path: root/unittests/ADT/APFloatTest.cpp

//===- llvm/unittest/ADT/APFloat.cpp - APFloat unit tests ---------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APSInt.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/raw_ostream.h"
#include "gtest/gtest.h"
#include <ostream>
#include <string>

using namespace llvm;

static double convertToDoubleFromString(const char *Str) {
  llvm::APFloat F(0.0);
  F.convertFromString(Str, llvm::APFloat::rmNearestTiesToEven);
  return F.convertToDouble();
}

static std::string convertToString(double d, unsigned Prec, unsigned Pad) {
  llvm::SmallVector<char, 100> Buffer;
  llvm::APFloat F(d);
  F.toString(Buffer, Prec, Pad);
  return std::string(Buffer.data(), Buffer.size());
}

namespace {

TEST(APFloatTest, FMA) {
  APFloat::roundingMode rdmd = APFloat::rmNearestTiesToEven;

  {
    APFloat f1(14.5f);
    APFloat f2(-14.5f);
    APFloat f3(225.0f);
    f1.fusedMultiplyAdd(f2, f3, APFloat::rmNearestTiesToEven);
    EXPECT_EQ(14.75f, f1.convertToFloat());
  }

  {
    APFloat Val2(2.0f);
    APFloat f1((float)1.17549435e-38F);
    APFloat f2((float)1.17549435e-38F);
    f1.divide(Val2, rdmd);
    f2.divide(Val2, rdmd);
    APFloat f3(12.0f);
    f1.fusedMultiplyAdd(f2, f3, APFloat::rmNearestTiesToEven);
    EXPECT_EQ(12.0f, f1.convertToFloat());
  }
}

TEST(APFloatTest, Denormal) {
  APFloat::roundingMode rdmd = APFloat::rmNearestTiesToEven;

  // Test single precision
  {
    const char *MinNormalStr = "1.17549435082228750797e-38";
    EXPECT_FALSE(APFloat(APFloat::IEEEsingle, MinNormalStr).isDenormal());
    EXPECT_FALSE(APFloat(APFloat::IEEEsingle, 0.0).isDenormal());

    APFloat Val2(APFloat::IEEEsingle, 2.0e0);
    APFloat T(APFloat::IEEEsingle, MinNormalStr);
    T.divide(Val2, rdmd);
    EXPECT_TRUE(T.isDenormal());
  }

  // Test double precision
  {
    const char *MinNormalStr = "2.22507385850720138309e-308";
    EXPECT_FALSE(APFloat(APFloat::IEEEdouble, MinNormalStr).isDenormal());
    EXPECT_FALSE(APFloat(APFloat::IEEEdouble, 0.0).isDenormal());

    APFloat Val2(APFloat::IEEEdouble, 2.0e0);
    APFloat T(APFloat::IEEEdouble, MinNormalStr);
    T.divide(Val2, rdmd);
    EXPECT_TRUE(T.isDenormal());
  }

  // Test Intel double-ext
  {
    const char *MinNormalStr = "3.36210314311209350626e-4932";
    EXPECT_FALSE(APFloat(APFloat::x87DoubleExtended, MinNormalStr).isDenormal());
    EXPECT_FALSE(APFloat(APFloat::x87DoubleExtended, 0.0).isDenormal());

    APFloat Val2(APFloat::x87DoubleExtended, 2.0e0);
    APFloat T(APFloat::x87DoubleExtended, MinNormalStr);
    T.divide(Val2, rdmd);
    EXPECT_TRUE(T.isDenormal());
  }

  // Test quadruple precision
  {
    const char *MinNormalStr = "3.36210314311209350626267781732175260e-4932";
    EXPECT_FALSE(APFloat(APFloat::IEEEquad, MinNormalStr).isDenormal());
    EXPECT_FALSE(APFloat(APFloat::IEEEquad, 0.0).isDenormal());

    APFloat Val2(APFloat::IEEEquad, 2.0e0);
    APFloat T(APFloat::IEEEquad, MinNormalStr);
    T.divide(Val2, rdmd);
    EXPECT_TRUE(T.isDenormal());
  }
}

TEST(APFloatTest, Zero) {
  EXPECT_EQ(0.0f,  APFloat(0.0f).convertToFloat());
  EXPECT_EQ(-0.0f, APFloat(-0.0f).convertToFloat());
  EXPECT_TRUE(APFloat(-0.0f).isNegative());

  EXPECT_EQ(0.0,  APFloat(0.0).convertToDouble());
  EXPECT_EQ(-0.0, APFloat(-0.0).convertToDouble());
  EXPECT_TRUE(APFloat(-0.0).isNegative());
}

TEST(APFloatTest, fromZeroDecimalString) {
  EXPECT_EQ( 0.0, APFloat(APFloat::IEEEdouble,  "0").convertToDouble());
  EXPECT_EQ(+0.0, APFloat(APFloat::IEEEdouble, "+0").convertToDouble());
  EXPECT_EQ(-0.0, APFloat(APFloat::IEEEdouble, "-0").convertToDouble());

  EXPECT_EQ( 0.0, APFloat(APFloat::IEEEdouble,  "0.").convertToDouble());
  EXPECT_EQ(+0.0, APFloat(APFloat::IEEEdouble, "+0.").convertToDouble());
  EXPECT_EQ(-0.0, APFloat(APFloat::IEEEdouble, "-0.").convertToDouble());

  EXPECT_EQ( 0.0, APFloat(APFloat::IEEEdouble,  ".0").convertToDouble());
  EXPECT_EQ(+0.0, APFloat(APFloat::IEEEdouble, "+.0").convertToDouble());
  EXPECT_EQ(-0.0, APFloat(APFloat::IEEEdouble, "-.0").convertToDouble());

  EXPECT_EQ( 0.0, APFloat(APFloat::