js/src/jsapi-tests/testFractionToDouble.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifdef JS_HAS_TEMPORAL_API
   6
   7 #  include <cmath>
   8 #  include <stdint.h>
   9
  10 #  include "builtin/temporal/Int128.h"
  11 #  include "builtin/temporal/Temporal.h"
  12 #  include "jsapi-tests/tests.h"
  13
  14 using namespace js::temporal;
  15
  16 // Simple test using numerators and denominators where the result can be
  17 // computed through standard double division.
  18 BEGIN_TEST(testFraction_simple) {
  19   int64_t numerators[] = {
  20       0, 1, 2, 10, 100, INT32_MIN, INT32_MAX,
  21   };
  22
  23   int64_t denominators[] = {
  24       1, 2, 3, 10, 100, 1000,
  25   };
  26
  27   for (auto numerator : numerators) {
  28     for (auto denominator : denominators) {
  29       double result = double(numerator) / double(denominator);
  30
  31       CHECK_EQUAL(FractionToDouble(numerator, denominator), result);
  32       CHECK_EQUAL(FractionToDouble(Int128{numerator}, Int128{denominator}),
  33                   result);
  34
  35       CHECK_EQUAL(FractionToDouble(-numerator, denominator),
  36                   std::copysign(result, -numerator));
  37       CHECK_EQUAL(FractionToDouble(-Int128{numerator}, Int128{denominator}),
  38                   std::copysign(result, -numerator));
  39     }
  40   }
  41
  42   return true;
  43 }
  44 END_TEST(testFraction_simple)
  45
  46 // Complex test with values exceeding Number.MAX_SAFE_INTEGER.
  47 BEGIN_TEST(testFraction_complex) {
  48   struct {
  49     int64_t numerator;
  50     int64_t denominator;
  51     double result;
  52   } values[] = {
  53       // Number.MAX_SAFE_INTEGER
  54       {9007199254740991, 2, 4503599627370495.5},
  55       {9007199254740992, 2, 4503599627370496},
  56       {9007199254740993, 2, 4503599627370496.5},
  57
  58       {INT64_MAX, 2, 4611686018427387903.5},
  59       {INT64_MIN, 2, -4611686018427387904.0},
  60   };
  61
  62   for (auto [numerator, denominator, result] : values) {
  63     CHECK_EQUAL(FractionToDouble(numerator, denominator), result);
  64     CHECK_EQUAL(FractionToDouble(Int128{numerator}, Int128{denominator}),
  65                 result);
  66   }
  67
  68   return true;
  69 }
  70 END_TEST(testFraction_complex)
  71
  72 // Complex test with Int128 values exceeding Number.MAX_SAFE_INTEGER.
  73 BEGIN_TEST(testFraction_complex_int128) {
  74   struct {
  75     Int128 numerator;
  76     Int128 denominator;
  77     double result;
  78   } values[] = {
  79       // Divide 1 by a growing divisor.
  80       {Int128{1}, Int128{1'000}, 0.001},
  81       {Int128{1}, Int128{1'000'000}, 0.000'001},
  82       {Int128{1}, Int128{1'000'000'000}, 0.000'000'001},
  83       {Int128{1}, Int128{1'000'000'000'000}, 0.000'000'000'001},
  84       {Int128{1}, Int128{1'000'000'000'000'000}, 0.000'000'000'000'001},
  85       {Int128{1}, Int128{1'000'000'000'000'000'000}, 0.000'000'000'000'000'001},
  86       {Int128{1}, Int128{1'000'000'000'000'000'000} * Int128{1'000},
  87        0.000'000'000'000'000'000'001},
  88       {Int128{1}, Int128{1'000'000'000'000'000'000} * Int128{1'000'000},
  89        0.000'000'000'000'000'000'000'001},
  90       {Int128{1}, Int128{1'000'000'000'000'000'000} * Int128{1'000'000'000},
  91        0.000'000'000'000'000'000'000'000'001},
  92       {Int128{1}, Int128{1'000'000'000'000'000'000} * Int128{1'000'000'000'000},
  93        0.000'000'000'000'000'000'000'000'000'001},
  94       {Int128{1},
  95        Int128{1'000'000'000'000'000'000} * Int128{1'000'000'000'000'000},
  96        0.000'000'000'000'000'000'000'000'000'000'001},
  97       {Int128{1},
  98        Int128{1'000'000'000'000'000'000} * Int128{1'000'000'000'000'000'000},
  99        0.000'000'000'000'000'000'000'000'000'000'000'001},
 100
 101       // Divide a number not representable as an int64.
