1 //===- llvm/unittest/Support/KnownBitsTest.cpp - KnownBits 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 // This file implements unit tests for KnownBits functions. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/ADT/ArrayRef.h" 14 #include "llvm/Support/KnownBits.h" 15 #include "KnownBitsTest.h" 16 #include "gtest/gtest.h" 17 18 using namespace llvm; 19 20 using UnaryBitsFn = llvm::function_ref<KnownBits(const KnownBits &)>; 21 using UnaryIntFn = llvm::function_ref<std::optional<APInt>(const APInt &)>; 22 using UnaryCheckFn = llvm::function_ref<bool(const KnownBits &)>; 23 24 using BinaryBitsFn = 25 llvm::function_ref<KnownBits(const KnownBits &, const KnownBits &)>; 26 using BinaryIntFn = 27 llvm::function_ref<std::optional<APInt>(const APInt &, const APInt &)>; 28 using BinaryCheckFn = 29 llvm::function_ref<bool(const KnownBits &, const KnownBits &)>; 30 31 static bool checkOptimalityUnary(const KnownBits &) { return true; } 32 static bool checkCorrectnessOnlyUnary(const KnownBits &) { return false; } 33 static bool checkOptimalityBinary(const KnownBits &, const KnownBits &) { 34 return true; 35 } 36 static bool checkCorrectnessOnlyBinary(const KnownBits &, const KnownBits &) { 37 return false; 38 } 39 40 static testing::AssertionResult isCorrect(const KnownBits &Exact, 41 const KnownBits &Computed, 42 ArrayRef<KnownBits> Inputs) { 43 if (Computed.Zero.isSubsetOf(Exact.Zero) && 44 Computed.One.isSubsetOf(Exact.One)) 45 return testing::AssertionSuccess(); 46 47 testing::AssertionResult Result = testing::AssertionFailure(); 48 Result << "Inputs = "; 49 for (const KnownBits &Input : Inputs) 50 Result << Input << ", "; 51 Result << "Computed = " << Computed << ", Exact = " << Exact; 52 return Result; 53 } 54 55 static testing::AssertionResult isOptimal(const KnownBits &Exact, 56 const KnownBits &Computed, 57 ArrayRef<KnownBits> Inputs) { 58 if (Computed == Exact) 59 return testing::AssertionSuccess(); 60 61 testing::AssertionResult Result = testing::AssertionFailure(); 62 Result << "Inputs = "; 63 for (const KnownBits &Input : Inputs) 64 Result << Input << ", "; 65 Result << "Computed = " << Computed << ", Exact = " << Exact; 66 return Result; 67 } 68 69 static void 70 testUnaryOpExhaustive(UnaryBitsFn BitsFn, UnaryIntFn IntFn, 71 UnaryCheckFn CheckOptimalityFn = checkOptimalityUnary) { 72 for (unsigned Bits : {1, 4}) { 73 ForeachKnownBits(Bits, [&](const KnownBits &Known) { 74 KnownBits Computed = BitsFn(Known); 75 KnownBits Exact(Bits); 76 Exact.Zero.setAllBits(); 77 Exact.One.setAllBits(); 78 79 ForeachNumInKnownBits(Known, [&](const APInt &N) { 80 if (std::optional<APInt> Res = IntFn(N)) { 81 Exact.One &= *Res; 82 Exact.Zero &= ~*Res; 83 } 84 }); 85 86 EXPECT_TRUE(!Computed.hasConflict()); 87 EXPECT_TRUE(isCorrect(Exact, Computed, Known)); 88 // We generally don't want to return conflicting known bits, even if it is 89 // legal for always poison results. 90 if (CheckOptimalityFn(Known) && !Exact.hasConflict()) { 91 EXPECT_TRUE(isOptimal(Exact, Computed, Known)); 92 } 93 }); 94 } 95 } 96 97 static void 98 testBinaryOpExhaustive(BinaryBitsFn BitsFn, BinaryIntFn IntFn, 99 BinaryCheckFn CheckOptimalityFn = checkOptimalityBinary, 100 bool RefinePoisonToZero = false) { 101 for (unsigned Bits : {1, 4}) { 102 ForeachKnownBits(Bits, [&](const KnownBits &Known1) { 103 ForeachKnownBits(Bits, [&](const KnownBits &Known2) { 104 KnownBits Computed = BitsFn(Known1, Known2); 105 KnownBits Exact(Bits); 106 Exact.Zero.setAllBits(); 107 Exact.One.setAllBits(); 108 109 ForeachNumInKnownBits(Known1, [&](const APInt &N1) { 110 ForeachNumInKnownBits(Known2, [&](const APInt &N2) { 111 if (std::optional<APInt> Res = IntFn(N1, N2)) { 112 Exact.One &= *Res; 113 Exact.Zero &= ~*Res; 114 } 115 }); 116 }); 117 118 EXPECT_TRUE(!Computed.hasConflict()); 119 EXPECT_TRUE(isCorrect(Exact, Computed, {Known1, Known2})); 120 // We generally don't want to return conflicting known bits, even if it 121 // is legal for always poison results. 