCCCCCDULL, FPU_REAL10_BIAS - 5, FALSE}, /* 1 / 20 */
};
/* PRIVATE FUNCTIONS **********************************************************/
#ifndef FAST486_NO_FPU
@ -527,7 +551,7 @@ Fast486FpuToPackedBcd(PFAST486_STATE State,
return TRUE;
}
static inline VOID FASTCALL
static inline BOOLEAN FASTCALL
Fast486FpuAdd(PFAST486_STATE State,
PCFAST486_FPU_DATA_REG FirstOperand,
PCFAST486_FPU_DATA_REG SecondOperand,
@ -545,7 +569,7 @@ Fast486FpuAdd(PFAST486_STATE State,
if (!State->FpuControl.Dm)
{
Fast486FpuException(State);
return;
return FALSE;
}
}
@ -604,7 +628,7 @@ Fast486FpuAdd(PFAST486_STATE State,
else
{
Fast486FpuException(State);
return;
return FALSE;
}
}
else
@ -617,11 +641,17 @@ Fast486FpuAdd(PFAST486_STATE State,
}
/* Normalize the result and return it */
Fast486FpuNormalize(State, &TempResult);
if (!Fast486FpuNormalize(State, &TempResult))
{
/* Exception occurred */
return FALSE;
}
*Result = TempResult;
return TRUE;
}
static inline VOID FASTCALL
static inline BOOLEAN FASTCALL
Fast486FpuSubtract(PFAST486_STATE State,
PCFAST486_FPU_DATA_REG FirstOperand,
PCFAST486_FPU_DATA_REG SecondOperand,
@ -633,7 +663,7 @@ Fast486FpuSubtract(PFAST486_STATE State,
NegativeSecondOperand.Sign = !NegativeSecondOperand.Sign;
/* And perform an addition instead */
Fast486FpuAdd(State, FirstOperand, &NegativeSecondOperand, Result);
return Fast486FpuAdd(State, FirstOperand, &NegativeSecondOperand, Result);
}
static inline VOID FASTCALL
@ -689,7 +719,7 @@ Fast486FpuCompare(PFAST486_STATE State,
}
}
static inline VOID FASTCALL
static inline BOOLEAN FASTCALL
Fast486FpuMultiply(PFAST486_STATE State,
PCFAST486_FPU_DATA_REG FirstOperand,
PCFAST486_FPU_DATA_REG SecondOperand,
@ -707,7 +737,7 @@ Fast486FpuMultiply(PFAST486_STATE State,
Result->Sign = TRUE;
Result->Exponent = FPU_MAX_EXPONENT + 1;
Result->Mantissa = FPU_INDEFINITE_MANTISSA;
return;
return TRUE;
}
if (FPU_IS_ZERO(FirstOperand) || FPU_IS_ZERO(SecondOperand))
@ -716,7 +746,7 @@ Fast486FpuMultiply(PFAST486_STATE State,
Result->Sign = FirstOperand->Sign ^ SecondOperand->Sign;
Result->Exponent = 0;
Result->Mantissa = 0ULL;
return;
return TRUE;
}
if (FPU_IS_INFINITY(FirstOperand) || FPU_IS_INFINITY(SecondOperand))
@ -725,7 +755,7 @@ Fast486FpuMultiply(PFAST486_STATE State,
Result->Sign = FirstOperand->Sign ^ SecondOperand->Sign;
Result->Exponent = FPU_MAX_EXPONENT + 1;
Result->Mantissa = FPU_MANTISSA_HIGH_BIT;
return;
return TRUE;
}
if ((!FPU_IS_NORMALIZED(FirstOperand) || !FPU_IS_NORMALIZED(SecondOperand)))
@ -736,7 +766,7 @@ Fast486FpuMultiply(PFAST486_STATE State,
if (!State->FpuControl.Dm)
{
Fast486FpuException(State);
return;
return FALSE;
}
}
@ -759,7 +789,7 @@ Fast486FpuMultiply(PFAST486_STATE State,
if (!State->FpuControl.Um)
{
Fast486FpuException(State);
return;
return FALSE;
}
/* The exponent will be zero */
@ -777,7 +807,7 @@ Fast486FpuMultiply(PFAST486_STATE State,
if (!State->FpuControl.Om)
{
Fast486FpuException(State);
return;
return FALSE;
}
/* Make the result infinity */
@ -787,11 +817,17 @@ Fast486FpuMultiply(PFAST486_STATE State,
else TempResult.Exponent = (USHORT)Exponent;
/* Normalize the result */
Fast486FpuNormalize(State, &TempResult);
if (!Fast486FpuNormalize(State, &TempResult))
