//===----------------------------------------------------------------------===//
#include "llvm/ADT/APFloat.h"
-#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/APSInt.h"
#include "llvm/ADT/FoldingSet.h"
+#include "llvm/ADT/Hashing.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringRef.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
-#include <limits.h>
#include <cstring>
+#include <limits.h>
using namespace llvm;
/* Number of bits in the significand. This includes the integer
bit. */
unsigned int precision;
-
- /* True if arithmetic is supported. */
- unsigned int arithmeticOK;
};
- const fltSemantics APFloat::IEEEhalf = { 15, -14, 11, true };
- const fltSemantics APFloat::IEEEsingle = { 127, -126, 24, true };
- const fltSemantics APFloat::IEEEdouble = { 1023, -1022, 53, true };
- const fltSemantics APFloat::IEEEquad = { 16383, -16382, 113, true };
- const fltSemantics APFloat::x87DoubleExtended = { 16383, -16382, 64, true };
- const fltSemantics APFloat::Bogus = { 0, 0, 0, true };
-
- // The PowerPC format consists of two doubles. It does not map cleanly
- // onto the usual format above. For now only storage of constants of
- // this type is supported, no arithmetic.
- const fltSemantics APFloat::PPCDoubleDouble = { 1023, -1022, 106, false };
+ const fltSemantics APFloat::IEEEhalf = { 15, -14, 11 };
+ const fltSemantics APFloat::IEEEsingle = { 127, -126, 24 };
+ const fltSemantics APFloat::IEEEdouble = { 1023, -1022, 53 };
+ const fltSemantics APFloat::IEEEquad = { 16383, -16382, 113 };
+ const fltSemantics APFloat::x87DoubleExtended = { 16383, -16382, 64 };
+ const fltSemantics APFloat::Bogus = { 0, 0, 0 };
+
+ /* The PowerPC format consists of two doubles. It does not map cleanly
+ onto the usual format above. It is approximated using twice the
+ mantissa bits. Note that for exponents near the double minimum,
+ we no longer can represent the full 106 mantissa bits, so those
+ will be treated as denormal numbers.
+
+ FIXME: While this approximation is equivalent to what GCC uses for
+ compile-time arithmetic on PPC double-double numbers, it is not able
+ to represent all possible values held by a PPC double-double number,
+ for example: (long double) 1.0 + (long double) 0x1p-106
+ Should this be replaced by a full emulation of PPC double-double? */
+ const fltSemantics APFloat::PPCDoubleDouble = { 1023, -1022 + 53, 53 + 53 };
/* A tight upper bound on number of parts required to hold the value
pow(5, power) is
power * 815 / (351 * integerPartWidth) + 1
-
+
However, whilst the result may require only this many parts,
because we are multiplying two values to get it, the
multiplication may require an extra part with the excess part
return c - '0';
}
-static unsigned int
-hexDigitValue(unsigned int c)
-{
- unsigned int r;
-
- r = c - '0';
- if(r <= 9)
- return r;
-
- r = c - 'A';
- if(r <= 5)
- return r + 10;
-
- r = c - 'a';
- if(r <= 5)
- return r + 10;
-
- return -1U;
-}
-
-static inline void
-assertArithmeticOK(const llvm::fltSemantics &semantics) {
- assert(semantics.arithmeticOK
- && "Compile-time arithmetic does not support these semantics");
-}
-
/* Return the value of a decimal exponent of the form
[+-]ddddddd.
value += absExponent * 10;
if (absExponent >= overlargeExponent) {
absExponent = overlargeExponent;
+ p = end; /* outwit assert below */
break;
}
absExponent = value;
{
int unsignedExponent;
bool negative, overflow;
- int exponent;
+ int exponent = 0;
assert(p != end && "Exponent has no digits");
negative = *p == '-';
- if(*p == '-' || *p == '+') {
+ if (*p == '-' || *p == '+') {
p++;
assert(p != end && "Exponent has no digits");
}
unsignedExponent = 0;
overflow = false;
- for(; p != end; ++p) {
+ for (; p != end; ++p) {
unsigned int value;
value = decDigitValue(*p);
assert(value < 10U && "Invalid character in exponent");
unsignedExponent = unsignedExponent * 10 + value;
- if(unsignedExponent > 65535)
+ if (unsignedExponent > 32767) {
overflow = true;
+ break;
+ }
}
- if(exponentAdjustment > 65535 || exponentAdjustment < -65536)
+ if (exponentAdjustment > 32767 || exponentAdjustment < -32768)
overflow = true;
- if(!overflow) {
+ if (!overflow) {
exponent = unsignedExponent;
- if(negative)
+ if (negative)
exponent = -exponent;
exponent += exponentAdjustment;
- if(exponent > 65535 || exponent < -65536)
+ if (exponent > 32767 || exponent < -32768)
overflow = true;
}
- if(overflow)
- exponent = negative ? -65536: 65535;
+ if (overflow)
+ exponent = negative ? -32768: 32767;
return exponent;
}
{
StringRef::iterator p = begin;
*dot = end;
- while(*p == '0' && p != end)
+ while (*p == '0' && p != end)
p++;
- if(*p == '.') {
+ if (*p == '.') {
*dot = p++;
assert(end - begin != 1 && "Significand has no digits");
- while(*p == '0' && p != end)
+ while (*p == '0' && p != end)
p++;
}
/* If the first trailing digit isn't 0 or 8 we can work out the
fraction immediately. */
- if(digitValue > 8)
+ if (digitValue > 8)
return lfMoreThanHalf;
- else if(digitValue < 8 && digitValue > 0)
+ else if (digitValue < 8 && digitValue > 0)
return lfLessThanHalf;
/* Otherwise we need to find the first non-zero digit. */
- while(*p == '0')
+ while (*p == '0')
p++;
assert(p != end && "Invalid trailing hexadecimal fraction!");
/* If we ran off the end it is exactly zero or one-half, otherwise
a little more. */
- if(hexDigit == -1U)
+ if (hexDigit == -1U)
return digitValue == 0 ? lfExactlyZero: lfExactlyHalf;
else
return digitValue == 0 ? lfLessThanHalf: lfMoreThanHalf;
lsb = APInt::tcLSB(parts, partCount);
/* Note this is guaranteed true if bits == 0, or LSB == -1U. */
- if(bits <= lsb)
+ if (bits <= lsb)
return lfExactlyZero;
- if(bits == lsb + 1)
+ if (bits == lsb + 1)
return lfExactlyHalf;
- if(bits <= partCount * integerPartWidth
- && APInt::tcExtractBit(parts, bits - 1))
+ if (bits <= partCount * integerPartWidth &&
+ APInt::tcExtractBit(parts, bits - 1))
return lfMoreThanHalf;
return lfLessThanHalf;
combineLostFractions(lostFraction moreSignificant,
lostFraction lessSignificant)
