1 //===- ValueTrackingTest.cpp - ValueTracking 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/Analysis/ValueTracking.h" 10 #include "llvm/Analysis/AssumptionCache.h" 11 #include "llvm/AsmParser/Parser.h" 12 #include "llvm/IR/ConstantRange.h" 13 #include "llvm/IR/Dominators.h" 14 #include "llvm/IR/Function.h" 15 #include "llvm/IR/IRBuilder.h" 16 #include "llvm/IR/InstIterator.h" 17 #include "llvm/IR/Instructions.h" 18 #include "llvm/IR/LLVMContext.h" 19 #include "llvm/IR/Module.h" 20 #include "llvm/Support/ErrorHandling.h" 21 #include "llvm/Support/KnownBits.h" 22 #include "llvm/Support/SourceMgr.h" 23 #include "llvm/Transforms/Utils/Local.h" 24 #include "gtest/gtest.h" 25 26 using namespace llvm; 27 28 namespace { 29 30 static Instruction *findInstructionByNameOrNull(Function *F, StringRef Name) { 31 for (Instruction &I : instructions(F)) 32 if (I.getName() == Name) 33 return &I; 34 35 return nullptr; 36 } 37 38 static Instruction &findInstructionByName(Function *F, StringRef Name) { 39 auto *I = findInstructionByNameOrNull(F, Name); 40 if (I) 41 return *I; 42 43 llvm_unreachable("Expected value not found"); 44 } 45 46 class ValueTrackingTest : public testing::Test { 47 protected: 48 std::unique_ptr<Module> parseModule(StringRef Assembly) { 49 SMDiagnostic Error; 50 std::unique_ptr<Module> M = parseAssemblyString(Assembly, Error, Context); 51 52 std::string errMsg; 53 raw_string_ostream os(errMsg); 54 Error.print("", os); 55 EXPECT_TRUE(M) << os.str(); 56 57 return M; 58 } 59 60 void parseAssembly(StringRef Assembly) { 61 M = parseModule(Assembly); 62 ASSERT_TRUE(M); 63 64 F = M->getFunction("test"); 65 ASSERT_TRUE(F) << "Test must have a function @test"; 66 if (!F) 67 return; 68 69 A = findInstructionByNameOrNull(F, "A"); 70 ASSERT_TRUE(A) << "@test must have an instruction %A"; 71 A2 = findInstructionByNameOrNull(F, "A2"); 72 A3 = findInstructionByNameOrNull(F, "A3"); 73 A4 = findInstructionByNameOrNull(F, "A4"); 74 75 CxtI = findInstructionByNameOrNull(F, "CxtI"); 76 CxtI2 = findInstructionByNameOrNull(F, "CxtI2"); 77 CxtI3 = findInstructionByNameOrNull(F, "CxtI3"); 78 } 79 80 LLVMContext Context; 81 std::unique_ptr<Module> M; 82 Function *F = nullptr; 83 Instruction *A = nullptr; 84 // Instructions (optional) 85 Instruction *A2 = nullptr, *A3 = nullptr, *A4 = nullptr; 86 87 // Context instructions (optional) 88 Instruction *CxtI = nullptr, *CxtI2 = nullptr, *CxtI3 = nullptr; 89 }; 90 91 class MatchSelectPatternTest : public ValueTrackingTest { 92 protected: 93 void expectPattern(const SelectPatternResult &P) { 94 Value *LHS, *RHS; 95 Instruction::CastOps CastOp; 96 SelectPatternResult R = matchSelectPattern(A, LHS, RHS, &CastOp); 97 EXPECT_EQ(P.Flavor, R.Flavor); 98 EXPECT_EQ(P.NaNBehavior, R.NaNBehavior); 99 EXPECT_EQ(P.Ordered, R.Ordered); 100 } 101 }; 102 103 class ComputeKnownBitsTest : public ValueTrackingTest { 104 protected: 105 void expectKnownBits(uint64_t Zero, uint64_t One) { 106 auto Known = computeKnownBits(A, M->getDataLayout()); 107 ASSERT_FALSE(Known.hasConflict()); 108 EXPECT_EQ(Known.One.getZExtValue(), One); 109 EXPECT_EQ(Known.Zero.getZExtValue(), Zero); 110 } 111 }; 112 113 } 114 115 TEST_F(MatchSelectPatternTest, SimpleFMin) { 116 parseAssembly( 117 "define float @test(float %a) {\n" 118 " %1 = fcmp ult float %a, 5.0\n" 119 " %A = select i1 %1, float %a, float 5.0\n" 120 " ret float %A\n" 121 "}\n"); 122 expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, false}); 123 } 124 125 TEST_F(MatchSelectPatternTest, SimpleFMax) { 126 parseAssembly( 127 "define float @test(float %a) {\n" 128 " %1 = fcmp ogt float %a, 5.0\n" 129 " %A = select i1 %1, float %a, float 5.0\n" 130 " ret float %A\n" 131 "}\n"); 132 expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, true}); 133 } 134 135 TEST_F(MatchSelectPatternTest, SwappedFMax) { 136 parseAssembly( 137 "define float @test(float %a) {\n" 138 " %1 = fcmp olt float 5.0, %a\n" 139 " %A = select i1 %1, float %a, float 5.0\n" 140 " ret float %A\n" 141 "}\n"); 142 expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, false}); 143 } 144 145 TEST_F(MatchSelectPatternTest, SwappedFMax2) { 146 parseAssembly( 147 "define float @test(float %a) {\n" 148 " %1 = fcmp olt float %a, 5.0\n" 149 " %A = select i1 %1, float 5.0, float %a\n" 150 " ret float %A\n" 151 "}\n"); 152 expectPattern({SPF_FMAXNUM, SPNB_RETURNS_NAN, false}); 153 } 154 155 TEST_F(MatchSelectPatternTest, SwappedFMax3) { 156 parseAssembly( 157 "define float @test(float %a) {\n" 158 " %1 = fcmp ult float %a, 5.0\n" 159 " %A = select i1 %1, float 5.0, float %a\n" 160 " ret float %A\n" 161 "}\n"); 162 expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, true}); 163 } 164 165 TEST_F(MatchSelectPatternTest, FastFMin) { 166 parseAssembly( 167 "define float @test(float %a) {\n" 168 " %1 = fcmp nnan olt float %a, 5.0\n" 169 " %A = select i1 %1, float %a, float 5.0\n" 170 " ret float %A\n" 171 "}\n"); 172 expectPattern({SPF_FMINNUM, SPNB_RETURNS_ANY, false}); 173 } 174 175 TEST_F(MatchSelectPatternTest, FMinConstantZero) { 176 parseAssembly( 177 "define float @test(float %a) {\n" 178 " %1 = fcmp ole float %a, 0.0\n" 179 " %A = select i1 %1, float %a, float 0.0\n" 180 " ret float %A\n" 181 "}\n"); 182 // This shouldn't be matched, as %a could be -0.0. 183 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 184 } 185 186 TEST_F(MatchSelectPatternTest, FMinConstantZeroNsz) { 187 parseAssembly( 188 "define float @test(float %a) {\n" 189 " %1 = fcmp nsz ole float %a, 0.0\n" 190 " %A = select i1 %1, float %a, float 0.0\n" 191 " ret float %A\n" 192 "}\n"); 193 // But this should be, because we've ignored signed zeroes. 194 expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, true}); 195 } 196 197 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero1) { 198 parseAssembly( 199 "define float @test(float %a) {\n" 200 " %1 = fcmp olt float -0.0, %a\n" 201 " %A = select i1 %1, float 0.0, float %a\n" 202 " ret float %A\n" 203 "}\n"); 204 // The sign of zero doesn't matter in fcmp. 205 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 206 } 207 208 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero2) { 209 parseAssembly( 210 "define float @test(float %a) {\n" 211 " %1 = fcmp ogt float %a, -0.0\n" 212 " %A = select i1 %1, float 0.0, float %a\n" 213 " ret float %A\n" 214 "}\n"); 215 // The sign of zero doesn't matter in fcmp. 216 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 217 } 218 219 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero3) { 220 parseAssembly( 221 "define float @test(float %a) {\n" 222 " %1 = fcmp olt float 0.0, %a\n" 223 " %A = select i1 %1, float -0.0, float %a\n" 224 " ret float %A\n" 225 "}\n"); 226 // The sign of zero doesn't matter in fcmp. 227 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 228 } 229 230 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero4) { 231 parseAssembly( 232 "define float @test(float %a) {\n" 233 " %1 = fcmp ogt float %a, 0.0\n" 234 " %A = select i1 %1, float -0.0, float %a\n" 235 " ret float %A\n" 236 "}\n"); 237 // The sign of zero doesn't matter in fcmp. 238 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 239 } 240 241 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero5) { 242 parseAssembly( 243 "define float @test(float %a) {\n" 244 " %1 = fcmp ogt float -0.0, %a\n" 245 " %A = select i1 %1, float %a, float 0.0\n" 246 " ret float %A\n" 247 "}\n"); 248 // The sign of zero doesn't matter in fcmp. 249 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 250 } 251 252 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero6) { 253 parseAssembly( 254 "define float @test(float %a) {\n" 255 " %1 = fcmp olt float %a, -0.0\n" 256 " %A = select i1 %1, float %a, float 0.0\n" 257 " ret float %A\n" 258 "}\n"); 259 // The sign of zero doesn't matter in fcmp. 260 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 261 } 262 263 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero7) { 264 parseAssembly( 265 "define float @test(float %a) {\n" 266 " %1 = fcmp ogt float 0.0, %a\n" 267 " %A = select i1 %1, float %a, float -0.0\n" 268 " ret float %A\n" 269 "}\n"); 270 // The sign of zero doesn't matter in fcmp. 271 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 272 } 273 274 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero8) { 275 parseAssembly( 276 "define float @test(float %a) {\n" 277 " %1 = fcmp olt float %a, 0.0\n" 278 " %A = select i1 %1, float %a, float -0.0\n" 279 " ret float %A\n" 280 "}\n"); 281 // The sign of zero doesn't matter in fcmp. 282 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 283 } 284 285 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero1) { 286 parseAssembly( 287 "define float @test(float %a) {\n" 288 " %1 = fcmp ogt float -0.0, %a\n" 289 " %A = select i1 %1, float 0.0, float %a\n" 290 " ret float %A\n" 291 "}\n"); 292 // The sign of zero doesn't matter in fcmp. 293 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 294 } 295 296 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero2) { 297 parseAssembly( 298 "define float @test(float %a) {\n" 299 " %1 = fcmp olt float %a, -0.0\n" 300 " %A = select i1 %1, float 0.0, float %a\n" 301 " ret float %A\n" 302 "}\n"); 303 // The sign of zero doesn't matter in fcmp. 304 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 305 } 306 307 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero3) { 308 parseAssembly( 309 "define float @test(float %a) {\n" 310 " %1 = fcmp ogt float 0.0, %a\n" 311 " %A = select i1 %1, float -0.0, float %a\n" 312 " ret float %A\n" 313 "}\n"); 314 // The sign of zero doesn't matter in fcmp. 315 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 316 } 317 318 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero4) { 