llvm/unittests/Transforms/Utils/LocalTest.cpp

   1 //===- Local.cpp - Unit tests for Local -----------------------------------===//
   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/Transforms/Utils/Local.h"
  10 #include "llvm/Analysis/DomTreeUpdater.h"
  11 #include "llvm/Analysis/InstructionSimplify.h"
  12 #include "llvm/Analysis/PostDominators.h"
  13 #include "llvm/Analysis/TargetTransformInfo.h"
  14 #include "llvm/AsmParser/Parser.h"
  15 #include "llvm/IR/BasicBlock.h"
  16 #include "llvm/IR/DIBuilder.h"
  17 #include "llvm/IR/DebugInfo.h"
  18 #include "llvm/IR/IRBuilder.h"
  19 #include "llvm/IR/Instructions.h"
  20 #include "llvm/IR/IntrinsicInst.h"
  21 #include "llvm/IR/LLVMContext.h"
  22 #include "llvm/IR/Verifier.h"
  23 #include "llvm/Support/SourceMgr.h"
  24 #include "gtest/gtest.h"
  25
  26 using namespace llvm;
  27
  28 TEST(Local, RecursivelyDeleteDeadPHINodes) {
  29   LLVMContext C;
  30
  31   IRBuilder<> builder(C);
  32
  33   // Make blocks
  34   BasicBlock *bb0 = BasicBlock::Create(C);
  35   BasicBlock *bb1 = BasicBlock::Create(C);
  36
  37   builder.SetInsertPoint(bb0);
  38   PHINode    *phi = builder.CreatePHI(Type::getInt32Ty(C), 2);
  39   BranchInst *br0 = builder.CreateCondBr(builder.getTrue(), bb0, bb1);
  40
  41   builder.SetInsertPoint(bb1);
  42   BranchInst *br1 = builder.CreateBr(bb0);
  43
  44   phi->addIncoming(phi, bb0);
  45   phi->addIncoming(phi, bb1);
  46
  47   // The PHI will be removed
  48   EXPECT_TRUE(RecursivelyDeleteDeadPHINode(phi));
  49
  50   // Make sure the blocks only contain the branches
  51   EXPECT_EQ(&bb0->front(), br0);
  52   EXPECT_EQ(&bb1->front(), br1);
  53
  54   builder.SetInsertPoint(bb0);
  55   phi = builder.CreatePHI(Type::getInt32Ty(C), 0);
  56
  57   EXPECT_TRUE(RecursivelyDeleteDeadPHINode(phi));
  58
  59   builder.SetInsertPoint(bb0);
  60   phi = builder.CreatePHI(Type::getInt32Ty(C), 0);
  61   builder.CreateAdd(phi, phi);
  62
  63   EXPECT_TRUE(RecursivelyDeleteDeadPHINode(phi));
  64
  65   bb0->dropAllReferences();
  66   bb1->dropAllReferences();
  67   delete bb0;
  68   delete bb1;
  69 }
  70
  71 TEST(Local, RemoveDuplicatePHINodes) {
  72   LLVMContext C;
  73   IRBuilder<> B(C);
  74
  75   std::unique_ptr<Function> F(
  76       Function::Create(FunctionType::get(B.getVoidTy(), false),
  77                        GlobalValue::ExternalLinkage, "F"));
  78   BasicBlock *Entry(BasicBlock::Create(C, "", F.get()));
  79   BasicBlock *BB(BasicBlock::Create(C, "", F.get()));
  80   BranchInst::Create(BB, Entry);
  81
  82   B.SetInsertPoint(BB);
  83
  84   AssertingVH<PHINode> P1 = B.CreatePHI(Type::getInt32Ty(C), 2);
  85   P1->addIncoming(B.getInt32(42), Entry);
  86
  87   PHINode *P2 = B.CreatePHI(Type::getInt32Ty(C), 2);
  88   P2->addIncoming(B.getInt32(42), Entry);
  89
  90   AssertingVH<PHINode> P3 = B.CreatePHI(Type::getInt32Ty(C), 2);
  91   P3->addIncoming(B.getInt32(42), Entry);
  92   P3->addIncoming(B.getInt32(23), BB);
  93
  94   PHINode *P4 = B.CreatePHI(Type::getInt32Ty(C), 2);
  95   P4->addIncoming(B.getInt32(42), Entry);
  96   P4->addIncoming(B.getInt32(23), BB);
  97
  98   P1->addIncoming(P3, BB);
  99   P2->addIncoming(P4, BB);
 100   BranchInst::Create(BB, BB);
 101
 102   // Verify that we can eliminate PHIs that become duplicates after chaning PHIs
 103   // downstream.
