//===----------------------------------------------------------------------===//
#include "llvm/ADT/APFloat.h"
+#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/FoldingSet.h"
+#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
+#include <limits.h>
#include <cstring>
using namespace llvm;
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 };
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
/ (351 * integerPartWidth));
}
-/* Put a bunch of private, handy routines in an anonymous namespace. */
-namespace {
+/* A bunch of private, handy routines. */
- static inline unsigned int
- partCountForBits(unsigned int bits)
- {
- return ((bits) + integerPartWidth - 1) / integerPartWidth;
- }
+static inline unsigned int
+partCountForBits(unsigned int bits)
+{
+ return ((bits) + integerPartWidth - 1) / integerPartWidth;
+}
- /* Returns 0U-9U. Return values >= 10U are not digits. */
- static inline unsigned int
- decDigitValue(unsigned int c)
- {
- return c - '0';
- }
+/* Returns 0U-9U. Return values >= 10U are not digits. */
+static inline unsigned int
+decDigitValue(unsigned int c)
+{
+ return c - '0';
+}
- static unsigned int
- hexDigitValue(unsigned int c)
- {
- unsigned int r;
+static unsigned int
+hexDigitValue(unsigned int c)
+{
+ unsigned int r;
- r = c - '0';
- if(r <= 9)
- return 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;
- r = c - 'a';
- if(r <= 5)
- return r + 10;
+ r = c - 'a';
+ if (r <= 5)
+ return r + 10;
- return -1U;
- }
+ return -1U;
+}
- static inline void
- assertArithmeticOK(const llvm::fltSemantics &semantics) {
- assert(semantics.arithmeticOK
- && "Compile-time arithmetic does not support these semantics");
- }
+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.
- /* Return the value of a decimal exponent of the form
- [+-]ddddddd.
+ If the exponent overflows, returns a large exponent with the
+ appropriate sign. */
+static int
+readExponent(StringRef::iterator begin, StringRef::iterator end)
+{
+ bool isNegative;
+ unsigned int absExponent;
+ const unsigned int overlargeExponent = 24000; /* FIXME. */
+ StringRef::iterator p = begin;
- If the exponent overflows, returns a large exponent with the
- appropriate sign. */
- static int
- readExponent(const char *p)
- {
- bool isNegative;
- unsigned int absExponent;
- const unsigned int overlargeExponent = 24000; /* FIXME. */
+ assert(p != end && "Exponent has no digits");
- isNegative = (*p == '-');
- if (*p == '-' || *p == '+')
- p++;
+ isNegative = (*p == '-');
+ if (*p == '-' || *p == '+') {
+ p++;
+ assert(p != end && "Exponent has no digits");
+ }
- absExponent = decDigitValue(*p++);
- assert (absExponent < 10U);
+ absExponent = decDigitValue(*p++);
+ assert(absExponent < 10U && "Invalid character in exponent");
- for (;;) {
- unsigned int value;
+ for (; p != end; ++p) {
+ unsigned int value;
- value = decDigitValue(*p);
- if (value >= 10U)
- break;
+ value = decDigitValue(*p);
+ assert(value < 10U && "Invalid character in exponent");
- p++;
- value += absExponent * 10;
- if (absExponent >= overlargeExponent) {
- absExponent = overlargeExponent;
- break;
- }
- absExponent = value;
+ value += absExponent * 10;
+ if (absExponent >= overlargeExponent) {
+ absExponent = overlargeExponent;
+ p = end; /* outwit assert below */
+ break;
}
-
- if (isNegative)
- return -(int) absExponent;
- else
- return (int) absExponent;
+ absExponent = value;
}
- /* This is ugly and needs cleaning up, but I don't immediately see
- how whilst remaining safe. */
- static int
- totalExponent(const char *p, int exponentAdjustment)
- {
- int unsignedExponent;
- bool negative, overflow;
- int exponent;
+ assert(p == end && "Invalid exponent in exponent");
- /* Move past the exponent letter and sign to the digits. */
- p++;
- negative = *p == '-';
- if(*p == '-' || *p == '+')
- p++;
+ if (isNegative)
+ return -(int) absExponent;
+ else
+ return (int) absExponent;
+}
- unsignedExponent = 0;
- overflow = false;
- for(;;) {
- unsigned int value;
+/* This is ugly and needs cleaning up, but I don't immediately see
+ how whilst remaining safe. */
+static int
+totalExponent(StringRef::iterator p, StringRef::iterator end,
+ int exponentAdjustment)
+{
+ int unsignedExponent;
+ bool negative, overflow;
+ int exponent = 0;
- value = decDigitValue(*p);
- if(value >= 10U)
- break;
+ assert(p != end && "Exponent has no digits");
- p++;
- unsignedExponent = unsignedExponent * 10 + value;
- if(unsignedExponent > 65535)
- overflow = true;
- }
+ negative = *p == '-';
+ if (*p == '-' || *p == '+') {
+ p++;
+ assert(p != end && "Exponent has no digits");
+ }
- if(exponentAdjustment > 65535 || exponentAdjustment < -65536)
- overflow = true;
+ unsignedExponent = 0;
+ overflow = false;
+ for (; p != end; ++p) {
+ unsigned int value;
- if(!overflow) {
- exponent = unsignedExponent;
- if(negative)
- exponent = -exponent;
- exponent += exponentAdjustment;
- if(exponent > 65535 || exponent < -65536)
- overflow = true;
- }
+ value = decDigitValue(*p);
+ assert(value < 10U && "Invalid character in exponent");
- if(overflow)
- exponent = negative ? -65536: 65535;
+ unsignedExponent = unsignedExponent * 10 + value;
+ if (unsignedExponent > 32767)
+ overflow = true;
+ }
- return exponent;
+ if (exponentAdjustment > 32767 || exponentAdjustment < -32768)
+ overflow = true;
+
+ if (!overflow) {
+ exponent = unsignedExponent;
+ if (negative)
+ exponent = -exponent;
+ exponent += exponentAdjustment;
+ if (exponent > 32767 || exponent < -32768)
+ overflow = true;
}
- static const char *
- skipLeadingZeroesAndAnyDot(const char *p, const char **dot)
- {
- *dot = 0;
- while(*p == '0')
- p++;
+ if (overflow)
+ exponent = negative ? -32768: 32767;
- if(*p == '.') {
- *dot = p++;
- while(*p == '0')
- p++;
- }
+ return exponent;
+}
- return p;
- }
+static StringRef::iterator
+skipLeadingZeroesAndAnyDot(StringRef::iterator begin, StringRef::iterator end,
+ StringRef::iterator *dot)
+{
+ StringRef::iterator p = begin;
+ *dot = end;
+ while (*p == '0' && p != end)
+ p++;
- /* Given a normal decimal floating point number of the form
+ if (*p == '.') {
+ *dot = p++;
- dddd.dddd[eE][+-]ddd
+ assert(end - begin != 1 && "Significand has no digits");
- where the decimal point and exponent are optional, fill out the
- structure D. Exponent is appropriate if the significand is
- treated as an integer, and normalizedExponent if the significand
- is taken to have the decimal point after a single leading
- non-zero digit.
+ while (*p == '0' && p != end)
+ p++;
+ }
- If the value is zero, V->firstSigDigit points to a non-digit, and
- the return exponent is zero.
- */
- struct decimalInfo {
- const char *firstSigDigit;
- const char *lastSigDigit;
- int exponent;
- int normalizedExponent;
- };
+ return p;
+}
- static void
- interpretDecimal(const char *p, decimalInfo *D)
- {
- const char *dot;
+/* Given a normal decimal floating point number of the form
- p = skipLeadingZeroesAndAnyDot (p, &dot);
+ dddd.dddd[eE][+-]ddd
- D->firstSigDigit = p;
- D->exponent = 0;
- D->normalizedExponent = 0;
+ where the decimal point and exponent are optional, fill out the
+ structure D. Exponent is appropriate if the significand is
+ treated as an integer, and normalizedExponent if the significand
+ is taken to have the decimal point after a single leading
+ non-zero digit.
- for (;;) {
- if (*p == '.') {
- assert(dot == 0);
- dot = p++;
- }
- if (decDigitValue(*p) >= 10U)
+ If the value is zero, V->firstSigDigit points to a non-digit, and
+ the return exponent is zero.
