libc/test/src/math/expm1f_test.cpp

   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/errno/libc_errno.h"
  11 #include "src/math/expm1f.h"
  12 #include "test/UnitTest/FPMatcher.h"
  13 #include "test/UnitTest/Test.h"
  14 #include "utils/MPFRWrapper/MPFRUtils.h"
  15 #include <math.h>
  16
  17 #include <stdint.h>
  18
  19 using LlvmLibcExpm1fTest = LIBC_NAMESPACE::testing::FPTest<float>;
  20
  21 namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
  22
  23 TEST_F(LlvmLibcExpm1fTest, SpecialNumbers) {
  24   libc_errno = 0;
  25
  26   EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::expm1f(aNaN));
  27   EXPECT_MATH_ERRNO(0);
  28
  29   EXPECT_FP_EQ(inf, LIBC_NAMESPACE::expm1f(inf));
  30   EXPECT_MATH_ERRNO(0);
  31
  32   EXPECT_FP_EQ(-1.0f, LIBC_NAMESPACE::expm1f(neg_inf));
  33   EXPECT_MATH_ERRNO(0);
  34
  35   EXPECT_FP_EQ(0.0f, LIBC_NAMESPACE::expm1f(0.0f));
  36   EXPECT_MATH_ERRNO(0);
  37
  38   EXPECT_FP_EQ(-0.0f, LIBC_NAMESPACE::expm1f(-0.0f));
  39   EXPECT_MATH_ERRNO(0);
  40 }
  41
  42 TEST_F(LlvmLibcExpm1fTest, Overflow) {
  43   libc_errno = 0;
  44   EXPECT_FP_EQ_WITH_EXCEPTION(
  45       inf, LIBC_NAMESPACE::expm1f(float(FPBits(0x7f7fffffU))), FE_OVERFLOW);
  46   EXPECT_MATH_ERRNO(ERANGE);
  47
  48   EXPECT_FP_EQ_WITH_EXCEPTION(
  49       inf, LIBC_NAMESPACE::expm1f(float(FPBits(0x42cffff8U))), FE_OVERFLOW);
  50   EXPECT_MATH_ERRNO(ERANGE);
  51
  52   EXPECT_FP_EQ_WITH_EXCEPTION(
  53       inf, LIBC_NAMESPACE::expm1f(float(FPBits(0x42d00008U))), FE_OVERFLOW);
  54   EXPECT_MATH_ERRNO(ERANGE);
  55 }
  56
  57 TEST_F(LlvmLibcExpm1fTest, Underflow) {
  58   libc_errno = 0;
  59   EXPECT_FP_EQ(-1.0f, LIBC_NAMESPACE::expm1f(float(FPBits(0xff7fffffU))));
  60
  61   float x = float(FPBits(0xc2cffff8U));
  62   EXPECT_FP_EQ(-1.0f, LIBC_NAMESPACE::expm1f(x));
  63
  64   x = float(FPBits(0xc2d00008U));
  65   EXPECT_FP_EQ(-1.0f, LIBC_NAMESPACE::expm1f(x));
  66 }
  67
  68 // Test with inputs which are the borders of underflow/overflow but still
  69 // produce valid results without setting errno.
  70 TEST_F(LlvmLibcExpm1fTest, Borderline) {
  71   float x;
  72
  73   libc_errno = 0;
  74   x = float(FPBits(0x42affff8U));
  75   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
  76                                  LIBC_NAMESPACE::expm1f(x), 0.5);
  77   EXPECT_MATH_ERRNO(0);
  78
  79   x = float(FPBits(0x42b00008U));
  80   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
  81                                  LIBC_NAMESPACE::expm1f(x), 0.5);
  82   EXPECT_MATH_ERRNO(0);
  83
  84   x = float(FPBits(0xc2affff8U));
  85   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
  86                                  LIBC_NAMESPACE::expm1f(x), 0.5);
  87   EXPECT_MATH_ERRNO(0);
  88
  89   x = float(FPBits(0xc2b00008U));
  90   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
  91                                  LIBC_NAMESPACE::expm1f(x), 0.5);
  92   EXPECT_MATH_ERRNO(0);
  93
  94   x = float(FPBits(0x3dc252ddU));
  95   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
  96                                  LIBC_NAMESPACE::expm1f(x), 0.5);
  97   EXPECT_MATH_ERRNO(0);
  98
  99   x = float(FPBits(0x3e35bec5U));
 100   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
 101                                  LIBC_NAMESPACE::expm1f(x), 0.5);
 102   EXPECT_MATH_ERRNO(0);
 103
 104   x = float(FPBits(0x942ed494U));
 105   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
 106                                  LIBC_NAMESPACE::expm1f(x), 0.5);
 107   EXPECT_MATH_ERRNO(0);
 108
 109   x = float(FPBits(0xbdc1c6cbU));
 110   ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
 111                                  LIBC_NAMESPACE::expm1f(x), 0.5);
 112   EXPECT_MATH_ERRNO(0);
 113 }
 114
 115 TEST_F(LlvmLibcExpm1fTest, InFloatRange) {
 116   constexpr uint32_t COUNT = 100'000;
 117   constexpr uint32_t STEP = UINT32_MAX / COUNT;
 118   for (uint32_t i = 0, v = 0; i <= COUNT; ++i, v += STEP) {
 119     float x = float(FPBits(v));
 120     if (isnan(x) || isinf(x))
 121       continue;
 122     libc_errno = 0;
 123     float result = LIBC_NAMESPACE::expm1f(x);
 124
 125     // If the computation resulted in an error or did not produce valid result
 126     // in the single-precision floating point range, then ignore comparing with
 127     // MPFR result as MPFR can still produce valid results because of its
 128     // wider precision.
 129     if (isnan(result) || isinf(result) || libc_errno != 0)
 130       continue;
 131     ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Expm1, x,
 132                                    LIBC_NAMESPACE::expm1f(x), 0.5);
 133   }
 134 }