//===-- Utility class to test different flavors of [l|ll]round --*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIBC_TEST_SRC_MATH_ROUNDTOINTEGERTEST_H
#define LLVM_LIBC_TEST_SRC_MATH_ROUNDTOINTEGERTEST_H
#include "src/__support/CPP/algorithm.h"
#include "src/__support/FPUtil/FEnvImpl.h"
#include "src/__support/FPUtil/FPBits.h"
#include "src/__support/macros/properties/architectures.h"
#include "test/UnitTest/FEnvSafeTest.h"
#include "test/UnitTest/FPMatcher.h"
#include "test/UnitTest/Test.h"
#include "utils/MPFRWrapper/MPFRUtils.h"
#include "hdr/math_macros.h"
namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
using LIBC_NAMESPACE::Sign;
static constexpr int ROUNDING_MODES[4] = {FE_UPWARD, FE_DOWNWARD, FE_TOWARDZERO,
FE_TONEAREST};
template <typename FloatType, typename IntType, bool TestModes = false>
class RoundToIntegerTestTemplate
: public LIBC_NAMESPACE::testing::FEnvSafeTest {
public:
typedef IntType (*RoundToIntegerFunc)(FloatType);
private:
using FPBits = LIBC_NAMESPACE::fputil::FPBits<FloatType>;
using StorageType = typename FPBits::StorageType;
const FloatType zero = FPBits::zero().get_val();
const FloatType neg_zero = FPBits::zero(Sign::NEG).get_val();
const FloatType inf = FPBits::inf().get_val();
const FloatType neg_inf = FPBits::inf(Sign::NEG).get_val();
const FloatType nan = FPBits::quiet_nan().get_val();
static constexpr StorageType MAX_NORMAL = FPBits::max_normal().uintval();
static constexpr StorageType MIN_NORMAL = FPBits::min_normal().uintval();
static constexpr StorageType MAX_SUBNORMAL =
FPBits::max_subnormal().uintval();
static constexpr StorageType MIN_SUBNORMAL =
FPBits::min_subnormal().uintval();
static constexpr IntType INTEGER_MIN = IntType(1)
<< (sizeof(IntType) * 8 - 1);
static constexpr IntType INTEGER_MAX = -(INTEGER_MIN + 1);
void test_one_input(RoundToIntegerFunc func, FloatType input,
IntType expected, bool expectError) {
LIBC_NAMESPACE::libc_errno = 0;
LIBC_NAMESPACE::fputil::clear_except(FE_ALL_EXCEPT);
ASSERT_EQ(func(input), expected);
// TODO: Handle the !expectError case. It used to expect
// 0 for errno and exceptions, but this doesn't hold for
// all math functions using RoundToInteger test:
// https://github.com/llvm/llvm-project/pull/88816
if (expectError) {
ASSERT_FP_EXCEPTION(FE_INVALID);
ASSERT_MATH_ERRNO(EDOM);
}
}
static inline mpfr::RoundingMode to_mpfr_rounding_mode(int mode) {
switch (mode) {
case FE_UPWARD:
return mpfr::RoundingMode::Upward;
case FE_DOWNWARD:
return mpfr::RoundingMode::Downward;
case FE_TOWARDZERO:
return mpfr::RoundingMode::TowardZero;
case FE_TONEAREST:
return mpfr::RoundingMode::Nearest;
default:
__builtin_unreachable();
}
}
public:
void SetUp() override {
LIBC_NAMESPACE::testing::FEnvSafeTest::SetUp();
if (math_errhandling & MATH_ERREXCEPT) {
// We will disable all exceptions so that the test will not
// crash with SIGFPE. We can still use fetestexcept to check
// if the appropriate flag was raised.
LIBC_NAMESPACE::fputil::disable_except(FE_ALL_EXCEPT);
}
}
void do_infinity_and_na_n_test(RoundToIntegerFunc func) {
test_one_input(func, inf, INTEGER_MAX, true);
test_one_input(func, neg_inf, INTEGER_MIN, true);
// This is currently never enabled, the
// LLVM_LIBC_IMPLEMENTATION_DEFINED_TEST_BEHAVIOR CMake option in
// libc/CMakeLists.txt is not forwarded to C++.
