1 //===-- Unittests for expm1f-----------------------------------------------===//
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 "src/__support/FPUtil/FPBits.h"
10 #include "src/math/expm1f.h"
11 #include "utils/MPFRWrapper/MPFRUtils.h"
12 #include "utils/UnitTest/FPMatcher.h"
13 #include "utils/UnitTest/Test.h"
14 #include <math.h>
15 
16 #include <errno.h>
17 #include <stdint.h>
18 
19 namespace mpfr = __llvm_libc::testing::mpfr;
20 
21 DECLARE_SPECIAL_CONSTANTS(float)
22 
TEST(LlvmLibcExpm1fTest,SpecialNumbers)23 TEST(LlvmLibcExpm1fTest, SpecialNumbers) {
24   errno = 0;
25 
26   EXPECT_FP_EQ(aNaN, __llvm_libc::expm1f(aNaN));
27   EXPECT_MATH_ERRNO(0);
28 
29   EXPECT_FP_EQ(inf, __llvm_libc::expm1f(inf));
30   EXPECT_MATH_ERRNO(0);
31 
32   EXPECT_FP_EQ(-1.0f, __llvm_libc::expm1f(neg_inf));
33   EXPECT_MATH_ERRNO(0);
34 
35   EXPECT_FP_EQ(0.0f, __llvm_libc::expm1f(0.0f));
36   EXPECT_MATH_ERRNO(0);
37 
38   EXPECT_FP_EQ(-0.0f, __llvm_libc::expm1f(-0.0f));
39   EXPECT_MATH_ERRNO(0);
40 }
41 
TEST(LlvmLibcExpm1fTest,Overflow)42 TEST(LlvmLibcExpm1fTest, Overflow) {
43   errno = 0;
44   EXPECT_FP_EQ(inf, __llvm_libc::expm1f(float(FPBits(0x7f7fffffU))));
45   EXPECT_MATH_ERRNO(ERANGE);
46 
47   EXPECT_FP_EQ(inf, __llvm_libc::expm1f(float(FPBits(0x42cffff8U))));
48   EXPECT_MATH_ERRNO(ERANGE);
49 
50   EXPECT_FP_EQ(inf, __llvm_libc::expm1f(float(FPBits(0x42d00008U))));
51   EXPECT_MATH_ERRNO(ERANGE);
52 }
53 
TEST(LlvmLibcExpm1fTest,Underflow)54 TEST(LlvmLibcExpm1fTest, Underflow) {
55   errno = 0;
56   EXPECT_FP_EQ(-1.0f, __llvm_libc::expm1f(float(FPBits(0xff7fffffU))));
57 
58   float x = float(FPBits(0xc2cffff8U));
59   EXPECT_FP_EQ(-1.0f, __llvm_libc::expm1f(x));
60 
61   x = float(FPBits(0xc2d00008U));
62   EXPECT_FP_EQ(-1.0f, __llvm_libc::expm1f(x));
63 }
64 
65 // Test with inputs which are the borders of underflow/overflow but still
66 // produce valid results without setting errno.
TEST(LlvmLibcExpm1fTest,Borderline)67 TEST(LlvmLibcExpm1fTest, Borderline) {
68   float x;
69 
70   errno = 0;
71   x = float(FPBits(0x42affff8U));
72   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
73                                  __llvm_libc::expm1f(x), 0.5);
74   EXPECT_MATH_ERRNO(0);
75 
76   x = float(FPBits(0x42b00008U));
77   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
78                                  __llvm_libc::expm1f(x), 0.5);
79   EXPECT_MATH_ERRNO(0);
80 
81   x = float(FPBits(0xc2affff8U));
82   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
83                                  __llvm_libc::expm1f(x), 0.5);
84   EXPECT_MATH_ERRNO(0);
85 
86   x = float(FPBits(0xc2b00008U));
87   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
88                                  __llvm_libc::expm1f(x), 0.5);
89   EXPECT_MATH_ERRNO(0);
90 
91   x = float(FPBits(0x3dc252ddU));
92   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
93                                  __llvm_libc::expm1f(x), 0.5);
94   EXPECT_MATH_ERRNO(0);
95 
96   x = float(FPBits(0x3e35bec5U));
97   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
98                                  __llvm_libc::expm1f(x), 0.5);
99   EXPECT_MATH_ERRNO(0);
100 
101   x = float(FPBits(0x942ed494U));
102   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
103                                  __llvm_libc::expm1f(x), 0.5);
104   EXPECT_MATH_ERRNO(0);
105 
106   x = float(FPBits(0xbdc1c6cbU));
107   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
108                                  __llvm_libc::expm1f(x), 0.5);
109   EXPECT_MATH_ERRNO(0);
110 }
111 
TEST(LlvmLibcExpm1fTest,InFloatRange)112 TEST(LlvmLibcExpm1fTest, InFloatRange) {
113   constexpr uint32_t COUNT = 1000000;
114   constexpr uint32_t STEP = UINT32_MAX / COUNT;
115   for (uint32_t i = 0, v = 0; i <= COUNT; ++i, v += STEP) {
116     float x = float(FPBits(v));
117     if (isnan(x) || isinf(x))
118       continue;
119     errno = 0;
120     float result = __llvm_libc::expm1f(x);
121 
122     // If the computation resulted in an error or did not produce valid result
123     // in the single-precision floating point range, then ignore comparing with
124     // MPFR result as MPFR can still produce valid results because of its
125     // wider precision.
126     if (isnan(result) || isinf(result) || errno != 0)
127       continue;
128     ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
129                                    __llvm_libc::expm1f(x), 0.5);
130   }
131 }
132