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Merge pull request #379 from TsudaKageyu/sizecheck
Robuster size checking for floating point types.
This commit is contained in:
Lukáš Lalinský
commit
909d28d4fe
@ -680,19 +680,21 @@ long long ByteVector::toInt64BE(size_t offset) const
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float ByteVector::toFloat32BE(size_t offset) const
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{
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typedef std::numeric_limits<float> Limits;
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if(offset > size() - 4) {
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debug("ByteVector::toFloat32BE() - offset is out of range. Returning 0.");
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return 0.0;
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}
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if(sizeof(float) == 4 && std::numeric_limits<float>::is_iec559)
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{
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if(Limits::is_iec559 && Limits::digits == 24) {
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// float is 32-bit wide and IEEE754 compliant.
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union {
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uint i;
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float f;
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} tmp;
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} tmp = {};
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::memcpy(&tmp, data() + offset, 4);
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if(Utils::SystemByteOrder == LittleEndian)
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@ -700,55 +702,61 @@ float ByteVector::toFloat32BE(size_t offset) const
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return tmp.f;
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}
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const uchar *bytes = reinterpret_cast<const uchar*>(data() + offset);
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// 1-bit sign
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const bool negative = ((bytes[0] & 0x80) != 0);
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// 8-bit exponent
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const int exponent = ((bytes[0] & 0x7F) << 1) | (bytes[1] >> 7);
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// 1-bit integer part (always 1) and 23-bit fraction.
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const uint fraction
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= (1U << 23)
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| (static_cast<uint>(bytes[1] & 0x7f) << 16)
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| (static_cast<uint>(bytes[2]) << 8)
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| (static_cast<uint>(bytes[3]));
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float val;
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if(exponent == 0 && fraction == 0)
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val = 0;
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else {
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if(exponent == 0xFF) {
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debug("ByteVector::toFloat32BE() - can't handle the infinity or NaN. Returning 0.");
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return 0.0;
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}
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else
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val = ::ldexp(static_cast<float>(fraction), exponent - 127 - 23);
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}
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if(negative)
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return -val;
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else
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return val;
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// float is not 32-bit or not IEEE754. Very unlikely in practice.
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const uchar *bytes = reinterpret_cast<const uchar*>(data() + offset);
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// 1-bit sign
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const bool negative = ((bytes[0] & 0x80) != 0);
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// 8-bit exponent
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const int exponent = ((bytes[0] & 0x7F) << 1) | (bytes[1] >> 7);
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// 24-bit fraction. Leading 1 is implied.
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const uint fraction
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= (1U << 23)
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| (static_cast<uint>(bytes[1] & 0x7f) << 16)
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| (static_cast<uint>(bytes[2]) << 8)
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| (static_cast<uint>(bytes[3]));
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float val;
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if(exponent == 0 && fraction == 0)
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val = 0;
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else {
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if(exponent == 0xFF) {
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debug("ByteVector::toFloat32BE() - can't handle the infinity or NaN. Returning 0.");
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return 0.0;
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}
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else
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val = ::ldexp(static_cast<float>(fraction), exponent - 127 - 23);
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}
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if(negative)
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return -val;
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else
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return val;
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}
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}
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double ByteVector::toFloat64BE(size_t offset) const
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{
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typedef std::numeric_limits<double> Limits;
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if(offset > size() - 8) {
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debug("ByteVector::toFloat64BE() - offset is out of range. Returning 0.");
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return 0.0;
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}
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if(sizeof(double) == 8 && std::numeric_limits<double>::is_iec559)
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{
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if(Limits::is_iec559 && Limits::digits == 53) {
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// double is 64-bit wide and IEEE754 compliant.
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union {
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ulonglong i;
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double f;
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} tmp;
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} tmp = {};
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::memcpy(&tmp, data() + offset, 8);
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if(Utils::SystemByteOrder == LittleEndian)
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@ -756,86 +764,118 @@ double ByteVector::toFloat64BE(size_t offset) const
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return tmp.f;
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}
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const uchar *bytes = reinterpret_cast<const uchar*>(data() + offset);
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// 1-bit sign
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const bool negative = ((bytes[0] & 0x80) != 0);
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// 11-bit exponent
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const int exponent = ((bytes[0] & 0x7F) << 4) | (bytes[1] >> 4);
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// 1-bit integer part (always 1) and 52-bit fraction.
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const ulonglong fraction
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= (1ULL << 52)
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| (static_cast<ulonglong>(bytes[1] & 0x0F) << 48)
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| (static_cast<ulonglong>(bytes[2]) << 40)
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| (static_cast<ulonglong>(bytes[3]) << 32)
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| (static_cast<ulonglong>(bytes[4]) << 24)
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| (static_cast<ulonglong>(bytes[5]) << 16)
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| (static_cast<ulonglong>(bytes[6]) << 8)
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| (static_cast<ulonglong>(bytes[7]));
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double val;
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if(exponent == 0 && fraction == 0)
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val = 0;
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else {
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if(exponent == 0x7FF) {
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debug("ByteVector::toFloat64BE() - can't handle the infinity or NaN. Returning 0.");
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return 0.0;
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}
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else
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val = ::ldexp(static_cast<double>(fraction), exponent - 1023 - 52);
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}
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if(negative)
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return -val;
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else
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return val;
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// double is not 64-bit or not IEEE754. Very unlikely in practice.