 102       {Int128{0x8000'0000} << 64, Int128{1'000},
 103        39614081257132168796771975.1680},
 104       {Int128{0x8000'0000} << 64, Int128{1'000'000},
 105        39614081257132168796771.9751680},
 106       {Int128{0x8000'0000} << 64, Int128{1'000'000'000},
 107        39614081257132168796.7719751680},
 108       {Int128{0x8000'0000} << 64, Int128{1'000'000'000'000},
 109        39614081257132168.7967719751680},
 110       {Int128{0x8000'0000} << 64, Int128{1'000'000'000'000'000},
 111        39614081257132.1687967719751680},
 112       {Int128{0x8000'0000} << 64, Int128{1'000'000'000'000'000'000},
 113        39614081257.1321687967719751680},
 114       {Int128{0x8000'0000} << 64,
 115        Int128{1'000'000'000'000'000'000} * Int128{1'000},
 116        39614081.2571321687967719751680},
 117       {Int128{0x8000'0000} << 64,
 118        Int128{1'000'000'000'000'000'000} * Int128{1'000'000},
 119        39614.0812571321687967719751680},
 120       {Int128{0x8000'0000} << 64,
 121        Int128{1'000'000'000'000'000'000} * Int128{1'000'000'000},
 122        39.6140812571321687967719751680},
 123       {Int128{0x8000'0000} << 64,
 124        Int128{1'000'000'000'000'000'000} * Int128{1'000'000'000'000},
 125        0.0396140812571321687967719751680},
 126       {Int128{0x8000'0000} << 64,
 127        Int128{1'000'000'000'000'000'000} * Int128{1'000'000'000'000'000},
 128        0.0000396140812571321687967719751680},
 129       {Int128{0x8000'0000} << 64,
 130        Int128{1'000'000'000'000'000'000} * Int128{1'000'000'000'000'000'000},
 131        0.0000000396140812571321687967719751680},
 132
 133       // Test divisor which isn't a multiple of ten.
 134       {Int128{0x8000'0000} << 64, Int128{2}, 19807040628566084398385987584.0},
 135       {Int128{0x8000'0000} << 64, Int128{3}, 13204693752377389598923991722.666},
 136       {Int128{0x8000'0000} << 64, Int128{3'333},
 137        11885412918431493788410433.5937},
 138       {Int128{0x8000'0000} << 64, Int128{3'333'333},
 139        11884225565562207195252.3120756},
 140       {Int128{0x8000'0000} << 64, Int128{3'333'333'333},
 141        11884224378328073076.864399858},
 142       {Int128{0x8000'0000} << 64, Int128{3'333'333'333'333},
 143        11884224377140839.0614693066343},
 144       {Int128{0x8000'0000} << 64, Int128{3'333'333'333'333'333},
 145        11884224377139.6518274540302643},
 146       {Int128{0x8000'0000} << 64, Int128{3'333'333'333'333'333'333},
 147        11884224377.1396506402200149881},
 148       {Int128{0x8000'0000} << 64,
 149        (Int128{3'333'333'333'333'333'333} * Int128{1'000}) + Int128{333},
 150        11884224.3771396506390327809728},
 151       {Int128{0x8000'0000} << 64,
 152        (Int128{3'333'333'333'333'333'333} * Int128{1'000'000}) +
 153            Int128{333'333},
 154        11884.2243771396506390315937388},
 155       {Int128{0x8000'0000} << 64,
 156        (Int128{3'333'333'333'333'333'333} * Int128{1'000'000'000}) +
 157            Int128{333'333'333},
 158        11.884224377139650639031592551588422437713965063903159255158842243},
 159       {Int128{0x8000'0000} << 64,
 160        (Int128{3'333'333'333'333'333'333} * Int128{1'000'000'000'000}) +
 161            Int128{333'333'333'333},
 162        0.0118842243771396506390315925504},
 163       {Int128{0x8000'0000} << 64,
 164        (Int128{3'333'333'333'333'333'333} * Int128{1'000'000'000'000'000}) +
 165            Int128{333'333'333'333'333},
 166        0.0000118842243771396506390315925504},
 167       {Int128{0x8000'0000} << 64,
 168        (Int128{3'333'333'333'333'333'333} * Int128{1'000'000'000'000'000'000}) +
 169            Int128{333'333'333'333'333'333},
 170        0.0000000118842243771396506390315925504},
 171   };
 172
 173   for (auto [numerator, denominator, result] : values) {
 174     CHECK_EQUAL(FractionToDouble(numerator, denominator), result);
 175   }
 176
 177   return true;
 178 }
 179 END_TEST(testFraction_complex_int128)
 180
 181 #endif