unittests/Support/MathExtrasTest.cpp

   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>(), 0);
 208   EXPECT_EQ(CTLog2<1ULL << 1>(), 1);
 209   EXPECT_EQ(CTLog2<1ULL << 2>(), 2);
 210   EXPECT_EQ(CTLog2<1ULL << 3>(), 3);
 211   EXPECT_EQ(CTLog2<1ULL << 4>(), 4);
 212   EXPECT_EQ(CTLog2<1ULL << 5>(), 5);
 213   EXPECT_EQ(CTLog2<1ULL << 6>(), 6);
 214   EXPECT_EQ(CTLog2<1ULL << 7>(), 7);
 215   EXPECT_EQ(CTLog2<1ULL << 8>(), 8);
 216   EXPECT_EQ(CTLog2<1ULL << 9>(), 9);
 217   EXPECT_EQ(CTLog2<1ULL << 10>(), 10);
 218   EXPECT_EQ(CTLog2<1ULL << 11>(), 11);
 219   EXPECT_EQ(CTLog2<1ULL << 12>(), 12);
 220   EXPECT_EQ(CTLog2<1ULL << 13>(), 13);
 221   EXPECT_EQ(CTLog2<1ULL << 14>(), 14);
 222   EXPECT_EQ(CTLog2<1ULL << 15>(), 15);
 223 }
 224
 225 TEST(MathExtras, ByteSwap_32) {
 226   EXPECT_EQ(0x44332211u, ByteSwap_32(0x11223344));
 227   EXPECT_EQ(0xDDCCBBAAu, ByteSwap_32(0xAABBCCDD));
 228 }
 229
 230 TEST(MathExtras, ByteSwap_64) {
 231   EXPECT_EQ(0x8877665544332211ULL, ByteSwap_64(0x1122334455667788LL));
 232   EXPECT_EQ(0x1100FFEEDDCCBBAAULL, ByteSwap_64(0xAABBCCDDEEFF0011LL));
 233 }
 234
 235 TEST(MathExtras, countLeadingOnes) {
 236   for (int i = 30; i >= 0; --i) {
 237     // Start with all ones and unset some bit.
 238     EXPECT_EQ(31u - i, countLeadingOnes(0xFFFFFFFF ^ (1 << i)));
 239   }
 240   for (int i = 62; i >= 0; --i) {
 241     // Start with all ones and unset some bit.
 242     EXPECT_EQ(63u - i, countLeadingOnes(0xFFFFFFFFFFFFFFFFULL ^ (1LL << i)));
 243   }
 244   for (int i = 30; i >= 0; --i) {
 245     // Start with all ones and unset some bit.
 246     EXPECT_EQ(31u - i, countLeadingOnes(0xFFFFFFFF ^ (1 << i)));
 247   }
 248 }
 249
 250 TEST(MathExtras, FloatBits) {
 251   static const float kValue = 5632.34f;
 252   EXPECT_FLOAT_EQ(kValue, BitsToFloat(FloatToBits(kValue)));
 253 }
 254
 255 TEST(MathExtras, DoubleBits) {
 256   static const double kValue = 87987234.983498;
 257   EXPECT_DOUBLE_EQ(kValue, BitsToDouble(DoubleToBits(kValue)));
 258 }
 259
 260 TEST(MathExtras, MinAlign) {
 261   EXPECT_EQ(1u, MinAlign(2, 3));
 262   EXPECT_EQ(2u, MinAlign(2, 4));
 263   EXPECT_EQ(1u, MinAlign(17, 64));
 264   EXPECT_EQ(256u, MinAlign(256, 512));
 265 }
 266
 267 TEST(MathExtras, NextPowerOf2) {
 268   EXPECT_EQ(4u, NextPowerOf2(3));
 269   EXPECT_EQ(16u, NextPowerOf2(15));
 270   EXPECT_EQ(256u, NextPowerOf2(128));
 271 }
 272
 273 TEST(MathExtras, alignTo) {
 274   EXPECT_EQ(8u, alignTo(5, 8));
 275   EXPECT_EQ(24u, alignTo(17, 8));
 276   EXPECT_EQ(0u, alignTo(~0LL, 8));
 277
 278   EXPECT_EQ(7u, alignTo(5, 8, 7));
 279   EXPECT_EQ(17u, alignTo(17, 8, 1));
 280   EXPECT_EQ(3u, alignTo(~0LL, 8, 3));
 281   EXPECT_EQ(552u, alignTo(321, 255, 42));
 282 }
 283
 284 template<typename T>
 285 void SaturatingAddTestHelper()
 286 {
 287   const T Max = std::numeric_limits<T>::max();
 288   bool ResultOverflowed;
 289
 290   EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2)));
 291   EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2), &ResultOverflowed));
 292   EXPECT_FALSE(ResultOverflowed);
 293
 294   EXPECT_EQ(Max, SaturatingAdd(Max, T(1)));
 295   EXPECT_EQ(Max, SaturatingAdd(Max, T(1), &ResultOverflowed));