122 if (CheckOptimalityFn(Known1, Known2) && !Exact.hasConflict()) { 123 EXPECT_TRUE(isOptimal(Exact, Computed, {Known1, Known2})); 124 } 125 // In some cases we choose to return zero if the result is always 126 // poison. 127 if (RefinePoisonToZero && Exact.hasConflict()) { 128 EXPECT_TRUE(Computed.isZero()); 129 } 130 }); 131 }); 132 } 133 } 134 135 namespace { 136 137 TEST(KnownBitsTest, AddCarryExhaustive) { 138 unsigned Bits = 4; 139 ForeachKnownBits(Bits, [&](const KnownBits &Known1) { 140 ForeachKnownBits(Bits, [&](const KnownBits &Known2) { 141 ForeachKnownBits(1, [&](const KnownBits &KnownCarry) { 142 // Explicitly compute known bits of the addition by trying all 143 // possibilities. 144 KnownBits Known(Bits); 145 Known.Zero.setAllBits(); 146 Known.One.setAllBits(); 147 ForeachNumInKnownBits(Known1, [&](const APInt &N1) { 148 ForeachNumInKnownBits(Known2, [&](const APInt &N2) { 149 ForeachNumInKnownBits(KnownCarry, [&](const APInt &Carry) { 150 APInt Add = N1 + N2; 151 if (Carry.getBoolValue()) 152 ++Add; 153 154 Known.One &= Add; 155 Known.Zero &= ~Add; 156 }); 157 }); 158 }); 159 160 KnownBits KnownComputed = 161 KnownBits::computeForAddCarry(Known1, Known2, KnownCarry); 162 EXPECT_EQ(Known, KnownComputed); 163 }); 164 }); 165 }); 166 } 167 168 static void TestAddSubExhaustive(bool IsAdd) { 169 unsigned Bits = 4; 170 ForeachKnownBits(Bits, [&](const KnownBits &Known1) { 171 ForeachKnownBits(Bits, [&](const KnownBits &Known2) { 172 KnownBits Known(Bits), KnownNSW(Bits), KnownNUW(Bits), 173 KnownNSWAndNUW(Bits); 174 Known.Zero.setAllBits(); 175 Known.One.setAllBits(); 176 KnownNSW.Zero.setAllBits(); 177 KnownNSW.One.setAllBits(); 178 KnownNUW.Zero.setAllBits(); 179 KnownNUW.One.setAllBits(); 180 KnownNSWAndNUW.Zero.setAllBits(); 181 KnownNSWAndNUW.One.setAllBits(); 182 183 ForeachNumInKnownBits(Known1, [&](const APInt &N1) { 184 ForeachNumInKnownBits(Known2, [&](const APInt &N2) { 185 bool SignedOverflow; 186 bool UnsignedOverflow; 187 APInt Res; 188 if (IsAdd) { 189 Res = N1.uadd_ov(N2, UnsignedOverflow); 190 Res = N1.sadd_ov(N2, SignedOverflow); 191 } else { 192 Res = N1.usub_ov(N2, UnsignedOverflow); 193 Res = N1.ssub_ov(N2, SignedOverflow); 194 } 195 196 Known.One &= Res; 197 Known.Zero &= ~Res; 198 199 if (!SignedOverflow) { 200 KnownNSW.One &= Res; 201 KnownNSW.Zero &= ~Res; 202 } 203 204 if (!UnsignedOverflow) { 205 KnownNUW.One &= Res; 206 KnownNUW.Zero &= ~Res; 207 } 208 209 if (!UnsignedOverflow && !SignedOverflow) { 210 KnownNSWAndNUW.One &= Res; 211 KnownNSWAndNUW.Zero &= ~Res; 212 } 213 }); 214 }); 215 216 KnownBits KnownComputed = KnownBits::computeForAddSub( 217 IsAdd, /*NSW=*/false, /*NUW=*/false, Known1, Known2); 218 EXPECT_TRUE(isOptimal(Known, KnownComputed, {Known1, Known2})); 219 220 KnownBits KnownNSWComputed = KnownBits::computeForAddSub( 221 IsAdd, /*NSW=*/true, /*NUW=*/false, Known1, Known2); 222 if (!KnownNSW.hasConflict()) 223 EXPECT_TRUE(isOptimal(KnownNSW, KnownNSWComputed, {Known1, Known2})); 224 225 KnownBits KnownNUWComputed = KnownBits::computeForAddSub( 226 IsAdd, /*NSW=*/false, /*NUW=*/true, Known1, Known2); 