+*/
+struct decimalInfo {
+ const char *firstSigDigit;
+ const char *lastSigDigit;
+ int exponent;
+ int normalizedExponent;
+};
+
+static void
+interpretDecimal(StringRef::iterator begin, StringRef::iterator end,
+ decimalInfo *D)
+{
+ StringRef::iterator dot = end;
+ StringRef::iterator p = skipLeadingZeroesAndAnyDot (begin, end, &dot);
+
+ D->firstSigDigit = p;
+ D->exponent = 0;
+ D->normalizedExponent = 0;
+
+ for (; p != end; ++p) {
+ if (*p == '.') {
+ assert(dot == end && "String contains multiple dots");
+ dot = p++;
+ if (p == end)
break;
- p++;
}
+ if (decDigitValue(*p) >= 10U)
+ break;
+ }
- /* If number is all zerooes accept any exponent. */
- if (p != D->firstSigDigit) {
- if (*p == 'e' || *p == 'E')
- D->exponent = readExponent(p + 1);
+ if (p != end) {
+ assert((*p == 'e' || *p == 'E') && "Invalid character in significand");
+ assert(p != begin && "Significand has no digits");
+ assert((dot == end || p - begin != 1) && "Significand has no digits");
- /* Implied decimal point? */
- if (!dot)
- dot = p;
+ /* p points to the first non-digit in the string */
+ D->exponent = readExponent(p + 1, end);
- /* Drop insignificant trailing zeroes. */
+ /* Implied decimal point? */
+ if (dot == end)
+ dot = p;
+ }
+
+ /* If number is all zeroes accept any exponent. */
+ if (p != D->firstSigDigit) {
+ /* Drop insignificant trailing zeroes. */
+ if (p != begin) {
do
do
p--;
- while (*p == '0');
- while (*p == '.');
-
- /* Adjust the exponents for any decimal point. */
- D->exponent += static_cast<exponent_t>((dot - p) - (dot > p));
- D->normalizedExponent = (D->exponent +
- static_cast<exponent_t>((p - D->firstSigDigit)
- - (dot > D->firstSigDigit && dot < p)));
+ while (p != begin && *p == '0');
+ while (p != begin && *p == '.');
}
- D->lastSigDigit = p;
+ /* Adjust the exponents for any decimal point. */
+ D->exponent += static_cast<exponent_t>((dot - p) - (dot > p));
+ D->normalizedExponent = (D->exponent +
+ static_cast<exponent_t>((p - D->firstSigDigit)
+ - (dot > D->firstSigDigit && dot < p)));
}
- /* Return the trailing fraction of a hexadecimal number.
- DIGITVALUE is the first hex digit of the fraction, P points to
- the next digit. */
- static lostFraction
- trailingHexadecimalFraction(const char *p, unsigned int digitValue)
- {
- unsigned int hexDigit;
+ D->lastSigDigit = p;
+}
+
+/* Return the trailing fraction of a hexadecimal number.
+ DIGITVALUE is the first hex digit of the fraction, P points to
+ the next digit. */
+static lostFraction
+trailingHexadecimalFraction(StringRef::iterator p, StringRef::iterator end,
+ unsigned int digitValue)
+{
+ unsigned int hexDigit;
- /* If the first trailing digit isn't 0 or 8 we can work out the
- fraction immediately. */
- if(digitValue > 8)
- return lfMoreThanHalf;
- else if(digitValue < 8 && digitValue > 0)
- return lfLessThanHalf;
+ /* If the first trailing digit isn't 0 or 8 we can work out the
+ fraction immediately. */
+ if (digitValue > 8)
+ return lfMoreThanHalf;
+ else if (digitValue < 8 && digitValue > 0)
+ return lfLessThanHalf;
- /* Otherwise we need to find the first non-zero digit. */
- while(*p == '0')
- p++;
+ /* Otherwise we need to find the first non-zero digit. */
+ while (*p == '0')
+ p++;
- hexDigit = hexDigitValue(*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)
- return digitValue == 0 ? lfExactlyZero: lfExactlyHalf;
- else
- return digitValue == 0 ? lfLessThanHalf: lfMoreThanHalf;
- }
+ hexDigit = hexDigitValue(*p);
- /* Return the fraction lost were a bignum truncated losing the least
- significant BITS bits. */
- static lostFraction
- lostFractionThroughTruncation(const integerPart *parts,
- unsigned int partCount,
- unsigned int bits)
- {
- unsigned int lsb;
+ /* If we ran off the end it is exactly zero or one-half, otherwise
+ a little more. */
+ if (hexDigit == -1U)
+ return digitValue == 0 ? lfExactlyZero: lfExactlyHalf;
+ else
+ return digitValue == 0 ? lfLessThanHalf: lfMoreThanHalf;
+}
- lsb = APInt::tcLSB(parts, partCount);
+/* Return the fraction lost were a bignum truncated losing the least
+ significant BITS bits. */
+static lostFraction
+lostFractionThroughTruncation(const integerPart *parts,
+ unsigned int partCount,
+ unsigned int bits)
+{
+ unsigned int lsb;
- /* Note this is guaranteed true if bits == 0, or LSB == -1U. */
- if(bits <= lsb)
- return lfExactlyZero;
- if(bits == lsb + 1)
- return lfExactlyHalf;
- if(bits <= partCount * integerPartWidth
- && APInt::tcExtractBit(parts, bits - 1))
- return lfMoreThanHalf;
+ lsb = APInt::tcLSB(parts, partCount);
- return lfLessThanHalf;
- }
+ /* Note this is guaranteed true if bits == 0, or LSB == -1U. */
+ if (bits <= lsb)
+ return lfExactlyZero;
+ if (bits == lsb + 1)
+ return lfExactlyHalf;
+ if (bits <= partCount * integerPartWidth &&
+ APInt::tcExtractBit(parts, bits - 1))
+ return lfMoreThanHalf;
- /* Shift DST right BITS bits noting lost fraction. */
- static lostFraction
- shiftRight(integerPart *dst, unsigned int parts, unsigned int bits)
- {
- lostFraction lost_fraction;
+ return lfLessThanHalf;
+}
- lost_fraction = lostFractionThroughTruncation(dst, parts, bits);
+/* Shift DST right BITS bits noting lost fraction. */
+static lostFraction
+shiftRight(integerPart *dst, unsigned int parts, unsigned int bits)
+{
+ lostFraction lost_fraction;
- APInt::tcShiftRight(dst, parts, bits);
+ lost_fraction = lostFractionThroughTruncation(dst, parts, bits);
- return lost_fraction;
- }
+ APInt::tcShiftRight(dst, parts, bits);
- /* Combine the effect of two lost fractions. */
- static lostFraction
- combineLostFractions(lostFraction moreSignificant,
- lostFraction lessSignificant)
- {
- if(lessSignificant != lfExactlyZero) {
- if(moreSignificant == lfExactlyZero)
- moreSignificant = lfLessThanHalf;
- else if(moreSignificant == lfExactlyHalf)
- moreSignificant = lfMoreThanHalf;
- }
+ return lost_fraction;
+}
- return moreSignificant;
+/* Combine the effect of two lost fractions. */
+static lostFraction
+combineLostFractions(lostFraction moreSignificant,
+ lostFraction lessSignificant)
+{
+ if (lessSignificant != lfExactlyZero) {
+ if (moreSignificant == lfExactlyZero)
+ moreSignificant = lfLessThanHalf;
+ else if (moreSignificant == lfExactlyHalf)
+ moreSignificant = lfMoreThanHalf;
}
- /* The error from the true value, in half-ulps, on multiplying two
- floating point numbers, which differ from the value they
- approximate by at most HUE1 and HUE2 half-ulps, is strictly less
- than the returned value.
+ return moreSignificant;
+}
- See "How to Read Floating Point Numbers Accurately" by William D
- Clinger. */
- static unsigned int
- HUerrBound(bool inexactMultiply, unsigned int HUerr1, unsigned int HUerr2)
- {
- assert(HUerr1 < 2 || HUerr2 < 2 || (HUerr1 + HUerr2 < 8));
+/* The error from the true value, in half-ulps, on multiplying two
+ floating point numbers, which differ from the value they
+ approximate by at most HUE1 and HUE2 half-ulps, is strictly less
+ than the returned value.
