Skip to content

Commit

Permalink
code hygiene on volatile qualifier
Browse files Browse the repository at this point in the history
  • Loading branch information
@Ravenwater
Ravenwater committed Aug 4, 2024
1 parent a1ae7c4 commit de0c4b2
Show file tree
Hide file tree
Showing 5 changed files with 92 additions and 47 deletions.
27 changes: 9 additions & 18 deletions include/universal/native/error_free_ops.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -46,10 +46,8 @@ namespace sw { namespace universal {
/// <param name="b">input</param>
/// <param name="r">reference to the residual</param>
/// <returns>the sum s</returns>
template<typename NativeFloat>
inline double quick_two_sum(volatile NativeFloat a, volatile NativeFloat b, volatile NativeFloat& r)
{
volatile NativeFloat s = a + b;
inline double quick_two_sum(double a, double b, volatile double& r) {
volatile double s = a + b;
r = (std::isfinite(s) ? b - (s - a) : 0.0);
return s;
}
Expand All @@ -61,9 +59,7 @@ namespace sw { namespace universal {
/// <param name="b">input</param>
/// <param name="r">reference to the residual</param>
/// <returns>the sum s</returns>
template<typename NativeFloat>
inline double two_sum(volatile NativeFloat a, volatile NativeFloat b, volatile NativeFloat& r)
{
inline double two_sum(double a, double b, volatile double& r) {
volatile double s = a + b;
if (std::isfinite(s)) {
volatile double bb = s - a;
Expand All @@ -87,8 +83,7 @@ namespace sw { namespace universal {
/// <param name="b">input</param>
/// <param name="r">reference to the residual</param>
/// <returns>the sum s</returns>
template<typename NativeFloat>
inline double quick_two_diff(volatile NativeFloat a, volatile NativeFloat b, volatile NativeFloat& r) {
inline double quick_two_diff(double a, double b, volatile double& r) {
volatile double s = a - b;
r = (std::isfinite(s) ? (a - s) - b : 0.0);
return s;
Expand All @@ -103,8 +98,7 @@ namespace sw { namespace universal {
/// <param name="b">input</param>
/// <param name="r">reference to the residual</param>
/// <returns>the difference s</returns>
template<typename NativeFloat>
inline NativeFloat two_diff(volatile NativeFloat a, volatile NativeFloat b, volatile NativeFloat& r) {
inline double two_diff(double a, double b, volatile double& r) {
volatile double s = a - b;
if (std::isfinite(s)) {
volatile double bb = s - a;
Expand All @@ -124,8 +118,7 @@ namespace sw { namespace universal {
/// <param name="a">input</param>
/// <param name="b">input</param>
/// <param name="c">input value, output residual</param>
inline void three_sum(volatile double& a, volatile double& b, volatile double& c)
{
inline void three_sum(volatile double& a, volatile double& b, volatile double& c) {
volatile double t1, t2, t3;

t1 = two_sum(a, b, t2);
Expand All @@ -138,8 +131,7 @@ namespace sw { namespace universal {

#if !defined( QD_FMS )
/* Computes high word and lo word of a */
inline void split(volatile double a, volatile double& hi, volatile double& lo)
{
inline void split(double a, volatile double& hi, volatile double& lo) {
int const QD_BITS = (std::numeric_limits< double >::digits + 1) / 2;
static double const QD_SPLITTER = std::ldexp(1.0, QD_BITS) + 1.0;
static double const QD_SPLIT_THRESHOLD = std::ldexp((std::numeric_limits< double >::max)(), -QD_BITS - 1);
Expand Down Expand Up @@ -173,7 +165,7 @@ namespace sw { namespace universal {
/// <param name="b">input</param>
/// <param name="r">reference to the residual</param>
/// <returns>the product of a * b</returns>
inline double two_prod(volatile double a, volatile double b, volatile double& r)
inline double two_prod(double a, double b, volatile double& r)
{
volatile double p = a * b;
if (std::isfinite(p)) {
Expand All @@ -198,8 +190,7 @@ namespace sw { namespace universal {
/// <param name="a">input</param>
/// <param name="r">reference to the residual</param>
/// <returns>the square product of a</returns>
inline double two_sqr(double a, double& r)
{
inline double two_sqr(double a, volatile double& r) {
volatile double p = a * a;
if (std::isfinite(p))
{
Expand Down
2 changes: 1 addition & 1 deletion include/universal/native/integers.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -146,7 +146,7 @@ inline int64_t fastipow(int64_t base, uint8_t exp) {
template<typename Integer,
typename = typename std::enable_if< std::is_integral<Integer>::value, Integer >::type
>
inline std::string to_binary(const Integer& number, int nbits = 0, bool bNibbleMarker = true) {
inline std::string to_binary(const Integer& number, bool bNibbleMarker = true, int nbits = 0) {
std::stringstream s;
if (nbits == 0) nbits = 8*sizeof(number);
s << "0b";
Expand Down
78 changes: 52 additions & 26 deletions include/universal/number/dd/dd_impl.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -103,7 +103,6 @@ class dd {
constexpr dd(unsigned long long iv) noexcept { *this = iv; }
constexpr dd(float iv) noexcept : hi{ iv }, lo{ 0.0 } {}
constexpr dd(double iv) noexcept : hi{ iv }, lo{ 0.0 } {}
dd(long double iv) noexcept { *this = iv; }