227 if (!KnownNUW.hasConflict()) 228 EXPECT_TRUE(isOptimal(KnownNUW, KnownNUWComputed, {Known1, Known2})); 229 230 KnownBits KnownNSWAndNUWComputed = KnownBits::computeForAddSub( 231 IsAdd, /*NSW=*/true, /*NUW=*/true, Known1, Known2); 232 if (!KnownNSWAndNUW.hasConflict()) 233 EXPECT_TRUE(isOptimal(KnownNSWAndNUW, KnownNSWAndNUWComputed, 234 {Known1, Known2})); 235 }); 236 }); 237 } 238 239 TEST(KnownBitsTest, AddSubExhaustive) { 240 TestAddSubExhaustive(true); 241 TestAddSubExhaustive(false); 242 } 243 244 TEST(KnownBitsTest, SubBorrowExhaustive) { 245 unsigned Bits = 4; 246 ForeachKnownBits(Bits, [&](const KnownBits &Known1) { 247 ForeachKnownBits(Bits, [&](const KnownBits &Known2) { 248 ForeachKnownBits(1, [&](const KnownBits &KnownBorrow) { 249 // Explicitly compute known bits of the subtraction by trying all 250 // possibilities. 251 KnownBits Known(Bits); 252 Known.Zero.setAllBits(); 253 Known.One.setAllBits(); 254 ForeachNumInKnownBits(Known1, [&](const APInt &N1) { 255 ForeachNumInKnownBits(Known2, [&](const APInt &N2) { 256 ForeachNumInKnownBits(KnownBorrow, [&](const APInt &Borrow) { 257 APInt Sub = N1 - N2; 258 if (Borrow.getBoolValue()) 259 --Sub; 260 261 Known.One &= Sub; 262 Known.Zero &= ~Sub; 263 }); 264 }); 265 }); 266 267 KnownBits KnownComputed = 268 KnownBits::computeForSubBorrow(Known1, Known2, KnownBorrow); 269 EXPECT_EQ(Known, KnownComputed); 270 }); 271 }); 272 }); 273 } 274 275 TEST(KnownBitsTest, SignBitUnknown) { 276 KnownBits Known(2); 277 EXPECT_TRUE(Known.isSignUnknown()); 278 Known.Zero.setBit(0); 279 EXPECT_TRUE(Known.isSignUnknown()); 280 Known.Zero.setBit(1); 281 EXPECT_FALSE(Known.isSignUnknown()); 282 Known.Zero.clearBit(0); 283 EXPECT_FALSE(Known.isSignUnknown()); 284 Known.Zero.clearBit(1); 285 EXPECT_TRUE(Known.isSignUnknown()); 286 287 Known.One.setBit(0); 288 EXPECT_TRUE(Known.isSignUnknown()); 289 Known.One.setBit(1); 290 EXPECT_FALSE(Known.isSignUnknown()); 291 Known.One.clearBit(0); 292 EXPECT_FALSE(Known.isSignUnknown()); 293 Known.One.clearBit(1); 294 EXPECT_TRUE(Known.isSignUnknown()); 295 } 296 297 TEST(KnownBitsTest, ABDUSpecialCase) { 298 // There are 2 implementations of abdu - both are currently needed to cover 299 // extra cases. 300 KnownBits LHS, RHS, Res; 301 302 // abdu(LHS,RHS) = sub(umax(LHS,RHS), umin(LHS,RHS)). 303 // Actual: false (Inputs = 1011, 101?, Computed = 000?, Exact = 000?) 304 LHS.One = APInt(4, 0b1011); 305 RHS.One = APInt(4, 0b1010); 306 LHS.Zero = APInt(4, 0b0100); 307 RHS.Zero = APInt(4, 0b0100); 308 Res = KnownBits::abdu(LHS, RHS); 309 EXPECT_EQ(0b0000ul, Res.One.getZExtValue()); 310 EXPECT_EQ(0b1110ul, Res.Zero.getZExtValue()); 311 312 // find the common bits between sub(LHS,RHS) and sub(RHS,LHS). 313 // Actual: false (Inputs = ???1, 1000, Computed = ???1, Exact = 0??1) 314 LHS.One = APInt(4, 0b0001); 315 RHS.One = APInt(4, 0b1000); 316 LHS.Zero = APInt(4, 0b0000); 317 RHS.Zero = APInt(4, 0b0111); 318 Res = KnownBits::abdu(LHS, RHS); 319 EXPECT_EQ(0b0001ul, Res.One.getZExtValue()); 320 EXPECT_EQ(0b0000ul, Res.Zero.getZExtValue()); 321 } 322 323 TEST(KnownBitsTest, ABDSSpecialCase) { 324 // There are 2 implementations of abds - both are currently needed to cover 325 // extra cases. 326 KnownBits LHS, RHS, Res; 327 328 // abds(LHS,RHS) = sub(smax(LHS,RHS), smin(LHS,RHS)). 329 // Actual: false (Inputs = 1011, 10??, Computed = ????, Exact = 00??) 330 LHS.One = APInt(4, 0b1011); 331 RHS.One = APInt(4, 0b1000); 332 LHS.Zero = APInt(4, 0b0100); 333 RHS.Zero = APInt(4, 0b0100); 334 Res = KnownBits::abds(LHS, RHS); 335 EXPECT_EQ(0, Res.One.getSExtValue()); 336 EXPECT_EQ(-4, Res.Zero.getSExtValue()); 337 338 // find the common bits between sub(LHS,RHS) and sub(RHS,LHS). 