#if LIBC_COPT_IMPLEMENTATION_DEFINED_TEST_BEHAVIOR
// Result is not well-defined, we always returns INTEGER_MAX
test_one_input(func, nan, INTEGER_MAX, true);
#endif // LIBC_COPT_IMPLEMENTATION_DEFINED_TEST_BEHAVIOR
}
void testInfinityAndNaN(RoundToIntegerFunc func) {
if (TestModes) {
for (int mode : ROUNDING_MODES) {
LIBC_NAMESPACE::fputil::set_round(mode);
do_infinity_and_na_n_test(func);
}
} else {
do_infinity_and_na_n_test(func);
}
}
void do_round_numbers_test(RoundToIntegerFunc func) {
test_one_input(func, zero, IntType(0), false);
test_one_input(func, neg_zero, IntType(0), false);
test_one_input(func, FloatType(1.0), IntType(1), false);
test_one_input(func, FloatType(-1.0), IntType(-1), false);
test_one_input(func, FloatType(10.0), IntType(10), false);
test_one_input(func, FloatType(-10.0), IntType(-10), false);
test_one_input(func, FloatType(1234.0), IntType(1234), false);
test_one_input(func, FloatType(-1234.0), IntType(-1234), false);
// The rest of this function compares with an equivalent MPFR function
// which rounds floating point numbers to long values. There is no MPFR
// function to round to long long or wider integer values. So, we will
// the remaining tests only if the width of IntType less than equal to that
// of long.
if (sizeof(IntType) > sizeof(long))
return;
constexpr int EXPONENT_LIMIT = sizeof(IntType) * 8 - 1;
constexpr int BIASED_EXPONENT_LIMIT = EXPONENT_LIMIT + FPBits::EXP_BIAS;
if (BIASED_EXPONENT_LIMIT > FPBits::MAX_BIASED_EXPONENT)
return;
// We start with 1.0 so that the implicit bit for x86 long doubles
// is set.
FPBits bits(FloatType(1.0));
bits.set_biased_exponent(BIASED_EXPONENT_LIMIT);
bits.set_sign(Sign::NEG);
bits.set_mantissa(0);
FloatType x = bits.get_val();
long mpfr_result;
bool erangeflag = mpfr::round_to_long(x, mpfr_result);
ASSERT_FALSE(erangeflag);
test_one_input(func, x, mpfr_result, false);
}
void testRoundNumbers(RoundToIntegerFunc func) {
if (TestModes) {
for (int mode : ROUNDING_MODES) {
LIBC_NAMESPACE::fputil::set_round(mode);
do_round_numbers_test(func);
}
} else {
do_round_numbers_test(func);
}
}
void do_fractions_test(RoundToIntegerFunc func, int mode) {
constexpr FloatType FRACTIONS[] = {
FloatType(0.5), FloatType(-0.5), FloatType(0.115),
FloatType(-0.115), FloatType(0.715), FloatType(-0.715),
};
for (FloatType x : FRACTIONS) {
long mpfr_long_result;
bool erangeflag;
if (TestModes)
erangeflag = mpfr::round_to_long(x, to_mpfr_rounding_mode(mode),
mpfr_long_result);
else
erangeflag = mpfr::round_to_long(x, mpfr_long_result);
ASSERT_FALSE(erangeflag);
IntType mpfr_result = mpfr_long_result;
test_one_input(func, x, mpfr_result, false);
}
}
void testFractions(RoundToIntegerFunc func) {
if (TestModes) {
for (int mode : ROUNDING_MODES) {
LIBC_NAMESPACE::fputil::set_round(mode);
do_fractions_test(func, mode);
}
} else {
// Passing 0 for mode has no effect as it is not used in doFractionsTest
// when `TestModes` is false;
do_fractions_test(func, 0);
}
}
void testIntegerOverflow(RoundToIntegerFunc func) {
// This function compares with an equivalent MPFR function which rounds
// floating point numbers to long values. There is no MPFR function to
// round to long long or wider integer values. So, we will peform the
// comparisons in this function only if the width of IntType less than equal
// to that of long.
if (sizeof(IntType) > sizeof(long))
return;
constexpr int EXPONENT_LIMIT = sizeof(IntType) * 8 - 1;
constexpr int BIASED_EXPONENT_LIMIT = EXPONENT_LIMIT + FPBits::EXP_BIAS;
if (BIASED_EXPONENT_LIMIT > FPBits::MAX_BIASED_EXPONENT)
return;
// We start with 1.0 so that the implicit bit for x86 long doubles
// is set.
FPBits bits(FloatType(1.0));
bits.set_biased_exponent(BIASED_EXPONENT_LIMIT);
bits.set_sign(Sign::NEG);
bits.set_mantissa(FPBits::FRACTION_MASK);
FloatType x = bits.get_val();
if (TestModes) {
for (int m : ROUNDING_MODES) {
LIBC_NAMESPACE::fputil::set_round(m);
long mpfr_long_result;
bool erangeflag =
mpfr::round_to_long(x, to_mpfr_rounding_mode(m), mpfr_long_result);
ASSERT_TRUE(erangeflag);
test_one_input(func, x, INTEGER_MIN, true);
}
} else {
long mpfr_long_result;
bool erangeflag = mpfr::round_to_long(x, mpfr_long_result);
ASSERT_TRUE(erangeflag);
test_one_input(func, x, INTEGER_MIN, true);
}
}
void testSubnormalRange(RoundToIntegerFunc func) {
constexpr int COUNT = 1'000'001;
constexpr StorageType STEP = LIBC_NAMESPACE::cpp::max(
static_cast<StorageType>((MAX_SUBNORMAL - MIN_SUBNORMAL) / COUNT),
StorageType(1));
for (StorageType i = MIN_SUBNORMAL; i <= MAX_SUBNORMAL; i += STEP) {
FloatType x = FPBits(i).get_val();
if (x == FloatType(0.0))
continue;
// All subnormal numbers should round to zero.
