1 //===- unittests/Support/MathExtrasTest.cpp - math utils tests ------------===// 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 "llvm/Support/MathExtras.h" 10 #include "gtest/gtest.h" 11 12 using namespace llvm; 13 14 namespace { 15 16 TEST(MathExtras, countTrailingZeros) { 17 uint8_t Z8 = 0; 18 uint16_t Z16 = 0; 19 uint32_t Z32 = 0; 20 uint64_t Z64 = 0; 21 EXPECT_EQ(8u, countTrailingZeros(Z8)); 22 EXPECT_EQ(16u, countTrailingZeros(Z16)); 23 EXPECT_EQ(32u, countTrailingZeros(Z32)); 24 EXPECT_EQ(64u, countTrailingZeros(Z64)); 25 26 uint8_t NZ8 = 42; 27 uint16_t NZ16 = 42; 28 uint32_t NZ32 = 42; 29 uint64_t NZ64 = 42; 30 EXPECT_EQ(1u, countTrailingZeros(NZ8)); 31 EXPECT_EQ(1u, countTrailingZeros(NZ16)); 32 EXPECT_EQ(1u, countTrailingZeros(NZ32)); 33 EXPECT_EQ(1u, countTrailingZeros(NZ64)); 34 } 35 36 TEST(MathExtras, countLeadingZeros) { 37 uint8_t Z8 = 0; 38 uint16_t Z16 = 0; 39 uint32_t Z32 = 0; 40 uint64_t Z64 = 0; 41 EXPECT_EQ(8u, countLeadingZeros(Z8)); 42 EXPECT_EQ(16u, countLeadingZeros(Z16)); 43 EXPECT_EQ(32u, countLeadingZeros(Z32)); 44 EXPECT_EQ(64u, countLeadingZeros(Z64)); 45 46 uint8_t NZ8 = 42; 47 uint16_t NZ16 = 42; 48 uint32_t NZ32 = 42; 49 uint64_t NZ64 = 42; 50 EXPECT_EQ(2u, countLeadingZeros(NZ8)); 51 EXPECT_EQ(10u, countLeadingZeros(NZ16)); 52 EXPECT_EQ(26u, countLeadingZeros(NZ32)); 53 EXPECT_EQ(58u, countLeadingZeros(NZ64)); 54 55 EXPECT_EQ(8u, countLeadingZeros(0x00F000FFu)); 56 EXPECT_EQ(8u, countLeadingZeros(0x00F12345u)); 57 for (unsigned i = 0; i <= 30; ++i) { 58 EXPECT_EQ(31 - i, countLeadingZeros(1u << i)); 59 } 60 61 EXPECT_EQ(8u, countLeadingZeros(0x00F1234500F12345ULL)); 62 EXPECT_EQ(1u, countLeadingZeros(1ULL << 62)); 63 for (unsigned i = 0; i <= 62; ++i) { 64 EXPECT_EQ(63 - i, countLeadingZeros(1ULL << i)); 65 } 66 } 67 68 TEST(MathExtras, onesMask) { 69 EXPECT_EQ(0U, maskLeadingOnes<uint8_t>(0)); 70 EXPECT_EQ(0U, maskTrailingOnes<uint8_t>(0)); 71 EXPECT_EQ(0U, maskLeadingOnes<uint16_t>(0)); 72 EXPECT_EQ(0U, maskTrailingOnes<uint16_t>(0)); 73 EXPECT_EQ(0U, maskLeadingOnes<uint32_t>(0)); 74 EXPECT_EQ(0U, maskTrailingOnes<uint32_t>(0)); 75 EXPECT_EQ(0U, maskLeadingOnes<uint64_t>(0)); 76 EXPECT_EQ(0U, maskTrailingOnes<uint64_t>(0)); 77 78 EXPECT_EQ(0x00000003U, maskTrailingOnes<uint32_t>(2U)); 79 EXPECT_EQ(0xC0000000U, maskLeadingOnes<uint32_t>(2U)); 80 81 EXPECT_EQ(0x000007FFU, maskTrailingOnes<uint32_t>(11U)); 82 EXPECT_EQ(0xFFE00000U, maskLeadingOnes<uint32_t>(11U)); 83 84 EXPECT_EQ(0xFFFFFFFFU, maskTrailingOnes<uint32_t>(32U)); 85 EXPECT_EQ(0xFFFFFFFFU, maskLeadingOnes<uint32_t>(32U)); 86 EXPECT_EQ(0xFFFFFFFFFFFFFFFFULL, maskTrailingOnes<uint64_t>(64U)); 