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Merge pull request #118 from pitrou/issue-117

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Fix #117: compilation warning with gcc 6.3.0
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Daniel Lemire 2021-11-30 14:58:33 -05:00 committed by GitHub
commit 62a8dba55a
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2 changed files with 48 additions and 31 deletions
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46
include/fast_float/digit_comparison.h
View File

@ -44,40 +44,24 @@ fastfloat_really_inline int32_t scientific_exponent(parsed_number_string& num) n
// this converts a native floating-point number to an extended-precision float.
template <typename T>
fastfloat_really_inline adjusted_mantissa to_extended(T value) noexcept {
using equiv_uint = typename binary_format<T>::equiv_uint;
constexpr equiv_uint exponent_mask = binary_format<T>::exponent_mask();
constexpr equiv_uint mantissa_mask = binary_format<T>::mantissa_mask();
constexpr equiv_uint hidden_bit_mask = binary_format<T>::hidden_bit_mask();
adjusted_mantissa am;
int32_t bias = binary_format<T>::mantissa_explicit_bits() - binary_format<T>::minimum_exponent();
if (std::is_same<T, float>::value) {
constexpr uint32_t exponent_mask = 0x7F800000;
constexpr uint32_t mantissa_mask = 0x007FFFFF;
constexpr uint64_t hidden_bit_mask = 0x00800000;
uint32_t bits;
::memcpy(&bits, &value, sizeof(T));
if ((bits & exponent_mask) == 0) {
// denormal
am.power2 = 1 - bias;
am.mantissa = bits & mantissa_mask;
} else {
// normal
am.power2 = int32_t((bits & exponent_mask) >> binary_format<T>::mantissa_explicit_bits());
am.power2 -= bias;
am.mantissa = (bits & mantissa_mask) | hidden_bit_mask;
}
equiv_uint bits;
::memcpy(&bits, &value, sizeof(T));
if ((bits & exponent_mask) == 0) {
// denormal
am.power2 = 1 - bias;
am.mantissa = bits & mantissa_mask;
} else {
constexpr uint64_t exponent_mask = 0x7FF0000000000000;
constexpr uint64_t mantissa_mask = 0x000FFFFFFFFFFFFF;
constexpr uint64_t hidden_bit_mask = 0x0010000000000000;
uint64_t bits;
::memcpy(&bits, &value, sizeof(T));
if ((bits & exponent_mask) == 0) {
// denormal
am.power2 = 1 - bias;
am.mantissa = bits & mantissa_mask;
} else {
// normal
am.power2 = int32_t((bits & exponent_mask) >> binary_format<T>::mantissa_explicit_bits());
am.power2 -= bias;
am.mantissa = (bits & mantissa_mask) | hidden_bit_mask;
}
// normal
am.power2 = int32_t((bits & exponent_mask) >> binary_format<T>::mantissa_explicit_bits());
am.power2 -= bias;
am.mantissa = (bits & mantissa_mask) | hidden_bit_mask;
}
return am;

33
include/fast_float/float_common.h
View File

@ -5,6 +5,7 @@
#include <cstdint>
#include <cassert>
#include <cstring>
#include <type_traits>
#if (defined(__x86_64) || defined(__x86_64__) || defined(_M_X64) \
|| defined(__amd64) || defined(__aarch64__) || defined(_M_ARM64) \
@ -219,6 +220,8 @@ constexpr static float powers_of_ten_float[] = {1e0, 1e1, 1e2, 1e3, 1e4, 1e5,
1e6, 1e7, 1e8, 1e9, 1e10};
template <typename T> struct binary_format {
using equiv_uint = typename std::conditional<sizeof(T) == 4, uint32_t, uint64_t>::type;
static inline constexpr int mantissa_explicit_bits();
static inline constexpr int minimum_exponent();
static inline constexpr int infinite_power();
@ -232,6 +235,9 @@ template <typename T> struct binary_format {
static inline constexpr int smallest_power_of_ten();
static inline constexpr T exact_power_of_ten(int64_t power);
static inline constexpr size_t max_digits();
static inline constexpr equiv_uint exponent_mask();
static inline constexpr equiv_uint mantissa_mask();
static inline constexpr equiv_uint hidden_bit_mask();
};
template <> inline constexpr int binary_format<double>::mantissa_explicit_bits() {
@ -339,6 +345,33 @@ template <> inline constexpr size_t binary_format<float>::max_digits() {
return 114;
}
template <> inline constexpr binary_format<float>::equiv_uint
binary_format<float>::exponent_mask() {
return 0x7F800000;
}
template <> inline constexpr binary_format<double>::equiv_uint
binary_format<double>::exponent_mask() {
return 0x7FF0000000000000;
}
template <> inline constexpr binary_format<float>::equiv_uint
binary_format<float>::mantissa_mask() {
return 0x007FFFFF;
}
template <> inline constexpr binary_format<double>::equiv_uint
binary_format<double>::mantissa_mask() {
return 0x000FFFFFFFFFFFFF;
}
template <> inline constexpr binary_format<float>::equiv_uint
binary_format<float>::hidden_bit_mask() {
return 0x00800000;
}
template <> inline constexpr binary_format<double>::equiv_uint
binary_format<double>::hidden_bit_mask() {
return 0x0010000000000000;
}
template<typename T>
fastfloat_really_inline void to_float(bool negative, adjusted_mantissa am, T &value) {
uint64_t word = am.mantissa;