319 parseAssembly( 320 "define float @test(float %a) {\n" 321 " %1 = fcmp olt float %a, 0.0\n" 322 " %A = select i1 %1, float -0.0, float %a\n" 323 " ret float %A\n" 324 "}\n"); 325 // The sign of zero doesn't matter in fcmp. 326 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 327 } 328 329 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero5) { 330 parseAssembly( 331 "define float @test(float %a) {\n" 332 " %1 = fcmp olt float -0.0, %a\n" 333 " %A = select i1 %1, float %a, float 0.0\n" 334 " ret float %A\n" 335 "}\n"); 336 // The sign of zero doesn't matter in fcmp. 337 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 338 } 339 340 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero6) { 341 parseAssembly( 342 "define float @test(float %a) {\n" 343 " %1 = fcmp ogt float %a, -0.0\n" 344 " %A = select i1 %1, float %a, float 0.0\n" 345 " ret float %A\n" 346 "}\n"); 347 // The sign of zero doesn't matter in fcmp. 348 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 349 } 350 351 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero7) { 352 parseAssembly( 353 "define float @test(float %a) {\n" 354 " %1 = fcmp olt float 0.0, %a\n" 355 " %A = select i1 %1, float %a, float -0.0\n" 356 " ret float %A\n" 357 "}\n"); 358 // The sign of zero doesn't matter in fcmp. 359 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 360 } 361 362 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero8) { 363 parseAssembly( 364 "define float @test(float %a) {\n" 365 " %1 = fcmp ogt float %a, 0.0\n" 366 " %A = select i1 %1, float %a, float -0.0\n" 367 " ret float %A\n" 368 "}\n"); 369 // The sign of zero doesn't matter in fcmp. 370 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 371 } 372 373 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZeroVecUndef) { 374 parseAssembly( 375 "define <2 x float> @test(<2 x float> %a) {\n" 376 " %1 = fcmp ogt <2 x float> %a, <float -0.0, float -0.0>\n" 377 " %A = select <2 x i1> %1, <2 x float> <float undef, float 0.0>, <2 x float> %a\n" 378 " ret <2 x float> %A\n" 379 "}\n"); 380 // An undef in a vector constant can not be back-propagated for this analysis. 381 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 382 } 383 384 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZeroVecUndef) { 385 parseAssembly( 386 "define <2 x float> @test(<2 x float> %a) {\n" 387 " %1 = fcmp ogt <2 x float> %a, zeroinitializer\n" 388 " %A = select <2 x i1> %1, <2 x float> %a, <2 x float> <float -0.0, float undef>\n" 389 " ret <2 x float> %A\n" 390 "}\n"); 391 // An undef in a vector constant can not be back-propagated for this analysis. 392 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 393 } 394 395 TEST_F(MatchSelectPatternTest, VectorFMinimum) { 396 parseAssembly( 397 "define <4 x float> @test(<4 x float> %a) {\n" 398 " %1 = fcmp ule <4 x float> %a, \n" 399 " <float 5.0, float 5.0, float 5.0, float 5.0>\n" 400 " %A = select <4 x i1> %1, <4 x float> %a,\n" 401 " <4 x float> <float 5.0, float 5.0, float 5.0, float 5.0>\n" 402 " ret <4 x float> %A\n" 403 "}\n"); 404 // Check that pattern matching works on vectors where each lane has the same 405 // unordered pattern. 406 expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, false}); 407 } 408 409 TEST_F(MatchSelectPatternTest, VectorFMinOtherOrdered) { 410 parseAssembly( 411 "define <4 x float> @test(<4 x float> %a) {\n" 412 " %1 = fcmp ole <4 x float> %a, \n" 413 " <float 5.0, float 5.0, float 5.0, float 5.0>\n" 414 " %A = select <4 x i1> %1, <4 x float> %a,\n" 415 " <4 x float> <float 5.0, float 5.0, float 5.0, float 5.0>\n" 416 " ret <4 x float> %A\n" 417 "}\n"); 418 // Check that pattern matching works on vectors where each lane has the same 419 // ordered pattern. 420 expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, true}); 421 } 422 423 TEST_F(MatchSelectPatternTest, VectorNotFMinimum) { 424 parseAssembly( 425 "define <4 x float> @test(<4 x float> %a) {\n" 426 " %1 = fcmp ule <4 x float> %a, \n" 427 " <float 5.0, float 0x7ff8000000000000, float 5.0, float 5.0>\n" 428 " %A = select <4 x i1> %1, <4 x float> %a,\n" 429 " <4 x float> <float 5.0, float 0x7ff8000000000000, float 5.0, float " 430 "5.0>\n" 431 " ret <4 x float> %A\n" 432 "}\n"); 433 // The lane that contains a NaN (0x7ff80...) behaves like a 434 // non-NaN-propagating min and the other lines behave like a NaN-propagating 435 // min, so check that neither is returned. 436 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 437 } 438 439 TEST_F(MatchSelectPatternTest, VectorNotFMinZero) { 440 parseAssembly( 441 "define <4 x float> @test(<4 x float> %a) {\n" 442 " %1 = fcmp ule <4 x float> %a, \n" 443 " <float 5.0, float -0.0, float 5.0, float 5.0>\n" 444 " %A = select <4 x i1> %1, <4 x float> %a,\n" 445 " <4 x float> <float 5.0, float 0.0, float 5.0, float 5.0>\n" 446 " ret <4 x float> %A\n" 447 "}\n"); 448 // Always selects the second lane of %a if it is positive or negative zero, so 449 // this is stricter than a min. 450 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 451 } 452 453 TEST_F(MatchSelectPatternTest, DoubleCastU) { 454 parseAssembly( 455 "define i32 @test(i8 %a, i8 %b) {\n" 456 " %1 = icmp ult i8 %a, %b\n" 457 " %2 = zext i8 %a to i32\n" 458 " %3 = zext i8 %b to i32\n" 459 " %A = select i1 %1, i32 %2, i32 %3\n" 460 " ret i32 %A\n" 461 "}\n"); 462 // We should be able to look through the situation where we cast both operands 463 // to the select. 464 expectPattern({SPF_UMIN, SPNB_NA, false}); 465 } 466 467 TEST_F(MatchSelectPatternTest, DoubleCastS) { 468 parseAssembly( 469 "define i32 @test(i8 %a, i8 %b) {\n" 470 " %1 = icmp slt i8 %a, %b\n" 471 " %2 = sext i8 %a to i32\n" 472 " %3 = sext i8 %b to i32\n" 473 " %A = select i1 %1, i32 %2, i32 %3\n" 474 " ret i32 %A\n" 475 "}\n"); 476 // We should be able to look through the situation where we cast both operands 477 // to the select. 478 expectPattern({SPF_SMIN, SPNB_NA, false}); 479 } 480 481 TEST_F(MatchSelectPatternTest, DoubleCastBad) { 482 parseAssembly( 483 "define i32 @test(i8 %a, i8 %b) {\n" 484 " %1 = icmp ult i8 %a, %b\n" 485 " %2 = zext i8 %a to i32\n" 486 " %3 = sext i8 %b to i32\n" 487 " %A = select i1 %1, i32 %2, i32 %3\n" 488 " ret i32 %A\n" 489 "}\n"); 490 // The cast types here aren't the same, so we cannot match an UMIN. 491 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 492 } 493 494 TEST_F(MatchSelectPatternTest, NotNotSMin) { 495 parseAssembly( 496 "define i8 @test(i8 %a, i8 %b) {\n" 497 " %cmp = icmp sgt i8 %a, %b\n" 498 " %an = xor i8 %a, -1\n" 499 " %bn = xor i8 %b, -1\n" 500 " %A = select i1 %cmp, i8 %an, i8 %bn\n" 501 " ret i8 %A\n" 502 "}\n"); 503 expectPattern({SPF_SMIN, SPNB_NA, false}); 504 } 505 506 TEST_F(MatchSelectPatternTest, NotNotSMinSwap) { 507 parseAssembly( 508 "define <2 x i8> @test(<2 x i8> %a, <2 x i8> %b) {\n" 509 " %cmp = icmp slt <2 x i8> %a, %b\n" 510 " %an = xor <2 x i8> %a, <i8 -1, i8-1>\n" 511 " %bn = xor <2 x i8> %b, <i8 -1, i8-1>\n" 512 " %A = select <2 x i1> %cmp, <2 x i8> %bn, <2 x i8> %an\n" 513 " ret <2 x i8> %A\n" 514 "}\n"); 515 expectPattern({SPF_SMIN, SPNB_NA, false}); 516 } 517 518 TEST_F(MatchSelectPatternTest, NotNotSMax) { 519 parseAssembly( 520 "define i8 @test(i8 %a, i8 %b) {\n" 521 " %cmp = icmp slt i8 %a, %b\n" 522 " %an = xor i8 %a, -1\n" 523 " %bn = xor i8 %b, -1\n" 524 " %A = select i1 %cmp, i8 %an, i8 %bn\n" 525 " ret i8 %A\n" 526 "}\n"); 527 expectPattern({SPF_SMAX, SPNB_NA, false}); 528 } 529 530 TEST_F(MatchSelectPatternTest, NotNotSMaxSwap) { 531 parseAssembly( 532 "define <2 x i8> @test(<2 x i8> %a, <2 x i8> %b) {\n" 533 " %cmp = icmp sgt <2 x i8> %a, %b\n" 534 " %an = xor <2 x i8> %a, <i8 -1, i8-1>\n" 535 " %bn = xor <2 x i8> %b, <i8 -1, i8-1>\n" 536 " %A = select <2 x i1> %cmp, <2 x i8> %bn, <2 x i8> %an\n" 537 " ret <2 x i8> %A\n" 538 "}\n"); 539 expectPattern({SPF_SMAX, SPNB_NA, false}); 540 } 541 542 TEST_F(MatchSelectPatternTest, NotNotUMin) { 543 parseAssembly( 544 "define <2 x i8> @test(<2 x i8> %a, <2 x i8> %b) {\n" 545 " %cmp = icmp ugt <2 x i8> %a, %b\n" 546 " %an = xor <2 x i8> %a, <i8 -1, i8-1>\n" 547 " %bn = xor <2 x i8> %b, <i8 -1, i8-1>\n" 548 " %A = select <2 x i1> %cmp, <2 x i8> %an, <2 x i8> %bn\n" 549 " ret <2 x i8> %A\n" 550 "}\n"); 551 expectPattern({SPF_UMIN, SPNB_NA, false}); 552 } 553 554 TEST_F(MatchSelectPatternTest, NotNotUMinSwap) { 555 parseAssembly( 556 "define i8 @test(i8 %a, i8 %b) {\n" 557 " %cmp = icmp ult i8 %a, %b\n" 558 " %an = xor i8 %a, -1\n" 559 " %bn = xor i8 %b, -1\n" 560 " %A = select i1 %cmp, i8 %bn, i8 %an\n" 561 " ret i8 %A\n" 562 "}\n"); 563 expectPattern({SPF_UMIN, SPNB_NA, false}); 564 } 565 566 TEST_F(MatchSelectPatternTest, NotNotUMax) { 567 parseAssembly( 568 "define <2 x i8> @test(<2 x i8> %a, <2 x i8> %b) {\n" 569 " %cmp = icmp ult <2 x i8> %a, %b\n" 570 " %an = xor <2 x i8> %a, <i8 -1, i8-1>\n" 571 " %bn = xor <2 x i8> %b, <i8 -1, i8-1>\n" 572 " %A = select <2 x i1> %cmp, <2 x i8> %an, <2 x i8> %bn\n" 573 " ret <2 x i8> %A\n" 574 "}\n"); 575 expectPattern({SPF_UMAX, SPNB_NA, false}); 576 } 577 578 TEST_F(MatchSelectPatternTest, NotNotUMaxSwap) { 579 parseAssembly( 580 "define i8 @test(i8 %a, i8 %b) {\n" 581 " %cmp = icmp ugt i8 %a, %b\n" 582 " %an = xor i8 %a, -1\n" 583 " %bn = xor i8 %b, -1\n" 584 " %A = select i1 %cmp, i8 %bn, i8 %an\n" 585 " ret i8 %A\n" 586 "}\n"); 587 expectPattern({SPF_UMAX, SPNB_NA, false}); 588 } 589 590 TEST_F(MatchSelectPatternTest, NotNotEq) { 591 parseAssembly( 592 "define i8 @test(i8 %a, i8 %b) {\n" 593 " %cmp = icmp eq i8 %a, %b\n" 594 " %an = xor i8 %a, -1\n" 595 " %bn = xor i8 %b, -1\n" 596 " %A = select i1 %cmp, i8 %bn, i8 %an\n" 597 " ret i8 %A\n" 598 "}\n"); 599 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 600 } 