- if (HUerr1 + HUerr2 == 0)
- return inexactMultiply * 2; /* <= inexactMultiply half-ulps. */
- else
- return inexactMultiply + 2 * (HUerr1 + HUerr2);
- }
+ See "How to Read Floating Point Numbers Accurately" by William D
+ Clinger. */
+static unsigned int
+HUerrBound(bool inexactMultiply, unsigned int HUerr1, unsigned int HUerr2)
+{
+ assert(HUerr1 < 2 || HUerr2 < 2 || (HUerr1 + HUerr2 < 8));
- /* The number of ulps from the boundary (zero, or half if ISNEAREST)
- when the least significant BITS are truncated. BITS cannot be
- zero. */
- static integerPart
- ulpsFromBoundary(const integerPart *parts, unsigned int bits, bool isNearest)
- {
- unsigned int count, partBits;
- integerPart part, boundary;
+ if (HUerr1 + HUerr2 == 0)
+ return inexactMultiply * 2; /* <= inexactMultiply half-ulps. */
+ else
+ return inexactMultiply + 2 * (HUerr1 + HUerr2);
+}
- assert (bits != 0);
+/* The number of ulps from the boundary (zero, or half if ISNEAREST)
+ when the least significant BITS are truncated. BITS cannot be
+ zero. */
+static integerPart
+ulpsFromBoundary(const integerPart *parts, unsigned int bits, bool isNearest)
+{
+ unsigned int count, partBits;
+ integerPart part, boundary;
- bits--;
- count = bits / integerPartWidth;
- partBits = bits % integerPartWidth + 1;
+ assert(bits != 0);
- part = parts[count] & (~(integerPart) 0 >> (integerPartWidth - partBits));
+ bits--;
+ count = bits / integerPartWidth;
+ partBits = bits % integerPartWidth + 1;
- if (isNearest)
- boundary = (integerPart) 1 << (partBits - 1);
- else
- boundary = 0;
+ part = parts[count] & (~(integerPart) 0 >> (integerPartWidth - partBits));
- if (count == 0) {
- if (part - boundary <= boundary - part)
- return part - boundary;
- else
- return boundary - part;
- }
+ if (isNearest)
+ boundary = (integerPart) 1 << (partBits - 1);
+ else
+ boundary = 0;
- if (part == boundary) {
- while (--count)
- if (parts[count])
- return ~(integerPart) 0; /* A lot. */
+ if (count == 0) {
+ if (part - boundary <= boundary - part)
+ return part - boundary;
+ else
+ return boundary - part;
+ }
- return parts[0];
- } else if (part == boundary - 1) {
- while (--count)
- if (~parts[count])
- return ~(integerPart) 0; /* A lot. */
+ if (part == boundary) {
+ while (--count)
+ if (parts[count])
+ return ~(integerPart) 0; /* A lot. */
- return -parts[0];
- }
+ return parts[0];
+ } else if (part == boundary - 1) {
+ while (--count)
+ if (~parts[count])
+ return ~(integerPart) 0; /* A lot. */
- return ~(integerPart) 0; /* A lot. */
+ return -parts[0];
}
- /* Place pow(5, power) in DST, and return the number of parts used.
- DST must be at least one part larger than size of the answer. */
- static unsigned int
- powerOf5(integerPart *dst, unsigned int power)
- {
- static const integerPart firstEightPowers[] = { 1, 5, 25, 125, 625, 3125,
- 15625, 78125 };
- static integerPart pow5s[maxPowerOfFiveParts * 2 + 5] = { 78125 * 5 };
- static unsigned int partsCount[16] = { 1 };
-
- integerPart scratch[maxPowerOfFiveParts], *p1, *p2, *pow5;
- unsigned int result;
+ return ~(integerPart) 0; /* A lot. */
+}
- assert(power <= maxExponent);
+/* Place pow(5, power) in DST, and return the number of parts used.
+ DST must be at least one part larger than size of the answer. */
+static unsigned int
+powerOf5(integerPart *dst, unsigned int power)
+{
+ static const integerPart firstEightPowers[] = { 1, 5, 25, 125, 625, 3125,
+ 15625, 78125 };
+ integerPart pow5s[maxPowerOfFiveParts * 2 + 5];
+ pow5s[0] = 78125 * 5;
- p1 = dst;
- p2 = scratch;
+ unsigned int partsCount[16] = { 1 };
+ integerPart scratch[maxPowerOfFiveParts], *p1, *p2, *pow5;
+ unsigned int result;
+ assert(power <= maxExponent);
- *p1 = firstEightPowers[power & 7];
- power >>= 3;
+ p1 = dst;
+ p2 = scratch;
- result = 1;
- pow5 = pow5s;
+ *p1 = firstEightPowers[power & 7];
+ power >>= 3;
- for (unsigned int n = 0; power; power >>= 1, n++) {
- unsigned int pc;
+ result = 1;
+ pow5 = pow5s;
- pc = partsCount[n];
+ for (unsigned int n = 0; power; power >>= 1, n++) {
+ unsigned int pc;
- /* Calculate pow(5,pow(2,n+3)) if we haven't yet. */
- if (pc == 0) {
- pc = partsCount[n - 1];
- APInt::tcFullMultiply(pow5, pow5 - pc, pow5 - pc, pc, pc);
- pc *= 2;
- if (pow5[pc - 1] == 0)
- pc--;
- partsCount[n] = pc;
- }
+ pc = partsCount[n];
- if (power & 1) {
- integerPart *tmp;
+ /* Calculate pow(5,pow(2,n+3)) if we haven't yet. */
+ if (pc == 0) {
+ pc = partsCount[n - 1];
+ APInt::tcFullMultiply(pow5, pow5 - pc, pow5 - pc, pc, pc);
+ pc *= 2;
+ if (pow5[pc - 1] == 0)
+ pc--;
+ partsCount[n] = pc;
+ }
- APInt::tcFullMultiply(p2, p1, pow5, result, pc);
- result += pc;
- if (p2[result - 1] == 0)
- result--;
+ if (power & 1) {
+ integerPart *tmp;
- /* Now result is in p1 with partsCount parts and p2 is scratch
- space. */
- tmp = p1, p1 = p2, p2 = tmp;
- }
+ APInt::tcFullMultiply(p2, p1, pow5, result, pc);
+ result += pc;
+ if (p2[result - 1] == 0)
+ result--;
- pow5 += pc;
+ /* Now result is in p1 with partsCount parts and p2 is scratch
+ space. */
+ tmp = p1, p1 = p2, p2 = tmp;
}
- if (p1 != dst)
- APInt::tcAssign(dst, p1, result);
-
- return result;
+ pow5 += pc;
}
- /* Zero at the end to avoid modular arithmetic when adding one; used
- when rounding up during hexadecimal output. */
- static const char hexDigitsLower[] = "0123456789abcdef0";
- static const char hexDigitsUpper[] = "0123456789ABCDEF0";
- static const char infinityL[] = "infinity";
- static const char infinityU[] = "INFINITY";
- static const char NaNL[] = "nan";
- static const char NaNU[] = "NAN";
+ if (p1 != dst)
+ APInt::tcAssign(dst, p1, result);
- /* Write out an integerPart in hexadecimal, starting with the most
- significant nibble. Write out exactly COUNT hexdigits, return
- COUNT. */
- static unsigned int
- partAsHex (char *dst, integerPart part, unsigned int count,
- const char *hexDigitChars)
- {
- unsigned int result = count;
+ return result;
+}
- assert (count != 0 && count <= integerPartWidth / 4);
+/* Zero at the end to avoid modular arithmetic when adding one; used
+ when rounding up during hexadecimal output. */
+static const char hexDigitsLower[] = "0123456789abcdef0";
+static const char hexDigitsUpper[] = "0123456789ABCDEF0";
+static const char infinityL[] = "infinity";
+static const char infinityU[] = "INFINITY";
+static const char NaNL[] = "nan";
+static const char NaNU[] = "NAN";
- part >>= (integerPartWidth - 4 * count);
- while (count--) {
- dst[count] = hexDigitChars[part & 0xf];
- part >>= 4;
- }
+/* Write out an integerPart in hexadecimal, starting with the most
+ significant nibble. Write out exactly COUNT hexdigits, return
+ COUNT. */
+static unsigned int
+partAsHex (char *dst, integerPart part, unsigned int count,
+ const char *hexDigitChars)
+{
+ unsigned int result = count;
- return result;
+ assert(count != 0 && count <= integerPartWidth / 4);
+
+ part >>= (integerPartWidth - 4 * count);
+ while (count--) {
+ dst[count] = hexDigitChars[part & 0xf];
+ part >>= 4;
}
- /* Write out an unsigned decimal integer. */
- static char *
- writeUnsignedDecimal (char *dst, unsigned int n)
- {
- char buff[40], *p;
+ return result;
+}
- p = buff;
- do
- *p++ = '0' + n % 10;
- while (n /= 10);
+/* Write out an unsigned decimal integer. */
+static char *
+writeUnsignedDecimal (char *dst, unsigned int n)
+{
+ char buff[40], *p;
- do
- *dst++ = *--p;
- while (p != buff);
+ p = buff;
+ do
+ *p++ = '0' + n % 10;
+ while (n /= 10);
- return dst;
- }
+ do
+ *dst++ = *--p;
+ while (p != buff);
- /* Write out a signed decimal integer. */
- static char *
- writeSignedDecimal (char *dst, int value)
- {
- if (value < 0) {
- *dst++ = '-';
- dst = writeUnsignedDecimal(dst, -(unsigned) value);
- } else
- dst = writeUnsignedDecimal(dst, value);
+ return dst;
+}
- return dst;
- }
+/* Write out a signed decimal integer. */
+static char *
+writeSignedDecimal (char *dst, int value)
+{
+ if (value < 0) {
+ *dst++ = '-';
+ dst = writeUnsignedDecimal(dst, -(unsigned) value);
+ } else
+ dst = writeUnsignedDecimal(dst, value);
+
+ return dst;
}
/* Constructors. */
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;
}
exponent = rhs.exponent;
sign2 = rhs.sign2;
exponent2 = rhs.exponent2;
- if(category == fcNormal || category == fcNaN)
+ if (category == fcNormal || category == fcNaN)
copySignificand(rhs);
}
}
/* Make this number a NaN, with an arbitrary but deterministic value
- for the significand. */
-void
-APFloat::makeNaN(void)
+ for the significand. If double or longer, this is a signalling NaN,
+ which may not be ideal. If float, this is QNaN(0). */
+void APFloat::makeNaN(bool SNaN, bool Negative, const APInt *fill)
{
category = fcNaN;
- APInt::tcSet(significandParts(), ~0U, partCount());
+ sign = Negative;
+
+ integerPart *significand = significandParts();
+ unsigned numParts = partCount();
+
+ // Set the significand bits to the fill.
