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, isShiftedMask_32) { 179 EXPECT_FALSE(isShiftedMask_32(0x01010101)); 180 EXPECT_TRUE(isShiftedMask_32(0xf0000000)); 181 EXPECT_TRUE(isShiftedMask_32(0xffff0000)); 182 EXPECT_TRUE(isShiftedMask_32(0xff << 1)); 183 184 unsigned MaskIdx, MaskLen; 185 EXPECT_FALSE(isShiftedMask_32(0x01010101, MaskIdx, MaskLen)); 186 EXPECT_TRUE(isShiftedMask_32(0xf0000000, MaskIdx, MaskLen)); 187 EXPECT_EQ(28, (int)MaskIdx); 188 EXPECT_EQ(4, (int)MaskLen); 189 EXPECT_TRUE(isShiftedMask_32(0xffff0000, MaskIdx, MaskLen)); 190 EXPECT_EQ(16, (int)MaskIdx); 191 EXPECT_EQ(16, (int)MaskLen); 192 EXPECT_TRUE(isShiftedMask_32(0xff << 1, MaskIdx, MaskLen)); 193 EXPECT_EQ(1, (int)MaskIdx); 194 EXPECT_EQ(8, (int)MaskLen); 195 } 196 197 TEST(MathExtras, isShiftedMask_64) { 198 EXPECT_FALSE(isShiftedMask_64(0x0101010101010101ull)); 199 EXPECT_TRUE(isShiftedMask_64(0xf000000000000000ull)); 200 EXPECT_TRUE(isShiftedMask_64(0xffff000000000000ull)); 201 EXPECT_TRUE(isShiftedMask_64(0xffull << 55)); 202 203 unsigned MaskIdx, MaskLen; 204 EXPECT_FALSE(isShiftedMask_64(0x0101010101010101ull, MaskIdx, MaskLen)); 205 EXPECT_TRUE(isShiftedMask_64(0xf000000000000000ull, MaskIdx, MaskLen)); 206 EXPECT_EQ(60, (int)MaskIdx); 207 EXPECT_EQ(4, (int)MaskLen); 208 EXPECT_TRUE(isShiftedMask_64(0xffff000000000000ull, MaskIdx, MaskLen)); 209 EXPECT_EQ(48, (int)MaskIdx); 210 EXPECT_EQ(16, (int)MaskLen); 211 EXPECT_TRUE(isShiftedMask_64(0xffull << 55, MaskIdx, MaskLen)); 212 EXPECT_EQ(55, (int)MaskIdx); 213 EXPECT_EQ(8, (int)MaskLen); 214 } 215 216 TEST(MathExtras, isPowerOf2_32) { 217 EXPECT_FALSE(isPowerOf2_32(0)); 218 EXPECT_TRUE(isPowerOf2_32(1 << 6)); 219 EXPECT_TRUE(isPowerOf2_32(1 << 12)); 220 EXPECT_FALSE(isPowerOf2_32((1 << 19) + 3)); 221 EXPECT_FALSE(isPowerOf2_32(0xABCDEF0)); 222 } 223 224 TEST(MathExtras, isPowerOf2_64) { 225 EXPECT_FALSE(isPowerOf2_64(0)); 226 EXPECT_TRUE(isPowerOf2_64(1LL << 46)); 227 EXPECT_TRUE(isPowerOf2_64(1LL << 12)); 228 EXPECT_FALSE(isPowerOf2_64((1LL << 53) + 3)); 229 EXPECT_FALSE(isPowerOf2_64(0xABCDEF0ABCDEF0LL)); 230 } 231 232 TEST(MathExtras, PowerOf2Ceil) { 233 EXPECT_EQ(0U, PowerOf2Ceil(0U)); 234 EXPECT_EQ(8U, PowerOf2Ceil(8U)); 235 EXPECT_EQ(8U, PowerOf2Ceil(7U)); 236 } 237 238 TEST(MathExtras, PowerOf2Floor) { 239 EXPECT_EQ(0U, PowerOf2Floor(0U)); 240 EXPECT_EQ(8U, PowerOf2Floor(8U)); 241 EXPECT_EQ(4U, PowerOf2Floor(7U)); 242 } 243 244 TEST(MathExtras, CTLog2) { 245 EXPECT_EQ(CTLog2<1ULL << 0>(), 0U); 246 EXPECT_EQ(CTLog2<1ULL << 1>(), 1U); 247 EXPECT_EQ(CTLog2<1ULL << 2>(), 2U); 248 EXPECT_EQ(CTLog2<1ULL << 3>(), 3U); 249 EXPECT_EQ(CTLog2<1ULL << 4>(), 4U); 250 EXPECT_EQ(CTLog2<1ULL << 5>(), 5U); 251 EXPECT_EQ(CTLog2<1ULL << 6>(), 6U); 252 EXPECT_EQ(CTLog2<1ULL << 7>(), 7U); 253 EXPECT_EQ(CTLog2<1ULL << 8>(), 8U); 254 EXPECT_EQ(CTLog2<1ULL << 9>(), 9U); 255 EXPECT_EQ(CTLog2<1ULL << 10>(), 10U); 256 EXPECT_EQ(CTLog2<1ULL << 11>(), 11U); 257 EXPECT_EQ(CTLog2<1ULL << 12>(), 12U); 258 EXPECT_EQ(CTLog2<1ULL << 13>(), 13U); 259 EXPECT_EQ(CTLog2<1ULL << 14>(), 14U); 260 EXPECT_EQ(CTLog2<1ULL << 15>(), 15U); 261 } 262 263 TEST(MathExtras, countLeadingOnes) { 264 for (int i = 30; i >= 0; --i) { 265 // Start with all ones and unset some bit. 266 EXPECT_EQ(31u - i, countLeadingOnes(0xFFFFFFFF ^ (1 << i))); 267 } 268 for (int i = 62; i >= 0; --i) { 269 // Start with all ones and unset some bit. 270 EXPECT_EQ(63u - i, countLeadingOnes(0xFFFFFFFFFFFFFFFFULL ^ (1LL << i))); 271 } 272 for (int i = 30; i >= 0; --i) { 273 // Start with all ones and unset some bit. 274 EXPECT_EQ(31u - i, countLeadingOnes(0xFFFFFFFF ^ (1 << i))); 275 } 276 } 277 278 TEST(MathExtras, FloatBits) { 279 static const float kValue = 5632.34f; 280 EXPECT_FLOAT_EQ(kValue, BitsToFloat(FloatToBits(kValue))); 281 } 282 283 TEST(MathExtras, DoubleBits) { 284 static const double kValue = 87987234.983498; 285 EXPECT_DOUBLE_EQ(kValue, BitsToDouble(DoubleToBits(kValue))); 286 } 287 288 TEST(MathExtras, MinAlign) { 289 EXPECT_EQ(1u, MinAlign(2, 3)); 290 EXPECT_EQ(2u, MinAlign(2, 4)); 291 EXPECT_EQ(1u, MinAlign(17, 64)); 292 EXPECT_EQ(256u, MinAlign(256, 512)); 293 } 294 295 TEST(MathExtras, NextPowerOf2) { 296 EXPECT_EQ(4u, NextPowerOf2(3)); 297 EXPECT_EQ(16u, NextPowerOf2(15)); 298 EXPECT_EQ(256u, NextPowerOf2(128)); 299 } 300 301 TEST(MathExtras, alignTo) { 302 EXPECT_EQ(8u, alignTo(5, 8)); 303 EXPECT_EQ(24u, alignTo(17, 8)); 304 EXPECT_EQ(0u, alignTo(~0LL, 8)); 305 306 EXPECT_EQ(7u, alignTo(5, 8, 7)); 307 EXPECT_EQ(17u, alignTo(17, 8, 1)); 308 EXPECT_EQ(3u, alignTo(~0LL, 8, 3)); 309 EXPECT_EQ(552u, alignTo(321, 255, 42)); 310 } 311 312 template <typename T> void SaturatingAddTestHelper() { 313 const T Max = std::numeric_limits<T>::max(); 314 bool ResultOverflowed; 315 316 EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2))); 317 EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2), &ResultOverflowed)); 318 EXPECT_FALSE(ResultOverflowed); 319 320 EXPECT_EQ(Max, SaturatingAdd(Max, T(1))); 321 EXPECT_EQ(Max, SaturatingAdd(Max, T(1), &ResultOverflowed)); 322 EXPECT_TRUE(ResultOverflowed); 323 324 EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1))); 325 EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1), &ResultOverflowed)); 326 EXPECT_FALSE(ResultOverflowed); 327 328 EXPECT_EQ(Max, SaturatingAdd(T(1), Max)); 329 EXPECT_EQ(Max, SaturatingAdd(T(1), Max, &ResultOverflowed)); 330 EXPECT_TRUE(ResultOverflowed); 