// assignment operators for native types
constexpr dd& operator=(signed char rhs) noexcept { return convert_signed(rhs); }
Expand All @@ -118,7 +117,24 @@ class dd {
constexpr dd& operator=(unsigned long long rhs) noexcept { return convert_unsigned(rhs); }
constexpr dd& operator=(float rhs) noexcept { return convert_ieee754(rhs); }
constexpr dd& operator=(double rhs) noexcept { return convert_ieee754(rhs); }
dd& operator=(long double rhs) noexcept { return convert_ieee754(rhs); }

// conversion operators
explicit operator int() const noexcept { return convert_to_signed<int>(); }
explicit operator long() const noexcept { return convert_to_signed<long>(); }
explicit operator long long() const noexcept { return convert_to_signed<long long>(); }
explicit operator unsigned int() const noexcept { return convert_to_unsigned<unsigned int>(); }
explicit operator unsigned long() const noexcept { return convert_to_unsigned<unsigned long>(); }
explicit operator unsigned long long() const noexcept { return convert_to_unsigned<unsigned long long>(); }
explicit operator float() const noexcept { return convert_to_ieee754<float>(); }
explicit operator double() const noexcept { return convert_to_ieee754<double>(); }


#if LONG_DOUBLE_SUPPORT
// can't be constexpr as remainder calculation requires volatile designation
dd(long double iv) noexcept { *this = iv; }
dd& operator=(long double rhs) noexcept { return convert_ieee754(rhs); }
explicit operator long double() const noexcept { return convert_to_ieee754<long double>(); }
#endif

// prefix operators
constexpr dd operator-() const noexcept {
Expand All @@ -128,10 +144,6 @@ class dd {
return negated;
}

// conversion operators
explicit operator float() const { return toNativeFloatingPoint<float>(); }
explicit operator double() const { return toNativeFloatingPoint<double>(); }
explicit operator long double() const { return toNativeFloatingPoint<long double>(); }

// arithmetic operators
dd& operator+=(const dd& rhs) {
Expand Down Expand Up @@ -449,12 +461,7 @@ class dd {
// if (fixed && (precision == 0) && (abs(*this) < 1.0)) {
// if (abs(*this) >= 0.5)
if (fixed && (precision == 0) && (std::abs(high()) < 1.0)) {
if (std::abs(high()) >= 0.5)

s += '1';
else
s += '0';

s += (std::abs(hi) >= 0.5) ? '1' : '0';
return s;
}

Expand All @@ -467,8 +474,7 @@ class dd {
}
}
else { // default

char* t; // = new char[d+1];
char* t;

if (fixed) {
t = new char[d_with_extra + 1];
Expand Down Expand Up @@ -540,13 +546,13 @@ class dd {


if (!fixed && !isinf()) {
/* Fill in exponent part */
// construct the exponent
s += uppercase ? 'E' : 'e';
append_expn(s, e);
}
}

/* Fill in the blanks */
// Fill
int len = s.length();
if (len < width) {
int delta = static_cast<int>(width) - len;
Expand Down Expand Up @@ -583,13 +589,7 @@ class dd {