+ if (!fill || fill->getNumWords() < numParts)
+ APInt::tcSet(significand, 0, numParts);
+ if (fill) {
+ APInt::tcAssign(significand, fill->getRawData(),
+ std::min(fill->getNumWords(), numParts));
+
+ // Zero out the excess bits of the significand.
+ unsigned bitsToPreserve = semantics->precision - 1;
+ unsigned part = bitsToPreserve / 64;
+ bitsToPreserve %= 64;
+ significand[part] &= ((1ULL << bitsToPreserve) - 1);
+ for (part++; part != numParts; ++part)
+ significand[part] = 0;
+ }
+
+ unsigned QNaNBit = semantics->precision - 2;
+
+ if (SNaN) {
+ // We always have to clear the QNaN bit to make it an SNaN.
+ APInt::tcClearBit(significand, QNaNBit);
+
+ // If there are no bits set in the payload, we have to set
+ // *something* to make it a NaN instead of an infinity;
+ // conventionally, this is the next bit down from the QNaN bit.
+ if (APInt::tcIsZero(significand, numParts))
+ APInt::tcSetBit(significand, QNaNBit - 1);
+ } else {
+ // We always have to set the QNaN bit to make it a QNaN.
+ APInt::tcSetBit(significand, QNaNBit);
+ }
+
+ // For x87 extended precision, we want to make a NaN, not a
+ // pseudo-NaN. Maybe we should expose the ability to make
+ // pseudo-NaNs?
+ if (semantics == &APFloat::x87DoubleExtended)
+ APInt::tcSetBit(significand, QNaNBit + 1);
+}
+
+APFloat APFloat::makeNaN(const fltSemantics &Sem, bool SNaN, bool Negative,
+ const APInt *fill) {
+ APFloat value(Sem, uninitialized);
+ value.makeNaN(SNaN, Negative, fill);
+ return value;
}
APFloat &
APFloat::operator=(const APFloat &rhs)
{
- if(this != &rhs) {
- if(semantics != rhs.semantics) {
+ if (this != &rhs) {
+ if (semantics != rhs.semantics) {
freeSignificand();
initialize(rhs.semantics);
}
}
APFloat::APFloat(const fltSemantics &ourSemantics, integerPart value)
-{
+ : exponent2(0), sign2(0) {
assertArithmeticOK(ourSemantics);
initialize(&ourSemantics);
sign = 0;
normalize(rmNearestTiesToEven, lfExactlyZero);
}
+APFloat::APFloat(const fltSemantics &ourSemantics) : exponent2(0), sign2(0) {
+ assertArithmeticOK(ourSemantics);
+ initialize(&ourSemantics);
+ category = fcZero;
+ sign = false;
+}
+
+APFloat::APFloat(const fltSemantics &ourSemantics, uninitializedTag tag)
+ : exponent2(0), sign2(0) {
+ assertArithmeticOK(ourSemantics);
+ // Allocates storage if necessary but does not initialize it.
+ initialize(&ourSemantics);
+}
+
APFloat::APFloat(const fltSemantics &ourSemantics,
fltCategory ourCategory, bool negative)
-{
+ : exponent2(0), sign2(0) {
assertArithmeticOK(ourSemantics);
initialize(&ourSemantics);
category = ourCategory;
sign = negative;
- if(category == fcNormal)
+ if (category == fcNormal)
category = fcZero;
else if (ourCategory == fcNaN)
makeNaN();
}
-APFloat::APFloat(const fltSemantics &ourSemantics, const char *text)
-{
+APFloat::APFloat(const fltSemantics &ourSemantics, StringRef text)
+ : exponent2(0), sign2(0) {
assertArithmeticOK(ourSemantics);
initialize(&ourSemantics);
convertFromString(text, rmNearestTiesToEven);
}
-APFloat::APFloat(const APFloat &rhs)
-{
+APFloat::APFloat(const APFloat &rhs) : exponent2(0), sign2(0) {
initialize(rhs.semantics);
assign(rhs);
}
// Profile - This method 'profiles' an APFloat for use with FoldingSet.
void APFloat::Profile(FoldingSetNodeID& ID) const {
- ID.Add(convertToAPInt());
+ ID.Add(bitcastToAPInt());
}
unsigned int
{
assert(category == fcNormal || category == fcNaN);
- if(partCount() > 1)
+ if (partCount() > 1)
return significand.parts;
else
return &significand.part;
integerPart scratch[4];
integerPart *fullSignificand;
lostFraction lost_fraction;
+ bool ignored;
assert(semantics == rhs.semantics);
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;
semantics = &extendedSemantics;
APFloat extendedAddend(*addend);
- status = extendedAddend.convert(extendedSemantics, rmTowardZero);
+ status = extendedAddend.convert(extendedSemantics, rmTowardZero, &ignored);
assert(status == opOK);
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;
/* Current callers never pass this so we don't handle it. */
assert(lost_fraction != lfExactlyZero);
- switch(rounding_mode) {
+ switch (rounding_mode) {
default:
- assert(0);
+ 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;
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
the exponent. */
/* 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. */
APFloat::opStatus
APFloat::addOrSubtractSpecials(const APFloat &rhs, bool subtract)
{
- switch(convolve(category, rhs.category)) {
+ switch (convolve(category, rhs.category)) {
default:
- assert(0);
+ llvm_unreachable(0);
case convolve(fcNaN, fcZero):
case convolve(fcNaN, fcNormal):
case convolve(fcInfinity, fcInfinity):
/* Differently signed infinities can only be validly
subtracted. */
- if((sign ^ rhs.sign) != 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);
} else {
- if(bits > 0) {
+ if (bits > 0) {
APFloat temp_rhs(rhs);
lost_fraction = temp_rhs.shiftSignificandRight(bits);
APFloat::opStatus
APFloat::multiplySpecials(const APFloat &rhs)
{
- switch(convolve(category, rhs.category)) {
+ switch (convolve(category, rhs.category)) {
default:
- assert(0);
+ llvm_unreachable(0);
case convolve(fcNaN, fcZero):
case convolve(fcNaN, fcNormal):
APFloat::opStatus
APFloat::divideSpecials(const APFloat &rhs)
{
- switch(convolve(category, rhs.category)) {
+ switch (convolve(category, rhs.category)) {
default:
- assert(0);
+ llvm_unreachable(0);
case convolve(fcNaN, fcZero):
case convolve(fcNaN, fcNormal):
}
}
+APFloat::opStatus
+APFloat::modSpecials(const APFloat &rhs)
+{
+ switch (convolve(category, rhs.category)) {
+ default:
+ llvm_unreachable(0);
+
+ case convolve(fcNaN, fcZero):
+ case convolve(fcNaN, fcNormal):
+ case convolve(fcNaN, fcInfinity):
+ case convolve(fcNaN, fcNaN):
+ case convolve(fcZero, fcInfinity):
+ case convolve(fcZero, fcNormal):
+ case convolve(fcNormal, fcInfinity):
+ return opOK;
+
+ case convolve(fcZero, fcNaN):
+ case convolve(fcNormal, fcNaN):
+ case convolve(fcInfinity, fcNaN):
+ category = fcNaN;
+ copySignificand(rhs);
+ return opOK;
+
+ case convolve(fcNormal, fcZero):
+ case convolve(fcInfinity, fcZero):
+ case convolve(fcInfinity, fcNormal):
+ case convolve(fcInfinity, fcInfinity):
+ case convolve(fcZero, fcZero):
+ makeNaN();
+ return opInvalidOp;
+
+ case convolve(fcNormal, fcNormal):
+ return opOK;
+ }
+}
+
/* Change sign. */
void
APFloat::changeSign()
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);
}
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);
}
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);
}
return fs;
}
-/* Normalized remainder. This is not currently doing TRT. */
+/* Normalized remainder. This is not currently correct in all cases. */
APFloat::opStatus
-APFloat::mod(const APFloat &rhs, roundingMode rounding_mode)
+APFloat::remainder(const APFloat &rhs)
{
opStatus fs;
APFloat V = *this;
int parts = partCount();
integerPart *x = new integerPart[parts];
+ bool ignored;
fs = V.convertToInteger(x, parts * integerPartWidth, true,
- rmNearestTiesToEven);
+ rmNearestTiesToEven, &ignored);
if (fs==opInvalidOp)
return fs;
rmNearestTiesToEven);
assert(fs==opOK); // should always work
- fs = V.multiply(rhs, rounding_mode);
+ fs = V.multiply(rhs, rmNearestTiesToEven);
assert(fs==opOK || fs==opInexact); // should not overflow or underflow
- fs = subtract(V, rounding_mode);
+ fs = subtract(V, rmNearestTiesToEven);
assert(fs==opOK || fs==opInexact); // likewise
if (isZero())
return fs;
}
+/* 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) {
+ APFloat V = *this;
+ unsigned int origSign = sign;
+
+ fs = V.divide(rhs, rmNearestTiesToEven);
+ if (fs == opDivByZero)
+ return fs;
+
+ int parts = partCount();
+ integerPart *x = new integerPart[parts];
+ bool ignored;
+ fs = V.convertToInteger(x, parts * integerPartWidth, true,
+ rmTowardZero, &ignored);
+ if (fs==opInvalidOp)
+ return fs;
+
+ fs = V.convertFromZeroExtendedInteger(x, parts * integerPartWidth, true,
+ rmNearestTiesToEven);
+ assert(fs==opOK); // should always work
+
+ fs = V.multiply(rhs, rounding_mode);
+ assert(fs==opOK || fs==opInexact); // should not overflow or underflow
+
+ fs = subtract(V, rounding_mode);
+ assert(fs==opOK || fs==opInexact); // likewise
+
+ if (isZero())