 104   EXPECT_TRUE(EliminateDuplicatePHINodes(BB));
 105   EXPECT_EQ(3U, BB->size());
 106 }
 107
 108 static std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
 109   SMDiagnostic Err;
 110   std::unique_ptr<Module> Mod = parseAssemblyString(IR, Err, C);
 111   if (!Mod)
 112     Err.print("UtilsTests", errs());
 113   return Mod;
 114 }
 115
 116 TEST(Local, ReplaceDbgDeclare) {
 117   LLVMContext C;
 118
 119   // Original C source to get debug info for a local variable:
 120   // void f() { int x; }
 121   std::unique_ptr<Module> M = parseIR(C,
 122                                       R"(
 123       define void @f() !dbg !8 {
 124       entry:
 125         %x = alloca i32, align 4
 126         call void @llvm.dbg.declare(metadata i32* %x, metadata !11, metadata !DIExpression()), !dbg !13
 127         call void @llvm.dbg.declare(metadata i32* %x, metadata !11, metadata !DIExpression()), !dbg !13
 128         ret void, !dbg !14
 129       }
 130       declare void @llvm.dbg.declare(metadata, metadata, metadata)
 131       !llvm.dbg.cu = !{!0}
 132       !llvm.module.flags = !{!3, !4}
 133       !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
 134       !1 = !DIFile(filename: "t2.c", directory: "foo")
 135       !2 = !{}
 136       !3 = !{i32 2, !"Dwarf Version", i32 4}
 137       !4 = !{i32 2, !"Debug Info Version", i32 3}
 138       !8 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !9, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: false, unit: !0, retainedNodes: !2)
 139       !9 = !DISubroutineType(types: !10)
 140       !10 = !{null}
 141       !11 = !DILocalVariable(name: "x", scope: !8, file: !1, line: 2, type: !12)
 142       !12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
 143       !13 = !DILocation(line: 2, column: 7, scope: !8)
 144       !14 = !DILocation(line: 3, column: 1, scope: !8)
 145       )");
 146   auto *GV = M->getNamedValue("f");
 147   ASSERT_TRUE(GV);
 148   auto *F = dyn_cast<Function>(GV);
 149   ASSERT_TRUE(F);
 150   Instruction *Inst = &F->front().front();
 151   auto *AI = dyn_cast<AllocaInst>(Inst);
 152   ASSERT_TRUE(AI);
 153   Inst = Inst->getNextNode()->getNextNode();
 154   ASSERT_TRUE(Inst);
 155   auto *DII = dyn_cast<DbgDeclareInst>(Inst);
 156   ASSERT_TRUE(DII);
 157   Value *NewBase = Constant::getNullValue(Type::getInt32PtrTy(C));
 158   DIBuilder DIB(*M);
 159   replaceDbgDeclare(AI, NewBase, DIB, DIExpression::ApplyOffset, 0);
 160
 161   // There should be exactly two dbg.declares.
 162   int Declares = 0;
 163   for (const Instruction &I : F->front())
 164     if (isa<DbgDeclareInst>(I))
 165       Declares++;
 166   EXPECT_EQ(2, Declares);
 167 }
 168
 169 /// Build the dominator tree for the function and run the Test.
 170 static void runWithDomTree(
 171     Module &M, StringRef FuncName,
 172     function_ref<void(Function &F, DominatorTree *DT)> Test) {
 173   auto *F = M.getFunction(FuncName);
 174   ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
 175   // Compute the dominator tree for the function.
 176   DominatorTree DT(*F);
 177   Test(*F, &DT);
 178 }
 179
 180 TEST(Local, MergeBasicBlockIntoOnlyPred) {
 181   LLVMContext C;
 182   std::unique_ptr<Module> M;
 183   auto resetIR = [&]() {
 184     M = parseIR(C,
 185                 R"(
 186       define i32 @f(i8* %str) {
 187       entry:
 188         br label %bb2.i
 189       bb2.i:                                            ; preds = %bb4.i, %entry
 190         br i1 false, label %bb4.i, label %base2flt.exit204
 191       bb4.i:                                            ; preds = %bb2.i
 192         br i1 false, label %base2flt.exit204, label %bb2.i
 193       bb10.i196.bb7.i197_crit_edge:                     ; No predecessors!
 194         br label %bb7.i197
 195       bb7.i197:                                         ; preds = %bb10.i196.bb7.i197_crit_edge
 196         %.reg2mem.0 = phi i32 [ %.reg2mem.0, %bb10.i196.bb7.i197_crit_edge ]
 197         br i1 undef, label %base2flt.exit204, label %base2flt.exit204
 198       base2flt.exit204:                                 ; preds = %bb7.i197, %bb7.i197, %bb2.i, %bb4.i
 199         ret i32 0
 200       }
 201       )");
 202   };
 203
 204   auto resetIRReplaceEntry = [&]() {
 205     M = parseIR(C,
 206                 R"(
 207       define i32 @f() {
 208       entry:
 209         br label %bb2.i
 210       bb2.i:                                            ; preds = %entry
 211         ret i32 0
 212       }
 213       )");
 214   };
 215
 216   auto Test = [&](Function &F, DomTreeUpdater &DTU) {
 217     for (Function::iterator I = F.begin(), E = F.end(); I != E;) {
 218       BasicBlock *BB = &*I++;
 219       BasicBlock *SinglePred = BB->getSinglePredecessor();
 220       if (!SinglePred || SinglePred == BB || BB->hasAddressTaken())
 221         continue;
 222       BranchInst *Term = dyn_cast<BranchInst>(SinglePred->getTerminator());
 223       if (Term && !Term->isConditional())
 224         MergeBasicBlockIntoOnlyPred(BB, &DTU);
 225     }
 226     if (DTU.hasDomTree()) {
 227       EXPECT_TRUE(DTU.getDomTree().verify());
 228     }
 229     if (DTU.hasPostDomTree()) {
 230       EXPECT_TRUE(DTU.getPostDomTree().verify());
 231     }
 232   };
 233
 234   // Test MergeBasicBlockIntoOnlyPred working under Eager UpdateStrategy with
 235   // both DT and PDT.