// HELPER methods

// convert to native floating-point, use conversion rules to cast down to float and double
template<typename NativeFloat>
NativeFloat toNativeFloatingPoint() const {
return NativeFloat(hi + lo);
}

constexpr dd& convert_signed(int64_t v) {
constexpr dd& convert_signed(int64_t v) noexcept {
if (0 == v) {
setzero();
}
Expand All @@ -600,7 +600,7 @@ class dd {
return *this;
}

constexpr dd& convert_unsigned(uint64_t v) {
constexpr dd& convert_unsigned(uint64_t v) noexcept {
if (0 == v) {
setzero();
}
Expand All @@ -612,23 +612,49 @@ class dd {
}

// no need to SFINAE this as it is an internal method that we ONLY call when we know the argument type is a native float
constexpr dd& convert_ieee754(float rhs) {
constexpr dd& convert_ieee754(float rhs) noexcept {
hi = double(rhs);
lo = 0.0;
return *this;
}
constexpr dd& convert_ieee754(double rhs) {
constexpr dd& convert_ieee754(double rhs) noexcept {
hi = rhs;
lo = 0.0;
return *this;
}
#if LONG_DOUBLE_SUPPORT
dd& convert_ieee754(long double rhs) {
volatile long double truncated = static_cast<long double>(double(rhs));
volatile double remainder = static_cast<double>(rhs - truncated);
hi = static_cast<double>(truncated);
lo = remainder;
return *this;
}
#endif

// convert to native unsigned integer, use C++ conversion rules to cast down to float and double
template<typename Unsigned>
Unsigned convert_to_unsigned() const noexcept {
uint64_t h = hi;
uint64_t l = lo; // TBD: lo could be negative
return Unsigned(h + l);
}

// convert to native unsigned integer, use C++ conversion rules to cast down to float and double
template<typename Signed>
Signed convert_to_signed() const noexcept {
int64_t h = hi;
int64_t l = lo;
return Signed(h + l);
}

// convert to native floating-point, use C++ conversion rules to cast down to float and double
template<typename Real>
Real convert_to_ieee754() const noexcept {
return Real(hi + lo);
}



void to_digits(char* s, int& expn, int precision) const {
int D = precision + 1; // number of digits to compute
Expand Down
2 changes: 1 addition & 1 deletion static/dd/api/api.cpp
View file
Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
// api.cpp: application programming interface tests for doubledouble number system
// api.cpp: application programming interface tests for double-double (dd) number system
//
// Copyright (C) 2017 Stillwater Supercomputing, Inc.
// SPDX-License-Identifier: MIT
Expand Down
30 changes: 29 additions & 1 deletion static/dd/conversion/conversion.cpp
View file
Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
// conversion.cpp: test suite runner for conversion operators for doubledouble
// conversion.cpp: test suite runner for conversion operators for double-double (dd) floating-point
//
// Copyright (C) 2017 Stillwater Supercomputing, Inc.
// SPDX-License-Identifier: MIT
Expand Down Expand Up @@ -41,6 +41,34 @@ try {

#if MANUAL_TESTING

uint64_t u64;
int64_t i64;

// check if we get all the bit of a 64-bit int
u64 = 0xFFFF'FFFF'FFFF'FFFFull;
i64 = 0x7FFF'FFFF'FFFF'FFFFll;

{
std::cout << to_binary(u64, false, 64) << " : " << u64 << '\n';
u64 = -1;
std::cout << to_binary(u64, false, 64) << " : " << u64 << '\n';
uint64_t v{ u64 };
double hi = static_cast<double>(v);
uint64_t h = static_cast<uint64_t>(hi);
std::cout << std::fixed << hi << '\n';
std::cout << to_binary(h) << '\n';
double lo = static_cast<double>(v - h); // difference is always positive

dd a(u64);
ReportValue(a, "0xFFFF'FFFF'FFFF'FFFF", 35, 32);
std::cout << to_pair(a) << '\n';
uint64_t i = uint64_t(a);
ReportValue(i, "0xFFFF'FFFF'FFFF'FFFF", 35, 32);
}
{
dd a(i64);
ReportValue(a, "0x7FFF'FFFF'FFFF'FFFF", 35, 32);
}

ReportTestSuiteResults(test_suite, nrOfFailedTestCases);
return EXIT_SUCCESS; // ignore failures
Expand Down

0 comments on commit de0c4b2

Please sign in to comment.