87 EXPECT_EQ(0xFFFFFFFFFFFFFFFFULL, maskLeadingOnes<uint64_t>(64U)); 88 89 EXPECT_EQ(0x0000FFFFFFFFFFFFULL, maskTrailingOnes<uint64_t>(48U)); 90 EXPECT_EQ(0xFFFFFFFFFFFF0000ULL, maskLeadingOnes<uint64_t>(48U)); 91 } 92 93 TEST(MathExtras, findFirstSet) { 94 uint8_t Z8 = 0; 95 uint16_t Z16 = 0; 96 uint32_t Z32 = 0; 97 uint64_t Z64 = 0; 98 EXPECT_EQ(0xFFULL, findFirstSet(Z8)); 99 EXPECT_EQ(0xFFFFULL, findFirstSet(Z16)); 100 EXPECT_EQ(0xFFFFFFFFULL, findFirstSet(Z32)); 101 EXPECT_EQ(0xFFFFFFFFFFFFFFFFULL, findFirstSet(Z64)); 102 103 uint8_t NZ8 = 42; 104 uint16_t NZ16 = 42; 105 uint32_t NZ32 = 42; 106 uint64_t NZ64 = 42; 107 EXPECT_EQ(1u, findFirstSet(NZ8)); 108 EXPECT_EQ(1u, findFirstSet(NZ16)); 109 EXPECT_EQ(1u, findFirstSet(NZ32)); 110 EXPECT_EQ(1u, findFirstSet(NZ64)); 111 } 112 113 TEST(MathExtras, findLastSet) { 114 uint8_t Z8 = 0; 115 uint16_t Z16 = 0; 116 uint32_t Z32 = 0; 117 uint64_t Z64 = 0; 118 EXPECT_EQ(0xFFULL, findLastSet(Z8)); 119 EXPECT_EQ(0xFFFFULL, findLastSet(Z16)); 120 EXPECT_EQ(0xFFFFFFFFULL, findLastSet(Z32)); 121 EXPECT_EQ(0xFFFFFFFFFFFFFFFFULL, findLastSet(Z64)); 122 123 uint8_t NZ8 = 42; 124 uint16_t NZ16 = 42; 125 uint32_t NZ32 = 42; 126 uint64_t NZ64 = 42; 127 EXPECT_EQ(5u, findLastSet(NZ8)); 128 EXPECT_EQ(5u, findLastSet(NZ16)); 129 EXPECT_EQ(5u, findLastSet(NZ32)); 130 EXPECT_EQ(5u, findLastSet(NZ64)); 131 } 132 133 TEST(MathExtras, isIntN) { 134 EXPECT_TRUE(isIntN(16, 32767)); 135 EXPECT_FALSE(isIntN(16, 32768)); 136 } 137 138 TEST(MathExtras, isUIntN) { 139 EXPECT_TRUE(isUIntN(16, 65535)); 140 EXPECT_FALSE(isUIntN(16, 65536)); 141 EXPECT_TRUE(isUIntN(1, 0)); 142 EXPECT_TRUE(isUIntN(6, 63)); 143 } 144 145 TEST(MathExtras, maxIntN) { 146 EXPECT_EQ(32767, maxIntN(16)); 147 EXPECT_EQ(2147483647, maxIntN(32)); 148 EXPECT_EQ(std::numeric_limits<int32_t>::max(), maxIntN(32)); 149 EXPECT_EQ(std::numeric_limits<int64_t>::max(), maxIntN(64)); 150 } 151 152 TEST(MathExtras, minIntN) { 153 EXPECT_EQ(-32768LL, minIntN(16)); 154 EXPECT_EQ(-64LL, minIntN(7)); 155 EXPECT_EQ(std::numeric_limits<int32_t>::min(), minIntN(32)); 156 EXPECT_EQ(std::numeric_limits<int64_t>::min(), minIntN(64)); 157 } 158 159 TEST(MathExtras, maxUIntN) { 160 EXPECT_EQ(0xffffULL, maxUIntN(16)); 161 EXPECT_EQ(0xffffffffULL, maxUIntN(32)); 162 EXPECT_EQ(0xffffffffffffffffULL, maxUIntN(64)); 163 EXPECT_EQ(1ULL, maxUIntN(1)); 164 EXPECT_EQ(0x0fULL, maxUIntN(4)); 165 } 166 167 TEST(MathExtras, reverseBits) { 168 uint8_t NZ8 = 42; 169 uint16_t NZ16 = 42; 170 uint32_t NZ32 = 42; 171 uint64_t NZ64 = 42; 172 EXPECT_EQ(0x54ULL, reverseBits(NZ8)); 173 EXPECT_EQ(0x5400ULL, reverseBits(NZ16)); 174 EXPECT_EQ(0x54000000ULL, reverseBits(NZ32)); 