 236   resetIR();
 237   runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
 238     PostDominatorTree PDT = PostDominatorTree(F);
 239     DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Eager);
 240     Test(F, DTU);
 241   });
 242
 243   // Test MergeBasicBlockIntoOnlyPred working under Eager UpdateStrategy with
 244   // DT.
 245   resetIR();
 246   runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
 247     DomTreeUpdater DTU(*DT, DomTreeUpdater::UpdateStrategy::Eager);
 248     Test(F, DTU);
 249   });
 250
 251   // Test MergeBasicBlockIntoOnlyPred working under Eager UpdateStrategy with
 252   // PDT.
 253   resetIR();
 254   runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
 255     PostDominatorTree PDT = PostDominatorTree(F);
 256     DomTreeUpdater DTU(PDT, DomTreeUpdater::UpdateStrategy::Eager);
 257     Test(F, DTU);
 258   });
 259
 260   // Test MergeBasicBlockIntoOnlyPred working under Lazy UpdateStrategy with
 261   // both DT and PDT.
 262   resetIR();
 263   runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
 264     PostDominatorTree PDT = PostDominatorTree(F);
 265     DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Lazy);
 266     Test(F, DTU);
 267   });
 268
 269   // Test MergeBasicBlockIntoOnlyPred working under Lazy UpdateStrategy with
 270   // PDT.
 271   resetIR();
 272   runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
 273     PostDominatorTree PDT = PostDominatorTree(F);
 274     DomTreeUpdater DTU(PDT, DomTreeUpdater::UpdateStrategy::Lazy);
 275     Test(F, DTU);
 276   });
 277
 278   // Test MergeBasicBlockIntoOnlyPred working under Lazy UpdateStrategy with DT.
 279   resetIR();
 280   runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
 281     DomTreeUpdater DTU(*DT, DomTreeUpdater::UpdateStrategy::Lazy);
 282     Test(F, DTU);
 283   });
 284
 285   // Test MergeBasicBlockIntoOnlyPred working under Eager UpdateStrategy with
 286   // both DT and PDT.
 287   resetIRReplaceEntry();
 288   runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
 289     PostDominatorTree PDT = PostDominatorTree(F);
 290     DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Eager);
 291     Test(F, DTU);
 292   });
 293
 294   // Test MergeBasicBlockIntoOnlyPred working under Eager UpdateStrategy with
 295   // DT.
 296   resetIRReplaceEntry();
 297   runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
 298     DomTreeUpdater DTU(*DT, DomTreeUpdater::UpdateStrategy::Eager);
 299     Test(F, DTU);
 300   });
 301
 302   // Test MergeBasicBlockIntoOnlyPred working under Eager UpdateStrategy with
 303   // PDT.
 304   resetIRReplaceEntry();
 305   runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
 306     PostDominatorTree PDT = PostDominatorTree(F);
 307     DomTreeUpdater DTU(PDT, DomTreeUpdater::UpdateStrategy::Eager);
 308     Test(F, DTU);
 309   });
 310
 311   // Test MergeBasicBlockIntoOnlyPred working under Lazy UpdateStrategy with
 312   // both DT and PDT.
 313   resetIRReplaceEntry();
 314   runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
 315     PostDominatorTree PDT = PostDominatorTree(F);
 316     DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Lazy);
 317     Test(F, DTU);
 318   });
 319
 320   // Test MergeBasicBlockIntoOnlyPred working under Lazy UpdateStrategy with
 321   // PDT.
 322   resetIRReplaceEntry();
 323   runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
 324     PostDominatorTree PDT = PostDominatorTree(F);
 325     DomTreeUpdater DTU(PDT, DomTreeUpdater::UpdateStrategy::Lazy);
 326     Test(F, DTU);
 327   });
 328
 329   // Test MergeBasicBlockIntoOnlyPred working under Lazy UpdateStrategy with DT.