+ sign = origSign; // IEEE754 requires this
+ delete[] x;
+ }
+ return fs;
+}
+
/* Normalized fused-multiply-add. */
APFloat::opStatus
APFloat::fusedMultiplyAdd(const APFloat &multiplicand,
/* 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);
}
assertArithmeticOK(*semantics);
assert(semantics == rhs.semantics);
- switch(convolve(category, rhs.category)) {
+ switch (convolve(category, rhs.category)) {
default:
- assert(0);
+ llvm_unreachable(0);
case convolve(fcNaN, fcZero):
case convolve(fcNaN, fcNormal):
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;
}
}
return result;
}
+/// APFloat::convert - convert a value of one floating point type to another.
+/// The return value corresponds to the IEEE754 exceptions. *losesInfo
+/// records whether the transformation lost information, i.e. whether
+/// converting the result back to the original type will produce the
+/// original value (this is almost the same as return value==fsOK, but there
+/// are edge cases where this is not so).
+
APFloat::opStatus
APFloat::convert(const fltSemantics &toSemantics,
- roundingMode rounding_mode)
+ roundingMode rounding_mode, bool *losesInfo)
{
lostFraction lostFraction;
unsigned int newPartCount, oldPartCount;
}
}
- if(category == fcNormal) {
+ if (category == fcNormal) {
/* Re-interpret our bit-pattern. */
exponent += toSemantics.precision - semantics->precision;
semantics = &toSemantics;
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)
- APInt::tcShiftRight(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);
+ }
// 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
} else {
semantics = &toSemantics;
fs = opOK;
+ *losesInfo = false;
}
return fs;
APFloat::opStatus
APFloat::convertToSignExtendedInteger(integerPart *parts, unsigned int width,
bool isSigned,
- roundingMode rounding_mode) const
+ roundingMode rounding_mode,
+ bool *isExact) const
{
lostFraction lost_fraction;
const integerPart *src;
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;
return opOK;
}
if (exponent < 0) {
/* Our absolute value is less than one; truncate everything. */
APInt::tcSet(parts, 0, dstPartsCount);
- truncatedBits = semantics->precision;
+ /* For exponent -1 the integer bit represents .5, look at that.
+ For smaller exponents leftmost truncated bit is 0. */
+ truncatedBits = semantics->precision -1U - exponent;
} else {
/* We want the most significant (exponent + 1) bits; the rest are
truncated. */
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. */
}
return opInvalidOp;
}
- if (lost_fraction == lfExactlyZero)
+ if (lost_fraction == lfExactlyZero) {
+ *isExact = true;
return opOK;
- else
+ } else
return opInexact;
}
/* Same as convertToSignExtendedInteger, except we provide
deterministic values in case of an invalid operation exception,
namely zero for NaNs and the minimal or maximal value respectively
- for underflow or overflow. */
+ for underflow or overflow.
+ The *isExact output tells whether the result is exact, in the sense
+ that converting it back to the original floating point type produces
+ the original value. This is almost equivalent to result==opOK,
+ except for negative zeroes.
+*/
APFloat::opStatus
APFloat::convertToInteger(integerPart *parts, unsigned int width,
bool isSigned,
- roundingMode rounding_mode) const
+ roundingMode rounding_mode, bool *isExact) const
{
opStatus fs;
- fs = convertToSignExtendedInteger(parts, width, isSigned, rounding_mode);
+ fs = convertToSignExtendedInteger(parts, width, isSigned, rounding_mode,
+ isExact);
if (fs == opInvalidOp) {
unsigned int bits, dstPartsCount;
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. */
APInt api = APInt(width, partCount, parts);
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 char *p,
- roundingMode rounding_mode)
+APFloat::convertFromHexadecimalString(StringRef s, roundingMode rounding_mode)
{
- lostFraction lost_fraction;
+ lostFraction lost_fraction = lfExactlyZero;
integerPart *significand;
unsigned int bitPos, partsCount;
- const char *dot, *firstSignificantDigit;
+ StringRef::iterator dot, firstSignificantDigit;
zeroSignificand();
exponent = 0;
bitPos = partsCount * integerPartWidth;
/* Skip leading zeroes and any (hexa)decimal point. */
- p = skipLeadingZeroesAndAnyDot(p, &dot);
+ StringRef::iterator begin = s.begin();
+ StringRef::iterator end = s.end();
+ StringRef::iterator p = skipLeadingZeroesAndAnyDot(begin, end, &dot);
firstSignificantDigit = p;
- for(;;) {
+ for (; p != end;) {
integerPart hex_value;
- if(*p == '.') {
- assert(dot == 0);
+ if (*p == '.') {
+ assert(dot == end && "String contains multiple dots");
dot = p++;
+ if (p == end) {
+ break;
+ }
}
hex_value = hexDigitValue(*p);
- if(hex_value == -1U) {
- lost_fraction = lfExactlyZero;
+ if (hex_value == -1U) {
break;
}
p++;
- /* Store the number whilst 4-bit nibbles remain. */
- if(bitPos) {
- bitPos -= 4;
- hex_value <<= bitPos % integerPartWidth;
- significand[bitPos / integerPartWidth] |= hex_value;
- } else {
- lost_fraction = trailingHexadecimalFraction(p, hex_value);
- while(hexDigitValue(*p) != -1U)
- p++;
+ if (p == end) {
break;
+ } else {
+ /* Store the number whilst 4-bit nibbles remain. */
+ 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)
+ p++;
+ break;
+ }
}
}
/* Hex floats require an exponent but not a hexadecimal point. */
- assert(*p == 'p' || *p == 'P');
+ assert(p != end && "Hex strings require an exponent");
+ assert((*p == 'p' || *p == 'P') && "Invalid character in significand");
+ assert(p != begin && "Significand has no digits");
+ 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? */
- if(!dot)
+ if (dot == end)
dot = p;
/* 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;
expAdjustment -= partsCount * integerPartWidth;
/* Adjust for the given exponent. */
- exponent = totalExponent(p, expAdjustment);
+ exponent = totalExponent(p + 1, end, expAdjustment);
}
return normalize(rounding_mode, lost_fraction);
integerPart pow5Parts[maxPowerOfFiveParts];
bool isNearest;
- isNearest = (rounding_mode == rmNearestTiesToEven
- || rounding_mode == rmNearestTiesToAway);
+ isNearest = (rounding_mode == rmNearestTiesToEven ||
+ rounding_mode == rmNearestTiesToAway);
parts = partCountForBits(semantics->precision + 11);
/* Both multiplySignificand and divideSignificand return the
result with the integer bit set. */
- assert (APInt::tcExtractBit
- (decSig.significandParts(), calcSemantics.precision - 1) == 1);
+ assert(APInt::tcExtractBit
+ (decSig.significandParts(), calcSemantics.precision - 1) == 1);
HUerr = HUerrBound(calcLostFraction != lfExactlyZero, sigStatus != opOK,
powHUerr);
}
APFloat::opStatus
-APFloat::convertFromDecimalString(const char *p, roundingMode rounding_mode)
+APFloat::convertFromDecimalString(StringRef str, roundingMode rounding_mode)
{
decimalInfo D;
opStatus fs;
/* Scan the text. */
- interpretDecimal(p, &D);
+ StringRef::iterator p = str.begin();
+ interpretDecimal(p, str.end(), &D);
/* Handle the quick cases. First the case of no significant digits,
i.e. zero, and then exponents that are obviously too large or too
if (decDigitValue(*D.firstSigDigit) >= 10U) {
category = fcZero;
fs = opOK;
- } else if ((D.normalizedExponent + 1) * 28738
- <= 8651 * (semantics->minExponent - (int) semantics->precision)) {
+
+ /* Check whether the normalized exponent is high enough to overflow
+ max during the log-rebasing in the max-exponent check below. */
+ } else if (D.normalizedExponent - 1 > INT_MAX / 42039) {
+ fs = handleOverflow(rounding_mode);
+
+ /* If it wasn't, then it also wasn't high enough to overflow max
+ during the log-rebasing in the min-exponent check. Check that it
+ won't overflow min in either check, then perform the min-exponent
+ check. */
+ } else if (D.normalizedExponent - 1 < INT_MIN / 42039 ||
+ (D.normalizedExponent + 1) * 28738 <=
+ 8651 * (semantics->minExponent - (int) semantics->precision)) {
/* Underflow to zero and round. */
zeroSignificand();
fs = normalize(rounding_mode, lfLessThanHalf);
+
+ /* We can finally safely perform the max-exponent check. */
} else if ((D.normalizedExponent - 1) * 42039
>= 12655 * semantics->maxExponent) {
/* Overflow and round. */
multiplier = 1;
do {
- if (*p == '.')
