170 lines · cpp
1//===-- Unittests for math_extras -----------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "src/__support/integer_literals.h"10#include "src/__support/macros/config.h"11#include "src/__support/math_extras.h"12#include "src/__support/uint128.h" // UInt<128>13#include "test/UnitTest/Test.h"14 15namespace LIBC_NAMESPACE_DECL {16 17// TODO: add UInt<128> support.18using UnsignedTypesNoBigInt = testing::TypeList<19#if defined(LIBC_TYPES_HAS_INT128)20 __uint128_t,21#endif // LIBC_TYPES_HAS_INT12822 unsigned char, unsigned short, unsigned int, unsigned long,23 unsigned long long, UInt<128>>;24 25TEST(LlvmLibcBlockMathExtrasTest, mask_trailing_ones) {26 EXPECT_EQ(0_u8, (mask_leading_ones<uint8_t, 0>()));27 EXPECT_EQ(0_u8, (mask_trailing_ones<uint8_t, 0>()));28 EXPECT_EQ(0_u16, (mask_leading_ones<uint16_t, 0>()));29 EXPECT_EQ(0_u16, (mask_trailing_ones<uint16_t, 0>()));30 EXPECT_EQ(0_u32, (mask_leading_ones<uint32_t, 0>()));31 EXPECT_EQ(0_u32, (mask_trailing_ones<uint32_t, 0>()));32 EXPECT_EQ(0_u64, (mask_leading_ones<uint64_t, 0>()));33 EXPECT_EQ(0_u64, (mask_trailing_ones<uint64_t, 0>()));34 35 EXPECT_EQ(0x00000003_u32, (mask_trailing_ones<uint32_t, 2>()));36 EXPECT_EQ(0xC0000000_u32, (mask_leading_ones<uint32_t, 2>()));37 38 EXPECT_EQ(0x000007FF_u32, (mask_trailing_ones<uint32_t, 11>()));39 EXPECT_EQ(0xFFE00000_u32, (mask_leading_ones<uint32_t, 11>()));40 41 EXPECT_EQ(0xFFFFFFFF_u32, (mask_trailing_ones<uint32_t, 32>()));42 EXPECT_EQ(0xFFFFFFFF_u32, (mask_leading_ones<uint32_t, 32>()));43 EXPECT_EQ(0xFFFFFFFFFFFFFFFF_u64, (mask_trailing_ones<uint64_t, 64>()));44 EXPECT_EQ(0xFFFFFFFFFFFFFFFF_u64, (mask_leading_ones<uint64_t, 64>()));45 46 EXPECT_EQ(0x0000FFFFFFFFFFFF_u64, (mask_trailing_ones<uint64_t, 48>()));47 EXPECT_EQ(0xFFFFFFFFFFFF0000_u64, (mask_leading_ones<uint64_t, 48>()));48 49 EXPECT_EQ(0_u128, (mask_trailing_ones<UInt128, 0>()));50 EXPECT_EQ(0_u128, (mask_leading_ones<UInt128, 0>()));51 52 EXPECT_EQ(0x00000000000000007FFFFFFFFFFFFFFF_u128,53 (mask_trailing_ones<UInt128, 63>()));54 EXPECT_EQ(0xFFFFFFFFFFFFFFFE0000000000000000_u128,55 (mask_leading_ones<UInt128, 63>()));56 57 EXPECT_EQ(0x0000000000000000FFFFFFFFFFFFFFFF_u128,58 (mask_trailing_ones<UInt128, 64>()));59 EXPECT_EQ(0xFFFFFFFFFFFFFFFF0000000000000000_u128,60 (mask_leading_ones<UInt128, 64>()));61 62 EXPECT_EQ(0x0000000000000001FFFFFFFFFFFFFFFF_u128,63 (mask_trailing_ones<UInt128, 65>()));64 EXPECT_EQ(0xFFFFFFFFFFFFFFFF8000000000000000_u128,65 (mask_leading_ones<UInt128, 65>()));66 67 EXPECT_EQ(0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF_u128,68 (mask_trailing_ones<UInt128, 128>()));69 EXPECT_EQ(0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF_u128,70 (mask_leading_ones<UInt128, 128>()));71}72 73TYPED_TEST(LlvmLibcBitTest, FirstLeadingZero, UnsignedTypesNoBigInt) {74 EXPECT_EQ(first_leading_zero<T>(cpp::numeric_limits<T>::max()), 0);75 for (int i = 0U; i != cpp::numeric_limits<T>::digits; ++i) {76 auto lhs = T(~(T(1) << size_t(i)));77 