175 EXPECT_EQ(0x5400000000000000ULL, reverseBits(NZ64)); 176 } 177 178 TEST(MathExtras, isPowerOf2_32) { 179 EXPECT_FALSE(isPowerOf2_32(0)); 180 EXPECT_TRUE(isPowerOf2_32(1 << 6)); 181 EXPECT_TRUE(isPowerOf2_32(1 << 12)); 182 EXPECT_FALSE(isPowerOf2_32((1 << 19) + 3)); 183 EXPECT_FALSE(isPowerOf2_32(0xABCDEF0)); 184 } 185 186 TEST(MathExtras, isPowerOf2_64) { 187 EXPECT_FALSE(isPowerOf2_64(0)); 188 EXPECT_TRUE(isPowerOf2_64(1LL << 46)); 189 EXPECT_TRUE(isPowerOf2_64(1LL << 12)); 190 EXPECT_FALSE(isPowerOf2_64((1LL << 53) + 3)); 191 EXPECT_FALSE(isPowerOf2_64(0xABCDEF0ABCDEF0LL)); 192 } 193 194 TEST(MathExtras, PowerOf2Ceil) { 195 EXPECT_EQ(0U, PowerOf2Ceil(0U)); 196 EXPECT_EQ(8U, PowerOf2Ceil(8U)); 197 EXPECT_EQ(8U, PowerOf2Ceil(7U)); 198 } 199 200 TEST(MathExtras, PowerOf2Floor) { 201 EXPECT_EQ(0U, PowerOf2Floor(0U)); 202 EXPECT_EQ(8U, PowerOf2Floor(8U)); 203 EXPECT_EQ(4U, PowerOf2Floor(7U)); 204 } 205 206 TEST(MathExtras, CTLog2) { 207 EXPECT_EQ(CTLog2<1ULL << 0>(), 0U); 208 EXPECT_EQ(CTLog2<1ULL << 1>(), 1U); 209 EXPECT_EQ(CTLog2<1ULL << 2>(), 2U); 210 EXPECT_EQ(CTLog2<1ULL << 3>(), 3U); 211 EXPECT_EQ(CTLog2<1ULL << 4>(), 4U); 212 EXPECT_EQ(CTLog2<1ULL << 5>(), 5U); 213 EXPECT_EQ(CTLog2<1ULL << 6>(), 6U); 214 EXPECT_EQ(CTLog2<1ULL << 7>(), 7U); 215 EXPECT_EQ(CTLog2<1ULL << 8>(), 8U); 216 EXPECT_EQ(CTLog2<1ULL << 9>(), 9U); 217 EXPECT_EQ(CTLog2<1ULL << 10>(), 10U); 218 EXPECT_EQ(CTLog2<1ULL << 11>(), 11U); 219 EXPECT_EQ(CTLog2<1ULL << 12>(), 12U); 220 EXPECT_EQ(CTLog2<1ULL << 13>(), 13U); 221 EXPECT_EQ(CTLog2<1ULL << 14>(), 14U); 222 EXPECT_EQ(CTLog2<1ULL << 15>(), 15U); 223 } 224 225 TEST(MathExtras, countLeadingOnes) { 226 for (int i = 30; i >= 0; --i) { 227 // Start with all ones and unset some bit. 228 EXPECT_EQ(31u - i, countLeadingOnes(0xFFFFFFFF ^ (1 << i))); 229 } 230 for (int i = 62; i >= 0; --i) { 231 // Start with all ones and unset some bit. 232 EXPECT_EQ(63u - i, countLeadingOnes(0xFFFFFFFFFFFFFFFFULL ^ (1LL << i))); 233 } 234 for (int i = 30; i >= 0; --i) { 235 // Start with all ones and unset some bit. 236 EXPECT_EQ(31u - i, countLeadingOnes(0xFFFFFFFF ^ (1 << i))); 237 } 238 } 239 240 TEST(MathExtras, FloatBits) { 241 static const float kValue = 5632.34f; 242 EXPECT_FLOAT_EQ(kValue, BitsToFloat(FloatToBits(kValue))); 243 } 244 245 TEST(MathExtras, DoubleBits) { 246 static const double kValue = 87987234.983498; 247 EXPECT_DOUBLE_EQ(kValue, BitsToDouble(DoubleToBits(kValue))); 248 } 249 250 TEST(MathExtras, MinAlign) { 251 EXPECT_EQ(1u, MinAlign(2, 3)); 252 EXPECT_EQ(2u, MinAlign(2, 4)); 253 EXPECT_EQ(1u, MinAlign(17, 64)); 254 EXPECT_EQ(256u, MinAlign(256, 