+ if (*p == '.') {
p++;
-
+ if (p == str.end()) {
+ break;
+ }
+ }
decValue = decDigitValue(*p++);
+ assert(decValue < 10U && "Invalid character in significand");
multiplier *= 10;
val = val * 10 + decValue;
/* The maximum number that can be multiplied by ten with any
}
APFloat::opStatus
-APFloat::convertFromString(const char *p, roundingMode rounding_mode)
+APFloat::convertFromString(StringRef str, roundingMode rounding_mode)
{
assertArithmeticOK(*semantics);
+ assert(!str.empty() && "Invalid string length");
/* Handle a leading minus sign. */
- if(*p == '-')
- sign = 1, p++;
- else
- sign = 0;
+ StringRef::iterator p = str.begin();
+ size_t slen = str.size();
+ sign = *p == '-' ? 1 : 0;
+ if (*p == '-' || *p == '+') {
+ p++;
+ slen--;
+ assert(slen && "String has no digits");
+ }
- if(p[0] == '0' && (p[1] == 'x' || p[1] == 'X'))
- return convertFromHexadecimalString(p + 2, rounding_mode);
- else
- return convertFromDecimalString(p, rounding_mode);
+ 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);
+ }
+
+ return convertFromDecimalString(StringRef(p, slen), rounding_mode);
}
/* Write out a hexadecimal representation of the floating point value
q--;
*q = hexDigitChars[hexDigitValue (*q) + 1];
} while (*q == '0');
- assert (q >= p);
+ assert(q >= p);
} else {
/* Add trailing zeroes. */
memset (dst, '0', outputDigits);
APFloat::convertF80LongDoubleAPFloatToAPInt() const
{
assert(semantics == (const llvm::fltSemantics*)&x87DoubleExtended);
- assert (partCount()==2);
+ assert(partCount()==2);
uint64_t myexponent, mysignificand;
}
uint64_t words[2];
- words[0] = ((uint64_t)(sign & 1) << 63) |
- ((myexponent & 0x7fffLL) << 48) |
- ((mysignificand >>16) & 0xffffffffffffLL);
- words[1] = mysignificand & 0xffff;
+ words[0] = mysignificand;
+ words[1] = ((uint64_t)(sign & 1) << 15) |
+ (myexponent & 0x7fffLL);
return APInt(80, 2, words);
}
APFloat::convertPPCDoubleDoubleAPFloatToAPInt() const
{
assert(semantics == (const llvm::fltSemantics*)&PPCDoubleDouble);
- assert (partCount()==2);
+ assert(partCount()==2);
uint64_t myexponent, mysignificand, myexponent2, mysignificand2;
return APInt(128, 2, words);
}
+APInt
+APFloat::convertQuadrupleAPFloatToAPInt() const
+{
+ assert(semantics == (const llvm::fltSemantics*)&IEEEquad);
+ assert(partCount()==2);
+
+ uint64_t myexponent, mysignificand, mysignificand2;
+
+ if (category==fcNormal) {
+ myexponent = exponent+16383; //bias
+ mysignificand = significandParts()[0];
+ mysignificand2 = significandParts()[1];
+ if (myexponent==1 && !(mysignificand2 & 0x1000000000000LL))
+ myexponent = 0; // denormal
+ } else if (category==fcZero) {
+ myexponent = 0;
+ mysignificand = mysignificand2 = 0;
+ } else if (category==fcInfinity) {
+ myexponent = 0x7fff;
+ mysignificand = mysignificand2 = 0;
+ } else {
+ assert(category == fcNaN && "Unknown category!");
+ myexponent = 0x7fff;
+ mysignificand = significandParts()[0];
+ mysignificand2 = significandParts()[1];
+ }
+
+ uint64_t words[2];
+ words[0] = mysignificand;
+ words[1] = ((uint64_t)(sign & 1) << 63) |
+ ((myexponent & 0x7fff) << 48) |
+ (mysignificand2 & 0xffffffffffffLL);
+
+ return APInt(128, 2, words);
+}
+
APInt
APFloat::convertDoubleAPFloatToAPInt() const
{
assert(semantics == (const llvm::fltSemantics*)&IEEEdouble);
- assert (partCount()==1);
+ assert(partCount()==1);
uint64_t myexponent, mysignificand;
APFloat::convertFloatAPFloatToAPInt() const
{
assert(semantics == (const llvm::fltSemantics*)&IEEEsingle);
- assert (partCount()==1);
+ assert(partCount()==1);
uint32_t myexponent, mysignificand;
(mysignificand & 0x7fffff)));
}
+APInt
+APFloat::convertHalfAPFloatToAPInt() const
+{
+ assert(semantics == (const llvm::fltSemantics*)&IEEEhalf);
+ assert(partCount()==1);
+
+ uint32_t myexponent, mysignificand;
+
+ if (category==fcNormal) {
+ myexponent = exponent+15; //bias
+ mysignificand = (uint32_t)*significandParts();
+ if (myexponent == 1 && !(mysignificand & 0x400))
+ myexponent = 0; // denormal
+ } else if (category==fcZero) {
+ myexponent = 0;
+ mysignificand = 0;
+ } else if (category==fcInfinity) {
+ myexponent = 0x1f;
+ mysignificand = 0;
+ } else {
+ assert(category == fcNaN && "Unknown category!");
+ myexponent = 0x1f;
+ mysignificand = (uint32_t)*significandParts();
+ }
+
+ return APInt(16, (((sign&1) << 15) | ((myexponent&0x1f) << 10) |
+ (mysignificand & 0x3ff)));
+}
+
// This function creates an APInt that is just a bit map of the floating
// point constant as it would appear in memory. It is not a conversion,
// and treating the result as a normal integer is unlikely to be useful.