331 332 EXPECT_EQ(Max, SaturatingAdd(Max, Max)); 333 EXPECT_EQ(Max, SaturatingAdd(Max, Max, &ResultOverflowed)); 334 EXPECT_TRUE(ResultOverflowed); 335 336 EXPECT_EQ(T(6), SaturatingAdd(T(1), T(2), T(3))); 337 EXPECT_EQ(T(6), SaturatingAdd(T(1), T(2), T(3), &ResultOverflowed)); 338 EXPECT_FALSE(ResultOverflowed); 339 340 EXPECT_EQ(T(10), SaturatingAdd(T(1), T(2), T(3), T(4))); 341 EXPECT_EQ(T(10), SaturatingAdd(T(1), T(2), T(3), T(4), &ResultOverflowed)); 342 EXPECT_FALSE(ResultOverflowed); 343 344 EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(0))); 345 EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(0), &ResultOverflowed)); 346 EXPECT_FALSE(ResultOverflowed); 347 348 EXPECT_EQ(Max, SaturatingAdd(T(0), T(0), Max)); 349 EXPECT_EQ(Max, SaturatingAdd(T(0), T(0), Max, &ResultOverflowed)); 350 EXPECT_FALSE(ResultOverflowed); 351 352 EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(1))); 353 EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(1), &ResultOverflowed)); 354 EXPECT_TRUE(ResultOverflowed); 355 356 EXPECT_EQ(Max, SaturatingAdd(T(0), T(1), Max)); 357 EXPECT_EQ(Max, SaturatingAdd(T(0), T(1), Max, &ResultOverflowed)); 358 EXPECT_TRUE(ResultOverflowed); 359 360 EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 2), T(1))); 361 EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 2), T(1), &ResultOverflowed)); 362 EXPECT_FALSE(ResultOverflowed); 363 364 EXPECT_EQ(Max, SaturatingAdd(T(1), T(1), T(Max - 2))); 365 EXPECT_EQ(Max, SaturatingAdd(T(1), T(1), T(Max - 2), &ResultOverflowed)); 366 EXPECT_FALSE(ResultOverflowed); 367 368 EXPECT_EQ(Max, SaturatingAdd(Max, Max, Max)); 369 EXPECT_EQ(Max, SaturatingAdd(Max, Max, Max, &ResultOverflowed)); 370 EXPECT_TRUE(ResultOverflowed); 371 } 372 373 TEST(MathExtras, SaturatingAdd) { 374 SaturatingAddTestHelper<uint8_t>(); 375 SaturatingAddTestHelper<uint16_t>(); 376 SaturatingAddTestHelper<uint32_t>(); 377 SaturatingAddTestHelper<uint64_t>(); 378 } 379 380 template<typename T> 381 void SaturatingMultiplyTestHelper() 382 { 383 const T Max = std::numeric_limits<T>::max(); 384 bool ResultOverflowed; 385 386 // Test basic multiplication. 387 EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3))); 388 EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3), &ResultOverflowed)); 389 EXPECT_FALSE(ResultOverflowed); 390 391 EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2))); 392 EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2), &ResultOverflowed)); 393 EXPECT_FALSE(ResultOverflowed); 394 395 // Test multiplication by zero. 396 EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0))); 397 EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0), &ResultOverflowed)); 