xref: /aosp_15_r20/external/llvm-libc/test/src/math/smoke/expm1_test.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- Unittests for e^x - 1 ---------------------------------------------===//
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 "hdr/math_macros.h"
10 #include "src/__support/FPUtil/FPBits.h"
11 #include "src/errno/libc_errno.h"
12 #include "src/math/expm1.h"
13 #include "test/UnitTest/FPMatcher.h"
14 #include "test/UnitTest/Test.h"
15 
16 #include <stdint.h>
17 
18 using LlvmLibcExpm1Test = LIBC_NAMESPACE::testing::FPTest<double>;
19 
TEST_F(LlvmLibcExpm1Test,SpecialNumbers)20 TEST_F(LlvmLibcExpm1Test, SpecialNumbers) {
21   EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::expm1(aNaN));
22   EXPECT_FP_EQ(inf, LIBC_NAMESPACE::expm1(inf));
23   EXPECT_FP_EQ_ALL_ROUNDING(-1.0, LIBC_NAMESPACE::expm1(neg_inf));
24   EXPECT_FP_EQ_WITH_EXCEPTION(inf, LIBC_NAMESPACE::expm1(0x1.0p20),
25                               FE_OVERFLOW);
26   EXPECT_FP_EQ_ALL_ROUNDING(zero, LIBC_NAMESPACE::expm1(zero));
27   EXPECT_FP_EQ_ALL_ROUNDING(neg_zero, LIBC_NAMESPACE::expm1(neg_zero));
28   // |x| < 2^-53, expm1(x) = x
29   EXPECT_FP_EQ(-0x1.23456789abcdep-55,
30                LIBC_NAMESPACE::expm1(-0x1.23456789abcdep-55));
31   EXPECT_FP_EQ(0x1.23456789abcdep-55,
32                LIBC_NAMESPACE::expm1(0x1.23456789abcdep-55));
33   // log(2^-54)
34   EXPECT_FP_EQ(-1.0, LIBC_NAMESPACE::expm1(-0x1.2b708872320e2p5));
35 }
36 
37 #ifdef LIBC_TEST_FTZ_DAZ
38 
39 using namespace LIBC_NAMESPACE::testing;
40 
TEST_F(LlvmLibcExpm1Test,FTZMode)41 TEST_F(LlvmLibcExpm1Test, FTZMode) {
42   ModifyMXCSR mxcsr(FTZ);
43 
44   EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::expm1(min_denormal));
45   EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::expm1(max_denormal));
46 }
47 
TEST_F(LlvmLibcExpm1Test,DAZMode)48 TEST_F(LlvmLibcExpm1Test, DAZMode) {
49   ModifyMXCSR mxcsr(DAZ);
50 
51   EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::expm1(min_denormal));
52   EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::expm1(max_denormal));
53 }
54 
TEST_F(LlvmLibcExpm1Test,FTZDAZMode)55 TEST_F(LlvmLibcExpm1Test, FTZDAZMode) {
56   ModifyMXCSR mxcsr(FTZ | DAZ);
57 
58   EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::expm1(min_denormal));
59   EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::expm1(max_denormal));
60 }
61 
62 #endif
63