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      1 // Copyright 2006-2008 the V8 project authors. All rights reserved.
      2 
      3 #include <stdlib.h>
      4 
      5 #include "v8.h"
      6 
      7 #include "platform.h"
      8 #include "cctest.h"
      9 #include "diy-fp.h"
     10 #include "double.h"
     11 
     12 
     13 using namespace v8::internal;
     14 
     15 
     16 TEST(Uint64Conversions) {
     17   // Start by checking the byte-order.
     18   uint64_t ordered = V8_2PART_UINT64_C(0x01234567, 89ABCDEF);
     19   CHECK_EQ(3512700564088504e-318, Double(ordered).value());
     20 
     21   uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
     22   CHECK_EQ(5e-324, Double(min_double64).value());
     23 
     24   uint64_t max_double64 = V8_2PART_UINT64_C(0x7fefffff, ffffffff);
     25   CHECK_EQ(1.7976931348623157e308, Double(max_double64).value());
     26 }
     27 
     28 TEST(AsDiyFp) {
     29   uint64_t ordered = V8_2PART_UINT64_C(0x01234567, 89ABCDEF);
     30   DiyFp diy_fp = Double(ordered).AsDiyFp();
     31   CHECK_EQ(0x12 - 0x3FF - 52, diy_fp.e());
     32   // The 52 mantissa bits, plus the implicit 1 in bit 52 as a UINT64.
     33   CHECK(V8_2PART_UINT64_C(0x00134567, 89ABCDEF) == diy_fp.f());  // NOLINT
     34 
     35   uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
     36   diy_fp = Double(min_double64).AsDiyFp();
     37   CHECK_EQ(-0x3FF - 52 + 1, diy_fp.e());
     38   // This is a denormal; so no hidden bit.
     39   CHECK(1 == diy_fp.f());  // NOLINT
     40 
     41   uint64_t max_double64 = V8_2PART_UINT64_C(0x7fefffff, ffffffff);
     42   diy_fp = Double(max_double64).AsDiyFp();
     43   CHECK_EQ(0x7FE - 0x3FF - 52, diy_fp.e());
     44   CHECK(V8_2PART_UINT64_C(0x001fffff, ffffffff) == diy_fp.f());  // NOLINT
     45 }
     46 
     47 
     48 TEST(AsNormalizedDiyFp) {
     49   uint64_t ordered = V8_2PART_UINT64_C(0x01234567, 89ABCDEF);
     50   DiyFp diy_fp = Double(ordered).AsNormalizedDiyFp();
     51   CHECK_EQ(0x12 - 0x3FF - 52 - 11, diy_fp.e());
     52   CHECK((V8_2PART_UINT64_C(0x00134567, 89ABCDEF) << 11) ==
     53         diy_fp.f());  // NOLINT
     54 
     55   uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
     56   diy_fp = Double(min_double64).AsNormalizedDiyFp();
     57   CHECK_EQ(-0x3FF - 52 + 1 - 63, diy_fp.e());
     58   // This is a denormal; so no hidden bit.