 296   EXPECT_TRUE(ResultOverflowed);
 297
 298   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1)));
 299   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1), &ResultOverflowed));
 300   EXPECT_FALSE(ResultOverflowed);
 301
 302   EXPECT_EQ(Max, SaturatingAdd(T(1), Max));
 303   EXPECT_EQ(Max, SaturatingAdd(T(1), Max, &ResultOverflowed));
 304   EXPECT_TRUE(ResultOverflowed);
 305
 306   EXPECT_EQ(Max, SaturatingAdd(Max, Max));
 307   EXPECT_EQ(Max, SaturatingAdd(Max, Max, &ResultOverflowed));
 308   EXPECT_TRUE(ResultOverflowed);
 309 }
 310
 311 TEST(MathExtras, SaturatingAdd) {
 312   SaturatingAddTestHelper<uint8_t>();
 313   SaturatingAddTestHelper<uint16_t>();
 314   SaturatingAddTestHelper<uint32_t>();
 315   SaturatingAddTestHelper<uint64_t>();
 316 }
 317
 318 template<typename T>
 319 void SaturatingMultiplyTestHelper()
 320 {
 321   const T Max = std::numeric_limits<T>::max();
 322   bool ResultOverflowed;
 323
 324   // Test basic multiplication.
 325   EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3)));
 326   EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3), &ResultOverflowed));
 327   EXPECT_FALSE(ResultOverflowed);
 328
 329   EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2)));
 330   EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2), &ResultOverflowed));
 331   EXPECT_FALSE(ResultOverflowed);
 332
 333   // Test multiplication by zero.
 334   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0)));
 335   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0), &ResultOverflowed));
 336   EXPECT_FALSE(ResultOverflowed);
 337
 338   EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0)));
 339   EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0), &ResultOverflowed));
 340   EXPECT_FALSE(ResultOverflowed);
 341
 342   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1)));
 343   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1), &ResultOverflowed));
 344   EXPECT_FALSE(ResultOverflowed);
 345
 346   EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0)));
 347   EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0), &ResultOverflowed));
 348   EXPECT_FALSE(ResultOverflowed);
 349
 350   EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max));
 351   EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max, &ResultOverflowed));
 352   EXPECT_FALSE(ResultOverflowed);
 353
 354   // Test multiplication by maximum value.
 355   EXPECT_EQ(Max, SaturatingMultiply(Max, T(2)));
 356   EXPECT_EQ(Max, SaturatingMultiply(Max, T(2), &ResultOverflowed));
 357   EXPECT_TRUE(ResultOverflowed);
 358
 359   EXPECT_EQ(Max, SaturatingMultiply(T(2), Max));
 360   EXPECT_EQ(Max, SaturatingMultiply(T(2), Max, &ResultOverflowed));
 361   EXPECT_TRUE(ResultOverflowed);
 362
 363   EXPECT_EQ(Max, SaturatingMultiply(Max, Max));
 364   EXPECT_EQ(Max, SaturatingMultiply(Max, Max, &ResultOverflowed));
 365   EXPECT_TRUE(ResultOverflowed);
 366
 367   // Test interesting boundary conditions for algorithm -
 368   // ((1 << A) - 1) * ((1 << B) + K) for K in [-1, 0, 1]
 369   // and A + B == std::numeric_limits<T>::digits.
 370   // We expect overflow iff A > B and K = 1.