601 602 TEST_F(MatchSelectPatternTest, NotNotNe) { 603 parseAssembly( 604 "define i8 @test(i8 %a, i8 %b) {\n" 605 " %cmp = icmp ne i8 %a, %b\n" 606 " %an = xor i8 %a, -1\n" 607 " %bn = xor i8 %b, -1\n" 608 " %A = select i1 %cmp, i8 %bn, i8 %an\n" 609 " ret i8 %A\n" 610 "}\n"); 611 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 612 } 613 614 TEST(ValueTracking, GuaranteedToTransferExecutionToSuccessor) { 615 StringRef Assembly = 616 "declare void @nounwind_readonly(i32*) nounwind readonly " 617 "declare void @nounwind_argmemonly(i32*) nounwind argmemonly " 618 "declare void @nounwind_willreturn(i32*) nounwind willreturn " 619 "declare void @throws_but_readonly(i32*) readonly " 620 "declare void @throws_but_argmemonly(i32*) argmemonly " 621 "declare void @throws_but_willreturn(i32*) willreturn " 622 " " 623 "declare void @unknown(i32*) " 624 " " 625 "define void @f(i32* %p) { " 626 " call void @nounwind_readonly(i32* %p) " 627 " call void @nounwind_argmemonly(i32* %p) " 628 " call void @nounwind_willreturn(i32* %p)" 629 " call void @throws_but_readonly(i32* %p) " 630 " call void @throws_but_argmemonly(i32* %p) " 631 " call void @throws_but_willreturn(i32* %p) " 632 " call void @unknown(i32* %p) nounwind readonly " 633 " call void @unknown(i32* %p) nounwind argmemonly " 634 " call void @unknown(i32* %p) nounwind willreturn " 635 " call void @unknown(i32* %p) readonly " 636 " call void @unknown(i32* %p) argmemonly " 637 " call void @unknown(i32* %p) willreturn " 638 " ret void " 639 "} "; 640 641 LLVMContext Context; 642 SMDiagnostic Error; 643 auto M = parseAssemblyString(Assembly, Error, Context); 644 assert(M && "Bad assembly?"); 645 646 auto *F = M->getFunction("f"); 647 assert(F && "Bad assembly?"); 648 649 auto &BB = F->getEntryBlock(); 650 bool ExpectedAnswers[] = { 651 false, // call void @nounwind_readonly(i32* %p) 652 false, // call void @nounwind_argmemonly(i32* %p) 653 true, // call void @nounwind_willreturn(i32* %p) 654 false, // call void @throws_but_readonly(i32* %p) 655 false, // call void @throws_but_argmemonly(i32* %p) 656 false, // call void @throws_but_willreturn(i32* %p) 657 false, // call void @unknown(i32* %p) nounwind readonly 658 false, // call void @unknown(i32* %p) nounwind argmemonly 659 true, // call void @unknown(i32* %p) nounwind willreturn 660 false, // call void @unknown(i32* %p) readonly 661 false, // call void @unknown(i32* %p) argmemonly 662 false, // call void @unknown(i32* %p) willreturn 663 false, // ret void 664 }; 665 666 int Index = 0; 667 for (auto &I : BB) { 668 EXPECT_EQ(isGuaranteedToTransferExecutionToSuccessor(&I), 669 ExpectedAnswers[Index]) 670 << "Incorrect answer at instruction " << Index << " = " << I; 671 Index++; 672 } 673 } 674 675 TEST_F(ValueTrackingTest, ComputeNumSignBits_PR32045) { 676 parseAssembly( 677 "define i32 @test(i32 %a) {\n" 678 " %A = ashr i32 %a, -1\n" 679 " ret i32 %A\n" 680 "}\n"); 681 EXPECT_EQ(ComputeNumSignBits(A, M->getDataLayout()), 1u); 682 } 683 684 // No guarantees for canonical IR in this analysis, so this just bails out. 685 TEST_F(ValueTrackingTest, ComputeNumSignBits_Shuffle) { 686 parseAssembly( 687 "define <2 x i32> @test() {\n" 688 " %A = shufflevector <2 x i32> undef, <2 x i32> undef, <2 x i32> <i32 0, i32 0>\n" 689 " ret <2 x i32> %A\n" 690 "}\n"); 691 EXPECT_EQ(ComputeNumSignBits(A, M->getDataLayout()), 1u); 692 } 693 694 // No guarantees for canonical IR in this analysis, so a shuffle element that 695 // references an undef value means this can't return any extra information. 696 TEST_F(ValueTrackingTest, ComputeNumSignBits_Shuffle2) { 697 parseAssembly( 698 "define <2 x i32> @test(<2 x i1> %x) {\n" 699 " %sext = sext <2 x i1> %x to <2 x i32>\n" 700 " %A = shufflevector <2 x i32> %sext, <2 x i32> undef, <2 x i32> <i32 0, i32 2>\n" 701 " ret <2 x i32> %A\n" 702 "}\n"); 703 EXPECT_EQ(ComputeNumSignBits(A, M->getDataLayout()), 1u); 704 } 705 706 TEST_F(ValueTrackingTest, impliesPoisonTest_Identity) { 707 parseAssembly("define void @test(i32 %x, i32 %y) {\n" 708 " %A = add i32 %x, %y\n" 709 " ret void\n" 710 "}"); 711 EXPECT_TRUE(impliesPoison(A, A)); 712 } 713 714 TEST_F(ValueTrackingTest, impliesPoisonTest_ICmp) { 715 parseAssembly("define void @test(i32 %x) {\n" 716 " %A2 = icmp eq i32 %x, 0\n" 717 " %A = icmp eq i32 %x, 1\n" 718 " ret void\n" 719 "}"); 720 EXPECT_TRUE(impliesPoison(A2, A)); 721 } 722 723 TEST_F(ValueTrackingTest, impliesPoisonTest_ICmpUnknown) { 724 parseAssembly("define void @test(i32 %x, i32 %y) {\n" 725 " %A2 = icmp eq i32 %x, %y\n" 726 " %A = icmp eq i32 %x, 1\n" 727 " ret void\n" 728 "}"); 729 EXPECT_FALSE(impliesPoison(A2, A)); 730 } 731 732 TEST_F(ValueTrackingTest, impliesPoisonTest_AddNswOkay) { 733 parseAssembly("define void @test(i32 %x) {\n" 734 " %A2 = add nsw i32 %x, 1\n" 735 " %A = add i32 %A2, 1\n" 736 " ret void\n" 737 "}"); 738 EXPECT_TRUE(impliesPoison(A2, A)); 739 } 740 741 TEST_F(ValueTrackingTest, impliesPoisonTest_AddNswOkay2) { 742 parseAssembly("define void @test(i32 %x) {\n" 743 " %A2 = add i32 %x, 1\n" 744 " %A = add nsw i32 %A2, 1\n" 745 " ret void\n" 746 "}"); 747 EXPECT_TRUE(impliesPoison(A2, A)); 748 } 749 750 TEST_F(ValueTrackingTest, impliesPoisonTest_AddNsw) { 751 parseAssembly("define void @test(i32 %x) {\n" 752 " %A2 = add nsw i32 %x, 1\n" 753 " %A = add i32 %x, 1\n" 754 " ret void\n" 755 "}"); 756 EXPECT_FALSE(impliesPoison(A2, A)); 757 } 758 759 TEST_F(ValueTrackingTest, impliesPoisonTest_Cmp) { 760 parseAssembly("define void @test(i32 %x, i32 %y, i1 %c) {\n" 761 " %A2 = icmp eq i32 %x, %y\n" 762 " %A0 = icmp ult i32 %x, %y\n" 763 " %A = or i1 %A0, %c\n" 764 " ret void\n" 765 "}"); 766 EXPECT_TRUE(impliesPoison(A2, A)); 767 } 768 769 TEST_F(ValueTrackingTest, impliesPoisonTest_FCmpFMF) { 770 parseAssembly("define void @test(float %x, float %y, i1 %c) {\n" 771 " %A2 = fcmp nnan oeq float %x, %y\n" 772 " %A0 = fcmp olt float %x, %y\n" 773 " %A = or i1 %A0, %c\n" 774 " ret void\n" 775 "}"); 776 EXPECT_FALSE(impliesPoison(A2, A)); 777 } 778 779 TEST_F(ValueTrackingTest, impliesPoisonTest_AddSubSameOps) { 780 parseAssembly("define void @test(i32 %x, i32 %y, i1 %c) {\n" 781 " %A2 = add i32 %x, %y\n" 782 " %A = sub i32 %x, %y\n" 783 " ret void\n" 784 "}"); 785 EXPECT_TRUE(impliesPoison(A2, A)); 786 } 787 788 TEST_F(ValueTrackingTest, impliesPoisonTest_MaskCmp) { 789 parseAssembly("define void @test(i32 %x, i32 %y, i1 %c) {\n" 790 " %M2 = and i32 %x, 7\n" 791 " %A2 = icmp eq i32 %M2, 1\n" 792 " %M = and i32 %x, 15\n" 793 " %A = icmp eq i32 %M, 3\n" 794 " ret void\n" 795 "}"); 796 EXPECT_TRUE(impliesPoison(A2, A)); 797 } 798 799 TEST_F(ValueTrackingTest, ComputeNumSignBits_Shuffle_Pointers) { 800 parseAssembly( 801 "define <2 x i32*> @test(<2 x i32*> %x) {\n" 802 " %A = shufflevector <2 x i32*> zeroinitializer, <2 x i32*> undef, <2 x i32> zeroinitializer\n" 803 " ret <2 x i32*> %A\n" 804 "}\n"); 805 EXPECT_EQ(ComputeNumSignBits(A, M->getDataLayout()), 64u); 806 } 807 808 TEST(ValueTracking, propagatesPoison) { 809 std::string AsmHead = 810 "declare i32 @g(i32)\n" 811 "declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)\n" 812 "declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)\n" 813 "declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)\n" 814 "declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)\n" 815 "declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)\n" 816 "declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)\n" 817 "declare float @llvm.sqrt.f32(float)\n" 818 "declare float @llvm.powi.f32.i32(float, i32)\n" 819 "declare float @llvm.sin.f32(float)\n" 820 "declare float @llvm.cos.f32(float)\n" 821 "declare float @llvm.pow.f32(float, float)\n" 822 "declare float @llvm.exp.f32(float)\n" 823 "declare float @llvm.exp2.f32(float)\n" 824 "declare float @llvm.log.f32(float)\n" 825 "declare float @llvm.log10.f32(float)\n" 826 "declare float @llvm.log2.f32(float)\n" 827 "declare float @llvm.fma.f32(float, float, float)\n" 828 "declare float @llvm.fabs.f32(float)\n" 829 "declare float @llvm.minnum.f32(float, float)\n" 830 "declare float @llvm.maxnum.f32(float, float)\n" 831 "declare float @llvm.minimum.f32(float, float)\n" 832 "declare float @llvm.maximum.f32(float, float)\n" 833 "declare float @llvm.copysign.f32(float, float)\n" 834 "declare float @llvm.floor.f32(float)\n" 835 "declare float @llvm.ceil.f32(float)\n" 836 "declare float @llvm.trunc.f32(float)\n" 837 "declare float @llvm.rint.f32(float)\n" 838 "declare float @llvm.nearbyint.f32(float)\n" 839 "declare float @llvm.round.f32(float)\n" 840 "declare float @llvm.roundeven.f32(float)\n" 841 "declare i32 @llvm.lround.f32(float)\n" 842 "declare i64 @llvm.llround.f32(float)\n" 843 "declare i32 @llvm.lrint.f32(float)\n" 844 "declare i64 @llvm.llrint.f32(float)\n" 845 "declare float @llvm.fmuladd.f32(float, float, float)\n" 846 "define void @f(i32 %x, i32 %y, float %fx, float %fy, " 847 "i1 %cond, i8* %p) {\n"; 848 std::string AsmTail = " ret void\n}"; 849 // (propagates poison?, IR instruction) 850 SmallVector<std::pair<bool, std::string>, 32> Data = { 851 {true, "add i32 %x, %y"}, 852 {true, "add nsw nuw i32 %x, %y"}, 853 {true, "ashr i32 %x, %y"}, 854 {true, "lshr exact i32 %x, 31"}, 855 {true, "fadd float %fx, %fy"}, 856 {true, "fsub float %fx, %fy"}, 857 {true, "fmul float %fx, %fy"}, 858 {true, "fdiv float %fx, %fy"}, 859 {true, "frem float %fx, %fy"}, 860 {true, "fneg float %fx"}, 861 {true, "fcmp oeq float %fx, %fy"}, 862 {true, "icmp eq i32 %x, %y"}, 863 {true, "getelementptr i8, i8* %p, i32 %x"}, 864 {true, "getelementptr inbounds i8, i8* %p, i32 %x"}, 865 {true, "bitcast float %fx to i32"}, 866 {false, "select i1 %cond, i32 %x, i32 %y"}, 867 {false, "freeze i32 %x"}, 868 {true, "udiv i32 %x, %y"}, 869 {true, "urem