398 EXPECT_FALSE(ResultOverflowed); 399 400 EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0))); 401 EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0), &ResultOverflowed)); 402 EXPECT_FALSE(ResultOverflowed); 403 404 EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1))); 405 EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1), &ResultOverflowed)); 406 EXPECT_FALSE(ResultOverflowed); 407 408 EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0))); 409 EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0), &ResultOverflowed)); 410 EXPECT_FALSE(ResultOverflowed); 411 412 EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max)); 413 EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max, &ResultOverflowed)); 414 EXPECT_FALSE(ResultOverflowed); 415 416 // Test multiplication by maximum value. 417 EXPECT_EQ(Max, SaturatingMultiply(Max, T(2))); 418 EXPECT_EQ(Max, SaturatingMultiply(Max, T(2), &ResultOverflowed)); 419 EXPECT_TRUE(ResultOverflowed); 420 421 EXPECT_EQ(Max, SaturatingMultiply(T(2), Max)); 422 EXPECT_EQ(Max, SaturatingMultiply(T(2), Max, &ResultOverflowed)); 423 EXPECT_TRUE(ResultOverflowed); 424 425 EXPECT_EQ(Max, SaturatingMultiply(Max, Max)); 426 EXPECT_EQ(Max, SaturatingMultiply(Max, Max, &ResultOverflowed)); 427 EXPECT_TRUE(ResultOverflowed); 428 429 // Test interesting boundary conditions for algorithm - 430 // ((1 << A) - 1) * ((1 << B) + K) for K in [-1, 0, 1] 431 // and A + B == std::numeric_limits<T>::digits. 432 // We expect overflow iff A > B and K = 1. 433 const int Digits = std::numeric_limits<T>::digits; 434 for (int A = 1, B = Digits - 1; B >= 1; ++A, --B) { 435 for (int K = -1; K <= 1; ++K) { 436 T X = (T(1) << A) - T(1); 437 T Y = (T(1) << B) + K; 438 bool OverflowExpected = A > B && K == 1; 439 440 if(OverflowExpected) { 441 EXPECT_EQ(Max, SaturatingMultiply(X, Y)); 442 EXPECT_EQ(Max, SaturatingMultiply(X, Y, &ResultOverflowed)); 443 EXPECT_TRUE(ResultOverflowed); 444 } else { 445 EXPECT_EQ(X * Y, SaturatingMultiply(X, Y)); 446 EXPECT_EQ(X * Y, SaturatingMultiply(X, Y, &ResultOverflowed)); 447 EXPECT_FALSE(ResultOverflowed); 448 } 449 } 450 } 451 } 452 453 TEST(MathExtras, SaturatingMultiply) { 454 SaturatingMultiplyTestHelper<uint8_t>(); 455 SaturatingMultiplyTestHelper<uint16_t>(); 456 SaturatingMultiplyTestHelper<uint32_t>(); 457 SaturatingMultiplyTestHelper<uint64_t>(); 458 } 459 460 template<typename T> 461 void SaturatingMultiplyAddTestHelper() 462 { 463 const T Max = std::numeric_limits<T>::max(); 464 bool ResultOverflowed; 465 466 // Test basic multiply-add. 467 EXPECT_EQ(T(16), SaturatingMultiplyAdd(T(2), T(3), T(10))); 468 EXPECT_EQ(T(16), SaturatingMultiplyAdd(T(2), T(3), T(10), &ResultOverflowed)); 