libc/test/src/math/pow_test.cpp

   1 //===-- Unittests for pow -------------------------------------------------===//
   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/math/pow.h"
  10 #include "test/UnitTest/FPMatcher.h"
  11 #include "test/UnitTest/Test.h"
  12 #include "utils/MPFRWrapper/MPFRUtils.h"
  13
  14 using LlvmLibcPowTest = LIBC_NAMESPACE::testing::FPTest<double>;
  15 using LIBC_NAMESPACE::testing::tlog;
  16
  17 namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
  18
  19 TEST_F(LlvmLibcPowTest, TrickyInputs) {
  20   constexpr mpfr::BinaryInput<double> INPUTS[] = {
  21       {0x1.0853408534085p-2, 0x1.0d148e03bcba8p-1},
  22       {0x1.65fbd65fbd657p-1, 0x1.f10d148e03bb6p+1},
  23       {0x1.c046a084d2e12p-1, 0x1.1f9p+12},
  24       {0x1.ae37ed1670326p-1, 0x1.f967df66a202p-1},
  25       {0x1.ffffffffffffcp-1, 0x1.fffffffffffffp-2},
  26       {0x1.f558a88a8aadep-1, 0x1.88ap+12},
  27       {0x1.e84d32731e593p-1, 0x1.2cb8p+13},
  28       {0x1.ffffffffffffcp-1, 0x1.fffffffffffffp-2},
  29   };
  30
  31   for (auto input : INPUTS) {
  32     double x = input.x;
  33     double y = input.y;
  34     EXPECT_MPFR_MATCH(mpfr::Operation::Pow, input, LIBC_NAMESPACE::pow(x, y),
  35                       1.5);
  36   }
  37 }
  38
  39 TEST_F(LlvmLibcPowTest, InFloatRange) {
  40   constexpr uint64_t X_COUNT = 123;
  41   constexpr uint64_t X_START = FPBits(0.25).uintval();
  42   constexpr uint64_t X_STOP = FPBits(4.0).uintval();
  43   constexpr uint64_t X_STEP = (X_STOP - X_START) / X_COUNT;
  44
  45   constexpr uint64_t Y_COUNT = 137;
  46   constexpr uint64_t Y_START = FPBits(0.25).uintval();
  47   constexpr uint64_t Y_STOP = FPBits(4.0).uintval();
  48   constexpr uint64_t Y_STEP = (Y_STOP - Y_START) / Y_COUNT;
  49
  50   auto test = [&](mpfr::RoundingMode rounding_mode) {
  51     mpfr::ForceRoundingMode __r(rounding_mode);
  52     if (!__r.success)
  53       return;
  54
  55     uint64_t fails = 0;
  56     uint64_t count = 0;
  57     uint64_t cc = 0;
  58     double mx = 0.0, my = 0.0, mr = 0.0;
  59     double tol = 1.5;
  60
  61     for (uint64_t i = 0, v = X_START; i <= X_COUNT; ++i, v += X_STEP) {
  62       double x = FPBits(v).get_val();
  63       if (FPBits(x).is_inf_or_nan() || x < 0.0)
  64         continue;
  65
  66       for (uint64_t j = 0, w = Y_START; j <= Y_COUNT; ++j, w += Y_STEP) {
  67         double y = FPBits(w).get_val();
  68         if (FPBits(y).is_inf_or_nan())
  69           continue;
  70
  71         double result = LIBC_NAMESPACE::pow(x, y);
  72         ++cc;
  73         if (FPBits(result).is_inf_or_nan())
  74           continue;
  75
  76         ++count;
  77         mpfr::BinaryInput<double> inputs{x, y};
  78
  79         if (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Pow, inputs,
  80                                                result, 1.5, rounding_mode)) {
  81           ++fails;
  82           while (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(
  83               mpfr::Operation::Pow, inputs, result, tol, rounding_mode)) {
  84             mx = x;
  85             my = y;
  86             mr = result;
  87
  88             if (tol > 1000.0)
  89               break;
  90
  91             tol *= 2.0;
  92           }
  93         }
  94       }
  95     }
  96     if (fails || (count < cc)) {
  97       tlog << " Pow failed: " << fails << "/" << count << "/" << cc
  98            << " tests.\n"
  99            << "   Max ULPs is at most: " << static_cast<uint64_t>(tol) << ".\n";
 100     }
 101     if (fails) {
 102       mpfr::BinaryInput<double> inputs{mx, my};
 103       EXPECT_MPFR_MATCH(mpfr::Operation::Pow, inputs, mr, 1.5, rounding_mode);
 104     }
 105   };
 106
 107   tlog << " Test Rounding To Nearest...\n";
 108   test(mpfr::RoundingMode::Nearest);
 109
 110   tlog << " Test Rounding Downward...\n";
 111   test(mpfr::RoundingMode::Downward);
 112
 113   tlog << " Test Rounding Upward...\n";
 114   test(mpfr::RoundingMode::Upward);
 115
 116   tlog << " Test Rounding Toward Zero...\n";
 117   test(mpfr::RoundingMode::TowardZero);
 118 }