339 // Actual: false (Inputs = ???1, 1000, Computed = ???1, Exact = 0??1) 340 LHS.One = APInt(4, 0b0001); 341 RHS.One = APInt(4, 0b1000); 342 LHS.Zero = APInt(4, 0b0000); 343 RHS.Zero = APInt(4, 0b0111); 344 Res = KnownBits::abds(LHS, RHS); 345 EXPECT_EQ(1, Res.One.getSExtValue()); 346 EXPECT_EQ(0, Res.Zero.getSExtValue()); 347 } 348 349 TEST(KnownBitsTest, BinaryExhaustive) { 350 testBinaryOpExhaustive( 351 [](const KnownBits &Known1, const KnownBits &Known2) { 352 return Known1 & Known2; 353 }, 354 [](const APInt &N1, const APInt &N2) { return N1 & N2; }); 355 testBinaryOpExhaustive( 356 [](const KnownBits &Known1, const KnownBits &Known2) { 357 return Known1 | Known2; 358 }, 359 [](const APInt &N1, const APInt &N2) { return N1 | N2; }); 360 testBinaryOpExhaustive( 361 [](const KnownBits &Known1, const KnownBits &Known2) { 362 return Known1 ^ Known2; 363 }, 364 [](const APInt &N1, const APInt &N2) { return N1 ^ N2; }); 365 testBinaryOpExhaustive(KnownBits::umax, APIntOps::umax); 366 testBinaryOpExhaustive(KnownBits::umin, APIntOps::umin); 367 testBinaryOpExhaustive(KnownBits::smax, APIntOps::smax); 368 testBinaryOpExhaustive(KnownBits::smin, APIntOps::smin); 369 testBinaryOpExhaustive(KnownBits::abdu, APIntOps::abdu, 370 checkCorrectnessOnlyBinary); 371 testBinaryOpExhaustive(KnownBits::abds, APIntOps::abds, 372 checkCorrectnessOnlyBinary); 373 testBinaryOpExhaustive( 374 [](const KnownBits &Known1, const KnownBits &Known2) { 375 return KnownBits::udiv(Known1, Known2); 376 }, 377 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 378 if (N2.isZero()) 379 return std::nullopt; 380 return N1.udiv(N2); 381 }, 382 checkCorrectnessOnlyBinary); 383 testBinaryOpExhaustive( 384 [](const KnownBits &Known1, const KnownBits &Known2) { 385 return KnownBits::udiv(Known1, Known2, /*Exact*/ true); 386 }, 387 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 388 if (N2.isZero() || !N1.urem(N2).isZero()) 389 return std::nullopt; 390 return N1.udiv(N2); 391 }, 392 checkCorrectnessOnlyBinary); 393 testBinaryOpExhaustive( 394 [](const KnownBits &Known1, const KnownBits &Known2) { 395 return KnownBits::sdiv(Known1, Known2); 396 }, 397 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 398 if (N2.isZero() || (N1.isMinSignedValue() && N2.isAllOnes())) 399 return std::nullopt; 400 return N1.sdiv(N2); 401 }, 402 checkCorrectnessOnlyBinary); 403 testBinaryOpExhaustive( 404 [](const KnownBits &Known1, const KnownBits &Known2) { 405 return KnownBits::sdiv(Known1, Known2, /*Exact*/ true); 406 }, 407 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 408 if (N2.isZero() || (N1.isMinSignedValue() && N2.isAllOnes()) || 409 !N1.srem(N2).isZero()) 410 return std::nullopt; 411 return N1.sdiv(N2); 412 }, 413 checkCorrectnessOnlyBinary); 414 testBinaryOpExhaustive( 415 KnownBits::urem, 416 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 417 if (N2.isZero()) 418 return std::nullopt; 419 return N1.urem(N2); 420 }, 421 checkCorrectnessOnlyBinary); 422 testBinaryOpExhaustive( 423 KnownBits::srem, 424 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 425 if (N2.isZero()) 426 return std::nullopt; 427 return N1.srem(N2); 428 }, 429 checkCorrectnessOnlyBinary); 430 testBinaryOpExhaustive( 431 KnownBits::sadd_sat, 432 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 433 return N1.sadd_sat(N2); 434 }, 435 checkCorrectnessOnlyBinary); 436 