469 EXPECT_FALSE(ResultOverflowed); 470 471 // Test multiply overflows, add doesn't overflow 472 EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, T(0), &ResultOverflowed)); 473 EXPECT_TRUE(ResultOverflowed); 474 475 // Test multiply doesn't overflow, add overflows 476 EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), T(1), Max, &ResultOverflowed)); 477 EXPECT_TRUE(ResultOverflowed); 478 479 // Test multiply-add with Max as operand 480 EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), T(1), Max, &ResultOverflowed)); 481 EXPECT_TRUE(ResultOverflowed); 482 483 EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), Max, T(1), &ResultOverflowed)); 484 EXPECT_TRUE(ResultOverflowed); 485 486 EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, T(1), &ResultOverflowed)); 487 EXPECT_TRUE(ResultOverflowed); 488 489 EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, Max, &ResultOverflowed)); 490 EXPECT_TRUE(ResultOverflowed); 491 492 // Test multiply-add with 0 as operand 493 EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(1), T(1), T(0), &ResultOverflowed)); 494 EXPECT_FALSE(ResultOverflowed); 495 496 EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(1), T(0), T(1), &ResultOverflowed)); 497 EXPECT_FALSE(ResultOverflowed); 498 499 EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(0), T(0), T(1), &ResultOverflowed)); 500 EXPECT_FALSE(ResultOverflowed); 501 502 EXPECT_EQ(T(0), SaturatingMultiplyAdd(T(0), T(0), T(0), &ResultOverflowed)); 503 EXPECT_FALSE(ResultOverflowed); 504 505 } 506 507 TEST(MathExtras, SaturatingMultiplyAdd) { 508 SaturatingMultiplyAddTestHelper<uint8_t>(); 509 SaturatingMultiplyAddTestHelper<uint16_t>(); 510 SaturatingMultiplyAddTestHelper<uint32_t>(); 511 SaturatingMultiplyAddTestHelper<uint64_t>(); 512 } 513 514 TEST(MathExtras, IsShiftedUInt) { 515 EXPECT_TRUE((isShiftedUInt<1, 0>(0))); 516 EXPECT_TRUE((isShiftedUInt<1, 0>(1))); 517 EXPECT_FALSE((isShiftedUInt<1, 0>(2))); 518 EXPECT_FALSE((isShiftedUInt<1, 0>(3))); 519 EXPECT_FALSE((isShiftedUInt<1, 0>(0x8000000000000000))); 520 EXPECT_TRUE((isShiftedUInt<1, 63>(0x8000000000000000))); 521 EXPECT_TRUE((isShiftedUInt<2, 62>(0xC000000000000000))); 522 EXPECT_FALSE((isShiftedUInt<2, 62>(0xE000000000000000))); 523 524 // 0x201 is ten bits long and has a 1 in the MSB and LSB. 525 EXPECT_TRUE((isShiftedUInt<10, 5>(uint64_t(0x201) << 5))); 526 EXPECT_FALSE((isShiftedUInt<10, 5>(uint64_t(0x201) << 4))); 527 EXPECT_FALSE((isShiftedUInt<10, 5>(uint64_t(0x201) << 6))); 528 } 529 530 TEST(MathExtras, IsShiftedInt) { 531 EXPECT_TRUE((isShiftedInt<1, 0>(0))); 532 EXPECT_TRUE((isShiftedInt<1, 0>(-1))); 533 EXPECT_FALSE((isShiftedInt<1, 