 371   const int Digits = std::numeric_limits<T>::digits;
 372   for (int A = 1, B = Digits - 1; B >= 1; ++A, --B) {
 373     for (int K = -1; K <= 1; ++K) {
 374       T X = (T(1) << A) - T(1);
 375       T Y = (T(1) << B) + K;
 376       bool OverflowExpected = A > B && K == 1;
 377
 378       if(OverflowExpected) {
 379         EXPECT_EQ(Max, SaturatingMultiply(X, Y));
 380         EXPECT_EQ(Max, SaturatingMultiply(X, Y, &ResultOverflowed));
 381         EXPECT_TRUE(ResultOverflowed);
 382       } else {
 383         EXPECT_EQ(X * Y, SaturatingMultiply(X, Y));
 384         EXPECT_EQ(X * Y, SaturatingMultiply(X, Y, &ResultOverflowed));
 385         EXPECT_FALSE(ResultOverflowed);
 386       }
 387     }
 388   }
 389 }
 390
 391 TEST(MathExtras, SaturatingMultiply) {
 392   SaturatingMultiplyTestHelper<uint8_t>();
 393   SaturatingMultiplyTestHelper<uint16_t>();
 394   SaturatingMultiplyTestHelper<uint32_t>();
 395   SaturatingMultiplyTestHelper<uint64_t>();
 396 }
 397
 398 template<typename T>
 399 void SaturatingMultiplyAddTestHelper()
 400 {
 401   const T Max = std::numeric_limits<T>::max();
 402   bool ResultOverflowed;
 403
 404   // Test basic multiply-add.
 405   EXPECT_EQ(T(16), SaturatingMultiplyAdd(T(2), T(3), T(10)));
 406   EXPECT_EQ(T(16), SaturatingMultiplyAdd(T(2), T(3), T(10), &ResultOverflowed));
 407   EXPECT_FALSE(ResultOverflowed);
 408
 409   // Test multiply overflows, add doesn't overflow
 410   EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, T(0), &ResultOverflowed));
 411   EXPECT_TRUE(ResultOverflowed);
 412
 413   // Test multiply doesn't overflow, add overflows
 414   EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), T(1), Max, &ResultOverflowed));
 415   EXPECT_TRUE(ResultOverflowed);
 416
 417   // Test multiply-add with Max as operand
 418   EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), T(1), Max, &ResultOverflowed));
 419   EXPECT_TRUE(ResultOverflowed);
 420
 421   EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), Max, T(1), &ResultOverflowed));
 422   EXPECT_TRUE(ResultOverflowed);
 423
 424   EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, T(1), &ResultOverflowed));
 425   EXPECT_TRUE(ResultOverflowed);
 426
 427   EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, Max, &ResultOverflowed));
 428   EXPECT_TRUE(ResultOverflowed);
 429
 430   // Test multiply-add with 0 as operand
 431   EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(1), T(1), T(0), &ResultOverflowed));
 432   EXPECT_FALSE(ResultOverflowed);
 433
 434   EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(1), T(0), T(1), &ResultOverflowed));
 435   EXPECT_FALSE(ResultOverflowed);
 436
 437   EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(0), T(0), T(1), &ResultOverflowed));
 438   EXPECT_FALSE(ResultOverflowed);
 439
 440   EXPECT_EQ(T(0), SaturatingMultiplyAdd(T(0), T(0), T(0), &ResultOverflowed));
 441   EXPECT_FALSE(ResultOverflowed);
 442
 443 }
 444
 445 TEST(MathExtras, SaturatingMultiplyAdd) {
 446   SaturatingMultiplyAddTestHelper<uint8_t>();
 447   SaturatingMultiplyAddTestHelper<uint16_t>();
 448   SaturatingMultiplyAddTestHelper<uint32_t>();
 449   SaturatingMultiplyAddTestHelper<uint64_t>();
 450 }
 451
 452 TEST(MathExtras, IsShiftedUInt) {
 453   EXPECT_TRUE((isShiftedUInt<1, 0>(0)));
 454   EXPECT_TRUE((isShiftedUInt<1, 0>(1)));
 455   EXPECT_FALSE((isShiftedUInt<1, 0>(2)));
 456   EXPECT_FALSE((isShiftedUInt<1, 0>(3)));
 457   EXPECT_FALSE((isShiftedUInt<1, 0>(0x8000000000000000)));
 458   EXPECT_TRUE((isShiftedUInt<1, 63>(0x8000000000000000)));
 459   EXPECT_TRUE((isShiftedUInt<2, 62>(0xC000000000000000)));
 460   EXPECT_FALSE((isShiftedUInt<2, 62>(0xE000000000000000)));
 461
 462   // 0x201 is ten bits long and has a 1 in the MSB and LSB.