testBinaryOpExhaustive( 437 KnownBits::uadd_sat, 438 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 439 return N1.uadd_sat(N2); 440 }, 441 checkCorrectnessOnlyBinary); 442 testBinaryOpExhaustive( 443 KnownBits::ssub_sat, 444 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 445 return N1.ssub_sat(N2); 446 }, 447 checkCorrectnessOnlyBinary); 448 testBinaryOpExhaustive( 449 KnownBits::usub_sat, 450 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 451 return N1.usub_sat(N2); 452 }, 453 checkCorrectnessOnlyBinary); 454 testBinaryOpExhaustive( 455 [](const KnownBits &Known1, const KnownBits &Known2) { 456 return KnownBits::shl(Known1, Known2); 457 }, 458 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 459 if (N2.uge(N2.getBitWidth())) 460 return std::nullopt; 461 return N1.shl(N2); 462 }, 463 checkOptimalityBinary, /* RefinePoisonToZero */ true); 464 testBinaryOpExhaustive( 465 [](const KnownBits &Known1, const KnownBits &Known2) { 466 return KnownBits::shl(Known1, Known2, /* NUW */ true); 467 }, 468 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 469 bool Overflow; 470 APInt Res = N1.ushl_ov(N2, Overflow); 471 if (Overflow) 472 return std::nullopt; 473 return Res; 474 }, 475 checkOptimalityBinary, /* RefinePoisonToZero */ true); 476 testBinaryOpExhaustive( 477 [](const KnownBits &Known1, const KnownBits &Known2) { 478 return KnownBits::shl(Known1, Known2, /* NUW */ false, /* NSW */ true); 479 }, 480 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 481 bool Overflow; 482 APInt Res = N1.sshl_ov(N2, Overflow); 483 if (Overflow) 484 return std::nullopt; 485 return Res; 486 }, 487 checkOptimalityBinary, /* RefinePoisonToZero */ true); 488 testBinaryOpExhaustive( 489 [](const KnownBits &Known1, const KnownBits &Known2) { 490 return KnownBits::shl(Known1, Known2, /* NUW */ true, /* NSW */ true); 491 }, 492 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 493 bool OverflowUnsigned, OverflowSigned; 494 APInt Res = N1.ushl_ov(N2, OverflowUnsigned); 495 (void)N1.sshl_ov(N2, OverflowSigned); 496 if (OverflowUnsigned || OverflowSigned) 497 return std::nullopt; 498 return Res; 499 }, 500 checkOptimalityBinary, /* RefinePoisonToZero */ true); 501 502 testBinaryOpExhaustive( 503 [](const KnownBits &Known1, const KnownBits &Known2) { 504 return KnownBits::lshr(Known1, Known2); 505 }, 506 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 507 if (N2.uge(N2.getBitWidth())) 508 return std::nullopt; 509 return N1.lshr(N2); 510 }, 511 checkOptimalityBinary, /* RefinePoisonToZero */ true); 512 testBinaryOpExhaustive( 513 [](const KnownBits &Known1, const KnownBits &Known2) { 514 return KnownBits::lshr(Known1, Known2, /*ShAmtNonZero=*/false, 515 /*Exact=*/true); 516 }, 517 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 518 if (N2.uge(N2.getBitWidth())) 519 return std::nullopt; 520 if (!N1.extractBits(N2.getZExtValue(), 0).isZero()) 521 return std::nullopt; 522 return N1.lshr(N2); 523 }, 524 checkOptimalityBinary, /* RefinePoisonToZero */ true); 525 testBinaryOpExhaustive( 526 [](const KnownBits &Known1, const KnownBits &Known2) { 527 return KnownBits::ashr(Known1, Known2); 528 }, 529 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 530 if (N2.uge(N2.getBitWidth())) 531 return std::nullopt; 532 return N1.ashr(N2); 533 }, 534 checkOptimalityBinary, /* RefinePoisonToZero */ true); 535 testBinaryOpExhaustive( 536 [](const KnownBits &Known1, const KnownBits &Known2) { 537 return KnownBits::ashr(Known1, Known2, /*ShAmtNonZero=*/false, 538 /*Exact=*/true); 539 }, 540 [](const