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