1 // Copyright 2018 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef V8_OBJECTS_HEAP_NUMBER_H_ 6 #define V8_OBJECTS_HEAP_NUMBER_H_ 7 8 #include "src/objects/primitive-heap-object.h" 9 10 // Has to be the last include (doesn't have include guards): 11 #include "src/objects/object-macros.h" 12 13 namespace v8 { 14 namespace internal { 15 16 #include "torque-generated/src/objects/heap-number-tq.inc" 17 18 // The HeapNumber class describes heap allocated numbers that cannot be 19 // represented in a Smi (small integer). 20 class HeapNumber 21 : public TorqueGeneratedHeapNumber<HeapNumber, PrimitiveHeapObject> { 22 public: 23 inline uint64_t value_as_bits() const; 24 inline void set_value_as_bits(uint64_t bits); 25 26 inline int get_exponent(); 27 inline int get_sign(); 28 29 // Layout description. 30 // IEEE doubles are two 32 bit words. The first is just mantissa, the second 31 // is a mixture of sign, exponent and mantissa. The offsets of two 32 bit 32 // words within double numbers are endian dependent and they are set 33 // accordingly. 34 #if defined(V8_TARGET_LITTLE_ENDIAN) 35 static const int kMantissaOffset = kValueOffset; 36 static const int kExponentOffset = kValueOffset + 4; 37 #elif defined(V8_TARGET_BIG_ENDIAN) 38 static const int kMantissaOffset = kValueOffset + 4; 39 static const int kExponentOffset = kValueOffset; 40 #else 41 #error Unknown byte ordering 42 #endif 43 44 static const uint32_t kSignMask = 0x80000000u; 45 static const uint32_t kExponentMask = 0x7ff00000u; 46 static const uint32_t kMantissaMask = 0xfffffu; 47 static const int kMantissaBits = 52; 48 static const int kExponentBits = 11; 49 static const int kExponentBias = 1023; 50 static const int kExponentShift = 20; 51 static const int kInfinityOrNanExponent = 52 (kExponentMask >> kExponentShift) - kExponentBias; 53 static const int kMantissaBitsInTopWord = 20; 54 static const int kNonMantissaBitsInTopWord = 12; 55 56 DECL_PRINTER(HeapNumber) 57 V8_EXPORT_PRIVATE void HeapNumberShortPrint(std::ostream& os); 58 59 TQ_OBJECT_CONSTRUCTORS(HeapNumber) 60 }; 61 62 } // namespace internal 63 } // namespace v8 64 65 #include "src/objects/object-macros-undef.h" 66 67 #endif // V8_OBJECTS_HEAP_NUMBER_H_ 68