 330   resetIRReplaceEntry();
 331   runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
 332     DomTreeUpdater DTU(*DT, DomTreeUpdater::UpdateStrategy::Lazy);
 333     Test(F, DTU);
 334   });
 335 }
 336
 337 TEST(Local, ConstantFoldTerminator) {
 338   LLVMContext C;
 339
 340   std::unique_ptr<Module> M = parseIR(C,
 341                                       R"(
 342       define void @br_same_dest() {
 343       entry:
 344         br i1 false, label %bb0, label %bb0
 345       bb0:
 346         ret void
 347       }
 348
 349       define void @br_different_dest() {
 350       entry:
 351         br i1 true, label %bb0, label %bb1
 352       bb0:
 353         br label %exit
 354       bb1:
 355         br label %exit
 356       exit:
 357         ret void
 358       }
 359
 360       define void @switch_2_different_dest() {
 361       entry:
 362         switch i32 0, label %default [ i32 0, label %bb0 ]
 363       default:
 364         ret void
 365       bb0:
 366         ret void
 367       }
 368       define void @switch_2_different_dest_default() {
 369       entry:
 370         switch i32 1, label %default [ i32 0, label %bb0 ]
 371       default:
 372         ret void
 373       bb0:
 374         ret void
 375       }
 376       define void @switch_3_different_dest() {
 377       entry:
 378         switch i32 0, label %default [ i32 0, label %bb0
 379                                        i32 1, label %bb1 ]
 380       default:
 381         ret void
 382       bb0:
 383         ret void
 384       bb1:
 385         ret void
 386       }
 387
 388       define void @switch_variable_2_default_dest(i32 %arg) {
 389       entry:
 390         switch i32 %arg, label %default [ i32 0, label %default ]
 391       default:
 392         ret void
 393       }
 394
 395       define void @switch_constant_2_default_dest() {
 396       entry:
 397         switch i32 1, label %default [ i32 0, label %default ]
 398       default:
 399         ret void
 400       }
 401
 402       define void @switch_constant_3_repeated_dest() {
 403       entry:
 404         switch i32 0, label %default [ i32 0, label %bb0
 405                                        i32 1, label %bb0 ]
 406        bb0:
 407          ret void
 408       default:
 409         ret void
 410       }
 411
 412       define void @indirectbr() {
 413       entry:
 414         indirectbr i8* blockaddress(@indirectbr, %bb0), [label %bb0, label %bb1]
 415       bb0:
 416         ret void
 417       bb1:
 418         ret void
 419       }
 420
 421       define void @indirectbr_repeated() {
 422       entry:
 423         indirectbr i8* blockaddress(@indirectbr_repeated, %bb0), [label %bb0, label %bb0]
 424       bb0:
 425         ret void
 426       }
 427
 428       define void @indirectbr_unreachable() {
 429       entry:
 430         indirectbr i8* blockaddress(@indirectbr_unreachable, %bb0), [label %bb1]
 431       bb0:
 432         ret void
 433       bb1:
 434         ret void
 435       }
 436         )");
 437
 438   auto CFAllTerminatorsEager = [&](Function &F, DominatorTree *DT) {
 439     PostDominatorTree PDT = PostDominatorTree(F);
 440     DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Eager);
 441     for (Function::iterator I = F.begin(), E = F.end(); I != E;) {
 442       BasicBlock *BB = &*I++;
 443       ConstantFoldTerminator(BB, true, nullptr, &DTU);
 444     }
 445
 446     EXPECT_TRUE(DTU.getDomTree().verify());
 447     EXPECT_TRUE(DTU.getPostDomTree().verify());
 448   };
 449
 450   auto CFAllTerminatorsLazy = [&](Function &F, DominatorTree *DT) {
 451     PostDominatorTree PDT = PostDominatorTree(F);
 452     DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Lazy);
 453     for (Function::iterator I = F.begin(), E = F.end(); I != E;) {
 454       BasicBlock *BB = &*I++;
 455       ConstantFoldTerminator(BB, true, nullptr, &DTU);
 456     }
 457
 458     EXPECT_TRUE(DTU.getDomTree().verify());
 459     EXPECT_TRUE(DTU.getPostDomTree().verify());
 460   };
 461
 462   // Test ConstantFoldTerminator under Eager UpdateStrategy.
 463   runWithDomTree(*M, "br_same_dest", CFAllTerminatorsEager);
 464   runWithDomTree(*M, "br_different_dest", CFAllTerminatorsEager);
 465   runWithDomTree(*M, "switch_2_different_dest", CFAllTerminatorsEager);
 466   runWithDomTree(*M, "switch_2_different_dest_default", CFAllTerminatorsEager);
 467   runWithDomTree(*M, "switch_3_different_dest", CFAllTerminatorsEager);
 468   runWithDomTree(*M, "switch_variable_2_default_dest", CFAllTerminatorsEager);
 469   runWithDomTree(*M, "switch_constant_2_default_dest", CFAllTerminatorsEager);
 470   runWithDomTree(*M, "switch_constant_3_repeated_dest", CFAllTerminatorsEager);
 471   runWithDomTree(*M, "indirectbr", CFAllTerminatorsEager);
 472   runWithDomTree(*M, "indirectbr_repeated", CFAllTerminatorsEager);
 473   runWithDomTree(*M, "indirectbr_unreachable", CFAllTerminatorsEager);
 474
 475   // Test ConstantFoldTerminator under Lazy UpdateStrategy.