0>(2))); 534 EXPECT_FALSE((isShiftedInt<1, 0>(3))); 535 EXPECT_FALSE((isShiftedInt<1, 0>(0x8000000000000000))); 536 EXPECT_TRUE((isShiftedInt<1, 63>(0x8000000000000000))); 537 EXPECT_TRUE((isShiftedInt<2, 62>(0xC000000000000000))); 538 EXPECT_FALSE((isShiftedInt<2, 62>(0xE000000000000000))); 539 540 // 0x201 is ten bits long and has a 1 in the MSB and LSB. 541 EXPECT_TRUE((isShiftedInt<11, 5>(int64_t(0x201) << 5))); 542 EXPECT_FALSE((isShiftedInt<11, 5>(int64_t(0x201) << 3))); 543 EXPECT_FALSE((isShiftedInt<11, 5>(int64_t(0x201) << 6))); 544 EXPECT_TRUE((isShiftedInt<11, 5>(-(int64_t(0x201) << 5)))); 545 EXPECT_FALSE((isShiftedInt<11, 5>(-(int64_t(0x201) << 3)))); 546 EXPECT_FALSE((isShiftedInt<11, 5>(-(int64_t(0x201) << 6)))); 547 548 EXPECT_TRUE((isShiftedInt<6, 10>(-(int64_t(1) << 15)))); 549 EXPECT_FALSE((isShiftedInt<6, 10>(int64_t(1) << 15))); 550 } 551 552 template <typename T> 553 class OverflowTest : public ::testing::Test { }; 554 555 using OverflowTestTypes = ::testing::Types<signed char, short, int, long, 556 long long>; 557 558 TYPED_TEST_SUITE(OverflowTest, OverflowTestTypes, ); 559 560 TYPED_TEST(OverflowTest, AddNoOverflow) { 561 TypeParam Result; 562 EXPECT_FALSE(AddOverflow<TypeParam>(1, 2, Result)); 563 EXPECT_EQ(Result, TypeParam(3)); 564 } 565 566 TYPED_TEST(OverflowTest, AddOverflowToNegative) { 567 TypeParam Result; 568 auto MaxValue = std::numeric_limits<TypeParam>::max(); 569 EXPECT_TRUE(AddOverflow<TypeParam>(MaxValue, MaxValue, Result)); 570 EXPECT_EQ(Result, TypeParam(-2)); 571 } 572 573 TYPED_TEST(OverflowTest, AddOverflowToMin) { 574 TypeParam Result; 575 auto MaxValue = std::numeric_limits<TypeParam>::max(); 576 EXPECT_TRUE(AddOverflow<TypeParam>(MaxValue, TypeParam(1), Result)); 577 EXPECT_EQ(Result, std::numeric_limits<TypeParam>::min()); 578 } 579 580 TYPED_TEST(OverflowTest, AddOverflowToZero) { 581 TypeParam Result; 582 auto MinValue = std::numeric_limits<TypeParam>::min(); 583 EXPECT_TRUE(AddOverflow<TypeParam>(MinValue, MinValue, Result)); 584 EXPECT_EQ(Result, TypeParam(0)); 585 } 586 587 TYPED_TEST(OverflowTest, AddOverflowToMax) { 588 TypeParam Result; 589 auto MinValue = std::numeric_limits<TypeParam>::min(); 590 EXPECT_TRUE(AddOverflow<TypeParam>(MinValue, TypeParam(-1), Result)); 591 EXPECT_EQ(Result, std::numeric_limits<TypeParam>::max()); 592 } 593 594 TYPED_TEST(OverflowTest, SubNoOverflow) { 595 TypeParam Result; 596 EXPECT_FALSE(SubOverflow<TypeParam>(1, 2, Result)); 597 EXPECT_EQ(Result, TypeParam(-1)); 598 } 599 600 TYPED_TEST(OverflowTest, SubOverflowToMax) { 601 TypeParam Result; 602 auto MinValue = std::numeric_limits<TypeParam>::min(); 603 EXPECT_TRUE(SubOverflow<TypeParam>(0, MinValue, Result)); 604 