xref: /aosp_15_r20/external/llvm-libc/test/src/stdfix/RoundTest.h (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- Utility class to test fixed-point round -----------------*- 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 #include "test/UnitTest/Test.h"
10 
11 #include "src/__support/fixed_point/fx_rep.h"
12 
13 template <typename T> class RoundTest : public LIBC_NAMESPACE::testing::Test {
14 
15   using FXRep = LIBC_NAMESPACE::fixed_point::FXRep<T>;
16   static constexpr T zero = FXRep::ZERO();
17   static constexpr T min = FXRep::MIN();
18   static constexpr T max = FXRep::MAX();
19   static constexpr T half = static_cast<T>(0.5);
20   static constexpr T neg_half = static_cast<T>(-0.5);
21   static constexpr T one =
22       (FXRep::INTEGRAL_LEN > 0) ? static_cast<T>(1) : FXRep::MAX();
23   static constexpr T neg_one = static_cast<T>(-1);
24   static constexpr T eps = FXRep::EPS();
25 
26 public:
27   typedef T (*RoundFunc)(T, int);
28 
testSpecialNumbers(RoundFunc func)29   void testSpecialNumbers(RoundFunc func) {
30     EXPECT_EQ(zero, func(zero, FXRep::FRACTION_LEN - 5));
31     EXPECT_EQ(min, func(min, 0));
32     EXPECT_EQ(max, func(max, FXRep::FRACTION_LEN));
33 
34     EXPECT_EQ(one, func(half, 0));
35     EXPECT_EQ(half, func(half, 1));
36     EXPECT_EQ(half, func(half, FXRep::FRACTION_LEN));
37     EXPECT_EQ(one, func(half + eps, 0));
38     EXPECT_EQ(half, func(half + eps, 1));
39     EXPECT_EQ(half, func(half + eps, 2));
40     EXPECT_EQ(zero, func(half - eps, 0));
41     EXPECT_EQ(half, func(half - eps, 1));
42     EXPECT_EQ(half, func(half - eps, 2));
43     EXPECT_EQ(eps, func(eps, FXRep::FRACTION_LEN + 10));
44     EXPECT_EQ(eps << 1, func(eps, FXRep::FRACTION_LEN - 1));
45     EXPECT_EQ(zero, func(eps, FXRep::FRACTION_LEN - 2));
46 
47     if constexpr (FXRep::SIGN_LEN) {
48       EXPECT_EQ(zero, func(neg_half, 0));
49       EXPECT_EQ(neg_half, func(neg_half, 1));
50       EXPECT_EQ(neg_half, func(neg_half, 3));
51       EXPECT_EQ(zero, func(neg_half + eps, 0));
52       EXPECT_EQ(neg_half, func(neg_half + eps, 1));
53       EXPECT_EQ(neg_half, func(neg_half + eps, 2));
54       EXPECT_EQ(neg_one, func(neg_half - eps, 0));
55       EXPECT_EQ(neg_half, func(neg_half - eps, 1));
56       EXPECT_EQ(neg_half, func(neg_half - eps, 2));
57       EXPECT_EQ(-eps, func(-eps, FXRep::FRACTION_LEN + 10));
58     }
59   }
60 };
61 
62 #define LIST_ROUND_TESTS(T, func)                                              \
63   using LlvmLibcRoundTest = RoundTest<T>;                                      \
64   TEST_F(LlvmLibcRoundTest, SpecialNumbers) { testSpecialNumbers(&func); }     \
65   static_assert(true, "Require semicolon.")
66