512)); 255 } 256 257 TEST(MathExtras, NextPowerOf2) { 258 EXPECT_EQ(4u, NextPowerOf2(3)); 259 EXPECT_EQ(16u, NextPowerOf2(15)); 260 EXPECT_EQ(256u, NextPowerOf2(128)); 261 } 262 263 TEST(MathExtras, alignTo) { 264 EXPECT_EQ(8u, alignTo(5, 8)); 265 EXPECT_EQ(24u, alignTo(17, 8)); 266 EXPECT_EQ(0u, alignTo(~0LL, 8)); 267 268 EXPECT_EQ(7u, alignTo(5, 8, 7)); 269 EXPECT_EQ(17u, alignTo(17, 8, 1)); 270 EXPECT_EQ(3u, alignTo(~0LL, 8, 3)); 271 EXPECT_EQ(552u, alignTo(321, 255, 42)); 272 } 273 274 template<typename T> 275 void SaturatingAddTestHelper() 276 { 277 const T Max = std::numeric_limits<T>::max(); 278 bool ResultOverflowed; 279 280 EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2))); 281 EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2), &ResultOverflowed)); 282 EXPECT_FALSE(ResultOverflowed); 283 284 EXPECT_EQ(Max, SaturatingAdd(Max, T(1))); 285 EXPECT_EQ(Max, SaturatingAdd(Max, T(1), &ResultOverflowed)); 286 EXPECT_TRUE(ResultOverflowed); 287 288 EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1))); 289 EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1), &ResultOverflowed)); 290 EXPECT_FALSE(ResultOverflowed); 291 292 EXPECT_EQ(Max, SaturatingAdd(T(1), Max)); 293 EXPECT_EQ(Max, SaturatingAdd(T(1), Max, &ResultOverflowed)); 294 EXPECT_TRUE(ResultOverflowed); 295 296 EXPECT_EQ(Max, SaturatingAdd(Max, Max)); 297 EXPECT_EQ(Max, SaturatingAdd(Max, Max, &ResultOverflowed)); 298 EXPECT_TRUE(ResultOverflowed); 299 } 300 301 TEST(MathExtras, SaturatingAdd) { 302 SaturatingAddTestHelper<uint8_t>(); 303 SaturatingAddTestHelper<uint16_t>(); 304 SaturatingAddTestHelper<uint32_t>(); 305 SaturatingAddTestHelper<uint64_t>(); 306 } 307 308 template<typename T> 309 void SaturatingMultiplyTestHelper() 310 { 311 const T Max = std::numeric_limits<T>::max(); 312 bool ResultOverflowed; 313 314 // Test basic multiplication. 315 EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3))); 316 EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3), &ResultOverflowed)); 317 EXPECT_FALSE(ResultOverflowed); 318 319 EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2))); 320 EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2), &ResultOverflowed)); 321 EXPECT_FALSE(ResultOverflowed); 322 323 // Test multiplication by zero. 324 EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0))); 325 EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0), &ResultOverflowed)); 326 EXPECT_FALSE(ResultOverflowed); 327 328 EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0))); 329 EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0), &ResultOverflowed)); 330 EXPECT_FALSE(ResultOverflowed); 331 