📄 float.c
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DoubleOperand1.MantissaHigh |= (DoubleValue.LowPart >> 30);
return KiNormalizeDouble(&ContextBlock,
&DoubleOperand1,
StickyBits);
} else {
break;
}
//
// Floating absolute operation.
//
// Floating absolute is accomplished by clearing the sign
// of the floating value.
//
case FLOAT_ABSOLUTE:
if (Format == FORMAT_SINGLE) {
//
// Clear the sign, normalize the result, and store in the
// destination register.
//
SingleOperand1.Sign = 0;
return KiNormalizeSingle(&ContextBlock,
&SingleOperand1,
0);
} else if (Format == FORMAT_DOUBLE) {
//
// Clear the sign, normalize the result, and store in the
// destination register.
//
DoubleOperand1.Sign = 0;
return KiNormalizeDouble(&ContextBlock,
&DoubleOperand1,
0);
} else {
break;
}
//
// Floating move operation.
//
// Floating move is accomplished by moving the source operand
// to the destination register.
//
case FLOAT_MOVE:
if (Format == FORMAT_SINGLE) {
//
// Normalize the result and store in the destination
// register.
//
return KiNormalizeSingle(&ContextBlock,
&SingleOperand1,
0);
} else if (Format == FORMAT_DOUBLE) {
//
// Normalize the result and store in the destination
// register.
//
return KiNormalizeDouble(&ContextBlock,
&DoubleOperand1,
0);
} else {
break;
}
//
// Floating negate operation.
//
// Floating absolute is accomplished by complementing the sign
// of the floating value.
//
case FLOAT_NEGATE:
if (Format == FORMAT_SINGLE) {
//
// Complement the sign, normalize the result, and store in the
// destination register.
//
SingleOperand1.Sign ^= 0x1;
return KiNormalizeSingle(&ContextBlock,
&SingleOperand1,
0);
} else if (Format == FORMAT_DOUBLE) {
//
// Complement the sign, normalize the result, and store in the
// destination register.
//
DoubleOperand1.Sign ^= 0x1;
return KiNormalizeDouble(&ContextBlock,
&DoubleOperand1,
0);
} else {
break;
}
//
// Floating compare single.
//
// This operation is performed after having separated out NaNs,
// and therefore the only comparison predicates left are equal
// and less.
//
// Floating compare single is accomplished by comparing signs,
// then exponents, and finally the mantissa if necessary.
//
// N.B. The sign of zero is ignored.
//
case FLOAT_COMPARE_SINGLE:
//
// If either operand is zero, then set the sign of the operand
// positive.
//
if ((SingleOperand1.Infinity == FALSE) &&
(SingleOperand1.Mantissa == 0)) {
SingleOperand1.Sign = 0;
SingleOperand1.Exponent = - 23;
}
if ((SingleOperand2.Infinity == FALSE) &&
(SingleOperand2.Mantissa == 0)) {
SingleOperand2.Sign = 0;
SingleOperand2.Exponent = - 23;
}
//
// Compare signs first.
//
if (SingleOperand1.Sign < SingleOperand2.Sign) {
//
// The first operand is greater than the second operand.
//
CompareEqual = FALSE;
CompareLess = FALSE;
} else if (SingleOperand1.Sign > SingleOperand2.Sign) {
//
// The first operand is less than the second operand.
//
CompareEqual = FALSE;
CompareLess = TRUE;
} else {
//
// The operand signs are equal.
//
// If the sign of the operand is negative, then the sense of
// the comparison is reversed.
//
if (SingleOperand1.Sign == 0) {
//
// Compare positive operand with positive operand.
//
if (SingleOperand1.Exponent > SingleOperand2.Exponent) {
CompareEqual = FALSE;
CompareLess = FALSE;
} else if (SingleOperand1.Exponent < SingleOperand2.Exponent) {
CompareEqual = FALSE;
CompareLess = TRUE;
} else {
if (SingleOperand1.Mantissa > SingleOperand2.Mantissa) {
CompareEqual = FALSE;
CompareLess = FALSE;
} else if (SingleOperand1.Mantissa < SingleOperand2.Mantissa) {
CompareEqual = FALSE;
CompareLess = TRUE;
} else {
CompareEqual = TRUE;
CompareLess = FALSE;
}
}
} else {
//
// Compare negative operand with negative operand.