 463   EXPECT_TRUE((isShiftedUInt<10, 5>(uint64_t(0x201) << 5)));
 464   EXPECT_FALSE((isShiftedUInt<10, 5>(uint64_t(0x201) << 4)));
 465   EXPECT_FALSE((isShiftedUInt<10, 5>(uint64_t(0x201) << 6)));
 466 }
 467
 468 TEST(MathExtras, IsShiftedInt) {
 469   EXPECT_TRUE((isShiftedInt<1, 0>(0)));
 470   EXPECT_TRUE((isShiftedInt<1, 0>(-1)));
 471   EXPECT_FALSE((isShiftedInt<1, 0>(2)));
 472   EXPECT_FALSE((isShiftedInt<1, 0>(3)));
 473   EXPECT_FALSE((isShiftedInt<1, 0>(0x8000000000000000)));
 474   EXPECT_TRUE((isShiftedInt<1, 63>(0x8000000000000000)));
 475   EXPECT_TRUE((isShiftedInt<2, 62>(0xC000000000000000)));
 476   EXPECT_FALSE((isShiftedInt<2, 62>(0xE000000000000000)));
 477
 478   // 0x201 is ten bits long and has a 1 in the MSB and LSB.
 479   EXPECT_TRUE((isShiftedInt<11, 5>(int64_t(0x201) << 5)));
 480   EXPECT_FALSE((isShiftedInt<11, 5>(int64_t(0x201) << 3)));
 481   EXPECT_FALSE((isShiftedInt<11, 5>(int64_t(0x201) << 6)));
 482   EXPECT_TRUE((isShiftedInt<11, 5>(-(int64_t(0x201) << 5))));
 483   EXPECT_FALSE((isShiftedInt<11, 5>(-(int64_t(0x201) << 3))));
 484   EXPECT_FALSE((isShiftedInt<11, 5>(-(int64_t(0x201) << 6))));
 485
 486   EXPECT_TRUE((isShiftedInt<6, 10>(-(int64_t(1) << 15))));
 487   EXPECT_FALSE((isShiftedInt<6, 10>(int64_t(1) << 15)));
 488 }
 489
 490 template <typename T>
 491 class OverflowTest : public ::testing::Test { };
 492
 493 using OverflowTestTypes = ::testing::Types<signed char, short, int, long,
 494                                            long long>;
 495
 496 TYPED_TEST_CASE(OverflowTest, OverflowTestTypes);
 497
 498 TYPED_TEST(OverflowTest, AddNoOverflow) {
 499   TypeParam Result;
 500   EXPECT_FALSE(AddOverflow<TypeParam>(1, 2, Result));
 501   EXPECT_EQ(Result, TypeParam(3));
 502 }
 503
 504 TYPED_TEST(OverflowTest, AddOverflowToNegative) {
 505   TypeParam Result;
 506   auto MaxValue = std::numeric_limits<TypeParam>::max();
 507   EXPECT_TRUE(AddOverflow<TypeParam>(MaxValue, MaxValue, Result));
 508   EXPECT_EQ(Result, TypeParam(-2));
 509 }
 510
 511 TYPED_TEST(OverflowTest, AddOverflowToMin) {
 512   TypeParam Result;
 513   auto MaxValue = std::numeric_limits<TypeParam>::max();
 514   EXPECT_TRUE(AddOverflow<TypeParam>(MaxValue, TypeParam(1), Result));
 515   EXPECT_EQ(Result, std::numeric_limits<TypeParam>::min());
 516 }
 517
 518 TYPED_TEST(OverflowTest, AddOverflowToZero) {
 519   TypeParam Result;
 520   auto MinValue = std::numeric_limits<TypeParam>::min();
 521   EXPECT_TRUE(AddOverflow<TypeParam>(MinValue, MinValue, Result));
 522   EXPECT_EQ(Result, TypeParam(0));
 523 }
 524
 525 TYPED_TEST(OverflowTest, AddOverflowToMax) {
 526   TypeParam Result;
 527   auto MinValue = std::numeric_limits<TypeParam>::min();
 528   EXPECT_TRUE(AddOverflow<TypeParam>(MinValue, TypeParam(-1), Result));
 529   EXPECT_EQ(Result, std::numeric_limits<TypeParam>::max());
 530 }
 531
 532 TYPED_TEST(OverflowTest, SubNoOverflow) {
 533   TypeParam Result;
 534   EXPECT_FALSE(SubOverflow<TypeParam>(1, 2, Result));
 535   EXPECT_EQ(Result, TypeParam(-1));
 536 }
 537