i32 %x, %y"}, 870 {true, "sdiv exact i32 %x, %y"}, 871 {true, "srem i32 %x, %y"}, 872 {false, "call i32 @g(i32 %x)"}, 873 {true, "call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %x, i32 %y)"}, 874 {true, "call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %x, i32 %y)"}, 875 {true, "call {i32, i1} @llvm.smul.with.overflow.i32(i32 %x, i32 %y)"}, 876 {true, "call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %x, i32 %y)"}, 877 {true, "call {i32, i1} @llvm.usub.with.overflow.i32(i32 %x, i32 %y)"}, 878 {true, "call {i32, i1} @llvm.umul.with.overflow.i32(i32 %x, i32 %y)"}, 879 {false, "call float @llvm.sqrt.f32(float %fx)"}, 880 {false, "call float @llvm.powi.f32.i32(float %fx, i32 %x)"}, 881 {false, "call float @llvm.sin.f32(float %fx)"}, 882 {false, "call float @llvm.cos.f32(float %fx)"}, 883 {false, "call float @llvm.pow.f32(float %fx, float %fy)"}, 884 {false, "call float @llvm.exp.f32(float %fx)"}, 885 {false, "call float @llvm.exp2.f32(float %fx)"}, 886 {false, "call float @llvm.log.f32(float %fx)"}, 887 {false, "call float @llvm.log10.f32(float %fx)"}, 888 {false, "call float @llvm.log2.f32(float %fx)"}, 889 {false, "call float @llvm.fma.f32(float %fx, float %fx, float %fy)"}, 890 {false, "call float @llvm.fabs.f32(float %fx)"}, 891 {false, "call float @llvm.minnum.f32(float %fx, float %fy)"}, 892 {false, "call float @llvm.maxnum.f32(float %fx, float %fy)"}, 893 {false, "call float @llvm.minimum.f32(float %fx, float %fy)"}, 894 {false, "call float @llvm.maximum.f32(float %fx, float %fy)"}, 895 {false, "call float @llvm.copysign.f32(float %fx, float %fy)"}, 896 {false, "call float @llvm.floor.f32(float %fx)"}, 897 {false, "call float @llvm.ceil.f32(float %fx)"}, 898 {false, "call float @llvm.trunc.f32(float %fx)"}, 899 {false, "call float @llvm.rint.f32(float %fx)"}, 900 {false, "call float @llvm.nearbyint.f32(float %fx)"}, 901 {false, "call float @llvm.round.f32(float %fx)"}, 902 {false, "call float @llvm.roundeven.f32(float %fx)"}, 903 {false, "call i32 @llvm.lround.f32(float %fx)"}, 904 {false, "call i64 @llvm.llround.f32(float %fx)"}, 905 {false, "call i32 @llvm.lrint.f32(float %fx)"}, 906 {false, "call i64 @llvm.llrint.f32(float %fx)"}, 907 {false, "call float @llvm.fmuladd.f32(float %fx, float %fx, float %fy)"}}; 908 909 std::string AssemblyStr = AsmHead; 910 for (auto &Itm : Data) 911 AssemblyStr += Itm.second + "\n"; 912 AssemblyStr += AsmTail; 913 914 LLVMContext Context; 915 SMDiagnostic Error; 916 auto M = parseAssemblyString(AssemblyStr, Error, Context); 917 assert(M && "Bad assembly?"); 918 919 auto *F = M->getFunction("f"); 920 assert(F && "Bad assembly?"); 921 922 auto &BB = F->getEntryBlock(); 923 924 int Index = 0; 925 for (auto &I : BB) { 926 if (isa<ReturnInst>(&I)) 927 break; 928 EXPECT_EQ(propagatesPoison(cast<Operator>(&I)), Data[Index].first) 929 << "Incorrect answer at instruction " << Index << " = " << I; 930 Index++; 931 } 932 } 933 934 TEST_F(ValueTrackingTest, programUndefinedIfPoison) { 935 parseAssembly("declare i32 @any_num()" 936 "define void @test(i32 %mask) {\n" 937 " %A = call i32 @any_num()\n" 938 " %B = or i32 %A, %mask\n" 939 " udiv i32 1, %B" 940 " ret void\n" 941 "}\n"); 942 // If %A was poison, udiv raises UB regardless of %mask's value 943 EXPECT_EQ(programUndefinedIfPoison(A), true); 944 } 945 946 TEST_F(ValueTrackingTest, programUndefinedIfUndefOrPoison) { 947 parseAssembly("declare i32 @any_num()" 948 "define void @test(i32 %mask) {\n" 949 " %A = call i32 @any_num()\n" 950 " %B = or i32 %A, %mask\n" 951 " udiv i32 1, %B" 952 " ret void\n" 953 "}\n"); 954 // If %A was undef and %mask was 1, udiv does not raise UB 955 EXPECT_EQ(programUndefinedIfUndefOrPoison(A), false); 956 } 957 958 TEST_F(ValueTrackingTest, isGuaranteedNotToBePoison_exploitBranchCond) { 959 parseAssembly("declare i1 @any_bool()" 960 "define void @test(i1 %y) {\n" 961 " %A = call i1 @any_bool()\n" 962 " %cond = and i1 %A, %y\n" 963 " br i1 %cond, label %BB1, label %BB2\n" 964 "BB1:\n" 965 " ret void\n" 966 "BB2:\n" 967 " ret void\n" 968 "}\n"); 969 DominatorTree DT(*F); 970 for (auto &BB : *F) { 971 if (&BB == &F->getEntryBlock()) 972 continue; 973 974 EXPECT_EQ(isGuaranteedNotToBePoison(A, nullptr, BB.getTerminator(), &DT), 975 true) 976 << "isGuaranteedNotToBePoison does not hold at " << *BB.getTerminator(); 977 } 978 } 979 980 TEST_F(ValueTrackingTest, isGuaranteedNotToBePoison_phi) { 981 parseAssembly("declare i32 @any_i32(i32)" 982 "define void @test() {\n" 983 "ENTRY:\n" 984 " br label %LOOP\n" 985 "LOOP:\n" 986 " %A = phi i32 [0, %ENTRY], [%A.next, %NEXT]\n" 987 " %A.next = call i32 @any_i32(i32 %A)\n" 988 " %cond = icmp eq i32 %A.next, 0\n" 989 " br i1 %cond, label %NEXT, label %EXIT\n" 990 "NEXT:\n" 991 " br label %LOOP\n" 992 "EXIT:\n" 993 " ret void\n" 994 "}\n"); 995 DominatorTree DT(*F); 996 for (auto &BB : *F) { 997 if (BB.getName() == "LOOP") { 998 EXPECT_EQ(isGuaranteedNotToBePoison(A, nullptr, A, &DT), true) 999 << "isGuaranteedNotToBePoison does not hold"; 1000 } 1001 } 1002 } 1003 1004 TEST_F(ValueTrackingTest, isGuaranteedNotToBeUndefOrPoison) { 1005 parseAssembly("declare void @f(i32 noundef)" 1006 "define void @test(i32 %x) {\n" 1007 " %A = bitcast i32 %x to i32\n" 1008 " call void @f(i32 noundef %x)\n" 1009 " ret void\n" 1010 "}\n"); 1011 EXPECT_EQ(isGuaranteedNotToBeUndefOrPoison(A), true); 1012 EXPECT_EQ(isGuaranteedNotToBeUndefOrPoison(UndefValue::get(IntegerType::get(Context, 8))), false); 1013 EXPECT_EQ(isGuaranteedNotToBeUndefOrPoison(PoisonValue::get(IntegerType::get(Context, 8))), false); 1014 EXPECT_EQ(isGuaranteedNotToBePoison(UndefValue::get(IntegerType::get(Context, 8))), true); 1015 EXPECT_EQ(isGuaranteedNotToBePoison(PoisonValue::get(IntegerType::get(Context, 8))), false); 1016 1017 Type *Int32Ty = Type::getInt32Ty(Context); 1018 Constant *CU = UndefValue::get(Int32Ty); 1019 Constant *CP = PoisonValue::get(Int32Ty); 1020 Constant *C1 = ConstantInt::get(Int32Ty, 1); 1021 Constant *C2 = ConstantInt::get(Int32Ty, 2); 1022 1023 { 1024 Constant *V1 = ConstantVector::get({C1, C2}); 1025 EXPECT_TRUE(isGuaranteedNotToBeUndefOrPoison(V1)); 1026 EXPECT_TRUE(isGuaranteedNotToBePoison(V1)); 1027 } 1028 1029 { 1030 Constant *V2 = ConstantVector::get({C1, CU}); 1031 EXPECT_FALSE(isGuaranteedNotToBeUndefOrPoison(V2)); 1032 EXPECT_TRUE(isGuaranteedNotToBePoison(V2)); 1033 } 1034 1035 { 1036 Constant *V3 = ConstantVector::get({C1, CP}); 1037 EXPECT_FALSE(isGuaranteedNotToBeUndefOrPoison(V3)); 1038 EXPECT_FALSE(isGuaranteedNotToBePoison(V3)); 1039 } 1040 } 1041 1042 TEST_F(ValueTrackingTest, isGuaranteedNotToBeUndefOrPoison_assume) { 1043 parseAssembly("declare i1 @f_i1()\n" 1044 "declare i32 @f_i32()\n" 1045 "declare void @llvm.assume(i1)\n" 1046 "define void @test() {\n" 1047 " %A = call i32 @f_i32()\n" 1048 " %cond = call i1 @f_i1()\n" 1049 " %CxtI = add i32 0, 0\n" 1050 " br i1 %cond, label %BB1, label %EXIT\n" 1051 "BB1:\n" 1052 " %CxtI2 = add i32 0, 0\n" 1053 " %cond2 = call i1 @f_i1()\n" 1054 " call void @llvm.assume(i1 true) [ \"noundef\"(i32 %A) ]\n" 1055 " br i1 %cond2, label %BB2, label %EXIT\n" 1056 "BB2:\n" 1057 " %CxtI3 = add i32 0, 0\n" 1058 " ret void\n" 1059 "EXIT:\n" 1060 " ret void\n" 1061 "}"); 1062 AssumptionCache AC(*F); 1063 DominatorTree DT(*F); 1064 EXPECT_FALSE(isGuaranteedNotToBeUndefOrPoison(A, &AC, CxtI, &DT)); 1065 EXPECT_FALSE(isGuaranteedNotToBeUndefOrPoison(A, &AC, CxtI2, &DT)); 1066 EXPECT_TRUE(isGuaranteedNotToBeUndefOrPoison(A, &AC, CxtI3, &DT)); 1067 } 1068 1069 TEST(ValueTracking, canCreatePoisonOrUndef) { 1070 std::string AsmHead = 1071 "@s = external dso_local global i32, align 1\n" 1072 "declare i32 @g(i32)\n" 1073 "declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)\n" 1074 "declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)\n" 1075 "declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)\n" 1076 "declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)\n" 1077 "declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)\n" 1078 "declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)\n" 1079 "define void @f(i32 %x, i32 %y, float %fx, float %fy, i1 %cond, " 1080 "<4 x i32> %vx, <4 x i32> %vx2, <vscale x 4 x i32> %svx, i8* %p) {\n"; 1081 std::string AsmTail = " ret void\n}"; 1082 // (can create poison?, can create undef?, IR instruction) 1083 SmallVector<std::pair<std::pair<bool, bool>, std::string>, 32> Data = { 1084 {{false, false}, "add i32 %x, %y"}, 1085 {{true, false}, "add nsw nuw i32 %x, %y"}, 1086 {{true, false}, "shl i32 %x, %y"}, 1087 {{true, false}, "shl <4 x i32> %vx, %vx2"}, 1088 {{true, false}, "shl nsw i32 %x, %y"}, 1089 {{true, false}, "shl nsw <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 3>"}, 1090 {{false, false}, "shl i32 %x, 31"}, 1091 {{true, false}, "shl i32 %x, 32"}, 1092 {{false, false}, "shl <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 3>"}, 1093 {{true, false}, "shl <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 32>"}, 1094 {{true, false}, "ashr i32 %x, %y"}, 1095 {{true, false}, "ashr exact i32 %x, %y"}, 1096 {{false, false}, "ashr i32 %x, 31"}, 1097 {{true, false}, "ashr exact i32 %x, 31"}, 1098 {{false, false}, "ashr <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 3>"}, 1099 {{true, false}, "ashr <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 32>"}, 1100 {{true, false}, "ashr exact <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 3>"}, 1101 {{true, false}, "lshr i32 %x, %y"}, 1102 {{true, false}, "lshr exact i32 %x, 31"}, 1103 {{false, false}, "udiv i32 %x, %y"}, 1104 {{true, false}, "udiv exact i32 %x, %y"}, 1105 {{false, false}, "getelementptr i8, i8* %p, i32 %x"}, 1106 {{true, false}, "getelementptr inbounds i8, i8* %p, i32 %x"}, 1107 {{true, false}, "fneg