332 EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1))); 333 EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1), &ResultOverflowed)); 334 EXPECT_FALSE(ResultOverflowed); 335 336 EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0))); 337 EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0), &ResultOverflowed)); 338 EXPECT_FALSE(ResultOverflowed); 339 340 EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max)); 341 EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max, &ResultOverflowed)); 342 EXPECT_FALSE(ResultOverflowed); 343 344 // Test multiplication by maximum value. 345 EXPECT_EQ(Max, SaturatingMultiply(Max, T(2))); 346 EXPECT_EQ(Max, SaturatingMultiply(Max, T(2), &ResultOverflowed)); 347 EXPECT_TRUE(ResultOverflowed); 348 349 EXPECT_EQ(Max, SaturatingMultiply(T(2), Max)); 350 EXPECT_EQ(Max, SaturatingMultiply(T(2), Max, &ResultOverflowed)); 351 EXPECT_TRUE(ResultOverflowed); 352 353 EXPECT_EQ(Max, SaturatingMultiply(Max, Max)); 354 EXPECT_EQ(Max, SaturatingMultiply(Max, Max, &ResultOverflowed)); 355 EXPECT_TRUE(ResultOverflowed); 356 357 // Test interesting boundary conditions for algorithm - 358 // ((1 << A) - 1) * ((1 << B) + K) for K in [-1, 0, 1] 359 // and A + B == std::numeric_limits<T>::digits. 360 // We expect overflow iff A > B and K = 1. 361 const int Digits = std::numeric_limits<T>::digits; 362 for (int A = 1, B = Digits - 1; B >= 1; ++A, --B) { 363 for (int K = -1; K <= 1; ++K) { 364 T X = (T(1) << A) - T(1); 365 T Y = (T(1) << B) + K; 366 bool OverflowExpected = A > B && K == 1; 367 368 if(OverflowExpected) { 369 EXPECT_EQ(Max, SaturatingMultiply(X, Y)); 370 EXPECT_EQ(Max, SaturatingMultiply(X, Y, &ResultOverflowed)); 371 EXPECT_TRUE(ResultOverflowed); 372 } else { 373 EXPECT_EQ(X * Y, SaturatingMultiply(X, Y)); 374 EXPECT_EQ(X * Y, SaturatingMultiply(X, Y, &ResultOverflowed)); 375 EXPECT_FALSE(ResultOverflowed); 376 } 377 } 378 } 379 } 380 381 TEST(MathExtras, SaturatingMultiply) { 382 SaturatingMultiplyTestHelper<uint8_t>(); 383 SaturatingMultiplyTestHelper<uint16_t>(); 384 SaturatingMultiplyTestHelper<uint32_t>(); 385 SaturatingMultiplyTestHelper<uint64_t>(); 386 } 387 388 template<typename T> 389 void SaturatingMultiplyAddTestHelper() 390 { 391 const T Max = std::numeric_limits<T>::max(); 392 bool ResultOverflowed; 393 394 // Test basic multiply-add. 395 EXPECT_EQ(T(16), SaturatingMultiplyAdd(T(2), T(3), T(10))); 396 EXPECT_EQ(T(16), SaturatingMultiplyAdd(T(2), T(3), T(10), &ResultOverflowed)); 397 EXPECT_FALSE(ResultOverflowed); 398 399 // Test multiply overflows, add doesn't overflow 400 EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, T(0), &ResultOverflowed)); 