1 //===-- Unittests for fabs ------------------------------------------------===//
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/math/fabs.h"
11 #include "utils/FPUtil/FPBits.h"
12 #include "utils/FPUtil/TestHelpers.h"
13 #include "utils/MPFRWrapper/MPFRUtils.h"
14 #include "utils/UnitTest/Test.h"
15 
16 using FPBits = __llvm_libc::fputil::FPBits<double>;
17 
18 static const double zero = FPBits::zero();
19 static const double negZero = FPBits::negZero();
20 static const double nan = FPBits::buildNaN(1);
21 static const double inf = FPBits::inf();
22 static const double negInf = FPBits::negInf();
23 
24 namespace mpfr = __llvm_libc::testing::mpfr;
25 
26 // Zero tolerance; As in, exact match with MPFR result.
27 static constexpr mpfr::Tolerance tolerance{mpfr::Tolerance::doublePrecision, 0,
28                                            0};
29 
30 TEST(FabsTest, SpecialNumbers) {
31   EXPECT_FP_EQ(nan, __llvm_libc::fabs(nan));
32 
33   EXPECT_FP_EQ(inf, __llvm_libc::fabs(inf));
34   EXPECT_FP_EQ(inf, __llvm_libc::fabs(negInf));
35 
36   EXPECT_FP_EQ(zero, __llvm_libc::fabs(zero));
37   EXPECT_FP_EQ(zero, __llvm_libc::fabs(negZero));
38 }
39 
40 TEST(FabsTest, InDoubleRange) {
41   using UIntType = FPBits::UIntType;
42   constexpr UIntType count = 10000000;
43   constexpr UIntType step = UIntType(-1) / count;
44   for (UIntType i = 0, v = 0; i <= count; ++i, v += step) {
45     double x = FPBits(v);
46     if (isnan(x) || isinf(x))
47       continue;
48     ASSERT_MPFR_MATCH(mpfr::Operation::Abs, x, __llvm_libc::fabs(x), tolerance);
49   }
50 }
51