nnan float %fx"}, 1108 {{false, false}, "fneg float %fx"}, 1109 {{false, false}, "fadd float %fx, %fy"}, 1110 {{true, false}, "fadd nnan float %fx, %fy"}, 1111 {{false, false}, "urem i32 %x, %y"}, 1112 {{true, false}, "fptoui float %fx to i32"}, 1113 {{true, false}, "fptosi float %fx to i32"}, 1114 {{false, false}, "bitcast float %fx to i32"}, 1115 {{false, false}, "select i1 %cond, i32 %x, i32 %y"}, 1116 {{true, false}, "select nnan i1 %cond, float %fx, float %fy"}, 1117 {{true, false}, "extractelement <4 x i32> %vx, i32 %x"}, 1118 {{false, false}, "extractelement <4 x i32> %vx, i32 3"}, 1119 {{true, false}, "extractelement <vscale x 4 x i32> %svx, i32 4"}, 1120 {{true, false}, "insertelement <4 x i32> %vx, i32 %x, i32 %y"}, 1121 {{false, false}, "insertelement <4 x i32> %vx, i32 %x, i32 3"}, 1122 {{true, false}, "insertelement <vscale x 4 x i32> %svx, i32 %x, i32 4"}, 1123 {{false, false}, "freeze i32 %x"}, 1124 {{false, false}, 1125 "shufflevector <4 x i32> %vx, <4 x i32> %vx2, " 1126 "<4 x i32> <i32 0, i32 1, i32 2, i32 3>"}, 1127 {{false, true}, 1128 "shufflevector <4 x i32> %vx, <4 x i32> %vx2, " 1129 "<4 x i32> <i32 0, i32 1, i32 2, i32 undef>"}, 1130 {{false, true}, 1131 "shufflevector <vscale x 4 x i32> %svx, " 1132 "<vscale x 4 x i32> %svx, <vscale x 4 x i32> undef"}, 1133 {{true, false}, "call i32 @g(i32 %x)"}, 1134 {{false, false}, "call noundef i32 @g(i32 %x)"}, 1135 {{true, false}, "fcmp nnan oeq float %fx, %fy"}, 1136 {{false, false}, "fcmp oeq float %fx, %fy"}, 1137 {{true, false}, 1138 "ashr <4 x i32> %vx, select (i1 icmp sgt (i32 ptrtoint (i32* @s to " 1139 "i32), i32 1), <4 x i32> zeroinitializer, <4 x i32> <i32 0, i32 1, i32 " 1140 "2, i32 3>)"}, 1141 {{false, false}, 1142 "call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %x, i32 %y)"}, 1143 {{false, false}, 1144 "call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %x, i32 %y)"}, 1145 {{false, false}, 1146 "call {i32, i1} @llvm.smul.with.overflow.i32(i32 %x, i32 %y)"}, 1147 {{false, false}, 1148 "call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %x, i32 %y)"}, 1149 {{false, false}, 1150 "call {i32, i1} @llvm.usub.with.overflow.i32(i32 %x, i32 %y)"}, 1151 {{false, false}, 1152 "call {i32, i1} @llvm.umul.with.overflow.i32(i32 %x, i32 %y)"}}; 1153 1154 std::string AssemblyStr = AsmHead; 1155 for (auto &Itm : Data) 1156 AssemblyStr += Itm.second + "\n"; 1157 AssemblyStr += AsmTail; 1158 1159 LLVMContext Context; 1160 SMDiagnostic Error; 1161 auto M = parseAssemblyString(AssemblyStr, Error, Context); 1162 assert(M && "Bad assembly?"); 1163 1164 auto *F = M->getFunction("f"); 1165 assert(F && "Bad assembly?"); 1166 1167 auto &BB = F->getEntryBlock(); 1168 1169 int Index = 0; 1170 for (auto &I : BB) { 1171 if (isa<ReturnInst>(&I)) 1172 break; 1173 bool Poison = Data[Index].first.first; 1174 bool Undef = Data[Index].first.second; 1175 EXPECT_EQ(canCreatePoison(cast<Operator>(&I)), Poison) 1176 << "Incorrect answer of canCreatePoison at instruction " << Index 1177 << " = " << I; 1178 EXPECT_EQ(canCreateUndefOrPoison(cast<Operator>(&I)), Undef || Poison) 1179 << "Incorrect answer of canCreateUndef at instruction " << Index 1180 << " = " << I; 1181 Index++; 1182 } 1183 } 1184 1185 TEST_F(ValueTrackingTest, computePtrAlignment) { 1186 parseAssembly("declare i1 @f_i1()\n" 1187 "declare i8* @f_i8p()\n" 1188 "declare void @llvm.assume(i1)\n" 1189 "define void @test() {\n" 1190 " %A = call i8* @f_i8p()\n" 1191 " %cond = call i1 @f_i1()\n" 1192 " %CxtI = add i32 0, 0\n" 1193 " br i1 %cond, label %BB1, label %EXIT\n" 1194 "BB1:\n" 1195 " %CxtI2 = add i32 0, 0\n" 1196 " %cond2 = call i1 @f_i1()\n" 1197 " call void @llvm.assume(i1 true) [ \"align\"(i8* %A, i64 16) ]\n" 1198 " br i1 %cond2, label %BB2, label %EXIT\n" 1199 "BB2:\n" 1200 " %CxtI3 = add i32 0, 0\n" 1201 " ret void\n" 1202 "EXIT:\n" 1203 " ret void\n" 1204 "}"); 1205 AssumptionCache AC(*F); 1206 DominatorTree DT(*F); 1207 const DataLayout &DL = M->getDataLayout(); 1208 EXPECT_EQ(getKnownAlignment(A, DL, CxtI, &AC, &DT), Align(1)); 1209 EXPECT_EQ(getKnownAlignment(A, DL, CxtI2, &AC, &DT), Align(1)); 1210 EXPECT_EQ(getKnownAlignment(A, DL, CxtI3, &AC, &DT), Align(16)); 1211 } 1212 1213 TEST_F(ComputeKnownBitsTest, ComputeKnownBits) { 1214 parseAssembly( 1215 "define i32 @test(i32 %a, i32 %b) {\n" 1216 " %ash = mul i32 %a, 8\n" 1217 " %aad = add i32 %ash, 7\n" 1218 " %aan = and i32 %aad, 4095\n" 1219 " %bsh = shl i32 %b, 4\n" 1220 " %bad = or i32 %bsh, 6\n" 1221 " %ban = and i32 %bad, 4095\n" 1222 " %A = mul i32 %aan, %ban\n" 1223 " ret i32 %A\n" 1224 "}\n"); 1225 expectKnownBits(/*zero*/ 4278190085u, /*one*/ 10u); 1226 } 1227 1228 TEST_F(ComputeKnownBitsTest, ComputeKnownMulBits) { 1229 parseAssembly( 1230 "define i32 @test(i32 %a, i32 %b) {\n" 1231 " %aa = shl i32 %a, 5\n" 1232 " %bb = shl i32 %b, 5\n" 1233 " %aaa = or i32 %aa, 24\n" 1234 " %bbb = or i32 %bb, 28\n" 1235 " %A = mul i32 %aaa, %bbb\n" 1236 " ret i32 %A\n" 1237 "}\n"); 1238 expectKnownBits(/*zero*/ 95u, /*one*/ 32u); 1239 } 1240 1241 TEST_F(ValueTrackingTest, isNonZeroRecurrence) { 1242 parseAssembly(R"( 1243 define i1 @test(i8 %n, i8 %r) { 1244 entry: 1245 br label %loop 1246 loop: 1247 %p = phi i8 [ -1, %entry ], [ %next, %loop ] 1248 %next = add nsw i8 %p, -1 1249 %cmp1 = icmp eq i8 %p, %n 1250 br i1 %cmp1, label %exit, label %loop 1251 exit: 1252 %A = or i8 %p, %r 1253 %CxtI = icmp eq i8 %A, 0 1254 ret i1 %CxtI 1255 } 1256 )"); 1257 const DataLayout &DL = M->getDataLayout(); 1258 AssumptionCache AC(*F); 1259 EXPECT_TRUE(isKnownNonZero(A, DL, 0, &AC, CxtI)); 1260 } 1261 1262 TEST_F(ValueTrackingTest, KnownNonZeroFromDomCond) { 1263 parseAssembly(R"( 1264 declare i8* @f_i8() 1265 define void @test(i1 %c) { 1266 %A = call i8* @f_i8() 1267 %B = call i8* @f_i8() 1268 %c1 = icmp ne i8* %A, null 1269 %cond = and i1 %c1, %c 1270 br i1 %cond, label %T, label %Q 1271 T: 1272 %CxtI = add i32 0, 0 1273 ret void 1274 Q: 1275 %CxtI2 = add i32 0, 0 1276 ret void 1277 } 1278 )"); 1279 AssumptionCache AC(*F); 1280 DominatorTree DT(*F); 1281 const DataLayout &DL = M->getDataLayout(); 1282 EXPECT_EQ(isKnownNonZero(A, DL, 0, &AC, CxtI, &DT), true); 1283 EXPECT_EQ(isKnownNonZero(A, DL, 0, &AC, CxtI2, &DT), false); 1284 } 1285 1286 TEST_F(ValueTrackingTest, KnownNonZeroFromDomCond2) { 1287 parseAssembly(R"( 1288 declare i8* @f_i8() 1289 define void @test(i1 %c) { 1290 %A = call i8* @f_i8() 1291 %B = call i8* @f_i8() 1292 %c1 = icmp ne i8* %A, null 1293 %cond = select i1 %c, i1 %c1, i1 false 1294 br i1 %cond, label %T, label %Q 1295 T: 1296 %CxtI = add i32 0, 0 1297 ret void 1298 Q: 1299 %CxtI2 = add i32 0, 0 1300 ret void 1301 } 1302 )"); 1303 AssumptionCache AC(*F); 1304 DominatorTree DT(*F); 1305 const DataLayout &DL = M->getDataLayout(); 1306 EXPECT_EQ(isKnownNonZero(A, DL, 0, &AC, CxtI, &DT), true); 1307 EXPECT_EQ(isKnownNonZero(A, DL, 0, &AC, CxtI2, &DT), false); 1308 } 1309 1310 TEST_F(ValueTrackingTest, IsImpliedConditionAnd) { 1311 parseAssembly(R"( 1312 define void @test(i32 %x, i32 %y) { 1313 %c1 = icmp ult i32 %x, 10 1314 %c2 = icmp ult i32 %y, 15 1315 %A = and i1 %c1, %c2 1316 ; x < 10 /\ y < 15 1317 %A2 = icmp ult i32 %x, 20 1318 %A3 = icmp uge i32 %y, 20 1319 %A4 = icmp ult i32 %x, 5 1320 ret void 1321 } 1322 )"); 1323 const DataLayout &DL = M->getDataLayout(); 1324 EXPECT_EQ(isImpliedCondition(A, A2, DL), true); 1325 EXPECT_EQ(isImpliedCondition(A, A3, DL), false); 1326 EXPECT_EQ(isImpliedCondition(A, A4, DL), std::nullopt); 1327 } 1328 1329 TEST_F(ValueTrackingTest, IsImpliedConditionAnd2) { 1330 parseAssembly(R"( 1331 define void @test(i32 %x, i32 %y) { 1332 %c1 = icmp ult i32 %x, 10 1333 %c2 = icmp ult i32 %y, 15 1334 %A = select i1 %c1, i1 %c2, i1 false 1335 ; x < 10 /\ y < 15 1336 %A2 = icmp ult i32 %x, 20 1337 %A3 = icmp uge i32 %y, 20 1338 %A4 = icmp ult i32 %x, 5 1339 ret void 1340 } 1341 )"); 1342 const DataLayout &DL = M->getDataLayout(); 1343 EXPECT_EQ(isImpliedCondition(A, A2, DL), true); 1344 EXPECT_EQ(isImpliedCondition(A, A3, DL), false); 1345 EXPECT_EQ(isImpliedCondition(A, A4, DL), std::nullopt); 1346 } 1347 1348 TEST_F(ValueTrackingTest, IsImpliedConditionAndVec) { 1349 parseAssembly(R"( 1350 define void @test(<2 x i8> %x, <2 x i8> %y) { 1351 %A = icmp ult <2 x i8> %x, %y 1352 %A2 = icmp ule <2 x i8> %x, %y 1353 ret void 1354 } 1355 )"); 1356 const DataLayout &DL = M->getDataLayout(); 1357 EXPECT_EQ(isImpliedCondition(A, A2, DL), true); 1358 } 1359 1360 TEST_F(ValueTrackingTest, IsImpliedConditionOr) { 1361 parseAssembly(R"( 1362 define void @test(i32 %x, i32 %y) { 1363 %c1 = icmp ult i32 %x, 10 1364 %c2 = icmp ult i32 %y, 15 1365 %A = or i1 %c1, %c2 ; negated 1366 ; x >= 10 /\ y >= 15 1367 %A2 = icmp ult i32 %x, 5 1368 %A3 = icmp uge i32 %y, 10 1369 %A4 = icmp ult i32 %x, 15 1370 ret void 1371 } 1372 )"); 1373 const DataLayout &DL = M->getDataLayout(); 1374 EXPECT_EQ(isImpliedCondition(A, A2, DL, false), false); 1375 EXPECT_EQ(isImpliedCondition(A, A3, DL, false), true); 1376 EXPECT_EQ(isImpliedCondition(A, A4, DL, false), std::nullopt); 1377 } 1378 1379 TEST_F(ValueTrackingTest, IsImpliedConditionOr2) { 1380 parseAssembly(R"( 1381 define void @test(i32 %x, i32 %y) { 1382 %c1 = icmp ult i32 %x, 10 1383 %c2 = icmp ult i32 %y, 15 1384 %A = select i1 %c1, i1 true, i1 %c2 ; negated 1385 ; x >= 10 /\ y >= 15 1386 %A2 = icmp ult i32 %x, 5 1387 %A3 = icmp uge i32 %y, 10 1388 %A4 = icmp ult i32 %x, 15 1389 ret void 1390 } 1391 )"); 1392 const DataLayout &DL = M->getDataLayout(); 1393 EXPECT_EQ(isImpliedCondition(A, A2, DL, false), false); 1394 EXPECT_EQ(isImpliedCondition(A, A3, DL, false), true); 1395 EXPECT_EQ(isImpliedCondition(A, A4, DL, false), std::nullopt); 1396 } 1397 1398 TEST_F(ComputeKnownBitsTest, KnownNonZeroShift) { 1399 // %q is known nonzero without known bits. 1400 // Because %q is nonzero, %A[0] is known to be zero. 1401 parseAssembly( 1402 "define i8 @test(i8 %p, i8* %pq) {\n" 1403 " %q = load i8, i8* %pq, !range !0\n" 1404 " %A = shl i8 %p, %q\n" 1405 " ret i8 %A\n" 1406 "}\n" 1407 "!0 = !