401 EXPECT_TRUE(ResultOverflowed); 402 403 // Test multiply doesn't overflow, add overflows 404 EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), T(1), Max, &ResultOverflowed)); 405 EXPECT_TRUE(ResultOverflowed); 406 407 // Test multiply-add with Max as operand 408 EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), T(1), Max, &ResultOverflowed)); 409 EXPECT_TRUE(ResultOverflowed); 410 411 EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), Max, T(1), &ResultOverflowed)); 412 EXPECT_TRUE(ResultOverflowed); 413 414 EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, T(1), &ResultOverflowed)); 415 EXPECT_TRUE(ResultOverflowed); 416 417 EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, Max, &ResultOverflowed)); 418 EXPECT_TRUE(ResultOverflowed); 419 420 // Test multiply-add with 0 as operand 421 EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(1), T(1), T(0), &ResultOverflowed)); 422 EXPECT_FALSE(ResultOverflowed); 423 424 EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(1), T(0), T(1), &ResultOverflowed)); 425 EXPECT_FALSE(ResultOverflowed); 426 427 EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(0), T(0), T(1), &ResultOverflowed)); 428 EXPECT_FALSE(ResultOverflowed); 429 430 EXPECT_EQ(T(0), SaturatingMultiplyAdd(T(0), T(0), T(0), &ResultOverflowed)); 431 EXPECT_FALSE(ResultOverflowed); 432 433 } 434 435 TEST(MathExtras, SaturatingMultiplyAdd) { 436 SaturatingMultiplyAddTestHelper<uint8_t>(); 437 SaturatingMultiplyAddTestHelper<uint16_t>(); 438 SaturatingMultiplyAddTestHelper<uint32_t>(); 439 SaturatingMultiplyAddTestHelper<uint64_t>(); 440 } 441 442 TEST(MathExtras, IsShiftedUInt) { 443 EXPECT_TRUE((isShiftedUInt<1, 0>(0))); 444 EXPECT_TRUE((isShiftedUInt<1, 0>(1))); 445 EXPECT_FALSE((isShiftedUInt<1, 0>(2))); 446 EXPECT_FALSE((isShiftedUInt<1, 0>(3))); 447 EXPECT_FALSE((isShiftedUInt<1, 0>(0x8000000000000000))); 448 EXPECT_TRUE((isShiftedUInt<1, 63>(0x8000000000000000))); 449 EXPECT_TRUE((isShiftedUInt<2, 62>(0xC000000000000000))); 450 EXPECT_FALSE((isShiftedUInt<2, 62>(0xE000000000000000))); 451 452 // 0x201 is ten bits long and has a 1 in the MSB and LSB. 453 EXPECT_TRUE((isShiftedUInt<10, 5>(uint64_t(0x201) << 5))); 454 EXPECT_FALSE((isShiftedUInt<10, 5>(uint64_t(0x201) << 4))); 455 EXPECT_FALSE((isShiftedUInt<10, 5>(uint64_t(0x201) << 6))); 456 } 457 458 TEST(MathExtras, IsShiftedInt) { 459 EXPECT_TRUE((isShiftedInt<1, 0>(0))); 460 EXPECT_TRUE((isShiftedInt<1, 0>(-1))); 461 EXPECT_FALSE((isShiftedInt<1, 0>(2))); 462 EXPECT_FALSE((isShiftedInt<1, 0>(3))); 463 EXPECT_FALSE((isShiftedInt<1, 0>(0x8000000000000000))); 464 