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 testSpecialNumbers(SqrtFunc func) {
31 EXPECT_EQ(zero, func(T(0)));
32
33 EXPECT_EQ(one, func(T(1)));
34 EXPECT_EQ(static_cast<OutType>(2.0), func(T(4)));
35 EXPECT_EQ(static_cast<OutType>(4.0), func(T(16)));
36 EXPECT_EQ(static_cast<OutType>(16.0), func(T(256)));
37
38 constexpr int COUNT = 255;
39 constexpr double ERR = 3.0 * static_cast<double>(eps);
40 double x_d = 0.0;
41 T x = 0;
42 for (int i = 0; i < COUNT; ++i) {
43 x_d += 1.0;
44 ++x;
45 double y_d = static_cast<double>(func(x));
46 double result = LIBC_NAMESPACE::fputil::sqrt(x: x_d);
47 double errors = LIBC_NAMESPACE::fputil::abs(x: (y_d / result) - 1.0);
48 if (errors > ERR) {
49 // Print out the failure input and output.
50 EXPECT_EQ(x, T(0));
51 EXPECT_EQ(func(x), zero);
52 }
53 ASSERT_TRUE(errors <= ERR);
54 }
55 }
56};
57
58#define LIST_ISQRT_TESTS(Name, T, func) \
59 using LlvmLibcISqrt##Name##Test = ISqrtTest<T>; \
60 TEST_F(LlvmLibcISqrt##Name##Test, SpecialNumbers) { \
61 testSpecialNumbers(&func); \
62 } \
63 static_assert(true, "Require semicolon.")
64

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