{ i8 1, i8 5 }\n"); 1408 expectKnownBits(/*zero*/ 1u, /*one*/ 0u); 1409 } 1410 1411 TEST_F(ComputeKnownBitsTest, ComputeKnownFshl) { 1412 // fshl(....1111....0000, 00..1111........, 6) 1413 // = 11....000000..11 1414 parseAssembly( 1415 "define i16 @test(i16 %a, i16 %b) {\n" 1416 " %aa = shl i16 %a, 4\n" 1417 " %bb = lshr i16 %b, 2\n" 1418 " %aaa = or i16 %aa, 3840\n" 1419 " %bbb = or i16 %bb, 3840\n" 1420 " %A = call i16 @llvm.fshl.i16(i16 %aaa, i16 %bbb, i16 6)\n" 1421 " ret i16 %A\n" 1422 "}\n" 1423 "declare i16 @llvm.fshl.i16(i16, i16, i16)\n"); 1424 expectKnownBits(/*zero*/ 1008u, /*one*/ 49155u); 1425 } 1426 1427 TEST_F(ComputeKnownBitsTest, ComputeKnownFshr) { 1428 // fshr(....1111....0000, 00..1111........, 26) 1429 // = 11....000000..11 1430 parseAssembly( 1431 "define i16 @test(i16 %a, i16 %b) {\n" 1432 " %aa = shl i16 %a, 4\n" 1433 " %bb = lshr i16 %b, 2\n" 1434 " %aaa = or i16 %aa, 3840\n" 1435 " %bbb = or i16 %bb, 3840\n" 1436 " %A = call i16 @llvm.fshr.i16(i16 %aaa, i16 %bbb, i16 26)\n" 1437 " ret i16 %A\n" 1438 "}\n" 1439 "declare i16 @llvm.fshr.i16(i16, i16, i16)\n"); 1440 expectKnownBits(/*zero*/ 1008u, /*one*/ 49155u); 1441 } 1442 1443 TEST_F(ComputeKnownBitsTest, ComputeKnownFshlZero) { 1444 // fshl(....1111....0000, 00..1111........, 0) 1445 // = ....1111....0000 1446 parseAssembly( 1447 "define i16 @test(i16 %a, i16 %b) {\n" 1448 " %aa = shl i16 %a, 4\n" 1449 " %bb = lshr i16 %b, 2\n" 1450 " %aaa = or i16 %aa, 3840\n" 1451 " %bbb = or i16 %bb, 3840\n" 1452 " %A = call i16 @llvm.fshl.i16(i16 %aaa, i16 %bbb, i16 0)\n" 1453 " ret i16 %A\n" 1454 "}\n" 1455 "declare i16 @llvm.fshl.i16(i16, i16, i16)\n"); 1456 expectKnownBits(/*zero*/ 15u, /*one*/ 3840u); 1457 } 1458 1459 TEST_F(ComputeKnownBitsTest, ComputeKnownUAddSatLeadingOnes) { 1460 // uadd.sat(1111...1, ........) 1461 // = 1111.... 1462 parseAssembly( 1463 "define i8 @test(i8 %a, i8 %b) {\n" 1464 " %aa = or i8 %a, 241\n" 1465 " %A = call i8 @llvm.uadd.sat.i8(i8 %aa, i8 %b)\n" 1466 " ret i8 %A\n" 1467 "}\n" 1468 "declare i8 @llvm.uadd.sat.i8(i8, i8)\n"); 1469 expectKnownBits(/*zero*/ 0u, /*one*/ 240u); 1470 } 1471 1472 TEST_F(ComputeKnownBitsTest, ComputeKnownUAddSatOnesPreserved) { 1473 // uadd.sat(00...011, .1...110) 1474 // = .......1 1475 parseAssembly( 1476 "define i8 @test(i8 %a, i8 %b) {\n" 1477 " %aa = or i8 %a, 3\n" 1478 " %aaa = and i8 %aa, 59\n" 1479 " %bb = or i8 %b, 70\n" 1480 " %bbb = and i8 %bb, 254\n" 1481 " %A = call i8 @llvm.uadd.sat.i8(i8 %aaa, i8 %bbb)\n" 1482 " ret i8 %A\n" 1483 "}\n" 1484 "declare i8 @llvm.uadd.sat.i8(i8, i8)\n"); 1485 expectKnownBits(/*zero*/ 0u, /*one*/ 1u); 1486 } 1487 1488 TEST_F(ComputeKnownBitsTest, ComputeKnownUSubSatLHSLeadingZeros) { 1489 // usub.sat(0000...0, ........) 1490 // = 0000.... 1491 parseAssembly( 1492 "define i8 @test(i8 %a, i8 %b) {\n" 1493 " %aa = and i8 %a, 14\n" 1494 " %A = call i8 @llvm.usub.sat.i8(i8 %aa, i8 %b)\n" 1495 " ret i8 %A\n" 1496 "}\n" 1497 "declare i8 @llvm.usub.sat.i8(i8, i8)\n"); 1498 expectKnownBits(/*zero*/ 240u, /*one*/ 0u); 1499 } 1500 1501 TEST_F(ComputeKnownBitsTest, ComputeKnownUSubSatRHSLeadingOnes) { 1502 // usub.sat(........, 1111...1) 1503 // = 0000.... 1504 parseAssembly( 1505 "define i8 @test(i8 %a, i8 %b) {\n" 1506 " %bb = or i8 %a, 241\n" 1507 " %A = call i8 @llvm.usub.sat.i8(i8 %a, i8 %bb)\n" 1508 " ret i8 %A\n" 1509 "}\n" 1510 "declare i8 @llvm.usub.sat.i8(i8, i8)\n"); 1511 expectKnownBits(/*zero*/ 240u, /*one*/ 0u); 1512 } 1513 1514 TEST_F(ComputeKnownBitsTest, ComputeKnownUSubSatZerosPreserved) { 1515 // usub.sat(11...011, .1...110) 1516 // = ......0. 1517 parseAssembly( 1518 "define i8 @test(i8 %a, i8 %b) {\n" 1519 " %aa = or i8 %a, 195\n" 1520 " %aaa = and i8 %aa, 251\n" 1521 " %bb = or i8 %b, 70\n" 1522 " %bbb = and i8 %bb, 254\n" 1523 " %A = call i8 @llvm.usub.sat.i8(i8 %aaa, i8 %bbb)\n" 1524 " ret i8 %A\n" 1525 "}\n" 1526 "declare i8 @llvm.usub.sat.i8(i8, i8)\n"); 1527 expectKnownBits(/*zero*/ 2u, /*one*/ 0u); 1528 } 1529 1530 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsPtrToIntTrunc) { 1531 // ptrtoint truncates the pointer type. 1532 parseAssembly( 1533 "define void @test(i8** %p) {\n" 1534 " %A = load i8*, i8** %p\n" 1535 " %i = ptrtoint i8* %A to i32\n" 1536 " %m = and i32 %i, 31\n" 1537 " %c = icmp eq i32 %m, 0\n" 1538 " call void @llvm.assume(i1 %c)\n" 1539 " ret void\n" 1540 "}\n" 1541 "declare void @llvm.assume(i1)\n"); 1542 AssumptionCache AC(*F); 1543 KnownBits Known = computeKnownBits( 1544 A, M->getDataLayout(), /* Depth */ 0, &AC, F->front().getTerminator()); 1545 EXPECT_EQ(Known.Zero.getZExtValue(), 31u); 1546 EXPECT_EQ(Known.One.getZExtValue(), 0u); 1547 } 1548 1549 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsPtrToIntZext) { 1550 // ptrtoint zero extends the pointer type. 1551 parseAssembly( 1552 "define void @test(i8** %p) {\n" 1553 " %A = load i8*, i8** %p\n" 1554 " %i = ptrtoint i8* %A to i128\n" 1555 " %m = and i128 %i, 31\n" 1556 " %c = icmp eq i128 %m, 0\n" 1557 " call void @llvm.assume(i1 %c)\n" 1558 " ret void\n" 1559 "}\n" 1560 "declare void @llvm.assume(i1)\n"); 1561 AssumptionCache AC(*F); 1562 KnownBits Known = computeKnownBits( 1563 A, M->getDataLayout(), /* Depth */ 0, &AC, F->front().getTerminator()); 1564 EXPECT_EQ(Known.Zero.getZExtValue(), 31u); 1565 EXPECT_EQ(Known.One.getZExtValue(), 0u); 1566 } 1567 1568 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsFreeze) { 1569 parseAssembly("define void @test() {\n" 1570 " %m = call i32 @any_num()\n" 1571 " %A = freeze i32 %m\n" 1572 " %n = and i32 %m, 31\n" 1573 " %c = icmp eq i32 %n, 0\n" 1574 " call void @llvm.assume(i1 %c)\n" 1575 " ret void\n" 1576 "}\n" 1577 "declare void @llvm.assume(i1)\n" 1578 "declare i32 @any_num()\n"); 1579 AssumptionCache AC(*F); 1580 KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC, 1581 F->front().getTerminator()); 1582 EXPECT_EQ(Known.Zero.getZExtValue(), 31u); 1583 EXPECT_EQ(Known.One.getZExtValue(), 0u); 1584 } 1585 1586 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsAddWithRange) { 1587 parseAssembly("define void @test(i64* %p) {\n" 1588 " %A = load i64, i64* %p, !range !{i64 64, i64 65536}\n" 1589 " %APlus512 = add i64 %A, 512\n" 1590 " %c = icmp ugt i64 %APlus512, 523\n" 1591 " call void @llvm.assume(i1 %c)\n" 1592 " ret void\n" 1593 "}\n" 1594 "declare void @llvm.assume(i1)\n"); 1595 AssumptionCache AC(*F); 1596 KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC, 1597 F->front().getTerminator()); 1598 EXPECT_EQ(Known.Zero.getZExtValue(), ~(65536llu - 1)); 1599 EXPECT_EQ(Known.One.getZExtValue(), 0u); 1600 Instruction &APlus512 = findInstructionByName(F, "APlus512"); 1601 Known = computeKnownBits(&APlus512, M->getDataLayout(), /* Depth */ 0, &AC, 1602 F->front().getTerminator()); 1603 // We know of one less zero because 512 may have produced a 1 that 1604 // got carried all the way to the first trailing zero. 1605 EXPECT_EQ(Known.Zero.getZExtValue(), (~(65536llu - 1)) << 1); 1606 EXPECT_EQ(Known.One.getZExtValue(), 0u); 1607 // The known range is not precise given computeKnownBits works 1608 // with the masks of zeros and ones, not the ranges. 1609 EXPECT_EQ(Known.getMinValue(), 0u); 1610 EXPECT_EQ(Known.getMaxValue(), 131071); 1611 } 1612 1613 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsUnknownVScale) { 1614 Module M("", Context); 1615 IRBuilder<> Builder(Context); 1616 Function *TheFn = 1617 Intrinsic::getDeclaration(&M, Intrinsic::vscale, {Builder.getInt32Ty()}); 1618 CallInst *CI = Builder.CreateCall(TheFn, {}, {}, ""); 1619 1620 KnownBits Known = computeKnownBits(CI, M.getDataLayout(), /* Depth */ 0); 1621 // There is no parent function so we cannot look up the vscale_range 1622 // attribute to determine the number of bits. 1623 EXPECT_EQ(Known.One.getZExtValue(), 0u); 1624 EXPECT_EQ(Known.Zero.getZExtValue(), 0u); 1625 1626 BasicBlock *BB = BasicBlock::Create(Context); 1627 CI->insertInto(BB, BB->end()); 1628 Known = computeKnownBits(CI, M.getDataLayout(), /* Depth */ 0); 1629 // There is no parent function so we cannot look up the vscale_range 1630 // attribute to determine the number of bits. 1631 EXPECT_EQ(Known.One.getZExtValue(), 0u); 1632 EXPECT_EQ(Known.Zero.getZExtValue(), 0u); 1633 1634 CI->removeFromParent(); 1635 delete CI; 1636 delete BB; 1637 } 1638 1639 // 512 + [32, 64) doesn't produce overlapping bits. 1640 // Make sure we get all the individual bits properly. 1641 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsAddWithRangeNoOverlap) { 1642 parseAssembly("define void @test(i64* %p) {\n" 1643 " %A = load i64, i64* %p, !range !{i64 32, i64 64}\n" 1644 " %APlus512 = add i64 %A, 512\n" 1645 " %c = icmp ugt i64 %APlus512, 523\n" 1646 " call void @llvm.assume(i1 %c)\n" 1647 " ret void\n" 1648 "}\n" 1649 "declare void @llvm.assume(i1)\n"); 1650 AssumptionCache AC(*F); 1651 KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC, 1652 F->front().getTerminator()); 1653 EXPECT_EQ(Known.Zero.getZExtValue(), ~(64llu - 1)); 1654 EXPECT_EQ(Known.One.getZExtValue(), 32u); 1655 Instruction &APlus512 = findInstructionByName(F, "APlus512"); 1656 Known = computeKnownBits(&APlus512, M->getDataLayout(), /* Depth */ 0, &AC, 1657 F->front().getTerminator()); 1658 EXPECT_EQ(Known.Zero.getZExtValue(), ~512llu & ~(64llu - 1)); 1659 EXPECT_EQ(Known.One.getZExtValue(), 512u | 32u); 1660 // The known range is not precise given computeKnownBits works 1661 // with the masks of zeros and ones, not the ranges. 