1//===-- Utility class to test integer sqrt ----------------------*- 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/FPMatcher.h"
10#include "test/UnitTest/Test.h"
11
12#include "src/__support/CPP/bit.h"
13#include "src/__support/FPUtil/BasicOperations.h"
14#include "src/__support/FPUtil/sqrt.h"
15#include "src/__support/fixed_point/fx_rep.h"
16#include "src/__support/fixed_point/sqrt.h"
17
18template <typename T> class ISqrtTest : public LIBC_NAMESPACE::testing::Test {
19
20 using OutType =
21 typename LIBC_NAMESPACE::fixed_point::internal::SqrtConfig<T>::OutType;
22 using FXRep = LIBC_NAMESPACE::fixed_point::FXRep<OutType>;
23 static constexpr OutType zero = FXRep::ZERO();
24 static constexpr OutType one = static_cast<OutType>(1);
25 static constexpr OutType eps = FXRep::EPS();
26
27public:
28 typedef OutType (*SqrtFunc)(T);
29
30 void testSpecificInput(T input, OutType result, double expected,
31 double tolerance) {
32 double y_d = static_cast<double>(result);
33 double errors = LIBC_NAMESPACE::fputil::abs((y_d / expected) - 1.0);
34 if (errors > tolerance) {
35 // Print out the failure input and output.
36 EXPECT_EQ(input, T(0));
37 EXPECT_EQ(result, zero);
38 }
39 ASSERT_TRUE(errors <= tolerance);
40 }
41
42 void testSpecialNumbers(SqrtFunc func) {
43 EXPECT_EQ(zero, func(T(0)));
44
45 EXPECT_EQ(one, func(T(1)));
46 EXPECT_EQ(static_cast<OutType>(2.0), func(T(4)));
47 EXPECT_EQ(static_cast<OutType>(4.0), func(T(16)));
48 EXPECT_EQ(static_cast<OutType>(16.0), func(T(256)));
49
50 constexpr int COUNT = 255;
51 constexpr double ERR = 3.0 * static_cast<double>(eps);
52 double x_d = 0.0;
53 T x = 0;
54 for (int i = 0; i < COUNT; ++i) {
55 x_d += 1.0;
56 ++x;
57 OutType result = func(x);
58 double expected = LIBC_NAMESPACE::fputil::sqrt<double>(x_d);
59 testSpecificInput(x, result, expected, ERR);
60 }
61 }
62};
63
64#define LIST_ISQRT_TESTS(Name, T, func) \
65 using LlvmLibcISqrt##Name##Test = ISqrtTest<T>; \
66 TEST_F(LlvmLibcISqrt##Name##Test, SpecialNumbers) { \
67 testSpecialNumbers(&func); \
68 } \
69 static_assert(true, "Require semicolon.")
70

source code of libc/test/src/stdfix/ISqrtTest.h