 538 TYPED_TEST(OverflowTest, SubOverflowToMax) {
 539   TypeParam Result;
 540   auto MinValue = std::numeric_limits<TypeParam>::min();
 541   EXPECT_TRUE(SubOverflow<TypeParam>(0, MinValue, Result));
 542   EXPECT_EQ(Result, MinValue);
 543 }
 544
 545 TYPED_TEST(OverflowTest, SubOverflowToMin) {
 546   TypeParam Result;
 547   auto MinValue = std::numeric_limits<TypeParam>::min();
 548   EXPECT_TRUE(SubOverflow<TypeParam>(0, MinValue, Result));
 549   EXPECT_EQ(Result, MinValue);
 550 }
 551
 552 TYPED_TEST(OverflowTest, SubOverflowToNegative) {
 553   TypeParam Result;
 554   auto MaxValue = std::numeric_limits<TypeParam>::max();
 555   auto MinValue = std::numeric_limits<TypeParam>::min();
 556   EXPECT_TRUE(SubOverflow<TypeParam>(MaxValue, MinValue, Result));
 557   EXPECT_EQ(Result, TypeParam(-1));
 558 }
 559
 560 TYPED_TEST(OverflowTest, SubOverflowToPositive) {
 561   TypeParam Result;
 562   auto MaxValue = std::numeric_limits<TypeParam>::max();
 563   auto MinValue = std::numeric_limits<TypeParam>::min();
 564   EXPECT_TRUE(SubOverflow<TypeParam>(MinValue, MaxValue, Result));
 565   EXPECT_EQ(Result, TypeParam(1));
 566 }
 567
 568 TYPED_TEST(OverflowTest, MulNoOverflow) {
 569   TypeParam Result;
 570   EXPECT_FALSE(MulOverflow<TypeParam>(1, 2, Result));
 571   EXPECT_EQ(Result, 2);
 572   EXPECT_FALSE(MulOverflow<TypeParam>(-1, 3, Result));
 573   EXPECT_EQ(Result, -3);
 574   EXPECT_FALSE(MulOverflow<TypeParam>(4, -2, Result));
 575   EXPECT_EQ(Result, -8);
 576   EXPECT_FALSE(MulOverflow<TypeParam>(-6, -5, Result));
 577   EXPECT_EQ(Result, 30);
 578 }
 579
 580 TYPED_TEST(OverflowTest, MulNoOverflowToMax) {
 581   TypeParam Result;
 582   auto MaxValue = std::numeric_limits<TypeParam>::max();
 583   auto MinValue = std::numeric_limits<TypeParam>::min();
 584   EXPECT_FALSE(MulOverflow<TypeParam>(MinValue + 1, -1, Result));
 585   EXPECT_EQ(Result, MaxValue);
 586 }
 587
 588 TYPED_TEST(OverflowTest, MulOverflowToMin) {
 589   TypeParam Result;
 590   auto MinValue = std::numeric_limits<TypeParam>::min();
 591   EXPECT_TRUE(MulOverflow<TypeParam>(MinValue, -1, Result));
 592   EXPECT_EQ(Result, MinValue);
 593 }
 594
 595 TYPED_TEST(OverflowTest, MulOverflowMax) {
 596   TypeParam Result;
 597   auto MinValue = std::numeric_limits<TypeParam>::min();
 598   auto MaxValue = std::numeric_limits<TypeParam>::max();
 599   EXPECT_TRUE(MulOverflow<TypeParam>(MinValue, MinValue, Result));
 600   EXPECT_EQ(Result, 0);
 601   EXPECT_TRUE(MulOverflow<TypeParam>(MaxValue, MaxValue, Result));
 602   EXPECT_EQ(Result, 1);
 603 }
 604
 605 TYPED_TEST(OverflowTest, MulResultZero) {
 606   TypeParam Result;
 607   EXPECT_FALSE(MulOverflow<TypeParam>(4, 0, Result));
 608   EXPECT_EQ(Result, TypeParam(0));
 609   EXPECT_FALSE(MulOverflow<TypeParam>(-5, 0, Result));
 610   EXPECT_EQ(Result, TypeParam(0));
 611   EXPECT_FALSE(MulOverflow<TypeParam>(0, 5, Result));
 612   EXPECT_EQ(Result, TypeParam(0));
 613   EXPECT_FALSE(MulOverflow<TypeParam>(0, -5, Result));
 614   EXPECT_EQ(Result, TypeParam(0));
 615 }
 616
 617 } // namespace