1662 EXPECT_EQ(Known.getMinValue(), 544); 1663 EXPECT_EQ(Known.getMaxValue(), 575); 1664 } 1665 1666 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsGEPWithRange) { 1667 parseAssembly( 1668 "define void @test(i64* %p) {\n" 1669 " %A = load i64, i64* %p, !range !{i64 64, i64 65536}\n" 1670 " %APtr = inttoptr i64 %A to float*" 1671 " %APtrPlus512 = getelementptr float, float* %APtr, i32 128\n" 1672 " %c = icmp ugt float* %APtrPlus512, inttoptr (i32 523 to float*)\n" 1673 " call void @llvm.assume(i1 %c)\n" 1674 " ret void\n" 1675 "}\n" 1676 "declare void @llvm.assume(i1)\n"); 1677 AssumptionCache AC(*F); 1678 KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC, 1679 F->front().getTerminator()); 1680 EXPECT_EQ(Known.Zero.getZExtValue(), ~(65536llu - 1)); 1681 EXPECT_EQ(Known.One.getZExtValue(), 0u); 1682 Instruction &APtrPlus512 = findInstructionByName(F, "APtrPlus512"); 1683 Known = computeKnownBits(&APtrPlus512, M->getDataLayout(), /* Depth */ 0, &AC, 1684 F->front().getTerminator()); 1685 // We know of one less zero because 512 may have produced a 1 that 1686 // got carried all the way to the first trailing zero. 1687 EXPECT_EQ(Known.Zero.getZExtValue(), ~(65536llu - 1) << 1); 1688 EXPECT_EQ(Known.One.getZExtValue(), 0u); 1689 // The known range is not precise given computeKnownBits works 1690 // with the masks of zeros and ones, not the ranges. 1691 EXPECT_EQ(Known.getMinValue(), 0u); 1692 EXPECT_EQ(Known.getMaxValue(), 131071); 1693 } 1694 1695 // 4*128 + [32, 64) doesn't produce overlapping bits. 1696 // Make sure we get all the individual bits properly. 1697 // This test is useful to check that we account for the scaling factor 1698 // in the gep. Indeed, gep float, [32,64), 128 is not 128 + [32,64). 1699 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsGEPWithRangeNoOverlap) { 1700 parseAssembly( 1701 "define void @test(i64* %p) {\n" 1702 " %A = load i64, i64* %p, !range !{i64 32, i64 64}\n" 1703 " %APtr = inttoptr i64 %A to float*" 1704 " %APtrPlus512 = getelementptr float, float* %APtr, i32 128\n" 1705 " %c = icmp ugt float* %APtrPlus512, inttoptr (i32 523 to float*)\n" 1706 " call void @llvm.assume(i1 %c)\n" 1707 " ret void\n" 1708 "}\n" 1709 "declare void @llvm.assume(i1)\n"); 1710 AssumptionCache AC(*F); 1711 KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC, 1712 F->front().getTerminator()); 1713 EXPECT_EQ(Known.Zero.getZExtValue(), ~(64llu - 1)); 1714 EXPECT_EQ(Known.One.getZExtValue(), 32u); 1715 Instruction &APtrPlus512 = findInstructionByName(F, "APtrPlus512"); 1716 Known = computeKnownBits(&APtrPlus512, M->getDataLayout(), /* Depth */ 0, &AC, 1717 F->front().getTerminator()); 1718 EXPECT_EQ(Known.Zero.getZExtValue(), ~512llu & ~(64llu - 1)); 1719 EXPECT_EQ(Known.One.getZExtValue(), 512u | 32u); 1720 // The known range is not precise given computeKnownBits works 1721 // with the masks of zeros and ones, not the ranges. 1722 EXPECT_EQ(Known.getMinValue(), 544); 1723 EXPECT_EQ(Known.getMaxValue(), 575); 1724 } 1725 1726 TEST_F(ValueTrackingTest, HaveNoCommonBitsSet) { 1727 { 1728 // Check for an inverted mask: (X & ~M) op (Y & M). 1729 auto M = parseModule(R"( 1730 define i32 @test(i32 %X, i32 %Y, i32 %M) { 1731 %1 = xor i32 %M, -1 1732 %LHS = and i32 %1, %X 1733 %RHS = and i32 %Y, %M 1734 %Ret = add i32 %LHS, %RHS 1735 ret i32 %Ret 1736 })"); 1737 1738 auto *F = M->getFunction("test"); 1739 auto *LHS = findInstructionByNameOrNull(F, "LHS"); 1740 auto *RHS = findInstructionByNameOrNull(F, "RHS"); 1741 1742 const DataLayout &DL = M->getDataLayout(); 1743 EXPECT_TRUE(haveNoCommonBitsSet(LHS, RHS, DL)); 1744 EXPECT_TRUE(haveNoCommonBitsSet(RHS, LHS, DL)); 1745 } 1746 { 1747 // Check for (A & B) and ~(A | B) 1748 auto M = parseModule(R"( 1749 define void @test(i32 %A, i32 %B) { 1750 %LHS = and i32 %A, %B 1751 %or = or i32 %A, %B 1752 %RHS = xor i32 %or, -1 1753 1754 %LHS2 = and i32 %B, %A 1755 %or2 = or i32 %A, %B 1756 %RHS2 = xor i32 %or2, -1 1757 1758 ret void 1759 })"); 1760 1761 auto *F = M->getFunction("test"); 1762 const DataLayout &DL = M->getDataLayout(); 1763 1764 auto *LHS = findInstructionByNameOrNull(F, "LHS"); 1765 auto *RHS = findInstructionByNameOrNull(F, "RHS"); 1766 EXPECT_TRUE(haveNoCommonBitsSet(LHS, RHS, DL)); 1767 EXPECT_TRUE(haveNoCommonBitsSet(RHS, LHS, DL)); 1768 1769 auto *LHS2 = findInstructionByNameOrNull(F, "LHS2"); 1770 auto *RHS2 = findInstructionByNameOrNull(F, "RHS2"); 1771 EXPECT_TRUE(haveNoCommonBitsSet(LHS2, RHS2, DL)); 1772 EXPECT_TRUE(haveNoCommonBitsSet(RHS2, LHS2, DL)); 1773 } 1774 { 1775 // Check for (A & B) and ~(A | B) in vector version 1776 auto M = parseModule(R"( 1777 define void @test(<2 x i32> %A, <2 x i32> %B) { 1778 %LHS = and <2 x i32> %A, %B 1779 %or = or <2 x i32> %A, %B 1780 %RHS = xor <2 x i32> %or, <i32 -1, i32 -1> 1781 1782 %LHS2 = and <2 x i32> %B, %A 1783 %or2 = or <2 x i32> %A, %B 1784 %RHS2 = xor <2 x i32> %or2, <i32 -1, i32 -1> 1785 1786 ret void 1787 })"); 1788 1789 auto *F = M->getFunction("test"); 1790 const DataLayout &DL = M->getDataLayout(); 1791 1792 auto *LHS = findInstructionByNameOrNull(F, "LHS"); 1793 auto *RHS = findInstructionByNameOrNull(F, "RHS"); 1794 EXPECT_TRUE(haveNoCommonBitsSet(LHS, RHS, DL)); 1795 EXPECT_TRUE(haveNoCommonBitsSet(RHS, LHS, DL)); 1796 1797 auto *LHS2 = findInstructionByNameOrNull(F, "LHS2"); 1798 auto *RHS2 = findInstructionByNameOrNull(F, "RHS2"); 1799 EXPECT_TRUE(haveNoCommonBitsSet(LHS2, RHS2, DL)); 1800 EXPECT_TRUE(haveNoCommonBitsSet(RHS2, LHS2, DL)); 1801 } 1802 } 1803 1804 class IsBytewiseValueTest : public ValueTrackingTest, 1805 public ::testing::WithParamInterface< 1806 std::pair<const char *, const char *>> { 1807 protected: 1808 }; 1809 1810 const std::pair<const char *, const char *> IsBytewiseValueTests[] = { 1811 { 1812 "i8 0", 1813 "i48* null", 1814 }, 1815 { 1816 "i8 undef", 1817 "i48* undef", 1818 }, 1819 { 1820 "i8 0", 1821 "i8 zeroinitializer", 1822 }, 1823 { 1824 "i8 0", 1825 "i8 0", 1826 }, 1827 { 1828 "i8 -86", 1829 "i8 -86", 1830 }, 1831 { 1832 "i8 -1", 1833 "i8 -1", 1834 }, 1835 { 1836 "i8 undef", 1837 "i16 undef", 1838 }, 1839 { 1840 "i8 0", 1841 "i16 0", 1842 }, 1843 { 1844 "", 1845 "i16 7", 1846 }, 1847 { 1848 "i8 -86", 1849 "i16 -21846", 1850 }, 1851 { 1852 "i8 -1", 1853 "i16 -1", 1854 }, 1855 { 1856 "i8 0", 1857 "i48 0", 1858 }, 1859 { 1860 "i8 -1", 1861 "i48 -1", 1862 }, 1863 { 1864 "i8 0", 1865 "i49 0", 1866 }, 1867 { 1868 "", 1869 "i49 -1", 1870 }, 1871 { 1872 "i8 0", 1873 "half 0xH0000", 1874 }, 1875 { 1876 "i8 -85", 1877 "half 0xHABAB", 1878 }, 1879 { 1880 "i8 0", 1881 "float 0.0", 1882 }, 1883 { 1884 "i8 -1", 1885 "float 0xFFFFFFFFE0000000", 1886 }, 1887 { 1888 "i8 0", 1889 "double 0.0", 1890 }, 1891 { 1892 "i8 -15", 1893 "double 0xF1F1F1F1F1F1F1F1", 1894 }, 1895 { 1896 "i8 undef", 1897 "i16* undef", 1898 }, 1899 { 1900 "i8 0", 1901 "i16* inttoptr (i64 0 to i16*)", 1902 }, 1903 { 1904 "i8 -1", 1905 "i16* inttoptr (i64 -1 to i16*)", 1906 }, 1907 { 1908 "i8 -86", 1909 "i16* inttoptr (i64 -6148914691236517206 to i16*)", 1910 }, 1911 { 1912 "", 1913 "i16* inttoptr (i48 -1 to i16*)", 1914 }, 1915 { 1916 "i8 -1", 1917 "i16* inttoptr (i96 -1 to i16*)", 1918 }, 1919 { 1920 "i8 undef", 1921 "[0 x i8] zeroinitializer", 1922 }, 1923 { 1924 "i8 undef", 1925 "[0 x i8] undef", 1926 }, 1927 { 1928 "i8 undef", 1929 "[5 x [0 x i8]] zeroinitializer", 1930 }, 1931 { 1932 "i8 undef", 1933 "[5 x [0 x i8]] undef", 1934 }, 1935 { 1936 "i8 0", 1937 "[6 x i8] zeroinitializer", 1938 }, 1939 { 1940 "i8 undef", 1941 "[6 x i8] undef", 1942 }, 1943 { 1944 "i8 1", 1945 "[5 x i8] [i8 1, i8 1, i8 1, i8 1, i8 1]", 1946 }, 1947 { 1948 "", 1949 "[5 x i64] [i64 1, i64 1, i64 1, i64 1, i64 1]", 1950 }, 1951 { 1952 "i8 -1", 1953 "[5 x i64] [i64 -1, i64 -1, i64 -1, i64 -1, i64 -1]", 1954 }, 1955 { 1956 "", 1957 "[4 x i8] [i8 1, i8 2, i8 1, i8 1]", 1958 }, 1959 { 1960 "i8 1", 1961 "[4 x i8] [i8 1, i8 undef, i8 1, i8 1]", 1962 }, 1963 { 1964 "i8 0", 1965 "<6 x i8> zeroinitializer", 1966 }, 1967 { 1968 "i8 undef", 1969 "<6 x i8> undef", 1970 }, 1971 { 1972 "i8 1", 1973 "<5 x i8> <i8 1, i8 1, i8 1, i8 1, i8 1>", 1974 }, 1975 { 1976 "", 1977 "<5 x i64> <i64 1, i64 1, i64 1, i64 1, i64 1>", 1978 }, 1979 { 1980 "i8 -1", 1981 "<5 x i64> <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1>", 1982 }, 1983 { 1984 "", 1985 "<4 x i8> <i8 1, i8 1, i8 2, i8 1>", 1986 }, 1987 { 1988 "i8 5", 1989 "<2 x i8> < i8 5, i8 undef >", 1990 }, 1991 { 1992 "i8 0", 1993 "[2 x [2 x i16]] zeroinitializer", 1994 }, 1995 { 1996 "i8 undef", 1997 "[2 x [2 x i16]] undef", 1998 }, 1999 { 2000 "i8 -86", 2001 "[2 x [2 x i16]] [[2 x i16] [i16 -21846, i16 -21846], " 2002 "[2 x i16] [i16 -21846, i16 -21846]]", 2003 }, 2004 { 2005 "", 2006 "[2 x [2 x i16]] [[2 x i16] [i16 -21846, i16 -21846], " 2007 "[2 x i16] [i16 -21836, i16 -21846]]", 2008 }, 2009 { 2010 "i8 undef", 2011 "{ } zeroinitializer", 2012 }, 2013 { 2014 "i8 undef", 2015 "{ } undef", 2016 }, 2017 { 2018 "i8 undef", 2019 "{ {}, {} } zeroinitializer", 2020 }, 2021 { 2022 "i8 undef", 2023 "{ {}, {} } undef", 2024 }, 2025 { 2026 "i8 0", 2027 "{i8, i64, i16*} zeroinitializer", 2028 }, 2029 { 2030 "i8 undef", 2031 "{i8, i64, i16*} undef", 2032 }, 2033 { 2034 "i8 -86", 2035 "{i8, i64, i16*} {i8 -86, i64 -6148914691236517206, i16* undef}", 2036 }, 2037 { 2038 "", 2039 "{i8, i64, i16*} {i8 86, i64 -6148914691236517206, i16* undef}", 2040 }, 2041 }; 2042 2043 INSTANTIATE_TEST_SUITE_P(IsBytewiseValueParamTests, IsBytewiseValueTest, 2044 ::testing::ValuesIn(IsBytewiseValueTests)); 2045 2046 TEST_P(IsBytewiseValueTest, IsBytewiseValue) { 2047 auto M = parseModule(std::string("@test = global ") + GetParam().second); 2048 GlobalVariable *GV = dyn_cast<GlobalVariable>(M->getNamedValue("test")); 2049 Value *Actual = isBytewiseValue(GV->getInitializer(), M->getDataLayout()); 