{
- if(lessSignificant != lfExactlyZero) {
- if(moreSignificant == lfExactlyZero)
+ if (lessSignificant != lfExactlyZero) {
+ if (moreSignificant == lfExactlyZero)
moreSignificant = lfLessThanHalf;
- else if(moreSignificant == lfExactlyHalf)
+ else if (moreSignificant == lfExactlyHalf)
moreSignificant = lfMoreThanHalf;
}
15625, 78125 };
integerPart pow5s[maxPowerOfFiveParts * 2 + 5];
pow5s[0] = 78125 * 5;
-
+
unsigned int partsCount[16] = { 1 };
integerPart scratch[maxPowerOfFiveParts], *p1, *p2, *pow5;
unsigned int result;
semantics = ourSemantics;
count = partCount();
- if(count > 1)
+ if (count > 1)
significand.parts = new integerPart[count];
}
void
APFloat::freeSignificand()
{
- if(partCount() > 1)
+ if (partCount() > 1)
delete [] significand.parts;
}
sign = rhs.sign;
category = rhs.category;
exponent = rhs.exponent;
- sign2 = rhs.sign2;
- exponent2 = rhs.exponent2;
- if(category == fcNormal || category == fcNaN)
+ if (category == fcNormal || category == fcNaN)
copySignificand(rhs);
}
APFloat &
APFloat::operator=(const APFloat &rhs)
{
- if(this != &rhs) {
- if(semantics != rhs.semantics) {
+ if (this != &rhs) {
+ if (semantics != rhs.semantics) {
freeSignificand();
initialize(rhs.semantics);
}
return *this;
}
+bool
+APFloat::isDenormal() const {
+ return isNormal() && (exponent == semantics->minExponent) &&
+ (APInt::tcExtractBit(significandParts(),
+ semantics->precision - 1) == 0);
+}
+
bool
APFloat::bitwiseIsEqual(const APFloat &rhs) const {
if (this == &rhs)
category != rhs.category ||
sign != rhs.sign)
return false;
- if (semantics==(const llvm::fltSemantics*)&PPCDoubleDouble &&
- sign2 != rhs.sign2)
- return false;
if (category==fcZero || category==fcInfinity)
return true;
else if (category==fcNormal && exponent!=rhs.exponent)
return false;
- else if (semantics==(const llvm::fltSemantics*)&PPCDoubleDouble &&
- exponent2!=rhs.exponent2)
- return false;
else {
int i= partCount();
const integerPart* p=significandParts();
}
}
-APFloat::APFloat(const fltSemantics &ourSemantics, integerPart value)
-{
- assertArithmeticOK(ourSemantics);
+APFloat::APFloat(const fltSemantics &ourSemantics, integerPart value) {
initialize(&ourSemantics);
sign = 0;
zeroSignificand();
}
APFloat::APFloat(const fltSemantics &ourSemantics) {
- assertArithmeticOK(ourSemantics);
initialize(&ourSemantics);
category = fcZero;
sign = false;
}
APFloat::APFloat(const fltSemantics &ourSemantics, uninitializedTag tag) {
- assertArithmeticOK(ourSemantics);
// Allocates storage if necessary but does not initialize it.
initialize(&ourSemantics);
}
APFloat::APFloat(const fltSemantics &ourSemantics,
- fltCategory ourCategory, bool negative)
-{
- assertArithmeticOK(ourSemantics);
+ fltCategory ourCategory, bool negative) {
initialize(&ourSemantics);
category = ourCategory;
sign = negative;
makeNaN();
}
-APFloat::APFloat(const fltSemantics &ourSemantics, const StringRef& text)
-{
- assertArithmeticOK(ourSemantics);
+APFloat::APFloat(const fltSemantics &ourSemantics, StringRef text) {
initialize(&ourSemantics);
convertFromString(text, rmNearestTiesToEven);
}
-APFloat::APFloat(const APFloat &rhs)
-{
+APFloat::APFloat(const APFloat &rhs) {
initialize(rhs.semantics);
assign(rhs);
}
/* Our callers should never cause us to overflow. */
assert(carry == 0);
+ (void)carry;
}
/* Add the significand of the RHS. Returns the carry flag. */
precision = semantics->precision;
newPartsCount = partCountForBits(precision * 2);
- if(newPartsCount > 4)
+ if (newPartsCount > 4)
fullSignificand = new integerPart[newPartsCount];
else
fullSignificand = scratch;
omsb = APInt::tcMSB(fullSignificand, newPartsCount) + 1;
exponent += rhs.exponent;
- if(addend) {
+ if (addend) {
Significand savedSignificand = significand;
const fltSemantics *savedSemantics = semantics;
fltSemantics extendedSemantics;
/* Normalize our MSB. */
extendedPrecision = precision + precision - 1;
- if(omsb != extendedPrecision)
- {
- APInt::tcShiftLeft(fullSignificand, newPartsCount,
- extendedPrecision - omsb);
- exponent -= extendedPrecision - omsb;
- }
+ if (omsb != extendedPrecision) {
+ APInt::tcShiftLeft(fullSignificand, newPartsCount,
+ extendedPrecision - omsb);
+ exponent -= extendedPrecision - omsb;
+ }
/* Create new semantics. */
extendedSemantics = *semantics;
extendedSemantics.precision = extendedPrecision;
- if(newPartsCount == 1)
+ if (newPartsCount == 1)
significand.part = fullSignificand[0];
else
significand.parts = fullSignificand;
APFloat extendedAddend(*addend);
status = extendedAddend.convert(extendedSemantics, rmTowardZero, &ignored);
assert(status == opOK);
+ (void)status;
lost_fraction = addOrSubtractSignificand(extendedAddend, false);
/* Restore our state. */
- if(newPartsCount == 1)
+ if (newPartsCount == 1)
fullSignificand[0] = significand.part;
significand = savedSignificand;
semantics = savedSemantics;
exponent -= (precision - 1);
- if(omsb > precision) {
+ if (omsb > precision) {
unsigned int bits, significantParts;
lostFraction lf;
APInt::tcAssign(lhsSignificand, fullSignificand, partsCount);
- if(newPartsCount > 4)
+ if (newPartsCount > 4)
delete [] fullSignificand;
return lost_fraction;
rhsSignificand = rhs.significandParts();
partsCount = partCount();
- if(partsCount > 2)
+ if (partsCount > 2)
dividend = new integerPart[partsCount * 2];
else
dividend = scratch;
divisor = dividend + partsCount;
/* Copy the dividend and divisor as they will be modified in-place. */
- for(i = 0; i < partsCount; i++) {
+ for (i = 0; i < partsCount; i++) {
dividend[i] = lhsSignificand[i];
divisor[i] = rhsSignificand[i];
lhsSignificand[i] = 0;
/* Normalize the divisor. */
bit = precision - APInt::tcMSB(divisor, partsCount) - 1;
- if(bit) {
+ if (bit) {
exponent += bit;
APInt::tcShiftLeft(divisor, partsCount, bit);
}
/* Normalize the dividend. */
bit = precision - APInt::tcMSB(dividend, partsCount) - 1;
- if(bit) {
+ if (bit) {
exponent -= bit;
APInt::tcShiftLeft(dividend, partsCount, bit);
}
/* Ensure the dividend >= divisor initially for the loop below.
