1 //===-- Unittests for cosf ------------------------------------------------===//
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 #include "include/math.h"
10 #include "src/errno/llvmlibc_errno.h"
11 #include "src/math/cosf.h"
12 #include "src/math/math_utils.h"
13 #include "test/src/math/float.h"
14 #include "test/src/math/sdcomp26094.h"
15 #include "utils/CPP/Array.h"
16 #include "utils/MPFRWrapper/MPFRUtils.h"
17 #include "utils/UnitTest/Test.h"
18 
19 #include <stdint.h>
20 
21 using __llvm_libc::as_float;
22 using __llvm_libc::as_uint32_bits;
23 
24 using __llvm_libc::testing::FloatBits;
25 using __llvm_libc::testing::sdcomp26094Values;
26 
27 namespace mpfr = __llvm_libc::testing::mpfr;
28 
29 // 12 additional bits of precision over the base precision of a |float|
30 // value.
31 static constexpr mpfr::Tolerance tolerance{mpfr::Tolerance::floatPrecision, 12,
32                                            3 * 0x1000 / 4};
33 
34 TEST(CosfTest, SpecialNumbers) {
35   llvmlibc_errno = 0;
36 
37   EXPECT_TRUE(FloatBits::isQNan(
38       as_uint32_bits(__llvm_libc::cosf(as_float(FloatBits::QNan)))));
39   EXPECT_EQ(llvmlibc_errno, 0);
40 
41   EXPECT_TRUE(FloatBits::isNegQNan(
42       as_uint32_bits(__llvm_libc::cosf(as_float(FloatBits::NegQNan)))));
43   EXPECT_EQ(llvmlibc_errno, 0);
44 
45   EXPECT_TRUE(FloatBits::isQNan(
46       as_uint32_bits(__llvm_libc::cosf(as_float(FloatBits::SNan)))));
47   EXPECT_EQ(llvmlibc_errno, 0);
48 
49   EXPECT_TRUE(FloatBits::isNegQNan(
50       as_uint32_bits(__llvm_libc::cosf(as_float(FloatBits::NegSNan)))));
51   EXPECT_EQ(llvmlibc_errno, 0);
52 
53   EXPECT_EQ(FloatBits::One,
54             as_uint32_bits(__llvm_libc::cosf(as_float(FloatBits::Zero))));
55   EXPECT_EQ(llvmlibc_errno, 0);
56 
57   EXPECT_EQ(FloatBits::One,
58             as_uint32_bits(__llvm_libc::cosf(as_float(FloatBits::NegZero))));
59   EXPECT_EQ(llvmlibc_errno, 0);
60 
61   llvmlibc_errno = 0;
62   EXPECT_TRUE(FloatBits::isQNan(
63       as_uint32_bits(__llvm_libc::cosf(as_float(FloatBits::Inf)))));
64   EXPECT_EQ(llvmlibc_errno, EDOM);
65 
66   llvmlibc_errno = 0;
67   EXPECT_TRUE(FloatBits::isNegQNan(
68       as_uint32_bits(__llvm_libc::cosf(as_float(FloatBits::NegInf)))));
69   EXPECT_EQ(llvmlibc_errno, EDOM);
70 }
71 
72 TEST(CosfTest, InFloatRange) {
73   constexpr uint32_t count = 1000000;
74   constexpr uint32_t step = UINT32_MAX / count;
75   for (uint32_t i = 0, v = 0; i <= count; ++i, v += step) {
76     float x = as_float(v);
77     if (isnan(x) || isinf(x))
78       continue;
79     ASSERT_MPFR_MATCH(mpfr::OP_Cos, x, __llvm_libc::cosf(x), tolerance);
80   }
81 }
82 
83 // For small values, cos(x) is 1.
84 TEST(CosfTest, SmallValues) {
85   float x = as_float(0x17800000);
86   float result = __llvm_libc::cosf(x);
87   EXPECT_MPFR_MATCH(mpfr::OP_Cos, x, result, tolerance);
88   EXPECT_EQ(FloatBits::One, as_uint32_bits(result));
89 
90   x = as_float(0x0040000);
91   result = __llvm_libc::cosf(x);
92   EXPECT_MPFR_MATCH(mpfr::OP_Cos, x, result, tolerance);
93   EXPECT_EQ(FloatBits::One, as_uint32_bits(result));
94 }
95 
96 // SDCOMP-26094: check cosf in the cases for which the range reducer
97 // returns values furthest beyond its nominal upper bound of pi/4.
98 TEST(CosfTest, SDCOMP_26094) {
99   for (uint32_t v : sdcomp26094Values) {
100     float x = as_float(v);
101     ASSERT_MPFR_MATCH(mpfr::OP_Cos, x, __llvm_libc::cosf(x), tolerance);
102   }
103 }
104