2050 std::string Buff; 2051 raw_string_ostream S(Buff); 2052 if (Actual) 2053 S << *Actual; 2054 EXPECT_EQ(GetParam().first, S.str()); 2055 } 2056 2057 TEST_F(ValueTrackingTest, ComputeConstantRange) { 2058 { 2059 // Assumptions: 2060 // * stride >= 5 2061 // * stride < 10 2062 // 2063 // stride = [5, 10) 2064 auto M = parseModule(R"( 2065 declare void @llvm.assume(i1) 2066 2067 define i32 @test(i32 %stride) { 2068 %gt = icmp uge i32 %stride, 5 2069 call void @llvm.assume(i1 %gt) 2070 %lt = icmp ult i32 %stride, 10 2071 call void @llvm.assume(i1 %lt) 2072 %stride.plus.one = add nsw nuw i32 %stride, 1 2073 ret i32 %stride.plus.one 2074 })"); 2075 Function *F = M->getFunction("test"); 2076 2077 AssumptionCache AC(*F); 2078 Value *Stride = &*F->arg_begin(); 2079 ConstantRange CR1 = computeConstantRange(Stride, false, true, &AC, nullptr); 2080 EXPECT_TRUE(CR1.isFullSet()); 2081 2082 Instruction *I = &findInstructionByName(F, "stride.plus.one"); 2083 ConstantRange CR2 = computeConstantRange(Stride, false, true, &AC, I); 2084 EXPECT_EQ(5, CR2.getLower()); 2085 EXPECT_EQ(10, CR2.getUpper()); 2086 } 2087 2088 { 2089 // Assumptions: 2090 // * stride >= 5 2091 // * stride < 200 2092 // * stride == 99 2093 // 2094 // stride = [99, 100) 2095 auto M = parseModule(R"( 2096 declare void @llvm.assume(i1) 2097 2098 define i32 @test(i32 %stride) { 2099 %gt = icmp uge i32 %stride, 5 2100 call void @llvm.assume(i1 %gt) 2101 %lt = icmp ult i32 %stride, 200 2102 call void @llvm.assume(i1 %lt) 2103 %eq = icmp eq i32 %stride, 99 2104 call void @llvm.assume(i1 %eq) 2105 %stride.plus.one = add nsw nuw i32 %stride, 1 2106 ret i32 %stride.plus.one 2107 })"); 2108 Function *F = M->getFunction("test"); 2109 2110 AssumptionCache AC(*F); 2111 Value *Stride = &*F->arg_begin(); 2112 Instruction *I = &findInstructionByName(F, "stride.plus.one"); 2113 ConstantRange CR = computeConstantRange(Stride, false, true, &AC, I); 2114 EXPECT_EQ(99, *CR.getSingleElement()); 2115 } 2116 2117 { 2118 // Assumptions: 2119 // * stride >= 5 2120 // * stride >= 50 2121 // * stride < 100 2122 // * stride < 200 2123 // 2124 // stride = [50, 100) 2125 auto M = parseModule(R"( 2126 declare void @llvm.assume(i1) 2127 2128 define i32 @test(i32 %stride, i1 %cond) { 2129 %gt = icmp uge i32 %stride, 5 2130 call void @llvm.assume(i1 %gt) 2131 %gt.2 = icmp uge i32 %stride, 50 2132 call void @llvm.assume(i1 %gt.2) 2133 br i1 %cond, label %bb1, label %bb2 2134 2135 bb1: 2136 %lt = icmp ult i32 %stride, 200 2137 call void @llvm.assume(i1 %lt) 2138 %lt.2 = icmp ult i32 %stride, 100 2139 call void @llvm.assume(i1 %lt.2) 2140 %stride.plus.one = add nsw nuw i32 %stride, 1 2141 ret i32 %stride.plus.one 2142 2143 bb2: 2144 ret i32 0 2145 })"); 2146 Function *F = M->getFunction("test"); 2147 2148 AssumptionCache AC(*F); 2149 Value *Stride = &*F->arg_begin(); 2150 Instruction *GT2 = &findInstructionByName(F, "gt.2"); 2151 ConstantRange CR = computeConstantRange(Stride, false, true, &AC, GT2); 2152 EXPECT_EQ(5, CR.getLower()); 2153 EXPECT_EQ(0, CR.getUpper()); 2154 2155 Instruction *I = &findInstructionByName(F, "stride.plus.one"); 2156 ConstantRange CR2 = computeConstantRange(Stride, false, true, &AC, I); 2157 EXPECT_EQ(50, CR2.getLower()); 2158 EXPECT_EQ(100, CR2.getUpper()); 2159 } 2160 2161 { 2162 // Assumptions: 2163 // * stride > 5 2164 // * stride < 5 2165 // 2166 // stride = empty range, as the assumptions contradict each other. 2167 auto M = parseModule(R"( 2168 declare void @llvm.assume(i1) 2169 2170 define i32 @test(i32 %stride, i1 %cond) { 2171 %gt = icmp ugt i32 %stride, 5 2172 call void @llvm.assume(i1 %gt) 2173 %lt = icmp ult i32 %stride, 5 2174 call void @llvm.assume(i1 %lt) 2175 %stride.plus.one = add nsw nuw i32 %stride, 1 2176 ret i32 %stride.plus.one 2177 })"); 2178 Function *F = M->getFunction("test"); 2179 2180 AssumptionCache AC(*F); 2181 Value *Stride = &*F->arg_begin(); 2182 2183 Instruction *I = &findInstructionByName(F, "stride.plus.one"); 2184 ConstantRange CR = computeConstantRange(Stride, false, true, &AC, I); 2185 EXPECT_TRUE(CR.isEmptySet()); 2186 } 2187 2188 { 2189 // Assumptions: 2190 // * x.1 >= 5 2191 // * x.2 < x.1 2192 // 2193 // stride = [0, -1) 2194 auto M = parseModule(R"( 2195 declare void @llvm.assume(i1) 2196 2197 define i32 @test(i32 %x.1, i32 %x.2) { 2198 %gt = icmp uge i32 %x.1, 5 2199 call void @llvm.assume(i1 %gt) 2200 %lt = icmp ult i32 %x.2, %x.1 2201 call void @llvm.assume(i1 %lt) 2202 %stride.plus.one = add nsw nuw i32 %x.1, 1 2203 ret i32 %stride.plus.one 2204 })"); 2205 Function *F = M->getFunction("test"); 2206 2207 AssumptionCache AC(*F); 2208 Value *X1 = &*(F->arg_begin()); 2209 Value *X2 = &*std::next(F->arg_begin()); 2210 2211 Instruction *I = &findInstructionByName(F, "stride.plus.one"); 2212 ConstantRange CR1 = computeConstantRange(X1, false, true, &AC, I); 2213 ConstantRange CR2 = computeConstantRange(X2, false, true, &AC, I); 2214 2215 EXPECT_EQ(5, CR1.getLower()); 2216 EXPECT_EQ(0, CR1.getUpper()); 2217 2218 EXPECT_EQ(0, CR2.getLower()); 2219 EXPECT_EQ(0xffffffff, CR2.getUpper()); 2220 2221 // Check the depth cutoff results in a conservative result (full set) by 2222 // passing Depth == MaxDepth == 6. 2223 ConstantRange CR3 = computeConstantRange(X2, false, true, &AC, I, nullptr, 6); 2224 EXPECT_TRUE(CR3.isFullSet()); 2225 } 2226 { 2227 // Assumptions: 2228 // * x.2 <= x.1 2229 auto M = parseModule(R"( 2230 declare void @llvm.assume(i1) 2231 2232 define i32 @test(i32 %x.1, i32 %x.2) { 2233 %lt = icmp ule i32 %x.2, %x.1 2234 call void @llvm.assume(i1 %lt) 2235 %stride.plus.one = add nsw nuw i32 %x.1, 1 2236 ret i32 %stride.plus.one 2237 })"); 2238 Function *F = M->getFunction("test"); 2239 2240 AssumptionCache AC(*F); 2241 Value *X2 = &*std::next(F->arg_begin()); 2242 2243 Instruction *I = &findInstructionByName(F, "stride.plus.one"); 2244 ConstantRange CR1 = computeConstantRange(X2, false, true, &AC, I); 2245 // If we don't know the value of x.2, we don't know the value of x.1. 2246 EXPECT_TRUE(CR1.isFullSet()); 2247 } 2248 } 2249 2250 struct FindAllocaForValueTestParams { 2251 const char *IR; 2252 bool AnyOffsetResult; 2253 bool ZeroOffsetResult; 2254 }; 2255 2256 class FindAllocaForValueTest 2257 : public ValueTrackingTest, 2258 public ::testing::WithParamInterface<FindAllocaForValueTestParams> { 2259 protected: 2260 }; 2261 2262 const FindAllocaForValueTestParams FindAllocaForValueTests[] = { 2263 {R"( 2264 define void @test() { 2265 %a = alloca i64 2266 %r = bitcast i64* %a to i32* 2267 ret void 2268 })", 2269 true, true}, 2270 2271 {R"( 2272 define void @test() { 2273 %a = alloca i32 2274 %r = getelementptr i32, i32* %a, i32 1 2275 ret void 2276 })", 2277 true, false}, 2278 2279 {R"( 2280 define void @test() { 2281 %a = alloca i32 2282 %r = getelementptr i32, i32* %a, i32 0 2283 ret void 2284 })", 2285 true, true}, 2286 2287 {R"( 2288 define void @test(i1 %cond) { 2289 entry: 2290 %a = alloca i32 2291 br label %bb1 2292 2293 bb1: 2294 %r = phi i32* [ %a, %entry ], [ %r, %bb1 ] 2295 br i1 %cond, label %bb1, label %exit 2296 2297 exit: 2298 ret void 2299 })", 2300 true, true}, 2301 2302 {R"( 2303 define void @test(i1 %cond) { 2304 %a = alloca i32 2305 %r = select i1 %cond, i32* %a, i32* %a 2306 ret void 2307 })", 2308 true, true}, 2309 2310 {R"( 2311 define void @test(i1 %cond) { 2312 %a = alloca i32 2313 %b = alloca i32 2314 %r = select i1 %cond, i32* %a, i32* %b 2315 ret void 2316 })", 2317 false, false}, 2318 2319 {R"( 2320 define void @test(i1 %cond) { 2321 entry: 2322 %a = alloca i64 2323 %a32 = bitcast i64* %a to i32* 2324 br label %bb1 2325 2326 bb1: 2327 %x = phi i32* [ %a32, %entry ], [ %x, %bb1 ] 2328 %r = getelementptr i32, i32* %x, i32 1 2329 br i1 %cond, label %bb1, label %exit 2330 2331 exit: 2332 ret void 2333 })", 2334 true, false}, 2335 2336 {R"( 2337 define void @test(i1 %cond) { 2338 entry: 2339 %a = alloca i64 2340 %a32 = bitcast i64* %a to i32* 2341 br label %bb1 2342 2343 bb1: 2344 %x = phi i32* [ %a32, %entry ], [ %r, %bb1 ] 2345 %r = getelementptr i32, i32* %x, i32 1 2346 br i1 %cond, label %bb1, label %exit 2347 2348 exit: 2349 ret void 2350 })", 2351 true, false}, 2352 2353 {R"( 2354 define void @test(i1 %cond, i64* %a) { 2355 entry: 2356 %r = bitcast i64* %a to i32* 2357 ret void 2358 })", 2359 false, false}, 2360 2361 {R"( 2362 define void @test(i1 %cond) { 2363 entry: 2364 %a = alloca i32 2365 %b = alloca i32 2366 br label %bb1 2367 2368 bb1: 2369 %r = phi i32* [ %a, %entry ], [ %b, %bb1 ] 2370 br i1 %cond, label %bb1, label %exit 2371 2372 exit: 2373 ret void 2374 })", 2375 false, false}, 2376 {R"( 2377 declare i32* @retptr(i32* returned) 2378 define void @test(i1 %cond) { 2379 %a = alloca i32 2380 %r = call i32* @retptr(i32* %a) 2381 ret void 2382 })", 2383 true, true}, 2384 {R"( 2385 declare i32* @fun(i32*) 2386 define void @test(i1 %cond) { 2387 %a = alloca i32 2388 %r = call i32* @fun(i32* %a) 2389 ret void 2390 })", 2391 false, false}, 2392 }; 2393 2394 TEST_P(FindAllocaForValueTest, findAllocaForValue) { 2395 auto M = parseModule(GetParam().IR); 2396 Function *F = M->getFunction("test"); 2397 Instruction *I = &findInstructionByName(F, "r"); 2398 const AllocaInst *AI = findAllocaForValue(I); 2399 EXPECT_EQ(!!AI, GetParam().AnyOffsetResult); 2400 } 2401 2402 TEST_P(FindAllocaForValueTest, findAllocaForValueZeroOffset) { 2403 auto M = parseModule(GetParam().IR); 2404 Function *F = M->getFunction("test"); 2405 Instruction *I = &findInstructionByName(F, "r"); 2406 const AllocaInst *AI = findAllocaForValue(I, true); 2407 EXPECT_EQ(!!AI, GetParam().ZeroOffsetResult); 2408 } 2409 2410 INSTANTIATE_TEST_SUITE_P(FindAllocaForValueTest, FindAllocaForValueTest, 2411 ::testing::ValuesIn(FindAllocaForValueTests)); 2412