libc/test/src/stdfix/RoundTest.h

   1 //===-- Utility class to test fixed-point round -----------------*- C++ -*-===//
   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 "test/UnitTest/Test.h"
  10
  11 #include "src/__support/fixed_point/fx_rep.h"
  12
  13 template <typename T> class RoundTest : public LIBC_NAMESPACE::testing::Test {
  14
  15   using FXRep = LIBC_NAMESPACE::fixed_point::FXRep<T>;
  16   static constexpr T zero = FXRep::ZERO();
  17   static constexpr T min = FXRep::MIN();
  18   static constexpr T max = FXRep::MAX();
  19   static constexpr T half = static_cast<T>(0.5);
  20   static constexpr T neg_half = static_cast<T>(-0.5);
  21   static constexpr T one =
  22       (FXRep::INTEGRAL_LEN > 0) ? static_cast<T>(1) : FXRep::MAX();
  23   static constexpr T neg_one = static_cast<T>(-1);
  24   static constexpr T eps = FXRep::EPS();
  25
  26 public:
  27   typedef T (*RoundFunc)(T, int);
  28
  29   void testSpecialNumbers(RoundFunc func) {
  30     EXPECT_EQ(zero, func(zero, FXRep::FRACTION_LEN - 5));
  31     EXPECT_EQ(min, func(min, 0));
  32     EXPECT_EQ(max, func(max, FXRep::FRACTION_LEN));
  33
  34     EXPECT_EQ(one, func(half, 0));
  35     EXPECT_EQ(half, func(half, 1));
  36     EXPECT_EQ(half, func(half, FXRep::FRACTION_LEN));
  37     EXPECT_EQ(one, func(half + eps, 0));
  38     EXPECT_EQ(half, func(half + eps, 1));
  39     EXPECT_EQ(half, func(half + eps, 2));
  40     EXPECT_EQ(zero, func(half - eps, 0));
  41     EXPECT_EQ(half, func(half - eps, 1));
  42     EXPECT_EQ(half, func(half - eps, 2));
  43     EXPECT_EQ(eps, func(eps, FXRep::FRACTION_LEN + 10));
  44     EXPECT_EQ(eps << 1, func(eps, FXRep::FRACTION_LEN - 1));
  45     EXPECT_EQ(zero, func(eps, FXRep::FRACTION_LEN - 2));
  46
  47     if constexpr (FXRep::SIGN_LEN) {
  48       EXPECT_EQ(zero, func(neg_half, 0));
  49       EXPECT_EQ(neg_half, func(neg_half, 1));
  50       EXPECT_EQ(neg_half, func(neg_half, 3));
  51       EXPECT_EQ(zero, func(neg_half + eps, 0));
  52       EXPECT_EQ(neg_half, func(neg_half + eps, 1));
  53       EXPECT_EQ(neg_half, func(neg_half + eps, 2));
  54       EXPECT_EQ(neg_one, func(neg_half - eps, 0));
  55       EXPECT_EQ(neg_half, func(neg_half - eps, 1));
  56       EXPECT_EQ(neg_half, func(neg_half - eps, 2));
  57       EXPECT_EQ(-eps, func(-eps, FXRep::FRACTION_LEN + 10));
  58     }
  59   }
  60 };
  61
  62 #define LIST_ROUND_TESTS(T, func)                                              \
  63   using LlvmLibcRoundTest = RoundTest<T>;                                      \
  64   TEST_F(LlvmLibcRoundTest, SpecialNumbers) { testSpecialNumbers(&func); }     \
  65   static_assert(true, "Require semicolon.")