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 = __llvm_libc::testing::mpfr;
  20
  21 template <typename T>
  22 class RemQuoTestTemplate : public __llvm_libc::testing::Test {
  23   using FPBits = __llvm_libc::fputil::FPBits<T>;
  24   using UIntType = typename FPBits::UIntType;
  25
  26   const T zero = T(__llvm_libc::fputil::FPBits<T>::zero());
  27   const T neg_zero = T(__llvm_libc::fputil::FPBits<T>::neg_zero());
  28   const T inf = T(__llvm_libc::fputil::FPBits<T>::inf());
  29   const T neg_inf = T(__llvm_libc::fputil::FPBits<T>::neg_inf());
  30   const T nan = T(__llvm_libc::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 = 1000001;
  99     constexpr UIntType STEP =
 100         (FPBits::MAX_SUBNORMAL - FPBits::MIN_SUBNORMAL) / COUNT;
 101     for (UIntType v = FPBits::MIN_SUBNORMAL, w = FPBits::MAX_SUBNORMAL;
 102          v <= FPBits::MAX_SUBNORMAL && w >= FPBits::MIN_SUBNORMAL;
 103          v += STEP, w -= STEP) {
 104       T x = T(FPBits(v)), y = T(FPBits(w));
 105       mpfr::BinaryOutput<T> result;
 106       mpfr::BinaryInput<T> input{x, y};
 107       result.f = func(x, y, &result.i);
 108       ASSERT_MPFR_MATCH(mpfr::Operation::RemQuo, input, result, 0.0);
 109     }
 110   }
 111
 112   void testNormalRange(RemQuoFunc func) {
 113     constexpr UIntType COUNT = 234561;
 114     constexpr UIntType STEP = (FPBits::MAX_NORMAL - FPBits::MIN_NORMAL) / COUNT;
 115     for (UIntType v = FPBits::MIN_NORMAL, w = FPBits::MAX_NORMAL;
 116          v <= FPBits::MAX_NORMAL && w >= FPBits::MIN_NORMAL;
 117          v += STEP, w -= STEP) {
 118       T x = T(FPBits(v)), y = T(FPBits(w));
 119       mpfr::BinaryOutput<T> result;
 120       mpfr::BinaryInput<T> input{x, y};
 121       result.f = func(x, y, &result.i);
 122
 123       // In normal range on x86 platforms, the long double implicit 1 bit can be
 124       // zero making the numbers NaN. Hence we test for them separately.
 125       if (isnan(x) || isnan(y)) {
 126         ASSERT_FP_EQ(result.f, nan);
 127         continue;
 128       }
 129
 130       ASSERT_MPFR_MATCH(mpfr::Operation::RemQuo, input, result, 0.0);
 131     }
 132   }
 133 };
 134
 135 #define LIST_REMQUO_TESTS(T, func)                                             \
 136   using LlvmLibcRemQuoTest = RemQuoTestTemplate<T>;                            \
 137   TEST_F(LlvmLibcRemQuoTest, SpecialNumbers) { testSpecialNumbers(&func); }    \
 138   TEST_F(LlvmLibcRemQuoTest, EqualNumeratorAndDenominator) {                   \
 139     testEqualNumeratorAndDenominator(&func);                                   \
 140   }                                                                            \
 141   TEST_F(LlvmLibcRemQuoTest, SubnormalRange) { testSubnormalRange(&func); }    \
 142   TEST_F(LlvmLibcRemQuoTest, NormalRange) { testNormalRange(&func); }
 143
 144 #endif // LLVM_LIBC_TEST_SRC_MATH_REMQUOTEST_H