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const uchar *bytes = reinterpret_cast<const uchar*>(data() + offset);
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// 1-bit sign
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const bool negative = ((bytes[0] & 0x80) != 0);
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// 11-bit exponent
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const int exponent = ((bytes[0] & 0x7F) << 4) | (bytes[1] >> 4);
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// 53-bit fraction. Leading 1 is implied.
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const ulonglong fraction
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= (1ULL << 52)
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| (static_cast<ulonglong>(bytes[1] & 0x0F) << 48)
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| (static_cast<ulonglong>(bytes[2]) << 40)
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| (static_cast<ulonglong>(bytes[3]) << 32)
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| (static_cast<ulonglong>(bytes[4]) << 24)
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| (static_cast<ulonglong>(bytes[5]) << 16)
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| (static_cast<ulonglong>(bytes[6]) << 8)
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| (static_cast<ulonglong>(bytes[7]));
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double val;
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if(exponent == 0 && fraction == 0)
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val = 0;
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else {
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if(exponent == 0x7FF) {
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debug("ByteVector::toFloat64BE() - can't handle the infinity or NaN. Returning 0.");
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return 0.0;
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}
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else
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val = ::ldexp(static_cast<double>(fraction), exponent - 1023 - 52);
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}
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if(negative)
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return -val;
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else
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return val;
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}
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}
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long double ByteVector::toFloat80BE(size_t offset) const
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{
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typedef std::numeric_limits<long double> Limits;
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if(offset > size() - 10) {
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debug("ByteVector::toFloat80BE() - offset is out of range. Returning 0.");
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return 0.0;
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}
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const uchar *bytes = reinterpret_cast<const uchar*>(data() + offset);
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if(Limits::is_iec559 && Limits::digits == 64) {
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// 1-bit sign
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const bool negative = ((bytes[0] & 0x80) != 0);
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// long double is 80-bit wide and IEEE754 compliant.
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// 15-bit exponent
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const int exponent = ((bytes[0] & 0x7F) << 8) | bytes[1];
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union {
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uchar c[10];
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long double f;
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} tmp = {};
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::memcpy(&tmp, data() + offset, 10);
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// 1-bit integer part and 63-bit fraction.
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const ulonglong fraction
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= (static_cast<ulonglong>(bytes[2]) << 56)
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| (static_cast<ulonglong>(bytes[3]) << 48)
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| (static_cast<ulonglong>(bytes[4]) << 40)
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| (static_cast<ulonglong>(bytes[5]) << 32)
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| (static_cast<ulonglong>(bytes[6]) << 24)
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| (static_cast<ulonglong>(bytes[7]) << 16)
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| (static_cast<ulonglong>(bytes[8]) << 8)
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| (static_cast<ulonglong>(bytes[9]));
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long double val;
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if(exponent == 0 && fraction == 0)
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val = 0;
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else {
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if(exponent == 0x7FFF) {
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debug("ByteVector::toFloat80BE() - can't handle the infinity or NaN. Returning 0.");
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return 0.0;
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if(Utils::SystemByteOrder == LittleEndian) {
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std::swap(tmp.c[0], tmp.c[9]);
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std::swap(tmp.c[1], tmp.c[8]);
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std::swap(tmp.c[2], tmp.c[7]);
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std::swap(tmp.c[3], tmp.c[6]);
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std::swap(tmp.c[4], tmp.c[5]);
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}
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else
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val = ::ldexp(static_cast<long double>(fraction), exponent - 16383 - 63);
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}
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if(negative)
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return -val;
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else
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return val;
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return tmp.f;
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}
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else {
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// long double is not 80-bit or not IEEE754.
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// GCC on ARM, MSVC, etc. will go this way.
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const uchar *bytes = reinterpret_cast<const uchar*>(data() + offset);
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// 1-bit sign
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const bool negative = ((bytes[0] & 0x80) != 0);
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// 15-bit exponent
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const int exponent = ((bytes[0] & 0x7F) << 8) | bytes[1];
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// 64-bit fraction. Leading 1 is explicit.
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const ulonglong fraction
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= (static_cast<ulonglong>(bytes[2]) << 56)
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| (static_cast<ulonglong>(bytes[3]) << 48)
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| (static_cast<ulonglong>(bytes[4]) << 40)
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| (static_cast<ulonglong>(bytes[5]) << 32)
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| (static_cast<ulonglong>(bytes[6]) << 24)
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| (static_cast<ulonglong>(bytes[7]) << 16)
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| (static_cast<ulonglong>(bytes[8]) << 8)
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| (static_cast<ulonglong>(bytes[9]));
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long double val;
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if(exponent == 0 && fraction == 0)
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val = 0;
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else {
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if(exponent == 0x7FFF) {
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debug("ByteVector::toFloat80BE() - can't handle the infinity or NaN. Returning 0.");
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return 0.0;
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}
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else
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val = ::ldexp(static_cast<long double>(fraction), exponent - 16383 - 63);
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}
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if(negative)
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return -val;
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else
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return val;
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}
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}
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const char &ByteVector::operator[](size_t index) const
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