 476   runWithDomTree(*M, "br_same_dest", CFAllTerminatorsLazy);
 477   runWithDomTree(*M, "br_different_dest", CFAllTerminatorsLazy);
 478   runWithDomTree(*M, "switch_2_different_dest", CFAllTerminatorsLazy);
 479   runWithDomTree(*M, "switch_2_different_dest_default", CFAllTerminatorsLazy);
 480   runWithDomTree(*M, "switch_3_different_dest", CFAllTerminatorsLazy);
 481   runWithDomTree(*M, "switch_variable_2_default_dest", CFAllTerminatorsLazy);
 482   runWithDomTree(*M, "switch_constant_2_default_dest", CFAllTerminatorsLazy);
 483   runWithDomTree(*M, "switch_constant_3_repeated_dest", CFAllTerminatorsLazy);
 484   runWithDomTree(*M, "indirectbr", CFAllTerminatorsLazy);
 485   runWithDomTree(*M, "indirectbr_repeated", CFAllTerminatorsLazy);
 486   runWithDomTree(*M, "indirectbr_unreachable", CFAllTerminatorsLazy);
 487 }
 488
 489 struct SalvageDebugInfoTest : ::testing::Test {
 490   LLVMContext C;
 491   std::unique_ptr<Module> M;
 492   Function *F = nullptr;
 493
 494   void SetUp() override {
 495     M = parseIR(C,
 496                 R"(
 497       define void @f() !dbg !8 {
 498       entry:
 499         %x = add i32 0, 1
 500         %y = add i32 %x, 2
 501         call void @llvm.dbg.value(metadata i32 %x, metadata !11, metadata !DIExpression()), !dbg !13
 502         call void @llvm.dbg.value(metadata i32 %y, metadata !11, metadata !DIExpression()), !dbg !13
 503         ret void, !dbg !14
 504       }
 505       declare void @llvm.dbg.value(metadata, metadata, metadata)
 506       !llvm.dbg.cu = !{!0}
 507       !llvm.module.flags = !{!3, !4}
 508       !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
 509       !1 = !DIFile(filename: "t2.c", directory: "foo")
 510       !2 = !{}
 511       !3 = !{i32 2, !"Dwarf Version", i32 4}
 512       !4 = !{i32 2, !"Debug Info Version", i32 3}
 513       !8 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !9, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: false, unit: !0, retainedNodes: !2)
 514       !9 = !DISubroutineType(types: !10)
 515       !10 = !{null}
 516       !11 = !DILocalVariable(name: "x", scope: !8, file: !1, line: 2, type: !12)
 517       !12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
 518       !13 = !DILocation(line: 2, column: 7, scope: !8)
 519       !14 = !DILocation(line: 3, column: 1, scope: !8)
 520       )");
 521
 522     auto *GV = M->getNamedValue("f");
 523     ASSERT_TRUE(GV);
 524     F = dyn_cast<Function>(GV);
 525     ASSERT_TRUE(F);
 526   }
 527
 528   bool doesDebugValueDescribeX(const DbgValueInst &DI) {
 529     if (DI.getNumVariableLocationOps() != 1u)
 530       return false;
 531     const auto &CI = *cast<ConstantInt>(DI.getValue(0));
 532     if (CI.isZero())
 533       return DI.getExpression()->getElements().equals(
 534           {dwarf::DW_OP_plus_uconst, 1, dwarf::DW_OP_stack_value});
 535     else if (CI.isOneValue())
 536       return DI.getExpression()->getElements().empty();
 537     return false;
 538   }
 539
 540   bool doesDebugValueDescribeY(const DbgValueInst &DI) {
 541     if (DI.getNumVariableLocationOps() != 1u)
 542       return false;
 543     const auto &CI = *cast<ConstantInt>(DI.getVariableLocationOp(0));
 544     if (CI.isZero())
 545       return DI.getExpression()->getElements().equals(
 546           {dwarf::DW_OP_plus_uconst, 1, dwarf::DW_OP_plus_uconst, 2,
 547            dwarf::DW_OP_stack_value});
 548     else if (CI.isOneValue())
 549       return DI.getExpression()->getElements().equals(
 550           {dwarf::DW_OP_plus_uconst, 2, dwarf::DW_OP_stack_value});
 551     return false;
 552   }
 553
 554   void verifyDebugValuesAreSalvaged() {
 555     // Check that the debug values for %x and %y are preserved.
 556     bool FoundX = false;
 557     bool FoundY = false;
 558     for (const Instruction &I : F->front()) {
 559       auto DI = dyn_cast<DbgValueInst>(&I);
 560       if (!DI) {
 561         // The function should only contain debug values and a terminator.
