| //===-- Unittests for x86 long double -------------------------------------===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "src/__support/FPUtil/FPBits.h" |
| #include "test/UnitTest/Test.h" |
| |
| #include <math.h> |
| |
| using FPBits = __llvm_libc::fputil::FPBits<long double>; |
| |
| TEST(LlvmLibcX86LongDoubleTest, is_nan) { |
| // In the nan checks below, we use the macro isnan from math.h to ensure that |
| // a number is actually a NaN. The isnan macro resolves to the compiler |
| // builtin function. Hence, matching LLVM-libc's notion of NaN with the |
| // isnan result ensures that LLVM-libc's behavior matches the compiler's |
| // behavior. |
| constexpr uint32_t COUNT = 100'000; |
| |
| FPBits bits(0.0l); |
| bits.set_unbiased_exponent(FPBits::MAX_EXPONENT); |
| for (unsigned int i = 0; i < COUNT; ++i) { |
| // If exponent has the max value and the implicit bit is 0, |
| // then the number is a NaN for all values of mantissa. |
| bits.set_mantissa(i); |
| long double nan = bits; |
| ASSERT_NE(static_cast<int>(isnan(nan)), 0); |
| ASSERT_TRUE(bits.is_nan()); |
| } |
| |
| bits.set_implicit_bit(1); |
| for (unsigned int i = 1; i < COUNT; ++i) { |
| // If exponent has the max value and the implicit bit is 1, |
| // then the number is a NaN for all non-zero values of mantissa. |
| // Note the initial value of |i| of 1 to avoid a zero mantissa. |
| bits.set_mantissa(i); |
| long double nan = bits; |
| ASSERT_NE(static_cast<int>(isnan(nan)), 0); |
| ASSERT_TRUE(bits.is_nan()); |
| } |
| |
| bits.set_unbiased_exponent(1); |
| bits.set_implicit_bit(0); |
| for (unsigned int i = 0; i < COUNT; ++i) { |
| // If exponent is non-zero and also not max, and the implicit bit is 0, |
| // then the number is a NaN for all values of mantissa. |
| bits.set_mantissa(i); |
| long double nan = bits; |
| ASSERT_NE(static_cast<int>(isnan(nan)), 0); |
| ASSERT_TRUE(bits.is_nan()); |
| } |
| |
| bits.set_unbiased_exponent(1); |
| bits.set_implicit_bit(1); |
| for (unsigned int i = 0; i < COUNT; ++i) { |
| // If exponent is non-zero and also not max, and the implicit bit is 1, |
| // then the number is normal value for all values of mantissa. |
| bits.set_mantissa(i); |
| long double valid = bits; |
| ASSERT_EQ(static_cast<int>(isnan(valid)), 0); |
| ASSERT_FALSE(bits.is_nan()); |
| } |
| |
| bits.set_unbiased_exponent(0); |
| bits.set_implicit_bit(1); |
| for (unsigned int i = 0; i < COUNT; ++i) { |
| // If exponent is zero, then the number is a valid but denormal value. |
| bits.set_mantissa(i); |
| long double valid = bits; |
| ASSERT_EQ(static_cast<int>(isnan(valid)), 0); |
| ASSERT_FALSE(bits.is_nan()); |
| } |
| |
| bits.set_unbiased_exponent(0); |
| bits.set_implicit_bit(0); |
| for (unsigned int i = 0; i < COUNT; ++i) { |
| // If exponent is zero, then the number is a valid but denormal value. |
| bits.set_mantissa(i); |
| long double valid = bits; |
| ASSERT_EQ(static_cast<int>(isnan(valid)), 0); |
| ASSERT_FALSE(bits.is_nan()); |
| } |
| } |