Incidentally, this means that the division loop below is
guaranteed to set the integer bit to one. */
- if(APInt::tcCompare(dividend, divisor, partsCount) < 0) {
+ if (APInt::tcCompare(dividend, divisor, partsCount) < 0) {
exponent--;
APInt::tcShiftLeft(dividend, partsCount, 1);
assert(APInt::tcCompare(dividend, divisor, partsCount) >= 0);
}
/* Long division. */
- for(bit = precision; bit; bit -= 1) {
- if(APInt::tcCompare(dividend, divisor, partsCount) >= 0) {
+ for (bit = precision; bit; bit -= 1) {
+ if (APInt::tcCompare(dividend, divisor, partsCount) >= 0) {
APInt::tcSubtract(dividend, divisor, 0, partsCount);
APInt::tcSetBit(lhsSignificand, bit - 1);
}
/* Figure out the lost fraction. */
int cmp = APInt::tcCompare(dividend, divisor, partsCount);
- if(cmp > 0)
+ if (cmp > 0)
lost_fraction = lfMoreThanHalf;
- else if(cmp == 0)
+ else if (cmp == 0)
lost_fraction = lfExactlyHalf;
- else if(APInt::tcIsZero(dividend, partsCount))
+ else if (APInt::tcIsZero(dividend, partsCount))
lost_fraction = lfExactlyZero;
else
lost_fraction = lfLessThanHalf;
- if(partsCount > 2)
+ if (partsCount > 2)
delete [] dividend;
return lost_fraction;
{
assert(bits < semantics->precision);
- if(bits) {
+ if (bits) {
unsigned int partsCount = partCount();
APInt::tcShiftLeft(significandParts(), partsCount, bits);
/* If exponents are equal, do an unsigned bignum comparison of the
significands. */
- if(compare == 0)
+ if (compare == 0)
compare = APInt::tcCompare(significandParts(), rhs.significandParts(),
partCount());
- if(compare > 0)
+ if (compare > 0)
return cmpGreaterThan;
- else if(compare < 0)
+ else if (compare < 0)
return cmpLessThan;
else
return cmpEqual;
APFloat::handleOverflow(roundingMode rounding_mode)
{
/* Infinity? */
- if(rounding_mode == rmNearestTiesToEven
- || rounding_mode == rmNearestTiesToAway
- || (rounding_mode == rmTowardPositive && !sign)
- || (rounding_mode == rmTowardNegative && sign))
- {
- category = fcInfinity;
- return (opStatus) (opOverflow | opInexact);
- }
+ if (rounding_mode == rmNearestTiesToEven ||
+ rounding_mode == rmNearestTiesToAway ||
+ (rounding_mode == rmTowardPositive && !sign) ||
+ (rounding_mode == rmTowardNegative && sign)) {
+ category = fcInfinity;
+ return (opStatus) (opOverflow | opInexact);
+ }
/* Otherwise we become the largest finite number. */
category = fcNormal;
assert(lost_fraction != lfExactlyZero);
switch (rounding_mode) {
- default:
- llvm_unreachable(0);
-
case rmNearestTiesToAway:
return lost_fraction == lfExactlyHalf || lost_fraction == lfMoreThanHalf;
case rmNearestTiesToEven:
- if(lost_fraction == lfMoreThanHalf)
+ if (lost_fraction == lfMoreThanHalf)
return true;
/* Our zeroes don't have a significand to test. */
- if(lost_fraction == lfExactlyHalf && category != fcZero)
+ if (lost_fraction == lfExactlyHalf && category != fcZero)
return APInt::tcExtractBit(significandParts(), bit);
return false;
case rmTowardNegative:
return sign == true;
}
+ llvm_unreachable("Invalid rounding mode found");
}
APFloat::opStatus
unsigned int omsb; /* One, not zero, based MSB. */
int exponentChange;
- if(category != fcNormal)
+ if (category != fcNormal)
return opOK;
/* Before rounding normalize the exponent of fcNormal numbers. */
omsb = significandMSB() + 1;
- if(omsb) {
+ if (omsb) {
/* OMSB is numbered from 1. We want to place it in the integer
- bit numbered PRECISON if possible, with a compensating change in
+ bit numbered PRECISION if possible, with a compensating change in
the exponent. */
exponentChange = omsb - semantics->precision;
/* If the resulting exponent is too high, overflow according to
the rounding mode. */
- if(exponent + exponentChange > semantics->maxExponent)
+ if (exponent + exponentChange > semantics->maxExponent)
return handleOverflow(rounding_mode);
/* Subnormal numbers have exponent minExponent, and their MSB
is forced based on that. */
- if(exponent + exponentChange < semantics->minExponent)
+ if (exponent + exponentChange < semantics->minExponent)
exponentChange = semantics->minExponent - exponent;
/* Shifting left is easy as we don't lose precision. */
- if(exponentChange < 0) {
+ if (exponentChange < 0) {
assert(lost_fraction == lfExactlyZero);
shiftSignificandLeft(-exponentChange);
return opOK;
}
- if(exponentChange > 0) {
+ if (exponentChange > 0) {
lostFraction lf;
/* Shift right and capture any new lost fraction. */
lost_fraction = combineLostFractions(lf, lost_fraction);
/* Keep OMSB up-to-date. */
- if(omsb > (unsigned) exponentChange)
+ if (omsb > (unsigned) exponentChange)
omsb -= exponentChange;
else
omsb = 0;
/* As specified in IEEE 754, since we do not trap we do not report
underflow for exact results. */
- if(lost_fraction == lfExactlyZero) {
+ if (lost_fraction == lfExactlyZero) {
/* Canonicalize zeroes. */
- if(omsb == 0)
+ if (omsb == 0)
category = fcZero;
return opOK;
}
/* Increment the significand if we're rounding away from zero. */
- if(roundAwayFromZero(rounding_mode, lost_fraction, 0)) {
- if(omsb == 0)
+ if (roundAwayFromZero(rounding_mode, lost_fraction, 0)) {
+ if (omsb == 0)
exponent = semantics->minExponent;
incrementSignificand();
omsb = significandMSB() + 1;
/* Did the significand increment overflow? */
- if(omsb == (unsigned) semantics->precision + 1) {
+ if (omsb == (unsigned) semantics->precision + 1) {
/* Renormalize by incrementing the exponent and shifting our
significand right one. However if we already have the
maximum exponent we overflow to infinity. */
- if(exponent == semantics->maxExponent) {
+ if (exponent == semantics->maxExponent) {
category = fcInfinity;
return (opStatus) (opOverflow | opInexact);
/* The normal case - we were and are not denormal, and any
significand increment above didn't overflow. */
- if(omsb == semantics->precision)
+ if (omsb == semantics->precision)