 562         ASSERT_TRUE(I.isTerminator());
 563         continue;
 564       }
 565       EXPECT_EQ(DI->getVariable()->getName(), "x");
 566       FoundX |= doesDebugValueDescribeX(*DI);
 567       FoundY |= doesDebugValueDescribeY(*DI);
 568     }
 569     ASSERT_TRUE(FoundX);
 570     ASSERT_TRUE(FoundY);
 571   }
 572 };
 573
 574 TEST_F(SalvageDebugInfoTest, RecursiveInstDeletion) {
 575   Instruction *Inst = &F->front().front();
 576   Inst = Inst->getNextNode(); // Get %y = add ...
 577   ASSERT_TRUE(Inst);
 578   bool Deleted = RecursivelyDeleteTriviallyDeadInstructions(Inst);
 579   ASSERT_TRUE(Deleted);
 580   verifyDebugValuesAreSalvaged();
 581 }
 582
 583 TEST_F(SalvageDebugInfoTest, RecursiveBlockSimplification) {
 584   BasicBlock *BB = &F->front();
 585   ASSERT_TRUE(BB);
 586   bool Deleted = SimplifyInstructionsInBlock(BB);
 587   ASSERT_TRUE(Deleted);
 588   verifyDebugValuesAreSalvaged();
 589 }
 590
 591 TEST(Local, SimplifyVScaleWithRange) {
 592   LLVMContext C;
 593   Module M("Module", C);
 594
 595   IntegerType *Ty = Type::getInt32Ty(C);
 596   Function *VScale = Intrinsic::getDeclaration(&M, Intrinsic::vscale, {Ty});
 597   auto *CI = CallInst::Create(VScale, {}, "vscale");
 598
 599   // Test that simplifyCall won't try to query it's parent function for
 600   // vscale_range attributes in order to simplify llvm.vscale -> constant.
 601   EXPECT_EQ(simplifyCall(CI, SimplifyQuery(M.getDataLayout())), nullptr);
 602   delete CI;
 603 }
 604
 605 TEST(Local, ChangeToUnreachable) {
 606   LLVMContext Ctx;
 607
 608   std::unique_ptr<Module> M = parseIR(Ctx,
 609                                       R"(
 610     define internal void @foo() !dbg !6 {
 611     entry:
 612       ret void, !dbg !8
 613     }
 614
 615     !llvm.dbg.cu = !{!0}
 616     !llvm.debugify = !{!3, !4}
 617     !llvm.module.flags = !{!5}
 618
 619     !0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "debugify", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
 620     !1 = !DIFile(filename: "test.ll", directory: "/")
 621     !2 = !{}
 622     !3 = !{i32 1}
 623     !4 = !{i32 0}
 624     !5 = !{i32 2, !"Debug Info Version", i32 3}
 625     !6 = distinct !DISubprogram(name: "foo", linkageName: "foo", scope: null, file: !1, line: 1, type: !7, isLocal: true, isDefinition: true, scopeLine: 1, isOptimized: true, unit: !0, retainedNodes: !2)
 626     !7 = !DISubroutineType(types: !2)
 627     !8 = !DILocation(line: 1, column: 1, scope: !6)
 628   )");
 629
 630   bool BrokenDebugInfo = true;
 631   verifyModule(*M, &errs(), &BrokenDebugInfo);
 632   ASSERT_FALSE(BrokenDebugInfo);
 633
 634   Function &F = *cast<Function>(M->getNamedValue("foo"));
 635
 636   BasicBlock &BB = F.front();
 637   Instruction &A = BB.front();
 638   DebugLoc DLA = A.getDebugLoc();
 639
 640   ASSERT_TRUE(isa<ReturnInst>(&A));
 641   // One instruction should be affected.
 642   EXPECT_EQ(changeToUnreachable(&A), 1U);
 643
 644   Instruction &B = BB.front();
 645
 646   // There should be an uncreachable instruction.
 647   ASSERT_TRUE(isa<UnreachableInst>(&B));
 648
 649   DebugLoc DLB = B.getDebugLoc();
 650   EXPECT_EQ(DLA, DLB);
 651 }
 652
 653 TEST(Local, ReplaceAllDbgUsesWith) {
 654   using namespace llvm::dwarf;
 655
 656   LLVMContext Ctx;
 657
 658   // Note: The datalayout simulates Darwin/x86_64.