     59   CHECK(V8_2PART_UINT64_C(0x80000000, 00000000) == diy_fp.f());  // NOLINT
     60 
     61   uint64_t max_double64 = V8_2PART_UINT64_C(0x7fefffff, ffffffff);
     62   diy_fp = Double(max_double64).AsNormalizedDiyFp();
     63   CHECK_EQ(0x7FE - 0x3FF - 52 - 11, diy_fp.e());
     64   CHECK((V8_2PART_UINT64_C(0x001fffff, ffffffff) << 11) ==
     65         diy_fp.f());  // NOLINT
     66 }
     67 
     68 
     69 TEST(IsDenormal) {
     70   uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
     71   CHECK(Double(min_double64).IsDenormal());
     72   uint64_t bits = V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF);
     73   CHECK(Double(bits).IsDenormal());
     74   bits = V8_2PART_UINT64_C(0x00100000, 00000000);
     75   CHECK(!Double(bits).IsDenormal());
     76 }
     77 
     78 
     79 TEST(IsSpecial) {
     80   CHECK(Double(V8_INFINITY).IsSpecial());
     81   CHECK(Double(-V8_INFINITY).IsSpecial());
     82   CHECK(Double(OS::nan_value()).IsSpecial());
     83   uint64_t bits = V8_2PART_UINT64_C(0xFFF12345, 00000000);
     84   CHECK(Double(bits).IsSpecial());
     85   // Denormals are not special:
     86   CHECK(!Double(5e-324).IsSpecial());
     87   CHECK(!Double(-5e-324).IsSpecial());
     88   // And some random numbers:
     89   CHECK(!Double(0.0).IsSpecial());
     90   CHECK(!Double(-0.0).IsSpecial());
     91   CHECK(!Double(1.0).IsSpecial());
     92   CHECK(!Double(-1.0).IsSpecial());
     93   CHECK(!Double(1000000.0).IsSpecial());
     94   CHECK(!Double(-1000000.0).IsSpecial());
     95   CHECK(!Double(1e23).IsSpecial());
     96   CHECK(!Double(-1e23).IsSpecial());
     97   CHECK(!Double(1.7976931348623157e308).IsSpecial());
     98   CHECK(!Double(-1.7976931348623157e308).IsSpecial());
     99 }
    100 
    101 
    102 TEST(IsInfinite) {
    103   CHECK(Double(V8_INFINITY).IsInfinite());
    104   CHECK(Double(-V8_INFINITY).IsInfinite());
    105   CHECK(!Double(OS::nan_value()).IsInfinite());
    106   CHECK(!Double(0.0).IsInfinite());
    107   CHECK(!Double(-0.0).IsInfinite());
    108   CHECK(!Double(1.0).IsInfinite());
    109   CHECK(!Double(-1.0).IsInfinite());
    110   uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
    111   CHECK(!Double(min_double64).IsInfinite());
    112 }
    113 
    114 
    115 TEST(IsNan) {
    116   CHECK(Double(OS::nan_value()).IsNan());
    117   uint64_t other_nan = V8_2PART_UINT64_C(0xFFFFFFFF, 00000001);
    118   CHECK(Double(other_nan).IsNan());
    119   CHECK(!Double(V8_INFINITY).IsNan());
    120   CHECK(!Double(-V8_INFINITY).IsNan());
    121   CHECK(!Double(0.0).IsNan());
    122   CHECK(!Double(-0.0).IsNan());
    123   CHECK(!Double(1.0).IsNan());
    124   CHECK(!Double(-1.0).IsNan());
    125   uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
    126   CHECK(!Double(min_double64).IsNan());
    127 }
    128 
    129 
    130 TEST(Sign) {
    131   CHECK_EQ(1, Double(1.0).Sign());
    132   CHECK_EQ(1, Double(V8_INFINITY).Sign());
    133   CHECK_EQ(-1, Double(-V8_INFINITY).Sign());
    134   CHECK_EQ(1, Double(0.0).Sign());
    135   CHECK_EQ(-1, Double(-0.0).Sign());
    136   uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
    137   CHECK_EQ(1, Double(min_double64).Sign());
    138 }
    139 
    140 
    141 TEST(NormalizedBoundaries) {
    142   DiyFp boundary_plus;
    143   DiyFp boundary_minus;
    144   DiyFp diy_fp = Double(1.5).AsNormalizedDiyFp();
    145   Double(1.5).NormalizedBoundaries(&boundary_minus, &boundary_plus);
    146   CHECK_EQ(diy_fp.e(), boundary_minus.e());
    147   CHECK_EQ(diy_fp.e(), boundary_plus.e());
    148   // 1.5 does not have a significand of the form 2^p (for some p).
    149   // Therefore its boundaries are at the same distance.
    150   CHECK(diy_fp.f() - boundary_minus.f() == boundary_plus.f() - diy_fp.f());
    151   CHECK((1 << 10) == diy_fp.f() - boundary_minus.f());  // NOLINT
    152 
    153   diy_fp = Double(1.0).AsNormalizedDiyFp();
    154   Double(1.0).NormalizedBoundaries(&boundary_minus, &boundary_plus);
    155   CHECK_EQ(diy_fp.e(), boundary_minus.e());
    156   CHECK_EQ(diy_fp.e(), boundary_plus.e());
    157   // 1.0 does have a significand of the form 2^p (for some p).
    158   // Therefore its lower boundary is twice as close as the upper boundary.