return opInexact;
/* We have a non-zero denormal. */
assert(omsb < semantics->precision);
/* Canonicalize zeroes. */
- if(omsb == 0)
+ if (omsb == 0)
category = fcZero;
/* The fcZero case is a denormal that underflowed to zero. */
case convolve(fcInfinity, fcInfinity):
/* Differently signed infinities can only be validly
subtracted. */
- if(((sign ^ rhs.sign)!=0) != subtract) {
+ if (((sign ^ rhs.sign)!=0) != subtract) {
makeNaN();
return opInvalidOp;
}
bits = exponent - rhs.exponent;
/* Subtraction is more subtle than one might naively expect. */
- if(subtract) {
+ if (subtract) {
APFloat temp_rhs(rhs);
bool reverse;
/* Invert the lost fraction - it was on the RHS and
subtracted. */
- if(lost_fraction == lfLessThanHalf)
+ if (lost_fraction == lfLessThanHalf)
lost_fraction = lfMoreThanHalf;
- else if(lost_fraction == lfMoreThanHalf)
+ else if (lost_fraction == lfMoreThanHalf)
lost_fraction = lfLessThanHalf;
/* The code above is intended to ensure that no borrow is
necessary. */
assert(!carry);
+ (void)carry;
} else {
- if(bits > 0) {
+ if (bits > 0) {
APFloat temp_rhs(rhs);
lost_fraction = temp_rhs.shiftSignificandRight(bits);
/* We have a guard bit; generating a carry cannot happen. */
assert(!carry);
+ (void)carry;
}
return lost_fraction;
{
opStatus fs;
- assertArithmeticOK(*semantics);
-
fs = addOrSubtractSpecials(rhs, subtract);
/* This return code means it was not a simple case. */
- if(fs == opDivByZero) {
+ if (fs == opDivByZero) {
lostFraction lost_fraction;
lost_fraction = addOrSubtractSignificand(rhs, subtract);
/* If two numbers add (exactly) to zero, IEEE 754 decrees it is a
positive zero unless rounding to minus infinity, except that
adding two like-signed zeroes gives that zero. */
- if(category == fcZero) {
- if(rhs.category != fcZero || (sign == rhs.sign) == subtract)
+ if (category == fcZero) {
+ if (rhs.category != fcZero || (sign == rhs.sign) == subtract)
sign = (rounding_mode == rmTowardNegative);
}
{
opStatus fs;
- assertArithmeticOK(*semantics);
sign ^= rhs.sign;
fs = multiplySpecials(rhs);
- if(category == fcNormal) {
+ if (category == fcNormal) {
lostFraction lost_fraction = multiplySignificand(rhs, 0);
fs = normalize(rounding_mode, lost_fraction);
- if(lost_fraction != lfExactlyZero)
+ if (lost_fraction != lfExactlyZero)
fs = (opStatus) (fs | opInexact);
}
{
opStatus fs;
- assertArithmeticOK(*semantics);
sign ^= rhs.sign;
fs = divideSpecials(rhs);
- if(category == fcNormal) {
+ if (category == fcNormal) {
lostFraction lost_fraction = divideSignificand(rhs);
fs = normalize(rounding_mode, lost_fraction);
- if(lost_fraction != lfExactlyZero)
+ if (lost_fraction != lfExactlyZero)
fs = (opStatus) (fs | opInexact);
}
APFloat V = *this;
unsigned int origSign = sign;
- assertArithmeticOK(*semantics);
fs = V.divide(rhs, rmNearestTiesToEven);
if (fs == opDivByZero)
return fs;
return fs;
}
-/* Normalized llvm frem (C fmod).
+/* Normalized llvm frem (C fmod).
This is not currently correct in all cases. */
APFloat::opStatus
APFloat::mod(const APFloat &rhs, roundingMode rounding_mode)
{
opStatus fs;
- assertArithmeticOK(*semantics);
fs = modSpecials(rhs);
if (category == fcNormal && rhs.category == fcNormal) {
{
opStatus fs;
- assertArithmeticOK(*semantics);
-
/* Post-multiplication sign, before addition. */
sign ^= multiplicand.sign;
/* If and only if all arguments are normal do we need to do an
extended-precision calculation. */
- if(category == fcNormal
- && multiplicand.category == fcNormal
- && addend.category == fcNormal) {
+ if (category == fcNormal &&
+ multiplicand.category == fcNormal &&
+ addend.category == fcNormal) {
lostFraction lost_fraction;
lost_fraction = multiplySignificand(multiplicand, &addend);
fs = normalize(rounding_mode, lost_fraction);
- if(lost_fraction != lfExactlyZero)
+ if (lost_fraction != lfExactlyZero)
fs = (opStatus) (fs | opInexact);
/* If two numbers add (exactly) to zero, IEEE 754 decrees it is a
positive zero unless rounding to minus infinity, except that
adding two like-signed zeroes gives that zero. */
- if(category == fcZero && sign != addend.sign)
+ if (category == fcZero && sign != addend.sign)
sign = (rounding_mode == rmTowardNegative);
} else {
fs = multiplySpecials(multiplicand);
If we need to do the addition we can do so with normal
precision. */
- if(fs == opOK)
+ if (fs == opOK)
fs = addOrSubtract(addend, rounding_mode, false);
}
return fs;
}
+/* Rounding-mode corrrect round to integral value. */
+APFloat::opStatus APFloat::roundToIntegral(roundingMode rounding_mode) {
+ opStatus fs;
+
+ // If the exponent is large enough, we know that this value is already
+ // integral, and the arithmetic below would potentially cause it to saturate
+ // to +/-Inf. Bail out early instead.
+ if (category == fcNormal && exponent+1 >= (int)semanticsPrecision(*semantics))
+ return opOK;
+
+ // The algorithm here is quite simple: we add 2^(p-1), where p is the
+ // precision of our format, and then subtract it back off again. The choice
+ // of rounding modes for the addition/subtraction determines the rounding mode
+ // for our integral rounding as well.
+ // NOTE: When the input value is negative, we do subtraction followed by
+ // addition instead.
+ APInt IntegerConstant(NextPowerOf2(semanticsPrecision(*semantics)), 1);
+ IntegerConstant <<= semanticsPrecision(*semantics)-1;
+ APFloat MagicConstant(*semantics);
+ fs = MagicConstant.convertFromAPInt(IntegerConstant, false,
+ rmNearestTiesToEven);
+ MagicConstant.copySign(*this);
+
+ if (fs != opOK)
+ return fs;
+
+ // Preserve the input sign so that we can handle 0.0/-0.0 cases correctly.
+ bool inputSign = isNegative();
+
+ fs = add(MagicConstant, rounding_mode);
+ if (fs != opOK && fs != opInexact)
+ return fs;
+
+ fs = subtract(MagicConstant, rounding_mode);
+
+ // Restore the input sign.