APInt &N1, const APInt &N2) -> std::optional<APInt> { 541 if (N2.uge(N2.getBitWidth())) 542 return std::nullopt; 543 if (!N1.extractBits(N2.getZExtValue(), 0).isZero()) 544 return std::nullopt; 545 return N1.ashr(N2); 546 }, 547 checkOptimalityBinary, /* RefinePoisonToZero */ true); 548 testBinaryOpExhaustive( 549 [](const KnownBits &Known1, const KnownBits &Known2) { 550 return KnownBits::mul(Known1, Known2); 551 }, 552 [](const APInt &N1, const APInt &N2) { return N1 * N2; }, 553 checkCorrectnessOnlyBinary); 554 testBinaryOpExhaustive( 555 KnownBits::mulhs, 556 [](const APInt &N1, const APInt &N2) { return APIntOps::mulhs(N1, N2); }, 557 checkCorrectnessOnlyBinary); 558 testBinaryOpExhaustive( 559 KnownBits::mulhu, 560 [](const APInt &N1, const APInt &N2) { return APIntOps::mulhu(N1, N2); }, 561 checkCorrectnessOnlyBinary); 562 } 563 564 TEST(KnownBitsTest, UnaryExhaustive) { 565 testUnaryOpExhaustive([](const KnownBits &Known) { return Known.abs(); }, 566 [](const APInt &N) { return N.abs(); }); 567 568 testUnaryOpExhaustive([](const KnownBits &Known) { return Known.abs(true); }, 569 [](const APInt &N) -> std::optional<APInt> { 570 if (N.isMinSignedValue()) 571 return std::nullopt; 572 return N.abs(); 573 }); 574 575 testUnaryOpExhaustive([](const KnownBits &Known) { return Known.blsi(); }, 576 [](const APInt &N) { return N & -N; }); 577 testUnaryOpExhaustive([](const KnownBits &Known) { return Known.blsmsk(); }, 578 [](const APInt &N) { return N ^ (N - 1); }); 579 580 testUnaryOpExhaustive( 581 [](const KnownBits &Known) { 582 return KnownBits::mul(Known, Known, /*SelfMultiply*/ true); 583 }, 584 [](const APInt &N) { return N * N; }, checkCorrectnessOnlyUnary); 585 } 586 587 TEST(KnownBitsTest, WideShifts) { 588 unsigned BitWidth = 128; 589 KnownBits Unknown(BitWidth); 590 KnownBits AllOnes = KnownBits::makeConstant(APInt::getAllOnes(BitWidth)); 591 592 KnownBits ShlResult(BitWidth); 593 ShlResult.makeNegative(); 594 EXPECT_EQ(KnownBits::shl(AllOnes, Unknown), ShlResult); 595 KnownBits LShrResult(BitWidth); 596 LShrResult.One.setBit(0); 597 EXPECT_EQ(KnownBits::lshr(AllOnes, Unknown), LShrResult); 598 EXPECT_EQ(KnownBits::ashr(AllOnes, Unknown), AllOnes); 599 } 600 601 TEST(KnownBitsTest, ICmpExhaustive) { 602 unsigned Bits = 4; 603 ForeachKnownBits(Bits, [&](const KnownBits &Known1) { 604 ForeachKnownBits(Bits, [&](const KnownBits &Known2) { 605 bool AllEQ = true, NoneEQ = true; 606 bool AllNE = true, NoneNE = true; 607 bool AllUGT = true, NoneUGT = true; 608 bool AllUGE = true, NoneUGE = true; 609 bool AllULT = true, NoneULT = true; 610 bool AllULE = true, NoneULE = true; 611 bool AllSGT = true, NoneSGT = true; 612 bool AllSGE = true, NoneSGE = true; 613 bool AllSLT = true, NoneSLT = true; 614 bool AllSLE = true, NoneSLE = true; 615 616 ForeachNumInKnownBits(Known1, [&](const APInt &N1) { 617 ForeachNumInKnownBits(Known2, [&](const APInt &N2) { 618 AllEQ &= N1.eq(N2); 619 AllNE &= N1.ne(N2); 620 AllUGT &= N1.ugt(N2); 621 AllUGE &= N1.uge(N2); 622 AllULT &= N1.ult(N2); 623 AllULE &= N1.ule(N2); 624 AllSGT &= N1.sgt(N2); 625 AllSGE &= N1.sge(N2); 626 AllSLT &= N1.slt(N2); 627 AllSLE &= N1.sle(N2); 628 NoneEQ &= !N1.eq(N2); 629 NoneNE &= !N1.ne(N2); 630 NoneUGT &= !N1.ugt(N2); 631 NoneUGE &= !N1.uge(N2); 632 NoneULT &= !N1.ult(N2); 633 NoneULE &= !N1.ule(N2); 634 NoneSGT &= !N1.sgt(N2); 635 NoneSGE &= !N1.sge(N2); 636 NoneSLT &= !N1.slt(N2); 637 NoneSLE &= !N1.sle(N2); 638 }); 639 }); 640 641 std::optional<bool> KnownEQ = KnownBits::eq(Known1, Known2); 642 std::optional<bool> KnownNE = KnownBits::ne(Known1, Known2); 643 std::optional<bool> KnownUGT = KnownBits::ugt(Known1, Known2); 644 std::optional<bool> KnownUGE = KnownBits::uge(Known1, Known2); 645 std::optional<bool> KnownULT = KnownBits::ult(Known1, Known2); 646 std::optional<bool> KnownULE = KnownBits::ule(Known1, Known2); 647 std::optional<bool> KnownSGT = KnownBits::sgt(Known1, Known2); 648 std::optional<bool> KnownSGE = KnownBits::sge(Known1, Known2); 649 std::optional<bool> KnownSLT = KnownBits::slt(Known1, Known2); 650 std::optional<bool> KnownSLE = KnownBits::sle(Known1, Known2); 651 652 EXPECT_EQ(AllEQ || NoneEQ, KnownEQ.has_value()); 653 EXPECT_EQ(AllNE || NoneNE, KnownNE.has_value()); 654 EXPECT_EQ(AllUGT || NoneUGT, KnownUGT.has_value()); 655 EXPECT_EQ(AllUGE || NoneUGE, KnownUGE.has_value()); 656 EXPECT_EQ(AllULT || NoneULT, KnownULT.has_value()); 657 EXPECT_EQ(AllULE || NoneULE, KnownULE.has_value()); 658 EXPECT_EQ(AllSGT || NoneSGT, KnownSGT.has_value()); 659 EXPECT_EQ(AllSGE || NoneSGE, KnownSGE.has_value()); 660 EXPECT_EQ(AllSLT || NoneSLT, KnownSLT.has_value()); 661 EXPECT_EQ(AllSLE || NoneSLE, KnownSLE.has_value()); 662 663 EXPECT_EQ(AllEQ, KnownEQ.has_value() && *KnownEQ); 664 EXPECT_EQ(AllNE, KnownNE.has_value() && *KnownNE); 665 EXPECT_EQ(AllUGT, KnownUGT.has_value() && *KnownUGT); 666 EXPECT_EQ(AllUGE, KnownUGE.has_value() && *KnownUGE); 667 EXPECT_EQ(AllULT, KnownULT.has_value() && *KnownULT); 668 EXPECT_EQ(AllULE, KnownULE.has_value() && *KnownULE); 669 EXPECT_EQ(AllSGT, KnownSGT.has_value() && *KnownSGT); 670 EXPECT_EQ(AllSGE, KnownSGE.has_value() && *KnownSGE); 671 EXPECT_EQ(AllSLT, KnownSLT.has_value() && *KnownSLT); 672 EXPECT_EQ(AllSLE, KnownSLE.has_value() && *KnownSLE); 673 674 EXPECT_EQ(NoneEQ, KnownEQ.has_value() && !*KnownEQ); 675 EXPECT_EQ(NoneNE, KnownNE.has_value() && !*KnownNE); 676 EXPECT_EQ(NoneUGT, KnownUGT.has_value() && !*KnownUGT); 677 EXPECT_EQ(NoneUGE, KnownUGE.has_value() && !*KnownUGE); 678 EXPECT_EQ(NoneULT, KnownULT.has_value() && !*KnownULT); 679 EXPECT_EQ(NoneULE, KnownULE.has_value() && !*KnownULE); 680 EXPECT_EQ(NoneSGT, KnownSGT.has_value() && !*KnownSGT); 681 EXPECT_EQ(NoneSGE, KnownSGE.has_value() && !*KnownSGE); 682 EXPECT_EQ(NoneSLT, KnownSLT.has_value() && !*KnownSLT); 683 EXPECT_EQ(NoneSLE, KnownSLE.has_value() && !*KnownSLE); 684 }); 685 }); 686 } 687 688 TEST(KnownBitsTest, GetMinMaxVal) { 689 unsigned Bits = 4; 690 ForeachKnownBits(Bits, [&](const KnownBits &Known) { 691 APInt Min = APInt::getMaxValue(Bits); 692 APInt Max = APInt::getMinValue(Bits); 693 ForeachNumInKnownBits(Known, [&](const APInt &N) { 694 Min = APIntOps::umin(Min, N); 695 Max = APIntOps::umax(Max, N); 696 }); 697 EXPECT_EQ(Min, Known.getMinValue()); 698 EXPECT_EQ(Max, Known.getMaxValue()); 699 }); 700 } 701 702 TEST(KnownBitsTest, GetSignedMinMaxVal) { 703 unsigned Bits = 4; 704 ForeachKnownBits(Bits, [&](const KnownBits &Known) { 705 APInt Min = APInt::getSignedMaxValue(Bits); 706 APInt Max = APInt::getSignedMinValue(Bits); 707 ForeachNumInKnownBits(Known, [&](const APInt &N) { 708 Min = APIntOps::smin(Min, N); 709 Max = APIntOps::smax(Max, N); 710 }); 711 EXPECT_EQ(Min, Known.getSignedMinValue()); 712 EXPECT_EQ(Max, Known.getSignedMaxValue()); 713 }); 714 } 715 716 TEST(KnownBitsTest, CountMaxActiveBits) { 717 unsigned Bits = 4; 718 ForeachKnownBits(Bits, [&](const KnownBits &Known) { 719 unsigned Expected = 0; 720 ForeachNumInKnownBits(Known, [&](const APInt &N) { 721 Expected = std::max(Expected, N.getActiveBits()); 722 }); 723 EXPECT_EQ(Expected, Known.countMaxActiveBits()); 