EXPECT_EQ(first_leading_zero<T>(lhs), cpp::numeric_limits<T>::digits - i);78 }79}80 81TYPED_TEST(LlvmLibcBitTest, FirstLeadingOne, UnsignedTypesNoBigInt) {82 EXPECT_EQ(first_leading_one<T>(static_cast<T>(0)), 0);83 for (int i = 0U; i != cpp::numeric_limits<T>::digits; ++i) {84 auto lhs = T(T(1) << size_t(i));85 EXPECT_EQ(first_leading_one<T>(lhs), cpp::numeric_limits<T>::digits - i);86 }87}88 89TYPED_TEST(LlvmLibcBitTest, FirstTrailingZero, UnsignedTypesNoBigInt) {90 EXPECT_EQ(first_trailing_zero<T>(cpp::numeric_limits<T>::max()), 0);91 for (int i = 0U; i != cpp::numeric_limits<T>::digits; ++i) {92 auto lhs = T(~(T(1) << size_t(i)));93 EXPECT_EQ(first_trailing_zero<T>(lhs), i + 1);94 }95}96 97TYPED_TEST(LlvmLibcBitTest, FirstTrailingOne, UnsignedTypesNoBigInt) {98 EXPECT_EQ(first_trailing_one<T>(static_cast<T>(0)), 0);99 EXPECT_EQ(first_trailing_one<T>(cpp::numeric_limits<T>::max()), 1);100 for (int i = 0U; i != cpp::numeric_limits<T>::digits; ++i) {101 auto lhs = T(T(1) << size_t(i));102 EXPECT_EQ(first_trailing_one<T>(lhs), i + 1);103 }104}105 106TYPED_TEST(LlvmLibcBitTest, CountZeros, UnsignedTypesNoBigInt) {107 EXPECT_EQ(count_zeros(T(0)), cpp::numeric_limits<T>::digits);108 for (int i = 0; i != cpp::numeric_limits<T>::digits; ++i)109 EXPECT_EQ(count_zeros<T>(cpp::numeric_limits<T>::max() >> size_t(i)), i);110}111 112using UnsignedTypes = testing::TypeList<113#if defined(LIBC_TYPES_HAS_INT128)114 __uint128_t,115#endif116 unsigned char, unsigned short, unsigned int, unsigned long,117 unsigned long long>;118 119TYPED_TEST(LlvmLibcBlockMathExtrasTest, add_overflow, UnsignedTypes) {120 constexpr T ZERO = cpp::numeric_limits<T>::min();121 constexpr T ONE(1);122 constexpr T MAX = cpp::numeric_limits<T>::max();123 constexpr T BEFORE_MAX = MAX - 1;124 125 const struct {126 T lhs;127 T rhs;128 T sum;129 bool carry;130 } TESTS[] = {131 {ZERO, ONE, ONE, false}, // 0x00 + 0x01 = 0x01132 {BEFORE_MAX, ONE, MAX, false}, // 0xFE + 0x01 = 0xFF133 {MAX, ONE, ZERO, true}, // 0xFF + 0x01 = 0x00 (carry)134 {MAX, MAX, BEFORE_MAX, true}, // 0xFF + 0xFF = 0xFE (carry)135 };136 for (auto tc : TESTS) {137 T sum;138 bool carry = add_overflow<T>(tc.lhs, tc.rhs, sum);139 EXPECT_EQ(sum, tc.sum);140 EXPECT_EQ(carry, tc.carry);141 }142}143 144TYPED_TEST(LlvmLibcBlockMathExtrasTest, sub_overflow, UnsignedTypes) {145 constexpr T ZERO = cpp::numeric_limits<T>::min();146 constexpr T ONE(1);147 constexpr T MAX = cpp::numeric_limits<T>::max();148 constexpr T BEFORE_MAX = MAX - 1;149 150 const struct {151 T lhs;152 T rhs;153 T sub;154 bool carry;155 } TESTS[] = {156 {ONE, ZERO, ONE, false}, // 0x01 - 0x00 = 0x01157 {MAX, MAX, ZERO, false}, // 0xFF - 0xFF = 0x00158 {ZERO, ONE, MAX, true}, // 0x00 - 0x01 = 0xFF (carry)159 {BEFORE_MAX, MAX, MAX, true}, // 0xFE - 0xFF = 0xFF (carry)160 };161 for (auto tc : TESTS) {162 T sub;163 bool carry = sub_overflow<T>(tc.lhs, tc.rhs, sub);164 EXPECT_EQ(sub, tc.sub);165 EXPECT_EQ(carry, tc.carry);166 }167}168 169} // namespace LIBC_NAMESPACE_DECL170