xref: /aosp_15_r20/external/llvm-libc/test/src/math/RemQuoTest.h (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
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 "hdr/math_macros.h"
13 #include "src/__support/FPUtil/BasicOperations.h"
14 #include "src/__support/FPUtil/FPBits.h"
15 #include "test/UnitTest/FEnvSafeTest.h"
16 #include "test/UnitTest/FPMatcher.h"
17 #include "test/UnitTest/Test.h"
18 #include "utils/MPFRWrapper/MPFRUtils.h"
19 
20 namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
21 using LIBC_NAMESPACE::Sign;
22 
23 template <typename T>
24 class RemQuoTestTemplate : public LIBC_NAMESPACE::testing::FEnvSafeTest {
25   using FPBits = LIBC_NAMESPACE::fputil::FPBits<T>;
26   using StorageType = typename FPBits::StorageType;
27 
28   const T inf = FPBits::inf(Sign::POS).get_val();
29   const T neg_inf = FPBits::inf(Sign::NEG).get_val();
30   const T zero = FPBits::zero(Sign::POS).get_val();
31   const T neg_zero = FPBits::zero(Sign::NEG).get_val();
32   const T nan = FPBits::quiet_nan().get_val();
33 
34   static constexpr StorageType MIN_SUBNORMAL =
35       FPBits::min_subnormal().uintval();
36   static constexpr StorageType MAX_SUBNORMAL =
37       FPBits::max_subnormal().uintval();
38   static constexpr StorageType MIN_NORMAL = FPBits::min_normal().uintval();
39   static constexpr StorageType MAX_NORMAL = FPBits::max_normal().uintval();
40 
41 public:
42   typedef T (*RemQuoFunc)(T, T, int *);
43 
testSpecialNumbers(RemQuoFunc func)44   void testSpecialNumbers(RemQuoFunc func) {
45     int quotient;
46     T x, y;
47 
48     y = T(1.0);
49     x = inf;
50     EXPECT_FP_EQ(nan, func(x, y, &quotient));
51     x = neg_inf;
52     EXPECT_FP_EQ(nan, func(x, y, &quotient));
53 
54     x = T(1.0);
55     y = zero;
56     EXPECT_FP_EQ(nan, func(x, y, &quotient));
57     y = neg_zero;
58     EXPECT_FP_EQ(nan, func(x, y, &quotient));
59 
60     y = nan;
61     x = T(1.0);
62     EXPECT_FP_EQ(nan, func(x, y, &quotient));
63 
64     y = T(1.0);
65     x = nan;
66     EXPECT_FP_EQ(nan, func(x, y, &quotient));
67 
68     x = nan;
69     y = nan;
70     EXPECT_FP_EQ(nan, func(x, y, &quotient));
71 
72     x = zero;
73     y = T(1.0);
74     EXPECT_FP_EQ(func(x, y, &quotient), zero);
75 
76     x = neg_zero;
77     y = T(1.0);
78     EXPECT_FP_EQ(func(x, y, &quotient), neg_zero);
79 
80     x = T(1.125);
81     y = inf;
82     EXPECT_FP_EQ(func(x, y, &quotient), x);
83     EXPECT_EQ(quotient, 0);
84   }
85 
testEqualNumeratorAndDenominator(RemQuoFunc func)86   void testEqualNumeratorAndDenominator(RemQuoFunc func) {
87     T x = T(1.125), y = T(1.125);
88     int q;
89 
90     // When the remainder is zero, the standard requires it to
91     // have the same sign as x.
92 
93     EXPECT_FP_EQ(func(x, y, &q), zero);
94     EXPECT_EQ(q, 1);
95 
96     EXPECT_FP_EQ(func(x, -y, &q), zero);
97     EXPECT_EQ(q, -1);
98 
99     EXPECT_FP_EQ(func(-x, y, &q), neg_zero);
100     EXPECT_EQ(q, -1);
101 
102     EXPECT_FP_EQ(func(-x, -y, &q), neg_zero);
103     EXPECT_EQ(q, 1);
104   }
105 
testSubnormalRange(RemQuoFunc func)106   void testSubnormalRange(RemQuoFunc func) {
107     constexpr StorageType COUNT = 100'001;
108     constexpr StorageType STEP = (MAX_SUBNORMAL - MIN_SUBNORMAL) / COUNT;
109     for (StorageType v = MIN_SUBNORMAL, w = MAX_SUBNORMAL;
110          v <= MAX_SUBNORMAL && w >= MIN_SUBNORMAL; v += STEP, w -= STEP) {
111       T x = FPBits(v).get_val(), y = FPBits(w).get_val();
112       mpfr::BinaryOutput<T> result;
113       mpfr::BinaryInput<T> input{x, y};
114       result.f = func(x, y, &result.i);
115       ASSERT_MPFR_MATCH(mpfr::Operation::RemQuo, input, result, 0.0);
116     }
117   }
118 
119   void testNormalRange(RemQuoFunc func) {
120     constexpr StorageType COUNT = 1'001;
121     constexpr StorageType STEP = (MAX_NORMAL - MIN_NORMAL) / COUNT;
122     for (StorageType v = MIN_NORMAL, w = MAX_NORMAL;
123          v <= MAX_NORMAL && w >= MIN_NORMAL; v += STEP, w -= STEP) {
124       T x = FPBits(v).get_val(), y = FPBits(w).get_val();
125       mpfr::BinaryOutput<T> result;
126       mpfr::BinaryInput<T> input{x, y};
127       result.f = func(x, y, &result.i);
128 
129       // In normal range on x86 platforms, the long double implicit 1 bit can be
130       // zero making the numbers NaN. Hence we test for them separately.
131       if (FPBits(v).is_nan() || FPBits(w).is_nan()) {
132         ASSERT_FP_EQ(result.f, nan);
133         continue;
134       }
135 
136       ASSERT_MPFR_MATCH(mpfr::Operation::RemQuo, input, result, 0.0);
137     }
138   }
139 };
140 
141 #define LIST_REMQUO_TESTS(T, func)                                             \
142   using LlvmLibcRemQuoTest = RemQuoTestTemplate<T>;                            \
143   TEST_F(LlvmLibcRemQuoTest, SpecialNumbers) { testSpecialNumbers(&func); }    \
144   TEST_F(LlvmLibcRemQuoTest, EqualNumeratorAndDenominator) {                   \
145     testEqualNumeratorAndDenominator(&func);                                   \
146   }                                                                            \
147   TEST_F(LlvmLibcRemQuoTest, SubnormalRange) { testSubnormalRange(&func); }    \
148   TEST_F(LlvmLibcRemQuoTest, NormalRange) { testNormalRange(&func); }
149 
150 #endif // LLVM_LIBC_TEST_SRC_MATH_REMQUOTEST_H
151