    159   CHECK_GT(boundary_plus.f() - diy_fp.f(), diy_fp.f() - boundary_minus.f());
    160   CHECK((1 << 9) == diy_fp.f() - boundary_minus.f());  // NOLINT
    161   CHECK((1 << 10) == boundary_plus.f() - diy_fp.f());  // NOLINT
    162 
    163   uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
    164   diy_fp = Double(min_double64).AsNormalizedDiyFp();
    165   Double(min_double64).NormalizedBoundaries(&boundary_minus, &boundary_plus);
    166   CHECK_EQ(diy_fp.e(), boundary_minus.e());
    167   CHECK_EQ(diy_fp.e(), boundary_plus.e());
    168   // min-value does not have a significand of the form 2^p (for some p).
    169   // Therefore its boundaries are at the same distance.
    170   CHECK(diy_fp.f() - boundary_minus.f() == boundary_plus.f() - diy_fp.f());
    171   // Denormals have their boundaries much closer.
    172   CHECK((static_cast<uint64_t>(1) << 62) ==
    173         diy_fp.f() - boundary_minus.f());  // NOLINT
    174 
    175   uint64_t smallest_normal64 = V8_2PART_UINT64_C(0x00100000, 00000000);
    176   diy_fp = Double(smallest_normal64).AsNormalizedDiyFp();
    177   Double(smallest_normal64).NormalizedBoundaries(&boundary_minus,
    178                                                  &boundary_plus);
    179   CHECK_EQ(diy_fp.e(), boundary_minus.e());
    180   CHECK_EQ(diy_fp.e(), boundary_plus.e());
    181   // Even though the significand is of the form 2^p (for some p), its boundaries
    182   // are at the same distance. (This is the only exception).
    183   CHECK(diy_fp.f() - boundary_minus.f() == boundary_plus.f() - diy_fp.f());
    184   CHECK((1 << 10) == diy_fp.f() - boundary_minus.f());  // NOLINT
    185 
    186   uint64_t largest_denormal64 = V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF);
    187   diy_fp = Double(largest_denormal64).AsNormalizedDiyFp();
    188   Double(largest_denormal64).NormalizedBoundaries(&boundary_minus,
    189                                                   &boundary_plus);
    190   CHECK_EQ(diy_fp.e(), boundary_minus.e());
    191   CHECK_EQ(diy_fp.e(), boundary_plus.e());
    192   CHECK(diy_fp.f() - boundary_minus.f() == boundary_plus.f() - diy_fp.f());
    193   CHECK((1 << 11) == diy_fp.f() - boundary_minus.f());  // NOLINT
    194 
    195   uint64_t max_double64 = V8_2PART_UINT64_C(0x7fefffff, ffffffff);
    196   diy_fp = Double(max_double64).AsNormalizedDiyFp();
    197   Double(max_double64).NormalizedBoundaries(&boundary_minus, &boundary_plus);
    198   CHECK_EQ(diy_fp.e(), boundary_minus.e());
    199   CHECK_EQ(diy_fp.e(), boundary_plus.e());
    200   // max-value does not have a significand of the form 2^p (for some p).
    201   // Therefore its boundaries are at the same distance.
    202   CHECK(diy_fp.f() - boundary_minus.f() == boundary_plus.f() - diy_fp.f());
    203   CHECK((1 << 10) == diy_fp.f() - boundary_minus.f());  // NOLINT
    204 }
    205 
    206 
    207 TEST(NextDouble) {
    208   CHECK_EQ(4e-324, Double(0.0).NextDouble());
    209   CHECK_EQ(0.0, Double(-0.0).NextDouble());
    210   CHECK_EQ(-0.0, Double(-4e-324).NextDouble());
    211   Double d0(-4e-324);
    212   Double d1(d0.NextDouble());
    213   Double d2(d1.NextDouble());
    214   CHECK_EQ(-0.0, d1.value());
    215   CHECK_EQ(0.0, d2.value());
    216   CHECK_EQ(4e-324, d2.NextDouble());
    217   CHECK_EQ(-1.7976931348623157e308, Double(-V8_INFINITY).NextDouble());
    218   CHECK_EQ(V8_INFINITY,
    219            Double(V8_2PART_UINT64_C(0x7fefffff, ffffffff)).NextDouble());
    220 }
    221