libc/test/src/math/RemQuoTest.h

   1 //===-- Utility class to test different flavors of remquo -------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_LIBC_TEST_SRC_MATH_REMQUOTEST_H
  10 #define LLVM_LIBC_TEST_SRC_MATH_REMQUOTEST_H
  11
  12 #include "src/__support/FPUtil/BasicOperations.h"
  13 #include "src/__support/FPUtil/FPBits.h"
  14 #include "test/UnitTest/FPMatcher.h"
  15 #include "test/UnitTest/Test.h"
  16 #include "utils/MPFRWrapper/MPFRUtils.h"
  17 #include <math.h>
  18
  19 namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
  20
  21 template <typename T>
  22 class RemQuoTestTemplate : public LIBC_NAMESPACE::testing::Test {
  23   using FPBits = LIBC_NAMESPACE::fputil::FPBits<T>;
  24   using UIntType = typename FPBits::UIntType;
  25
  26   const T zero = T(LIBC_NAMESPACE::fputil::FPBits<T>::zero());
  27   const T neg_zero = T(LIBC_NAMESPACE::fputil::FPBits<T>::neg_zero());
  28   const T inf = T(LIBC_NAMESPACE::fputil::FPBits<T>::inf());
  29   const T neg_inf = T(LIBC_NAMESPACE::fputil::FPBits<T>::neg_inf());
  30   const T nan = T(LIBC_NAMESPACE::fputil::FPBits<T>::build_quiet_nan(1));
  31
  32 public:
  33   typedef T (*RemQuoFunc)(T, T, int *);
  34
  35   void testSpecialNumbers(RemQuoFunc func) {
  36     int quotient;
  37     T x, y;
  38
  39     y = T(1.0);
  40     x = inf;
  41     EXPECT_FP_EQ(nan, func(x, y, &quotient));
  42     x = neg_inf;
  43     EXPECT_FP_EQ(nan, func(x, y, &quotient));
  44
  45     x = T(1.0);
  46     y = zero;
  47     EXPECT_FP_EQ(nan, func(x, y, &quotient));
  48     y = neg_zero;
  49     EXPECT_FP_EQ(nan, func(x, y, &quotient));
  50
  51     y = nan;
  52     x = T(1.0);
  53     EXPECT_FP_EQ(nan, func(x, y, &quotient));
  54
  55     y = T(1.0);
  56     x = nan;
  57     EXPECT_FP_EQ(nan, func(x, y, &quotient));
  58
  59     x = nan;
  60     y = nan;
  61     EXPECT_FP_EQ(nan, func(x, y, &quotient));
  62
  63     x = zero;
  64     y = T(1.0);
  65     EXPECT_FP_EQ(func(x, y, &quotient), zero);
  66
  67     x = neg_zero;
  68     y = T(1.0);
  69     EXPECT_FP_EQ(func(x, y, &quotient), neg_zero);
  70
  71     x = T(1.125);
  72     y = inf;
  73     EXPECT_FP_EQ(func(x, y, &quotient), x);
  74     EXPECT_EQ(quotient, 0);
  75   }
  76
  77   void testEqualNumeratorAndDenominator(RemQuoFunc func) {
  78     T x = T(1.125), y = T(1.125);
  79     int q;
  80
  81     // When the remainder is zero, the standard requires it to
  82     // have the same sign as x.
  83
  84     EXPECT_FP_EQ(func(x, y, &q), zero);
  85     EXPECT_EQ(q, 1);
  86
  87     EXPECT_FP_EQ(func(x, -y, &q), zero);
  88     EXPECT_EQ(q, -1);
  89
  90     EXPECT_FP_EQ(func(-x, y, &q), neg_zero);
  91     EXPECT_EQ(q, -1);
  92
  93     EXPECT_FP_EQ(func(-x, -y, &q), neg_zero);
  94     EXPECT_EQ(q, 1);
  95   }
  96
  97   void testSubnormalRange(RemQuoFunc func) {
  98     constexpr UIntType COUNT = 100'001;
  99     constexpr UIntType STEP =
 100         (UIntType(FPBits::MAX_SUBNORMAL) - UIntType(FPBits::MIN_SUBNORMAL)) /
 101         COUNT;
 102     for (UIntType v = FPBits::MIN_SUBNORMAL, w = FPBits::MAX_SUBNORMAL;
 103          v <= FPBits::MAX_SUBNORMAL && w >= FPBits::MIN_SUBNORMAL;
 104          v += STEP, w -= STEP) {
 105       T x = T(FPBits(v)), y = T(FPBits(w));
 106       mpfr::BinaryOutput<T> result;
 107       mpfr::BinaryInput<T> input{x, y};
 108       result.f = func(x, y, &result.i);
 109       ASSERT_MPFR_MATCH(mpfr::Operation::RemQuo, input, result, 0.0);
 110     }
 111   }
 112
 113   void testNormalRange(RemQuoFunc func) {
 114     constexpr UIntType COUNT = 1'001;
 115     constexpr UIntType STEP =
 116         (UIntType(FPBits::MAX_NORMAL) - UIntType(FPBits::MIN_NORMAL)) / COUNT;
 117     for (UIntType v = FPBits::MIN_NORMAL, w = FPBits::MAX_NORMAL;
 118          v <= FPBits::MAX_NORMAL && w >= FPBits::MIN_NORMAL;
 119          v += STEP, w -= STEP) {
 120       T x = T(FPBits(v)), y = T(FPBits(w));
 121       mpfr::BinaryOutput<T> result;
 122       mpfr::BinaryInput<T> input{x, y};
 123       result.f = func(x, y, &result.i);
 124
 125       // In normal range on x86 platforms, the long double implicit 1 bit can be
 126       // zero making the numbers NaN. Hence we test for them separately.
 127       if (isnan(x) || isnan(y)) {
 128         ASSERT_FP_EQ(result.f, nan);
 129         continue;
 130       }
 131
 132       ASSERT_MPFR_MATCH(mpfr::Operation::RemQuo, input, result, 0.0);
 133     }
 134   }
 135 };
 136
 137 #define LIST_REMQUO_TESTS(T, func)                                             \
 138   using LlvmLibcRemQuoTest = RemQuoTestTemplate<T>;                            \
 139   TEST_F(LlvmLibcRemQuoTest, SpecialNumbers) { testSpecialNumbers(&func); }    \
 140   TEST_F(LlvmLibcRemQuoTest, EqualNumeratorAndDenominator) {                   \
 141     testEqualNumeratorAndDenominator(&func);                                   \
 142   }                                                                            \
 143   TEST_F(LlvmLibcRemQuoTest, SubnormalRange) { testSubnormalRange(&func); }    \
 144   TEST_F(LlvmLibcRemQuoTest, NormalRange) { testNormalRange(&func); }
 145
 146 #endif // LLVM_LIBC_TEST_SRC_MATH_REMQUOTEST_H