if (TestModes) {
if (x > 0) {
LIBC_NAMESPACE::fputil::set_round(FE_UPWARD);
test_one_input(func, x, IntType(1), false);
LIBC_NAMESPACE::fputil::set_round(FE_DOWNWARD);
test_one_input(func, x, IntType(0), false);
LIBC_NAMESPACE::fputil::set_round(FE_TOWARDZERO);
test_one_input(func, x, IntType(0), false);
LIBC_NAMESPACE::fputil::set_round(FE_TONEAREST);
test_one_input(func, x, IntType(0), false);
} else {
LIBC_NAMESPACE::fputil::set_round(FE_UPWARD);
test_one_input(func, x, IntType(0), false);
LIBC_NAMESPACE::fputil::set_round(FE_DOWNWARD);
test_one_input(func, x, IntType(-1), false);
LIBC_NAMESPACE::fputil::set_round(FE_TOWARDZERO);
test_one_input(func, x, IntType(0), false);
LIBC_NAMESPACE::fputil::set_round(FE_TONEAREST);
test_one_input(func, x, IntType(0), false);
}
} else {
test_one_input(func, x, 0L, false);
}
}
}
void testNormalRange(RoundToIntegerFunc func) {
// This function compares with an equivalent MPFR function which rounds
// floating point numbers to long values. There is no MPFR function to
// round to long long or wider integer values. So, we will peform the
// comparisons in this function only if the width of IntType less than equal
// to that of long.
if (sizeof(IntType) > sizeof(long))
return;
constexpr int COUNT = 1'000'001;
constexpr StorageType STEP = LIBC_NAMESPACE::cpp::max(
static_cast<StorageType>((MAX_NORMAL - MIN_NORMAL) / COUNT),
StorageType(1));
for (StorageType i = MIN_NORMAL; i <= MAX_NORMAL; i += STEP) {
FPBits xbits(i);
FloatType x = xbits.get_val();
// In normal range on x86 platforms, the long double implicit 1 bit can be
// zero making the numbers NaN. We will skip them.
if (xbits.is_nan())
continue;
if (TestModes) {
for (int m : ROUNDING_MODES) {
long mpfr_long_result;
bool erangeflag = mpfr::round_to_long(x, to_mpfr_rounding_mode(m),
mpfr_long_result);
IntType mpfr_result = mpfr_long_result;
LIBC_NAMESPACE::fputil::set_round(m);
if (erangeflag)
test_one_input(func, x, x > 0 ? INTEGER_MAX : INTEGER_MIN, true);
else
test_one_input(func, x, mpfr_result, false);
}
} else {
long mpfr_long_result;
bool erangeflag = mpfr::round_to_long(x, mpfr_long_result);
IntType mpfr_result = mpfr_long_result;
if (erangeflag)
test_one_input(func, x, x > 0 ? INTEGER_MAX : INTEGER_MIN, true);
else
test_one_input(func, x, mpfr_result, false);
}
}
}
};
#define LIST_ROUND_TO_INTEGER_TESTS_HELPER(FloatType, IntType, func, \
TestModes) \
using LlvmLibcRoundToIntegerTest = \
RoundToIntegerTestTemplate<FloatType, IntType, TestModes>; \
TEST_F(LlvmLibcRoundToIntegerTest, InfinityAndNaN) { \
testInfinityAndNaN(&func); \
} \
TEST_F(LlvmLibcRoundToIntegerTest, RoundNumbers) { \
testRoundNumbers(&func); \
} \
TEST_F(LlvmLibcRoundToIntegerTest, Fractions) { testFractions(&func); } \
TEST_F(LlvmLibcRoundToIntegerTest, IntegerOverflow) { \
testIntegerOverflow(&func); \
} \
TEST_F(LlvmLibcRoundToIntegerTest, SubnormalRange) { \
testSubnormalRange(&func); \
} \
TEST_F(LlvmLibcRoundToIntegerTest, NormalRange) { testNormalRange(&func); }
#define LIST_ROUND_TO_INTEGER_TESTS(FloatType, IntType, func) \
LIST_ROUND_TO_INTEGER_TESTS_HELPER(FloatType, IntType, func, false)
#define LIST_ROUND_TO_INTEGER_TESTS_WITH_MODES(FloatType, IntType, func) \
LIST_ROUND_TO_INTEGER_TESTS_HELPER(FloatType, IntType, func, true)
#endif // LLVM_LIBC_TEST_SRC_MATH_ROUNDTOINTEGERTEST_H
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