APInt
-APFloat::convertToAPInt() const
+APFloat::bitcastToAPInt() const
{
+ if (semantics == (const llvm::fltSemantics*)&IEEEhalf)
+ return convertHalfAPFloatToAPInt();
+
if (semantics == (const llvm::fltSemantics*)&IEEEsingle)
return convertFloatAPFloatToAPInt();
-
+
if (semantics == (const llvm::fltSemantics*)&IEEEdouble)
return convertDoubleAPFloatToAPInt();
+ if (semantics == (const llvm::fltSemantics*)&IEEEquad)
+ return convertQuadrupleAPFloatToAPInt();
+
if (semantics == (const llvm::fltSemantics*)&PPCDoubleDouble)
return convertPPCDoubleDoubleAPFloatToAPInt();
float
APFloat::convertToFloat() const
{
- assert(semantics == (const llvm::fltSemantics*)&IEEEsingle);
- APInt api = convertToAPInt();
+ assert(semantics == (const llvm::fltSemantics*)&IEEEsingle &&
+ "Float semantics are not IEEEsingle");
+ APInt api = bitcastToAPInt();
return api.bitsToFloat();
}
double
APFloat::convertToDouble() const
{
- assert(semantics == (const llvm::fltSemantics*)&IEEEdouble);
- APInt api = convertToAPInt();
+ assert(semantics == (const llvm::fltSemantics*)&IEEEdouble &&
+ "Float semantics are not IEEEdouble");
+ APInt api = bitcastToAPInt();
return api.bitsToDouble();
}
assert(api.getBitWidth()==80);
uint64_t i1 = api.getRawData()[0];
uint64_t i2 = api.getRawData()[1];
- uint64_t myexponent = (i1 >> 48) & 0x7fff;
- uint64_t mysignificand = ((i1 << 16) & 0xffffffffffff0000ULL) |
- (i2 & 0xffff);
+ uint64_t myexponent = (i2 & 0x7fff);
+ uint64_t mysignificand = i1;
initialize(&APFloat::x87DoubleExtended);
assert(partCount()==2);
- sign = static_cast<unsigned int>(i1>>63);
+ sign = static_cast<unsigned int>(i2>>15);
if (myexponent==0 && mysignificand==0) {
// exponent, significand meaningless
category = fcZero;
// 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
+ // exponent meaningless. So is the whole second word, but keep it
// for determinism.
category = fcNaN;
exponent2 = myexponent2;
exponent = -1022;
else
significandParts()[0] |= 0x10000000000000LL; // integer bit
- if (myexponent2==0)
+ if (myexponent2==0)
exponent2 = -1022;
else
significandParts()[1] |= 0x10000000000000LL; // integer bit
}
}
+void
+APFloat::initFromQuadrupleAPInt(const APInt &api)
+{
+ assert(api.getBitWidth()==128);
+ uint64_t i1 = api.getRawData()[0];
+ uint64_t i2 = api.getRawData()[1];
+ uint64_t myexponent = (i2 >> 48) & 0x7fff;
+ uint64_t mysignificand = i1;
+ uint64_t mysignificand2 = i2 & 0xffffffffffffLL;
+
+ initialize(&APFloat::IEEEquad);
+ assert(partCount()==2);
+
+ sign = static_cast<unsigned int>(i2>>63);
+ if (myexponent==0 &&
+ (mysignificand==0 && mysignificand2==0)) {
+ // exponent, significand meaningless
+ category = fcZero;
+ } else if (myexponent==0x7fff &&
+ (mysignificand==0 && mysignificand2==0)) {
+ // exponent, significand meaningless
+ category = fcInfinity;
+ } else if (myexponent==0x7fff &&
+ (mysignificand!=0 || mysignificand2 !=0)) {
+ // exponent meaningless
+ category = fcNaN;
+ significandParts()[0] = mysignificand;
+ significandParts()[1] = mysignificand2;
+ } else {
+ category = fcNormal;
+ exponent = myexponent - 16383;
+ significandParts()[0] = mysignificand;
+ significandParts()[1] = mysignificand2;
+ if (myexponent==0) // denormal
+ exponent = -16382;
+ else
+ significandParts()[1] |= 0x1000000000000LL; // integer bit
+ }
+}
+
void
APFloat::initFromDoubleAPInt(const APInt &api)
{
}
}
+void
+APFloat::initFromHalfAPInt(const APInt & api)
+{
+ assert(api.getBitWidth()==16);
+ uint32_t i = (uint32_t)*api.getRawData();
+ uint32_t myexponent = (i >> 10) & 0x1f;
+ uint32_t mysignificand = i & 0x3ff;
+
+ initialize(&APFloat::IEEEhalf);
+ assert(partCount()==1);
+
+ sign = i >> 15;
+ if (myexponent==0 && mysignificand==0) {
+ // exponent, significand meaningless
+ category = fcZero;
+ } else if (myexponent==0x1f && mysignificand==0) {
+ // exponent, significand meaningless
+ category = fcInfinity;
+ } else if (myexponent==0x1f && mysignificand!=0) {
+ // sign, exponent, significand meaningless
+ category = fcNaN;
+ *significandParts() = mysignificand;
+ } else {
+ category = fcNormal;
+ exponent = myexponent - 15; //bias
+ *significandParts() = mysignificand;
+ if (myexponent==0) // denormal
+ exponent = -14;
+ else
+ *significandParts() |= 0x400; // integer bit
+ }
+}
+
/// Treat api as containing the bits of a floating point number. Currently
/// we infer the floating point type from the size of the APInt. The
/// isIEEE argument distinguishes between PPC128 and IEEE128 (not meaningful
void
APFloat::initFromAPInt(const APInt& api, bool isIEEE)
{
- if (api.getBitWidth() == 32)
+ if (api.getBitWidth() == 16)
+ return initFromHalfAPInt(api);
+ else if (api.getBitWidth() == 32)
return initFromFloatAPInt(api);
else if (api.getBitWidth()==64)
return initFromDoubleAPInt(api);
else if (api.getBitWidth()==80)
return initFromF80LongDoubleAPInt(api);
- else if (api.getBitWidth()==128 && !isIEEE)
- return initFromPPCDoubleDoubleAPInt(api);
+ else if (api.getBitWidth()==128)
+ return (isIEEE ?
+ initFromQuadrupleAPInt(api) : initFromPPCDoubleDoubleAPInt(api));
else
- assert(0);
+ llvm_unreachable(0);
}
-APFloat::APFloat(const APInt& api, bool isIEEE)
+APFloat
+APFloat::getAllOnesValue(unsigned BitWidth, bool isIEEE)
{
+ return APFloat(APInt::getAllOnesValue(BitWidth), isIEEE);
+}
+
+APFloat APFloat::getLargest(const fltSemantics &Sem, bool Negative) {
+ APFloat Val(Sem, fcNormal, Negative);
+
+ // We want (in interchange format):
+ // sign = {Negative}
+ // exponent = 1..10
+ // significand = 1..1
+
+ Val.exponent = Sem.maxExponent; // unbiased
+
+ // 1-initialize all bits....
+ Val.zeroSignificand();
+ integerPart *significand = Val.significandParts();
+ unsigned N = partCountForBits(Sem.precision);
+ for (unsigned i = 0; i != N; ++i)
+ significand[i] = ~((integerPart) 0);
+
+ // ...and then clear the top bits for internal consistency.
+ significand[N-1] &=
+ (((integerPart) 1) << ((Sem.precision % integerPartWidth) - 1)) - 1;
+
+ return Val;
+}
+
+APFloat APFloat::getSmallest(const fltSemantics &Sem, bool Negative) {
+ APFloat Val(Sem, fcNormal, Negative);
+
+ // We want (in interchange format):
+ // sign = {Negative}
+ // exponent = 0..0
+ // significand = 0..01
+
+ Val.exponent = Sem.minExponent; // unbiased
+ Val.zeroSignificand();
+ Val.significandParts()[0] = 1;
+ return Val;
+}
+
+APFloat APFloat::getSmallestNormalized(const fltSemantics &Sem, bool Negative) {
+ APFloat Val(Sem, fcNormal, Negative);
+
+ // We want (in interchange format):
+ // sign = {Negative}
+ // exponent = 0..0
+ // significand = 10..0
+
+ Val.exponent = Sem.minExponent;
+ Val.zeroSignificand();
+ Val.significandParts()[partCountForBits(Sem.precision)-1] |=
+ (((integerPart) 1) << ((Sem.precision % integerPartWidth) - 1));
+
+ return Val;
+}
+
+APFloat::APFloat(const APInt& api, bool isIEEE) : exponent2(0), sign2(0) {
initFromAPInt(api, isIEEE);
}
-APFloat::APFloat(float f)
-{
- APInt api = APInt(32, 0);
- initFromAPInt(api.floatToBits(f));
+APFloat::APFloat(float f) : exponent2(0), sign2(0) {
+ initFromAPInt(APInt::floatToBits(f));
}
-APFloat::APFloat(double d)
-{
- APInt api = APInt(64, 0);
- initFromAPInt(api.doubleToBits(d));
+APFloat::APFloat(double d) : exponent2(0), sign2(0) {
+ initFromAPInt(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);
+ }
+
+ /// Removes data from the given significand until it is no more
+ /// precise than is required for the desired precision.