+ if (inputSign != isNegative())
+ changeSign();
+
+ return fs;
+}
+
+
/* Comparison requires normalized numbers. */
APFloat::cmpResult
APFloat::compare(const APFloat &rhs) const
{
cmpResult result;
- assertArithmeticOK(*semantics);
assert(semantics == rhs.semantics);
switch (convolve(category, rhs.category)) {
case convolve(fcInfinity, fcNormal):
case convolve(fcInfinity, fcZero):
case convolve(fcNormal, fcZero):
- if(sign)
+ if (sign)
return cmpLessThan;
else
return cmpGreaterThan;
case convolve(fcNormal, fcInfinity):
case convolve(fcZero, fcInfinity):
case convolve(fcZero, fcNormal):
- if(rhs.sign)
+ if (rhs.sign)
return cmpGreaterThan;
else
return cmpLessThan;
case convolve(fcInfinity, fcInfinity):
- if(sign == rhs.sign)
+ if (sign == rhs.sign)
return cmpEqual;
- else if(sign)
+ else if (sign)
return cmpLessThan;
else
return cmpGreaterThan;
}
/* Two normal numbers. Do they have the same sign? */
- if(sign != rhs.sign) {
- if(sign)
+ if (sign != rhs.sign) {
+ if (sign)
result = cmpLessThan;
else
result = cmpGreaterThan;
/* Compare absolute values; invert result if negative. */
result = compareAbsoluteValue(rhs);
- if(sign) {
- if(result == cmpLessThan)
+ if (sign) {
+ if (result == cmpLessThan)
result = cmpGreaterThan;
- else if(result == cmpGreaterThan)
+ else if (result == cmpGreaterThan)
result = cmpLessThan;
}
}
lostFraction lostFraction;
unsigned int newPartCount, oldPartCount;
opStatus fs;
+ int shift;
+ const fltSemantics &fromSemantics = *semantics;
- assertArithmeticOK(*semantics);
- assertArithmeticOK(toSemantics);
lostFraction = lfExactlyZero;
newPartCount = partCountForBits(toSemantics.precision + 1);
oldPartCount = partCount();
+ shift = toSemantics.precision - fromSemantics.precision;
+
+ bool X86SpecialNan = false;
+ if (&fromSemantics == &APFloat::x87DoubleExtended &&
+ &toSemantics != &APFloat::x87DoubleExtended && category == fcNaN &&
+ (!(*significandParts() & 0x8000000000000000ULL) ||
+ !(*significandParts() & 0x4000000000000000ULL))) {
+ // x86 has some unusual NaNs which cannot be represented in any other
+ // format; note them here.
+ X86SpecialNan = true;
+ }
+
+ // If this is a truncation, perform the shift before we narrow the storage.
+ if (shift < 0 && (category==fcNormal || category==fcNaN))
+ lostFraction = shiftRight(significandParts(), oldPartCount, -shift);
- /* Handle storage complications. If our new form is wider,
- re-allocate our bit pattern into wider storage. If it is
- narrower, we ignore the excess parts, but if narrowing to a
- single part we need to free the old storage.
- Be careful not to reference significandParts for zeroes
- and infinities, since it aborts. */
+ // Fix the storage so it can hold to new value.
if (newPartCount > oldPartCount) {
+ // The new type requires more storage; make it available.
integerPart *newParts;
newParts = new integerPart[newPartCount];
APInt::tcSet(newParts, 0, newPartCount);
APInt::tcAssign(newParts, significandParts(), oldPartCount);
freeSignificand();
significand.parts = newParts;
- } else if (newPartCount < oldPartCount) {
- /* Capture any lost fraction through truncation of parts so we get
- correct rounding whilst normalizing. */
- if (category==fcNormal)
- lostFraction = lostFractionThroughTruncation
- (significandParts(), oldPartCount, toSemantics.precision);
- if (newPartCount == 1) {
- integerPart newPart = 0;
- if (category==fcNormal || category==fcNaN)
- newPart = significandParts()[0];
- freeSignificand();
- significand.part = newPart;
- }
+ } else if (newPartCount == 1 && oldPartCount != 1) {
+ // Switch to built-in storage for a single part.
+ integerPart newPart = 0;
+ if (category==fcNormal || category==fcNaN)
+ newPart = significandParts()[0];
+ freeSignificand();
+ significand.part = newPart;
}
- if(category == fcNormal) {
- /* Re-interpret our bit-pattern. */
- exponent += toSemantics.precision - semantics->precision;
- semantics = &toSemantics;
+ // Now that we have the right storage, switch the semantics.
+ semantics = &toSemantics;
+
+ // If this is an extension, perform the shift now that the storage is
+ // available.
+ if (shift > 0 && (category==fcNormal || category==fcNaN))
+ APInt::tcShiftLeft(significandParts(), newPartCount, shift);
+
+ if (category == fcNormal) {
fs = normalize(rounding_mode, lostFraction);
*losesInfo = (fs != opOK);
} else if (category == fcNaN) {
- int shift = toSemantics.precision - semantics->precision;
- // Do this now so significandParts gets the right answer
- const fltSemantics *oldSemantics = semantics;
- semantics = &toSemantics;
- *losesInfo = false;
- // No normalization here, just truncate
- if (shift>0)
- APInt::tcShiftLeft(significandParts(), newPartCount, shift);
- else if (shift < 0) {
- unsigned ushift = -shift;
- // Figure out if we are losing information. This happens
- // if are shifting out something other than 0s, or if the x87 long
- // double input did not have its integer bit set (pseudo-NaN), or if the
- // x87 long double input did not have its QNan bit set (because the x87
- // hardware sets this bit when converting a lower-precision NaN to
- // x87 long double).
- if (APInt::tcLSB(significandParts(), newPartCount) < ushift)
- *losesInfo = true;
- if (oldSemantics == &APFloat::x87DoubleExtended &&
- (!(*significandParts() & 0x8000000000000000ULL) ||
- !(*significandParts() & 0x4000000000000000ULL)))
- *losesInfo = true;
- APInt::tcShiftRight(significandParts(), newPartCount, ushift);
- }
+ *losesInfo = lostFraction != lfExactlyZero || X86SpecialNan;
+
+ // For x87 extended precision, we want to make a NaN, not a special NaN if
+ // the input wasn't special either.
+ if (!X86SpecialNan && semantics == &APFloat::x87DoubleExtended)
+ APInt::tcSetBit(significandParts(), semantics->precision - 1);
+
// gcc forces the Quiet bit on, which means (float)(double)(float_sNan)
// does not give you back the same bits. This is dubious, and we
// don't currently do it. You're really supposed to get
// an invalid operation signal at runtime, but nobody does that.
fs = opOK;
} else {
- semantics = &toSemantics;
- fs = opOK;
*losesInfo = false;
+ fs = opOK;
}
return fs;
const integerPart *src;
unsigned int dstPartsCount, truncatedBits;
- assertArithmeticOK(*semantics);
-
*isExact = false;
/* Handle the three special cases first. */
- if(category == fcInfinity || category == fcNaN)
+ if (category == fcInfinity || category == fcNaN)
return opInvalidOp;
dstPartsCount = partCountForBits(width);
- if(category == fcZero) {
+ if (category == fcZero) {
APInt::tcSet(parts, 0, dstPartsCount);
// Negative zero can't be represented as an int.
*isExact = !sign;
if (truncatedBits) {
lost_fraction = lostFractionThroughTruncation(src, partCount(),
truncatedBits);
- if (lost_fraction != lfExactlyZero
- && roundAwayFromZero(rounding_mode, lost_fraction, truncatedBits)) {
+ if (lost_fraction != lfExactlyZero &&
+ roundAwayFromZero(rounding_mode, lost_fraction, truncatedBits)) {
if (APInt::tcIncrement(parts, dstPartsCount))
return opInvalidOp; /* Overflow. */
}
{
opStatus fs;
- fs = convertToSignExtendedInteger(parts, width, isSigned, rounding_mode,
+ fs = convertToSignExtendedInteger(parts, width, isSigned, rounding_mode,
isExact);
if (fs == opInvalidOp) {
return fs;
}
+/* Same as convertToInteger(integerPart*, ...), except the result is returned in
+ an APSInt, whose initial bit-width and signed-ness are used to determine the
+ precision of the conversion.