724 }); 725 } 726 727 TEST(KnownBitsTest, CountMaxSignificantBits) { 728 unsigned Bits = 4; 729 ForeachKnownBits(Bits, [&](const KnownBits &Known) { 730 unsigned Expected = 0; 731 ForeachNumInKnownBits(Known, [&](const APInt &N) { 732 Expected = std::max(Expected, N.getSignificantBits()); 733 }); 734 EXPECT_EQ(Expected, Known.countMaxSignificantBits()); 735 }); 736 } 737 738 TEST(KnownBitsTest, SExtOrTrunc) { 739 const unsigned NarrowerSize = 4; 740 const unsigned BaseSize = 6; 741 const unsigned WiderSize = 8; 742 APInt NegativeFitsNarrower(BaseSize, -4, /*isSigned*/ true); 743 APInt NegativeDoesntFitNarrower(BaseSize, -28, /*isSigned*/ true); 744 APInt PositiveFitsNarrower(BaseSize, 14); 745 APInt PositiveDoesntFitNarrower(BaseSize, 36); 746 auto InitKnownBits = [&](KnownBits &Res, const APInt &Input) { 747 Res = KnownBits(Input.getBitWidth()); 748 Res.One = Input; 749 Res.Zero = ~Input; 750 }; 751 752 for (unsigned Size : {NarrowerSize, BaseSize, WiderSize}) { 753 for (const APInt &Input : 754 {NegativeFitsNarrower, NegativeDoesntFitNarrower, PositiveFitsNarrower, 755 PositiveDoesntFitNarrower}) { 756 KnownBits Test; 757 InitKnownBits(Test, Input); 758 KnownBits Baseline; 759 InitKnownBits(Baseline, Input.sextOrTrunc(Size)); 760 Test = Test.sextOrTrunc(Size); 761 EXPECT_EQ(Test, Baseline); 762 } 763 } 764 } 765 766 TEST(KnownBitsTest, SExtInReg) { 767 unsigned Bits = 4; 768 for (unsigned FromBits = 1; FromBits <= Bits; ++FromBits) { 769 ForeachKnownBits(Bits, [&](const KnownBits &Known) { 770 APInt CommonOne = APInt::getAllOnes(Bits); 771 APInt CommonZero = APInt::getAllOnes(Bits); 772 unsigned ExtBits = Bits - FromBits; 773 ForeachNumInKnownBits(Known, [&](const APInt &N) { 774 APInt Ext = N << ExtBits; 775 Ext.ashrInPlace(ExtBits); 776 CommonOne &= Ext; 777 CommonZero &= ~Ext; 778 }); 779 KnownBits KnownSExtInReg = Known.sextInReg(FromBits); 780 EXPECT_EQ(CommonOne, KnownSExtInReg.One); 781 EXPECT_EQ(CommonZero, KnownSExtInReg.Zero); 782 }); 783 } 784 } 785 786 TEST(KnownBitsTest, CommonBitsSet) { 787 unsigned Bits = 4; 788 ForeachKnownBits(Bits, [&](const KnownBits &Known1) { 789 ForeachKnownBits(Bits, [&](const KnownBits &Known2) { 790 bool HasCommonBitsSet = false; 791 ForeachNumInKnownBits(Known1, [&](const APInt &N1) { 792 ForeachNumInKnownBits(Known2, [&](const APInt &N2) { 793 HasCommonBitsSet |= N1.intersects(N2); 794 }); 795 }); 796 EXPECT_EQ(!HasCommonBitsSet, 797 KnownBits::haveNoCommonBitsSet(Known1, Known2)); 798 }); 799 }); 800 } 801 802 TEST(KnownBitsTest, ConcatBits) { 803 unsigned Bits = 4; 804 for (unsigned LoBits = 1; LoBits < Bits; ++LoBits) { 805 unsigned HiBits = Bits - LoBits; 806 ForeachKnownBits(LoBits, [&](const KnownBits &KnownLo) { 807 ForeachKnownBits(HiBits, [&](const KnownBits &KnownHi) { 808 KnownBits KnownAll = KnownHi.concat(KnownLo); 809 810 EXPECT_EQ(KnownLo.countMinPopulation() + KnownHi.countMinPopulation(), 811 KnownAll.countMinPopulation()); 812 EXPECT_EQ(KnownLo.countMaxPopulation() + KnownHi.countMaxPopulation(), 813 KnownAll.countMaxPopulation()); 814 815 KnownBits ExtractLo = KnownAll.extractBits(LoBits, 0); 816 KnownBits ExtractHi = KnownAll.extractBits(HiBits, LoBits); 817 818 EXPECT_EQ(KnownLo.One.getZExtValue(), ExtractLo.One.getZExtValue()); 819 EXPECT_EQ(KnownHi.One.getZExtValue(), ExtractHi.One.getZExtValue()); 820 EXPECT_EQ(KnownLo.Zero.getZExtValue(), ExtractLo.Zero.getZExtValue()); 821 EXPECT_EQ(KnownHi.Zero.getZExtValue(), ExtractHi.Zero.getZExtValue()); 822 }); 823 }); 824 } 825 } 826 827 } // end anonymous namespace 828