 659   std::unique_ptr<Module> M = parseIR(Ctx,
 660                                       R"(
 661     target datalayout = "e-m:o-i63:64-f80:128-n8:16:32:64-S128"
 662
 663     declare i32 @escape(i32)
 664
 665     define void @f() !dbg !6 {
 666     entry:
 667       %a = add i32 0, 1, !dbg !15
 668       call void @llvm.dbg.value(metadata i32 %a, metadata !9, metadata !DIExpression()), !dbg !15
 669
 670       %b = add i64 0, 1, !dbg !16
 671       call void @llvm.dbg.value(metadata i64 %b, metadata !11, metadata !DIExpression()), !dbg !16
 672       call void @llvm.dbg.value(metadata i64 %b, metadata !11, metadata !DIExpression(DW_OP_lit0, DW_OP_mul)), !dbg !16
 673       call void @llvm.dbg.value(metadata i64 %b, metadata !11, metadata !DIExpression(DW_OP_lit0, DW_OP_mul, DW_OP_stack_value)), !dbg !16
 674       call void @llvm.dbg.value(metadata i64 %b, metadata !11, metadata !DIExpression(DW_OP_LLVM_fragment, 0, 8)), !dbg !16
 675       call void @llvm.dbg.value(metadata i64 %b, metadata !11, metadata !DIExpression(DW_OP_lit0, DW_OP_mul, DW_OP_LLVM_fragment, 0, 8)), !dbg !16
 676       call void @llvm.dbg.value(metadata i64 %b, metadata !11, metadata !DIExpression(DW_OP_lit0, DW_OP_mul, DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 8)), !dbg !16
 677
 678       %c = inttoptr i64 0 to i64*, !dbg !17
 679       call void @llvm.dbg.declare(metadata i64* %c, metadata !13, metadata !DIExpression()), !dbg !17
 680
 681       %d = inttoptr i64 0 to i32*, !dbg !18
 682       call void @llvm.dbg.addr(metadata i32* %d, metadata !20, metadata !DIExpression()), !dbg !18
 683
 684       %e = add <2 x i16> zeroinitializer, zeroinitializer
 685       call void @llvm.dbg.value(metadata <2 x i16> %e, metadata !14, metadata !DIExpression()), !dbg !18
 686
 687       %f = call i32 @escape(i32 0)
 688       call void @llvm.dbg.value(metadata i32 %f, metadata !9, metadata !DIExpression()), !dbg !15
 689
 690       %barrier = call i32 @escape(i32 0)
 691
 692       %g = call i32 @escape(i32 %f)
 693       call void @llvm.dbg.value(metadata i32 %g, metadata !9, metadata !DIExpression()), !dbg !15
 694
 695       ret void, !dbg !19
 696     }
 697
 698     declare void @llvm.dbg.addr(metadata, metadata, metadata)
 699     declare void @llvm.dbg.declare(metadata, metadata, metadata)
 700     declare void @llvm.dbg.value(metadata, metadata, metadata)
 701
 702     !llvm.dbg.cu = !{!0}
 703     !llvm.module.flags = !{!5}
 704
 705     !0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "debugify", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
 706     !1 = !DIFile(filename: "/Users/vsk/Desktop/foo.ll", directory: "/")
 707     !2 = !{}
 708     !5 = !{i32 2, !"Debug Info Version", i32 3}
 709     !6 = distinct !DISubprogram(name: "f", linkageName: "f", scope: null, file: !1, line: 1, type: !7, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: true, unit: !0, retainedNodes: !8)
 710     !7 = !DISubroutineType(types: !2)
 711     !8 = !{!9, !11, !13, !14}
 712     !9 = !DILocalVariable(name: "1", scope: !6, file: !1, line: 1, type: !10)
 713     !10 = !DIBasicType(name: "ty32", size: 32, encoding: DW_ATE_signed)
 714     !11 = !DILocalVariable(name: "2", scope: !6, file: !1, line: 2, type: !12)
 715     !12 = !DIBasicType(name: "ty64", size: 64, encoding: DW_ATE_signed)
 716     !13 = !DILocalVariable(name: "3", scope: !6, file: !1, line: 3, type: !12)
 717     !14 = !DILocalVariable(name: "4", scope: !6, file: !1, line: 4, type: !10)
 718     !15 = !DILocation(line: 1, column: 1, scope: !6)
 719     !16 = !DILocation(line: 2, column: 1, scope: !6)
 720     !17 = !DILocation(line: 3, column: 1, scope: !6)
 721     !18 = !DILocation(line: 4, column: 1, scope: !6)
 722     !19 = !DILocation(line: 5, column: 1, scope: !6)
 723     !20 = !DILocalVariable(name: "5", scope: !6, file: !1, line: 5, type: !10)
 724   )");
 725
 726   bool BrokenDebugInfo = true;
 727   verifyModule(*M, &errs(), &BrokenDebugInfo);
 728   ASSERT_FALSE(BrokenDebugInfo);
 729
 730   Function &F = *cast<Function>(M->getNamedValue("f"));
 731   DominatorTree DT{F};
 732
 733   BasicBlock &BB = F.front();
 734   Instruction &A = BB.front();
 735   Instruction &B = *A.getNextNonDebugInstruction();
 736   Instruction &C = *B.getNextNonDebugInstruction();
 737   Instruction &D = *C.getNextNonDebugInstruction();
 738   Instruction &E = *D.getNextNonDebugInstruction();
 739   Instruction &F_ = *E.getNextNonDebugInstruction();
 740   Instruction &Barrier = *F_.getNextNonDebugInstruction();
 741   Instruction &G = *Barrier.getNextNonDebugInstruction();
 742
 743   // Simulate i32 <-> i64* conversion. Expect no updates: the datalayout says
 744   // pointers are 64 bits, so the conversion would be lossy.