EXPECT_EQ(Result, MinValue); 605 } 606 607 TYPED_TEST(OverflowTest, SubOverflowToMin) { 608 TypeParam Result; 609 auto MinValue = std::numeric_limits<TypeParam>::min(); 610 EXPECT_TRUE(SubOverflow<TypeParam>(0, MinValue, Result)); 611 EXPECT_EQ(Result, MinValue); 612 } 613 614 TYPED_TEST(OverflowTest, SubOverflowToNegative) { 615 TypeParam Result; 616 auto MaxValue = std::numeric_limits<TypeParam>::max(); 617 auto MinValue = std::numeric_limits<TypeParam>::min(); 618 EXPECT_TRUE(SubOverflow<TypeParam>(MaxValue, MinValue, Result)); 619 EXPECT_EQ(Result, TypeParam(-1)); 620 } 621 622 TYPED_TEST(OverflowTest, SubOverflowToPositive) { 623 TypeParam Result; 624 auto MaxValue = std::numeric_limits<TypeParam>::max(); 625 auto MinValue = std::numeric_limits<TypeParam>::min(); 626 EXPECT_TRUE(SubOverflow<TypeParam>(MinValue, MaxValue, Result)); 627 EXPECT_EQ(Result, TypeParam(1)); 628 } 629 630 TYPED_TEST(OverflowTest, MulNoOverflow) { 631 TypeParam Result; 632 EXPECT_FALSE(MulOverflow<TypeParam>(1, 2, Result)); 633 EXPECT_EQ(Result, 2); 634 EXPECT_FALSE(MulOverflow<TypeParam>(-1, 3, Result)); 635 EXPECT_EQ(Result, -3); 636 EXPECT_FALSE(MulOverflow<TypeParam>(4, -2, Result)); 637 EXPECT_EQ(Result, -8); 638 EXPECT_FALSE(MulOverflow<TypeParam>(-6, -5, Result)); 639 EXPECT_EQ(Result, 30); 640 } 641 642 TYPED_TEST(OverflowTest, MulNoOverflowToMax) { 643 TypeParam Result; 644 auto MaxValue = std::numeric_limits<TypeParam>::max(); 645 auto MinValue = std::numeric_limits<TypeParam>::min(); 646 EXPECT_FALSE(MulOverflow<TypeParam>(MinValue + 1, -1, Result)); 647 EXPECT_EQ(Result, MaxValue); 648 } 649 650 TYPED_TEST(OverflowTest, MulOverflowToMin) { 651 TypeParam Result; 652 auto MinValue = std::numeric_limits<TypeParam>::min(); 653 EXPECT_TRUE(MulOverflow<TypeParam>(MinValue, -1, Result)); 654 EXPECT_EQ(Result, MinValue); 655 } 656 657 TYPED_TEST(OverflowTest, MulOverflowMax) { 658 TypeParam Result; 659 auto MinValue = std::numeric_limits<TypeParam>::min(); 660 auto MaxValue = std::numeric_limits<TypeParam>::max(); 661 EXPECT_TRUE(MulOverflow<TypeParam>(MinValue, MinValue, Result)); 662 EXPECT_EQ(Result, 0); 663 EXPECT_TRUE(MulOverflow<TypeParam>(MaxValue, MaxValue, Result)); 664 EXPECT_EQ(Result, 1); 665 } 666 667 TYPED_TEST(OverflowTest, MulResultZero) { 668 TypeParam Result; 669 EXPECT_FALSE(MulOverflow<TypeParam>(4, 0, Result)); 670 EXPECT_EQ(Result, TypeParam(0)); 671 EXPECT_FALSE(MulOverflow<TypeParam>(-5, 0, Result)); 672 EXPECT_EQ(Result, TypeParam(0)); 673 EXPECT_FALSE(MulOverflow<TypeParam>(0, 5, Result)); 674 EXPECT_EQ(Result, TypeParam(0)); 675 EXPECT_FALSE(MulOverflow<TypeParam>(0, -5, Result)); 676 EXPECT_EQ(Result, TypeParam(0)); 677 } 678 679 } // namespace 680