+ */
+APFloat::opStatus
+APFloat::convertToInteger(APSInt &result,
+ roundingMode rounding_mode, bool *isExact) const
+{
+ unsigned bitWidth = result.getBitWidth();
+ SmallVector<uint64_t, 4> parts(result.getNumWords());
+ opStatus status = convertToInteger(
+ parts.data(), bitWidth, result.isSigned(), rounding_mode, isExact);
+ // Keeps the original signed-ness.
+ result = APInt(bitWidth, parts);
+ return status;
+}
+
/* Convert an unsigned integer SRC to a floating point number,
rounding according to ROUNDING_MODE. The sign of the floating
point number is not modified. */
integerPart *dst;
lostFraction lost_fraction;
- assertArithmeticOK(*semantics);
category = fcNormal;
omsb = APInt::tcMSB(src, srcCount) + 1;
dst = significandParts();
dstCount = partCount();
precision = semantics->precision;
- /* We want the most significant PRECISON bits of SRC. There may not
+ /* We want the most significant PRECISION bits of SRC. There may not
be that many; extract what we can. */
if (precision <= omsb) {
exponent = omsb - 1;
{
opStatus status;
- assertArithmeticOK(*semantics);
- if (isSigned
- && APInt::tcExtractBit(src, srcCount * integerPartWidth - 1)) {
+ if (isSigned &&
+ APInt::tcExtractBit(src, srcCount * integerPartWidth - 1)) {
integerPart *copy;
/* If we're signed and negative negate a copy. */
roundingMode rounding_mode)
{
unsigned int partCount = partCountForBits(width);
- APInt api = APInt(width, partCount, parts);
+ APInt api = APInt(width, makeArrayRef(parts, partCount));
sign = false;
- if(isSigned && APInt::tcExtractBit(parts, width - 1)) {
+ if (isSigned && APInt::tcExtractBit(parts, width - 1)) {
sign = true;
api = -api;
}
}
APFloat::opStatus
-APFloat::convertFromHexadecimalString(const StringRef &s,
- roundingMode rounding_mode)
+APFloat::convertFromHexadecimalString(StringRef s, roundingMode rounding_mode)
{
lostFraction lost_fraction = lfExactlyZero;
integerPart *significand;
StringRef::iterator p = skipLeadingZeroesAndAnyDot(begin, end, &dot);
firstSignificantDigit = p;
- for(; p != end;) {
+ for (; p != end;) {
integerPart hex_value;
- if(*p == '.') {
+ if (*p == '.') {
assert(dot == end && "String contains multiple dots");
dot = p++;
if (p == end) {
}
hex_value = hexDigitValue(*p);
- if(hex_value == -1U) {
+ if (hex_value == -1U) {
break;
}
break;
} else {
/* Store the number whilst 4-bit nibbles remain. */
- if(bitPos) {
+ if (bitPos) {
bitPos -= 4;
hex_value <<= bitPos % integerPartWidth;
significand[bitPos / integerPartWidth] |= hex_value;
} else {
lost_fraction = trailingHexadecimalFraction(p, end, hex_value);
- while(p != end && hexDigitValue(*p) != -1U)
+ while (p != end && hexDigitValue(*p) != -1U)
p++;
break;
}
assert((dot == end || p - begin != 1) && "Significand has no digits");
/* Ignore the exponent if we are zero. */
- if(p != firstSignificantDigit) {
+ if (p != firstSignificantDigit) {
int expAdjustment;
/* Implicit hexadecimal point? */
/* Calculate the exponent adjustment implicit in the number of
significant digits. */
expAdjustment = static_cast<int>(dot - firstSignificantDigit);
- if(expAdjustment < 0)
+ if (expAdjustment < 0)
expAdjustment++;
expAdjustment = expAdjustment * 4 - 1;
roundingMode rounding_mode)
{
unsigned int parts, pow5PartCount;
- fltSemantics calcSemantics = { 32767, -32767, 0, true };
+ fltSemantics calcSemantics = { 32767, -32767, 0 };
integerPart pow5Parts[maxPowerOfFiveParts];
bool isNearest;
- isNearest = (rounding_mode == rmNearestTiesToEven
- || rounding_mode == rmNearestTiesToAway);
+ isNearest = (rounding_mode == rmNearestTiesToEven ||
+ rounding_mode == rmNearestTiesToAway);
parts = partCountForBits(semantics->precision + 11);
}
APFloat::opStatus
-APFloat::convertFromDecimalString(const StringRef &str, roundingMode rounding_mode)
+APFloat::convertFromDecimalString(StringRef str, roundingMode rounding_mode)
{
decimalInfo D;
opStatus fs;
}
APFloat::opStatus
-APFloat::convertFromString(const StringRef &str, roundingMode rounding_mode)
+APFloat::convertFromString(StringRef str, roundingMode rounding_mode)
{
- assertArithmeticOK(*semantics);
assert(!str.empty() && "Invalid string length");
/* Handle a leading minus sign. */
StringRef::iterator p = str.begin();
size_t slen = str.size();
sign = *p == '-' ? 1 : 0;
- if(*p == '-' || *p == '+') {
+ if (*p == '-' || *p == '+') {
p++;
slen--;
assert(slen && "String has no digits");
}
- if(slen >= 2 && p[0] == '0' && (p[1] == 'x' || p[1] == 'X')) {
+ if (slen >= 2 && p[0] == '0' && (p[1] == 'x' || p[1] == 'X')) {
assert(slen - 2 && "Invalid string");
return convertFromHexadecimalString(StringRef(p + 2, slen - 2),
rounding_mode);
{
char *p;
- assertArithmeticOK(*semantics);
-
p = dst;
if (sign)
*dst++ = '-';
return writeSignedDecimal (dst, exponent);
}
-// For good performance it is desirable for different APFloats
-// to produce different integers.
-uint32_t
-APFloat::getHashValue() const
-{
- if (category==fcZero) return sign<<8 | semantics->precision ;
- else if (category==fcInfinity) return sign<<9 | semantics->precision;
- else if (category==fcNaN) return 1<<10 | semantics->precision;
- else {
- uint32_t hash = sign<<11 | semantics->precision | exponent<<12;
- const integerPart* p = significandParts();
- for (int i=partCount(); i>0; i--, p++)
- hash ^= ((uint32_t)*p) ^ (uint32_t)((*p)>>32);
- return hash;
- }
+hash_code llvm::hash_value(const APFloat &Arg) {
+ if (Arg.category != APFloat::fcNormal)
+ return hash_combine((uint8_t)Arg.category,
+ // NaN has no sign, fix it at zero.
+ Arg.isNaN() ? (uint8_t)0 : (uint8_t)Arg.sign,
+ Arg.semantics->precision);
+
+ // Normal floats need their exponent and significand hashed.