//
if (SingleOperand2.Exponent > SingleOperand1.Exponent) {
CompareEqual = FALSE;
CompareLess = FALSE;
} else if (SingleOperand2.Exponent < SingleOperand1.Exponent) {
CompareEqual = FALSE;
CompareLess = TRUE;
} else {
if (SingleOperand2.Mantissa > SingleOperand1.Mantissa) {
CompareEqual = FALSE;
CompareLess = FALSE;
} else if (SingleOperand2.Mantissa < SingleOperand1.Mantissa) {
CompareEqual = FALSE;
CompareLess = TRUE;
} else {
CompareEqual = TRUE;
CompareLess = FALSE;
}
}
}
}
//
// Form the condition code using the comparison information
// and the compare function predicate bits.
//
if (((CompareLess != FALSE) &&
((CompareFunction & COMPARE_LESS_MASK) != 0)) ||
((CompareEqual != FALSE) &&
((CompareFunction & COMPARE_EQUAL_MASK) != 0))) {
((PFSR)&pctx->Fsr)->CC = 1;
} else {
((PFSR)&pctx->Fsr)->CC = 0;
}
pctx->Fir = ContextBlock.BranchAddress;
return TRUE;
//
// Floating compare double.
//
// This operation is performed after having separated out NaNs,
// and therefore the only comparison predicates left are equal
// and less.
//
// Floating compare double is accomplished by comparing signs,
// then exponents, and finally the mantissa if necessary.
//
// N.B. The sign of zero is ignored.
//
case FLOAT_COMPARE_DOUBLE:
//
// If either operand is zero, then set the sign of the operand
// positive.
//
if ((DoubleOperand1.Infinity == FALSE) &&
(DoubleOperand1.MantissaHigh == 0)) {
DoubleOperand1.Sign = 0;
DoubleOperand1.Exponent = - 52;
}
if ((DoubleOperand2.Infinity == FALSE) &&
(DoubleOperand2.MantissaHigh == 0)) {
DoubleOperand2.Sign = 0;
DoubleOperand2.Exponent = - 52;
}
//
// Compare signs first.
//
if (DoubleOperand1.Sign < DoubleOperand2.Sign) {
//
// The first operand is greater than the second operand.
//
CompareEqual = FALSE;
CompareLess = FALSE;
} else if (DoubleOperand1.Sign > DoubleOperand2.Sign) {
//
// The first operand is less than the second operand.
//
CompareEqual = FALSE;
CompareLess = TRUE;
} else {
//
// The operand signs are equal.
//
// If the sign of the operand is negative, then the sense of
// the comparison is reversed.
//
if (DoubleOperand1.Sign == 0) {
//
// Compare positive operand with positive operand.
//
if (DoubleOperand1.Exponent > DoubleOperand2.Exponent) {
CompareEqual = FALSE;
CompareLess = FALSE;
} else if (DoubleOperand1.Exponent < DoubleOperand2.Exponent) {
CompareEqual = FALSE;
CompareLess = TRUE;
} else {
if (DoubleOperand1.MantissaHigh >
DoubleOperand2.MantissaHigh) {
CompareEqual = FALSE;
CompareLess = FALSE;
} else if (DoubleOperand1.MantissaHigh <
DoubleOperand2.MantissaHigh) {
CompareEqual = FALSE;
CompareLess = TRUE;
} else {
if (DoubleOperand1.MantissaLow >
DoubleOperand2.MantissaLow) {
CompareEqual = FALSE;
CompareLess = FALSE;
} else if (DoubleOperand1.MantissaLow <
DoubleOperand2.MantissaL⌨️ 快捷键说明
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