{
/* Exception occurred */
return FALSE;
}
*Result = TempResult;
return TRUE;
}
static inline VOID FASTCALL
static inline BOOLEAN FASTCALL
Fast486FpuDivide(PFAST486_STATE State,
PCFAST486_FPU_DATA_REG FirstOperand,
PCFAST486_FPU_DATA_REG SecondOperand,
@ -815,10 +851,13 @@ Fast486FpuDivide(PFAST486_STATE State,
Result->Sign = TRUE;
Result->Exponent = FPU_MAX_EXPONENT + 1;
Result->Mantissa = FPU_INDEFINITE_MANTISSA;
return TRUE;
}
else
{
Fast486FpuException(State);
return FALSE;
}
else Fast486FpuException(State);
return;
}
if (FPU_IS_ZERO(SecondOperand) || FPU_IS_INFINITY(FirstOperand))
@ -832,10 +871,13 @@ Fast486FpuDivide(PFAST486_STATE State,
Result->Sign = FirstOperand->Sign;
Result->Exponent = FPU_MAX_EXPONENT + 1;
Result->Mantissa = FPU_MANTISSA_HIGH_BIT;
return TRUE;
}
else
{
Fast486FpuException(State);
return FALSE;
}
else Fast486FpuException(State);
return;
}
/* Calculate the sign of the result */
@ -847,7 +889,7 @@ Fast486FpuDivide(PFAST486_STATE State,
Result->Sign = TempResult.Sign;
Result->Mantissa = 0ULL;
Result->Exponent = 0;
return;
return TRUE;
}
/* Calculate the exponent of the result */
@ -886,7 +928,62 @@ Fast486FpuDivide(PFAST486_STATE State,
TempResult.Exponent = (USHORT)(Exponent + FPU_REAL10_BIAS);
/* Normalize the result */
Fast486FpuNormalize(State, &TempResult);
if (!Fast486FpuNormalize(State, &TempResult))
{
/* Exception occurred */
return FALSE;
}
*Result = TempResult;
return TRUE;
}
/*
* Calculates using the identity:
* 2 ^ x - 1 = 1 + sum { 2 * (((x - 1) * ln(2)) ^ n) / n! }
*/
static inline VOID FASTCALL
Fast486FpuCalculateTwoPowerMinusOne(PFAST486_STATE State,
PFAST486_FPU_DATA_REG Operand,
PFAST486_FPU_DATA_REG Result)
{
INT i;
FAST486_FPU_DATA_REG TempResult = FpuOne;
FAST486_FPU_DATA_REG Value;
FAST486_FPU_DATA_REG SeriesElement;
/* Calculate the first series element, which is 2 * (x - 1) * ln(2) */
Fast486FpuSubtract(State, Operand, &FpuOne, &Value);
Fast486FpuMultiply(State, &Value, &FpuLnTwo, &Value);
Fast486FpuAdd(State, &Value, &Value, &SeriesElement);
for (i = 2; i < INVERSE_NUMBERS_COUNT; i++)
{
/* Add the series element to the final sum */
if (!Fast486FpuAdd(State, &TempResult, &SeriesElement, &TempResult))
{
/* An exception occurred */
return;
}
/*
* Calculate the next series element (partially) by multiplying
* it with (x - 1) * ln(2)
*/
if (!Fast486FpuMultiply(State, &SeriesElement, &Value, &SeriesElement))
{
/* An exception occurred */
return;
}
/* And now multiply the series element by the inverse counter */
if (!Fast486FpuMultiply(State, &SeriesElement, &FpuInverseNumber[i], &SeriesElement))
{
/* An exception occurred */
return;
}
}
*Result = TempResult;
}
@ -1471,8 +1568,10 @@ FAST486_OPCODE_HANDLER(Fast486FpuOpcodeD9)
/* F2XM1 */
case 0x30:
{
// TODO: NOT IMPLEMENTED
UNIMPLEMENTED;
FPU_SAVE_LAST_INST();
Fast486FpuCalculateTwoPowerMinusOne(State, &FPU_ST(0), &FPU_ST(0));
FPU_UPDATE_TAG(0);
break;
}

2
reactos/lib/fast486/fpu.h
View file

@ -71,6 +71,8 @@
#define FPU_IS_NEG_INF(x) (FPU_IS_INFINITY(x) && (x)->Sign)
#define FPU_IS_INDEFINITE(x) (FPU_IS_NAN(x) && !FPU_IS_INFINITY(x))
#define INVERSE_NUMBERS_COUNT 21
enum
{
FPU_SINGLE_PRECISION = 0,