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/math/expm1f.h"
  11 #include "test/UnitTest/FPMatcher.h"
  12 #include "test/UnitTest/Test.h"
  13 #include "utils/MPFRWrapper/MPFRUtils.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
  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
  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
  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.
  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
 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 }