EXPECT_TRUE((isShiftedInt<1, 63>(0x8000000000000000))); 465 EXPECT_TRUE((isShiftedInt<2, 62>(0xC000000000000000))); 466 EXPECT_FALSE((isShiftedInt<2, 62>(0xE000000000000000))); 467 468 // 0x201 is ten bits long and has a 1 in the MSB and LSB. 469 EXPECT_TRUE((isShiftedInt<11, 5>(int64_t(0x201) << 5))); 470 EXPECT_FALSE((isShiftedInt<11, 5>(int64_t(0x201) << 3))); 471 EXPECT_FALSE((isShiftedInt<11, 5>(int64_t(0x201) << 6))); 472 EXPECT_TRUE((isShiftedInt<11, 5>(-(int64_t(0x201) << 5)))); 473 EXPECT_FALSE((isShiftedInt<11, 5>(-(int64_t(0x201) << 3)))); 474 EXPECT_FALSE((isShiftedInt<11, 5>(-(int64_t(0x201) << 6)))); 475 476 EXPECT_TRUE((isShiftedInt<6, 10>(-(int64_t(1) << 15)))); 477 EXPECT_FALSE((isShiftedInt<6, 10>(int64_t(1) << 15))); 478 } 479 480 template <typename T> 481 class OverflowTest : public ::testing::Test { }; 482 483 using OverflowTestTypes = ::testing::Types<signed char, short, int, long, 484 long long>; 485 486 TYPED_TEST_SUITE(OverflowTest, OverflowTestTypes); 487 488 TYPED_TEST(OverflowTest, AddNoOverflow) { 489 TypeParam Result; 490 EXPECT_FALSE(AddOverflow<TypeParam>(1, 2, Result)); 491 EXPECT_EQ(Result, TypeParam(3)); 492 } 493 494 TYPED_TEST(OverflowTest, AddOverflowToNegative) { 495 TypeParam Result; 496 auto MaxValue = std::numeric_limits<TypeParam>::max(); 497 EXPECT_TRUE(AddOverflow<TypeParam>(MaxValue, MaxValue, Result)); 498 EXPECT_EQ(Result, TypeParam(-2)); 499 } 500 501 TYPED_TEST(OverflowTest, AddOverflowToMin) { 502 TypeParam Result; 503 auto MaxValue = std::numeric_limits<TypeParam>::max(); 504 EXPECT_TRUE(AddOverflow<TypeParam>(MaxValue, TypeParam(1), Result)); 505 EXPECT_EQ(Result, std::numeric_limits<TypeParam>::min()); 506 } 507 508 TYPED_TEST(OverflowTest, AddOverflowToZero) { 509 TypeParam Result; 510 auto MinValue = std::numeric_limits<TypeParam>::min(); 511 EXPECT_TRUE(AddOverflow<TypeParam>(MinValue, MinValue, Result)); 512 EXPECT_EQ(Result, TypeParam(0)); 513 } 514 515 TYPED_TEST(OverflowTest, AddOverflowToMax) { 516 TypeParam Result; 517 auto MinValue = std::numeric_limits<TypeParam>::min(); 518 EXPECT_TRUE(AddOverflow<TypeParam>(MinValue, TypeParam(-1), Result)); 519 EXPECT_EQ(Result, std::numeric_limits<TypeParam>::max()); 520 } 521 522 TYPED_TEST(OverflowTest, SubNoOverflow) { 523 TypeParam Result; 524 EXPECT_FALSE(SubOverflow<TypeParam>(1, 2, Result)); 525 EXPECT_EQ(Result, TypeParam(-1)); 526 } 527 528 TYPED_TEST(OverflowTest, SubOverflowToMax) { 529 TypeParam Result; 530 auto MinValue = std::numeric_limits<TypeParam>::min(); 531 EXPECT_TRUE(SubOverflow<TypeParam>(0, MinValue, Result)); 532 EXPECT_EQ(Result, MinValue); 533 } 534 535 