+ return hash_combine((uint8_t)Arg.category, (uint8_t)Arg.sign,
+ Arg.semantics->precision, Arg.exponent,
+ hash_combine_range(
+ Arg.significandParts(),
+ Arg.significandParts() + Arg.partCount()));
}
// Conversion from APFloat to/from host float/double. It may eventually be
words[0] = mysignificand;
words[1] = ((uint64_t)(sign & 1) << 15) |
(myexponent & 0x7fffLL);
- return APInt(80, 2, words);
+ return APInt(80, words);
}
APInt
assert(semantics == (const llvm::fltSemantics*)&PPCDoubleDouble);
assert(partCount()==2);
- uint64_t myexponent, mysignificand, myexponent2, mysignificand2;
-
- if (category==fcNormal) {
- myexponent = exponent + 1023; //bias
- myexponent2 = exponent2 + 1023;
- mysignificand = significandParts()[0];
- mysignificand2 = significandParts()[1];
- if (myexponent==1 && !(mysignificand & 0x10000000000000LL))
- myexponent = 0; // denormal
- if (myexponent2==1 && !(mysignificand2 & 0x10000000000000LL))
- myexponent2 = 0; // denormal
- } else if (category==fcZero) {
- myexponent = 0;
- mysignificand = 0;
- myexponent2 = 0;
- mysignificand2 = 0;
- } else if (category==fcInfinity) {
- myexponent = 0x7ff;
- myexponent2 = 0;
- mysignificand = 0;
- mysignificand2 = 0;
+ uint64_t words[2];
+ opStatus fs;
+ bool losesInfo;
+
+ // Convert number to double. To avoid spurious underflows, we re-
+ // normalize against the "double" minExponent first, and only *then*
+ // truncate the mantissa. The result of that second conversion
+ // may be inexact, but should never underflow.
+ // Declare fltSemantics before APFloat that uses it (and
+ // saves pointer to it) to ensure correct destruction order.
+ fltSemantics extendedSemantics = *semantics;
+ extendedSemantics.minExponent = IEEEdouble.minExponent;
+ APFloat extended(*this);
+ fs = extended.convert(extendedSemantics, rmNearestTiesToEven, &losesInfo);
+ assert(fs == opOK && !losesInfo);
+ (void)fs;
+
+ APFloat u(extended);
+ fs = u.convert(IEEEdouble, rmNearestTiesToEven, &losesInfo);
+ assert(fs == opOK || fs == opInexact);
+ (void)fs;
+ words[0] = *u.convertDoubleAPFloatToAPInt().getRawData();
+
+ // If conversion was exact or resulted in a special case, we're done;
+ // just set the second double to zero. Otherwise, re-convert back to
+ // the extended format and compute the difference. This now should
+ // convert exactly to double.
+ if (u.category == fcNormal && losesInfo) {
+ fs = u.convert(extendedSemantics, rmNearestTiesToEven, &losesInfo);
+ assert(fs == opOK && !losesInfo);
+ (void)fs;
+
+ APFloat v(extended);
+ v.subtract(u, rmNearestTiesToEven);
+ fs = v.convert(IEEEdouble, rmNearestTiesToEven, &losesInfo);
+ assert(fs == opOK && !losesInfo);
+ (void)fs;
+ words[1] = *v.convertDoubleAPFloatToAPInt().getRawData();
} else {
- assert(category == fcNaN && "Unknown category");
- myexponent = 0x7ff;
- mysignificand = significandParts()[0];
- myexponent2 = exponent2;
- mysignificand2 = significandParts()[1];
+ words[1] = 0;
}
- uint64_t words[2];
- words[0] = ((uint64_t)(sign & 1) << 63) |
- ((myexponent & 0x7ff) << 52) |
- (mysignificand & 0xfffffffffffffLL);
- words[1] = ((uint64_t)(sign2 & 1) << 63) |
- ((myexponent2 & 0x7ff) << 52) |
- (mysignificand2 & 0xfffffffffffffLL);
- return APInt(128, 2, words);
+ return APInt(128, words);
}
APInt
((myexponent & 0x7fff) << 48) |
(mysignificand2 & 0xffffffffffffLL);
- return APInt(128, 2, words);
+ return APInt(128, words);
}
APInt
assert(api.getBitWidth()==128);
uint64_t i1 = api.getRawData()[0];
uint64_t i2 = api.getRawData()[1];
- uint64_t myexponent = (i1 >> 52) & 0x7ff;
- uint64_t mysignificand = i1 & 0xfffffffffffffLL;
- uint64_t myexponent2 = (i2 >> 52) & 0x7ff;
- uint64_t mysignificand2 = i2 & 0xfffffffffffffLL;
+ opStatus fs;
+ bool losesInfo;
- initialize(&APFloat::PPCDoubleDouble);
- assert(partCount()==2);
+ // Get the first double and convert to our format.
+ initFromDoubleAPInt(APInt(64, i1));
+ fs = convert(PPCDoubleDouble, rmNearestTiesToEven, &losesInfo);
+ assert(fs == opOK && !losesInfo);
+ (void)fs;
- sign = static_cast<unsigned int>(i1>>63);
- sign2 = static_cast<unsigned int>(i2>>63);
- if (myexponent==0 && mysignificand==0) {
- // exponent, significand meaningless
- // exponent2 and significand2 are required to be 0; we don't check
- category = fcZero;
- } else if (myexponent==0x7ff && mysignificand==0) {
- // exponent, significand meaningless
- // exponent2 and significand2 are required to be 0; we don't check
- category = fcInfinity;
- } else if (myexponent==0x7ff && mysignificand!=0) {
- // exponent meaningless. So is the whole second word, but keep it
- // for determinism.
- category = fcNaN;
- exponent2 = myexponent2;
- significandParts()[0] = mysignificand;
- significandParts()[1] = mysignificand2;
- } else {
- category = fcNormal;
- // Note there is no category2; the second word is treated as if it is
- // fcNormal, although it might be something else considered by itself.
- exponent = myexponent - 1023;
- exponent2 = myexponent2 - 1023;
- significandParts()[0] = mysignificand;
- significandParts()[1] = mysignificand2;
- if (myexponent==0) // denormal
- exponent = -1022;
- else
- significandParts()[0] |= 0x10000000000000LL; // integer bit
- if (myexponent2==0)
- exponent2 = -1022;
- else
- significandParts()[1] |= 0x10000000000000LL; // integer bit
+ // Unless we have a special case, add in second double.
+ if (category == fcNormal) {
+ APFloat v(IEEEdouble, APInt(64, i2));
+ fs = v.convert(PPCDoubleDouble, rmNearestTiesToEven, &losesInfo);
+ assert(fs == opOK && !losesInfo);
+ (void)fs;
+
+ add(v, rmNearestTiesToEven);
}
}
/// isIEEE argument distinguishes between PPC128 and IEEE128 (not meaningful
/// when the size is anything else).
void
-APFloat::initFromAPInt(const APInt& api, bool isIEEE)
+APFloat::initFromAPInt(const fltSemantics* Sem, const APInt& api)
{
- if (api.getBitWidth() == 16)
+ if (Sem == &IEEEhalf)
return initFromHalfAPInt(api);
- else if (api.getBitWidth() == 32)
+ if (Sem == &IEEEsingle)
return initFromFloatAPInt(api);
- else if (api.getBitWidth()==64)
+ if (Sem == &IEEEdouble)
return initFromDoubleAPInt(api);
- else if (api.getBitWidth()==80)
+ if (Sem == &x87DoubleExtended)
return initFromF80LongDoubleAPInt(api);
- else if (api.getBitWidth()==128)
- return (isIEEE ?
