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      1 // Copyright 2013 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_ARM64_UTILS_ARM64_H_
      6 #define V8_ARM64_UTILS_ARM64_H_
      7 
      8 #include <cmath>
      9 #include "src/v8.h"
     10 
     11 #include "src/arm64/constants-arm64.h"
     12 
     13 #define REGISTER_CODE_LIST(R)                                                  \
     14 R(0)  R(1)  R(2)  R(3)  R(4)  R(5)  R(6)  R(7)                                 \
     15 R(8)  R(9)  R(10) R(11) R(12) R(13) R(14) R(15)                                \
     16 R(16) R(17) R(18) R(19) R(20) R(21) R(22) R(23)                                \
     17 R(24) R(25) R(26) R(27) R(28) R(29) R(30) R(31)
     18 
     19 namespace v8 {
     20 namespace internal {
     21 
     22 // These are global assumptions in v8.
     23 STATIC_ASSERT((static_cast<int32_t>(-1) >> 1) == -1);
     24 STATIC_ASSERT((static_cast<uint32_t>(-1) >> 1) == 0x7FFFFFFF);
     25 
     26 // Floating point representation.
     27 static inline uint32_t float_to_rawbits(float value) {
     28   uint32_t bits = 0;
     29   memcpy(&bits, &value, 4);
     30   return bits;
     31 }
     32 
     33 
     34 static inline uint64_t double_to_rawbits(double value) {
     35   uint64_t bits = 0;
     36   memcpy(&bits, &value, 8);
     37   return bits;
     38 }
     39 
     40 
     41 static inline float rawbits_to_float(uint32_t bits) {
     42   float value = 0.0;
     43   memcpy(&value, &bits, 4);
     44   return value;
     45 }
     46 
     47 
     48 static inline double rawbits_to_double(uint64_t bits) {
     49   double value = 0.0;
     50   memcpy(&value, &bits, 8);
     51   return value;
     52 }
     53 
     54 
     55 // Bit counting.
     56 int CountLeadingZeros(uint64_t value, int width);
     57 int CountLeadingSignBits(int64_t value, int width);
     58 int CountTrailingZeros(uint64_t value, int width);
     59 int CountSetBits(uint64_t value, int width);
     60 uint64_t LargestPowerOf2Divisor(uint64_t value);
     61 int MaskToBit(uint64_t mask);
     62 
     63 
     64 // NaN tests.
     65 inline bool IsSignallingNaN(double num) {
     66   uint64_t raw = double_to_rawbits(num);
     67   if (std::isnan(num) && ((raw & kDQuietNanMask) == 0)) {
     68     return true;
     69   }
     70   return false;
     71 }
     72 
     73 
     74 inline bool IsSignallingNaN(float num) {
     75   uint32_t raw = float_to_rawbits(num);
     76   if (std::isnan(num) && ((raw & kSQuietNanMask) == 0)) {
     77     return true;
     78   }
     79   return false;
     80 }
     81 
     82 
     83 template <typename T>
     84 inline bool IsQuietNaN(T num) {
     85   return std::isnan(num) && !IsSignallingNaN(num);
     86 }
     87 
     88 
     89 // Convert the NaN in 'num' to a quiet NaN.
     90 inline double ToQuietNaN(double num) {
     91   DCHECK(std::isnan(num));
     92   return rawbits_to_double(double_to_rawbits(num) | kDQuietNanMask);
     93 }
     94 
     95 
     96 inline float ToQuietNaN(float num) {
     97   DCHECK(std::isnan(num));
     98   return rawbits_to_float(float_to_rawbits(num) | kSQuietNanMask);
     99 }
    100 
    101 
    102 // Fused multiply-add.
    103 inline double FusedMultiplyAdd(double op1, double op2, double a) {
    104   return fma(op1, op2, a);
    105 }
    106 
    107 
    108 inline float FusedMultiplyAdd(float op1, float op2, float a) {
    109   return fmaf(op1, op2, a);
    110 }
    111 
    112 } }  // namespace v8::internal
    113 
    114 #endif  // V8_ARM64_UTILS_ARM64_H_
    115