TYPED_TEST(OverflowTest, SubOverflowToMin) { 536 TypeParam Result; 537 auto MinValue = std::numeric_limits<TypeParam>::min(); 538 EXPECT_TRUE(SubOverflow<TypeParam>(0, MinValue, Result)); 539 EXPECT_EQ(Result, MinValue); 540 } 541 542 TYPED_TEST(OverflowTest, SubOverflowToNegative) { 543 TypeParam Result; 544 auto MaxValue = std::numeric_limits<TypeParam>::max(); 545 auto MinValue = std::numeric_limits<TypeParam>::min(); 546 EXPECT_TRUE(SubOverflow<TypeParam>(MaxValue, MinValue, Result)); 547 EXPECT_EQ(Result, TypeParam(-1)); 548 } 549 550 TYPED_TEST(OverflowTest, SubOverflowToPositive) { 551 TypeParam Result; 552 auto MaxValue = std::numeric_limits<TypeParam>::max(); 553 auto MinValue = std::numeric_limits<TypeParam>::min(); 554 EXPECT_TRUE(SubOverflow<TypeParam>(MinValue, MaxValue, Result)); 555 EXPECT_EQ(Result, TypeParam(1)); 556 } 557 558 TYPED_TEST(OverflowTest, MulNoOverflow) { 559 TypeParam Result; 560 EXPECT_FALSE(MulOverflow<TypeParam>(1, 2, Result)); 561 EXPECT_EQ(Result, 2); 562 EXPECT_FALSE(MulOverflow<TypeParam>(-1, 3, Result)); 563 EXPECT_EQ(Result, -3); 564 EXPECT_FALSE(MulOverflow<TypeParam>(4, -2, Result)); 565 EXPECT_EQ(Result, -8); 566 EXPECT_FALSE(MulOverflow<TypeParam>(-6, -5, Result)); 567 EXPECT_EQ(Result, 30); 568 } 569 570 TYPED_TEST(OverflowTest, MulNoOverflowToMax) { 571 TypeParam Result; 572 auto MaxValue = std::numeric_limits<TypeParam>::max(); 573 auto MinValue = std::numeric_limits<TypeParam>::min(); 574 EXPECT_FALSE(MulOverflow<TypeParam>(MinValue + 1, -1, Result)); 575 EXPECT_EQ(Result, MaxValue); 576 } 577 578 TYPED_TEST(OverflowTest, MulOverflowToMin) { 579 TypeParam Result; 580 auto MinValue = std::numeric_limits<TypeParam>::min(); 581 EXPECT_TRUE(MulOverflow<TypeParam>(MinValue, -1, Result)); 582 EXPECT_EQ(Result, MinValue); 583 } 584 585 TYPED_TEST(OverflowTest, MulOverflowMax) { 586 TypeParam Result; 587 auto MinValue = std::numeric_limits<TypeParam>::min(); 588 auto MaxValue = std::numeric_limits<TypeParam>::max(); 589 EXPECT_TRUE(MulOverflow<TypeParam>(MinValue, MinValue, Result)); 590 EXPECT_EQ(Result, 0); 591 EXPECT_TRUE(MulOverflow<TypeParam>(MaxValue, MaxValue, Result)); 592 EXPECT_EQ(Result, 1); 593 } 594 595 TYPED_TEST(OverflowTest, MulResultZero) { 596 TypeParam Result; 597 EXPECT_FALSE(MulOverflow<TypeParam>(4, 0, Result)); 598 EXPECT_EQ(Result, TypeParam(0)); 599 EXPECT_FALSE(MulOverflow<TypeParam>(-5, 0, Result)); 600 EXPECT_EQ(Result, TypeParam(0)); 601 EXPECT_FALSE(MulOverflow<TypeParam>(0, 5, Result)); 602 EXPECT_EQ(Result, TypeParam(0)); 603 EXPECT_FALSE(MulOverflow<TypeParam>(0, -5, Result)); 604 EXPECT_EQ(Result, TypeParam(0)); 605 } 606 607 } // namespace 608