- initFromQuadrupleAPInt(api) : initFromPPCDoubleDoubleAPInt(api));
- else
- llvm_unreachable(0);
+ if (Sem == &IEEEquad)
+ return initFromQuadrupleAPInt(api);
+ if (Sem == &PPCDoubleDouble)
+ return initFromPPCDoubleDoubleAPInt(api);
+
+ llvm_unreachable(0);
+}
+
+APFloat
+APFloat::getAllOnesValue(unsigned BitWidth, bool isIEEE)
+{
+ switch (BitWidth) {
+ case 16:
+ return APFloat(IEEEhalf, APInt::getAllOnesValue(BitWidth));
+ case 32:
+ return APFloat(IEEEsingle, APInt::getAllOnesValue(BitWidth));
+ case 64:
+ return APFloat(IEEEdouble, APInt::getAllOnesValue(BitWidth));
+ case 80:
+ return APFloat(x87DoubleExtended, APInt::getAllOnesValue(BitWidth));
+ case 128:
+ if (isIEEE)
+ return APFloat(IEEEquad, APInt::getAllOnesValue(BitWidth));
+ return APFloat(PPCDoubleDouble, APInt::getAllOnesValue(BitWidth));
+ default:
+ llvm_unreachable("Unknown floating bit width");
+ }
}
APFloat APFloat::getLargest(const fltSemantics &Sem, bool Negative) {
significand[i] = ~((integerPart) 0);
// ...and then clear the top bits for internal consistency.
- significand[N-1]
- &= (((integerPart) 1) << ((Sem.precision % integerPartWidth) - 1)) - 1;
+ if (Sem.precision % integerPartWidth != 0)
+ significand[N-1] &=
+ (((integerPart) 1) << (Sem.precision % integerPartWidth)) - 1;
return Val;
}
Val.exponent = Sem.minExponent;
Val.zeroSignificand();
- Val.significandParts()[partCountForBits(Sem.precision)-1]
- |= (((integerPart) 1) << ((Sem.precision % integerPartWidth) - 1));
+ Val.significandParts()[partCountForBits(Sem.precision)-1] |=
+ (((integerPart) 1) << ((Sem.precision - 1) % integerPartWidth));
return Val;
}
-APFloat::APFloat(const APInt& api, bool isIEEE)
-{
- initFromAPInt(api, isIEEE);
+APFloat::APFloat(const fltSemantics &Sem, const APInt &API) {
+ initFromAPInt(&Sem, API);
}
-APFloat::APFloat(float f)
-{
- APInt api = APInt(32, 0);
- initFromAPInt(api.floatToBits(f));
+APFloat::APFloat(float f) {
+ initFromAPInt(&IEEEsingle, APInt::floatToBits(f));
}
-APFloat::APFloat(double d)
-{
- APInt api = APInt(64, 0);
- initFromAPInt(api.doubleToBits(d));
+APFloat::APFloat(double d) {
+ initFromAPInt(&IEEEdouble, APInt::doubleToBits(d));
}
namespace {
- static void append(SmallVectorImpl<char> &Buffer,
- unsigned N, const char *Str) {
- unsigned Start = Buffer.size();
- Buffer.set_size(Start + N);
- memcpy(&Buffer[Start], Str, N);
- }
-
- template <unsigned N>
- void append(SmallVectorImpl<char> &Buffer, const char (&Str)[N]) {
- append(Buffer, N, Str);
+ void append(SmallVectorImpl<char> &Buffer, StringRef Str) {
+ Buffer.append(Str.begin(), Str.end());
}
/// Removes data from the given significand until it is no more
// Truncate the significand down to its active bit count, but
// don't try to drop below 32.
unsigned newPrecision = std::max(32U, significand.getActiveBits());
- significand.trunc(newPrecision);
+ significand = significand.trunc(newPrecision);
}
// Rounding down is just a truncation, except we also want to drop
// trailing zeros from the new result.
if (buffer[FirstSignificant - 1] < '5') {
- while (buffer[FirstSignificant] == '0')
+ while (FirstSignificant < N && buffer[FirstSignificant] == '0')
FirstSignificant++;
exp += FirstSignificant;
// Decompose the number into an APInt and an exponent.
int exp = exponent - ((int) semantics->precision - 1);
APInt significand(semantics->precision,
- partCountForBits(semantics->precision),
- significandParts());
+ makeArrayRef(significandParts(),
+ partCountForBits(semantics->precision)));
// Set FormatPrecision if zero. We want to do this before we
// truncate trailing zeros, as those are part of the precision.
// Nothing to do.
} else if (exp > 0) {
// Just shift left.
- significand.zext(semantics->precision + exp);
+ significand = significand.zext(semantics->precision + exp);
significand <<= exp;
exp = 0;
} else { /* exp < 0 */
// log2(N * 5^e) == log2(N) + e * log2(5)
// <= semantics->precision + e * 137 / 59
// (log_2(5) ~ 2.321928 < 2.322034 ~ 137/59)
-
- unsigned precision = semantics->precision + 137 * texp / 59;
+
+ unsigned precision = semantics->precision + (137 * texp + 136) / 59;
// Multiply significand by 5^e.
// N * 5^0101 == N * 5^(1*1) * 5^(0*2) * 5^(1*4) * 5^(0*8)
- significand.zext(precision);
+ significand = significand.zext(precision);
APInt five_to_the_i(precision, 5);
while (true) {
if (texp & 1) significand *= five_to_the_i;
-
+
texp >>= 1;
if (!texp) break;
five_to_the_i *= five_to_the_i;
AdjustToPrecision(significand, exp, FormatPrecision);
- llvm::SmallVector<char, 256> buffer;
+ SmallVector<char, 256> buffer;
// Fill the buffer.
unsigned precision = significand.getBitWidth();
for (; I != NDigits; ++I)
Str.push_back(buffer[NDigits-I-1]);
}
+
+bool APFloat::getExactInverse(APFloat *inv) const {
+ // Special floats and denormals have no exact inverse.
+ if (category != fcNormal)
+ return false;
+
+ // Check that the number is a power of two by making sure that only the
+ // integer bit is set in the significand.
+ if (significandLSB() != semantics->precision - 1)
+ return false;
+
+ // Get the inverse.
+ APFloat reciprocal(*semantics, 1ULL);
+ if (reciprocal.divide(*this, rmNearestTiesToEven) != opOK)
+ return false;
+
+ // Avoid multiplication with a denormal, it is not safe on all platforms and
+ // may be slower than a normal division.
+ if (reciprocal.significandMSB() + 1 < reciprocal.semantics->precision)
+ return false;
+
+ assert(reciprocal.category == fcNormal &&
+ reciprocal.significandLSB() == reciprocal.semantics->precision - 1);
+
+ if (inv)
+ *inv = reciprocal;
+
+ return true;
+}