+ void AdjustToPrecision(APInt &significand,
+ int &exp, unsigned FormatPrecision) {
+ unsigned bits = significand.getActiveBits();
+
+ // 196/59 is a very slight overestimate of lg_2(10).
+ unsigned bitsRequired = (FormatPrecision * 196 + 58) / 59;
+
+ if (bits <= bitsRequired) return;
+
+ unsigned tensRemovable = (bits - bitsRequired) * 59 / 196;
+ if (!tensRemovable) return;
+
+ exp += tensRemovable;
+
+ APInt divisor(significand.getBitWidth(), 1);
+ APInt powten(significand.getBitWidth(), 10);
+ while (true) {
+ if (tensRemovable & 1)
+ divisor *= powten;
+ tensRemovable >>= 1;
+ if (!tensRemovable) break;
+ powten *= powten;
+ }
+
+ significand = significand.udiv(divisor);
+
+ // 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 = significand.trunc(newPrecision);
+ }
+
+
+ void AdjustToPrecision(SmallVectorImpl<char> &buffer,
+ int &exp, unsigned FormatPrecision) {
+ unsigned N = buffer.size();
+ if (N <= FormatPrecision) return;
+
+ // The most significant figures are the last ones in the buffer.
+ unsigned FirstSignificant = N - FormatPrecision;
+
+ // Round.
+ // FIXME: this probably shouldn't use 'round half up'.
+
+ // 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')
+ FirstSignificant++;
+
+ exp += FirstSignificant;
+ buffer.erase(&buffer[0], &buffer[FirstSignificant]);
+ return;
+ }
+
+ // Rounding up requires a decimal add-with-carry. If we continue
+ // the carry, the newly-introduced zeros will just be truncated.
+ for (unsigned I = FirstSignificant; I != N; ++I) {
+ if (buffer[I] == '9') {
+ FirstSignificant++;
+ } else {
+ buffer[I]++;
+ break;
+ }
+ }
+
+ // If we carried through, we have exactly one digit of precision.
+ if (FirstSignificant == N) {
+ exp += FirstSignificant;
+ buffer.clear();
+ buffer.push_back('1');
+ return;
+ }
+
+ exp += FirstSignificant;
+ buffer.erase(&buffer[0], &buffer[FirstSignificant]);
+ }
+}
+
+void APFloat::toString(SmallVectorImpl<char> &Str,
+ unsigned FormatPrecision,
+ unsigned FormatMaxPadding) const {
+ switch (category) {
+ case fcInfinity:
+ if (isNegative())
+ return append(Str, "-Inf");
+ else
+ return append(Str, "+Inf");
+
+ case fcNaN: return append(Str, "NaN");
+
+ case fcZero:
+ if (isNegative())
+ Str.push_back('-');
+
+ if (!FormatMaxPadding)
+ append(Str, "0.0E+0");
+ else
+ Str.push_back('0');
+ return;
+
+ case fcNormal:
+ break;
+ }
+
+ if (isNegative())
+ Str.push_back('-');
+
+ // Decompose the number into an APInt and an exponent.
+ int exp = exponent - ((int) semantics->precision - 1);
+ APInt significand(semantics->precision,
+ partCountForBits(semantics->precision),
+ significandParts());
+
+ // Set FormatPrecision if zero. We want to do this before we
+ // truncate trailing zeros, as those are part of the precision.
+ if (!FormatPrecision) {
+ // It's an interesting question whether to use the nominal
+ // precision or the active precision here for denormals.
+
+ // FormatPrecision = ceil(significandBits / lg_2(10))
+ FormatPrecision = (semantics->precision * 59 + 195) / 196;
+ }
+
+ // Ignore trailing binary zeros.
+ int trailingZeros = significand.countTrailingZeros();
+ exp += trailingZeros;
+ significand = significand.lshr(trailingZeros);
+
+ // Change the exponent from 2^e to 10^e.
+ if (exp == 0) {
+ // Nothing to do.
+ } else if (exp > 0) {
+ // Just shift left.
+ significand = significand.zext(semantics->precision + exp);
+ significand <<= exp;
+ exp = 0;
+ } else { /* exp < 0 */
+ int texp = -exp;
+
+ // We transform this using the identity:
+ // (N)(2^-e) == (N)(5^e)(10^-e)
+ // This means we have to multiply N (the significand) by 5^e.
+ // To avoid overflow, we have to operate on numbers large
+ // enough to store N * 5^e:
+ // 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;
+
+ // Multiply significand by 5^e.
+ // N * 5^0101 == N * 5^(1*1) * 5^(0*2) * 5^(1*4) * 5^(0*8)
+ 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;
+
+ // Fill the buffer.
+ unsigned precision = significand.getBitWidth();
+ APInt ten(precision, 10);
+ APInt digit(precision, 0);
+
+ bool inTrail = true;
+ while (significand != 0) {
+ // digit <- significand % 10
+ // significand <- significand / 10
+ APInt::udivrem(significand, ten, significand, digit);
+
+ unsigned d = digit.getZExtValue();
+
+ // Drop trailing zeros.
+ if (inTrail && !d) exp++;
+ else {
+ buffer.push_back((char) ('0' + d));
+ inTrail = false;
+ }
+ }
+
+ assert(!buffer.empty() && "no characters in buffer!");
+
+ // Drop down to FormatPrecision.
+ // TODO: don't do more precise calculations above than are required.
+ AdjustToPrecision(buffer, exp, FormatPrecision);
+
+ unsigned NDigits = buffer.size();
+
+ // Check whether we should use scientific notation.
+ bool FormatScientific;
+ if (!FormatMaxPadding)
+ FormatScientific = true;
+ else {
+ if (exp >= 0) {
+ // 765e3 --> 765000
+ // ^^^
+ // But we shouldn't make the number look more precise than it is.
+ FormatScientific = ((unsigned) exp > FormatMaxPadding ||
+ NDigits + (unsigned) exp > FormatPrecision);
+ } else {
+ // Power of the most significant digit.
+ int MSD = exp + (int) (NDigits - 1);
+ if (MSD >= 0) {
+ // 765e-2 == 7.65
+ FormatScientific = false;
+ } else {
+ // 765e-5 == 0.00765
+ // ^ ^^
+ FormatScientific = ((unsigned) -MSD) > FormatMaxPadding;
+ }
+ }
+ }
+
+ // Scientific formatting is pretty straightforward.
+ if (FormatScientific) {
+ exp += (NDigits - 1);
+
+ Str.push_back(buffer[NDigits-1]);
+ Str.push_back('.');
+ if (NDigits == 1)
+ Str.push_back('0');
+ else
+ for (unsigned I = 1; I != NDigits; ++I)
+ Str.push_back(buffer[NDigits-1-I]);
+ Str.push_back('E');
+
+ Str.push_back(exp >= 0 ? '+' : '-');
+ if (exp < 0) exp = -exp;
+ SmallVector<char, 6> expbuf;
+ do {
+ expbuf.push_back((char) ('0' + (exp % 10)));
+ exp /= 10;
+ } while (exp);
+ for (unsigned I = 0, E = expbuf.size(); I != E; ++I)
+ Str.push_back(expbuf[E-1-I]);
+ return;
+ }
+
+ // Non-scientific, positive exponents.
+ if (exp >= 0) {
+ for (unsigned I = 0; I != NDigits; ++I)
+ Str.push_back(buffer[NDigits-1-I]);
+ for (unsigned I = 0; I != (unsigned) exp; ++I)
+ Str.push_back('0');
+ return;
+ }
+
+ // Non-scientific, negative exponents.
+
+ // The number of digits to the left of the decimal point.
+ int NWholeDigits = exp + (int) NDigits;
+
+ unsigned I = 0;
+ if (NWholeDigits > 0) {
+ for (; I != (unsigned) NWholeDigits; ++I)
+ Str.push_back(buffer[NDigits-I-1]);
+ Str.push_back('.');
+ } else {
+ unsigned NZeros = 1 + (unsigned) -NWholeDigits;
+
+ Str.push_back('0');
+ Str.push_back('.');
+ for (unsigned Z = 1; Z != NZeros; ++Z)
+ Str.push_back('0');
+ }
+
+ for (; I != NDigits; ++I)
+ Str.push_back(buffer[NDigits-I-1]);
+}
+
+bool APFloat::getExactInverse(APFloat *inv) const {
+ // We can only guarantee the existence of an exact inverse for IEEE floats.
+ if (semantics != &IEEEhalf && semantics != &IEEEsingle &&
+ semantics != &IEEEdouble && semantics != &IEEEquad)
+ return false;
+
+ // 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;
}
projects / oota-llvm.git / blobdiff