 745   EXPECT_FALSE(replaceAllDbgUsesWith(A, C, C, DT));
 746   EXPECT_FALSE(replaceAllDbgUsesWith(C, A, A, DT));
 747
 748   // Simulate i32 <-> <2 x i16> conversion. This is unsupported.
 749   EXPECT_FALSE(replaceAllDbgUsesWith(E, A, A, DT));
 750   EXPECT_FALSE(replaceAllDbgUsesWith(A, E, E, DT));
 751
 752   // Simulate i32* <-> i64* conversion.
 753   EXPECT_TRUE(replaceAllDbgUsesWith(D, C, C, DT));
 754
 755   SmallVector<DbgVariableIntrinsic *, 2> CDbgVals;
 756   findDbgUsers(CDbgVals, &C);
 757   EXPECT_EQ(2U, CDbgVals.size());
 758   EXPECT_TRUE(any_of(CDbgVals, [](DbgVariableIntrinsic *DII) {
 759     return isa<DbgAddrIntrinsic>(DII);
 760   }));
 761   EXPECT_TRUE(any_of(CDbgVals, [](DbgVariableIntrinsic *DII) {
 762     return isa<DbgDeclareInst>(DII);
 763   }));
 764
 765   EXPECT_TRUE(replaceAllDbgUsesWith(C, D, D, DT));
 766
 767   SmallVector<DbgVariableIntrinsic *, 2> DDbgVals;
 768   findDbgUsers(DDbgVals, &D);
 769   EXPECT_EQ(2U, DDbgVals.size());
 770   EXPECT_TRUE(any_of(DDbgVals, [](DbgVariableIntrinsic *DII) {
 771     return isa<DbgAddrIntrinsic>(DII);
 772   }));
 773   EXPECT_TRUE(any_of(DDbgVals, [](DbgVariableIntrinsic *DII) {
 774     return isa<DbgDeclareInst>(DII);
 775   }));
 776
 777   // Introduce a use-before-def. Check that the dbg.value for %a is salvaged.
 778   EXPECT_TRUE(replaceAllDbgUsesWith(A, F_, F_, DT));
 779
 780   auto *ADbgVal = cast<DbgValueInst>(A.getNextNode());
 781   EXPECT_EQ(ADbgVal->getNumVariableLocationOps(), 1u);
 782   EXPECT_EQ(ConstantInt::get(A.getType(), 0), ADbgVal->getVariableLocationOp(0));
 783
 784   // Introduce a use-before-def. Check that the dbg.values for %f become undef.
 785   EXPECT_TRUE(replaceAllDbgUsesWith(F_, G, G, DT));
 786
 787   auto *FDbgVal = cast<DbgValueInst>(F_.getNextNode());
 788   EXPECT_EQ(FDbgVal->getNumVariableLocationOps(), 1u);
 789   EXPECT_TRUE(FDbgVal->isUndef());
 790
 791   SmallVector<DbgValueInst *, 1> FDbgVals;
 792   findDbgValues(FDbgVals, &F_);
 793   EXPECT_EQ(0U, FDbgVals.size());
 794
 795   // Simulate i32 -> i64 conversion to test sign-extension. Here are some
 796   // interesting cases to handle:
 797   //  1) debug user has empty DIExpression
 798   //  2) debug user has non-empty, non-stack-value'd DIExpression
 799   //  3) debug user has non-empty, stack-value'd DIExpression
 800   //  4-6) like (1-3), but with a fragment
 801   EXPECT_TRUE(replaceAllDbgUsesWith(B, A, A, DT));
 802
 803   SmallVector<DbgValueInst *, 8> ADbgVals;
 804   findDbgValues(ADbgVals, &A);
 805   EXPECT_EQ(6U, ADbgVals.size());
 806
 807   // Check that %a has a dbg.value with a DIExpression matching \p Ops.
 808   auto hasADbgVal = [&](ArrayRef<uint64_t> Ops) {
 809     return any_of(ADbgVals, [&](DbgValueInst *DVI) {
 810       assert(DVI->getVariable()->getName() == "2");
 811       return DVI->getExpression()->getElements() == Ops;
 812     });
 813   };
 814
 815   // Case 1: The original expr is empty, so no deref is needed.
 816   EXPECT_TRUE(hasADbgVal({DW_OP_LLVM_convert, 32, DW_ATE_signed,
 817                          DW_OP_LLVM_convert, 64, DW_ATE_signed,
 818                          DW_OP_stack_value}));
 819
 820   // Case 2: Perform an address calculation with the original expr, deref it,
 821   // then sign-extend the result.
 822   EXPECT_TRUE(hasADbgVal({DW_OP_lit0, DW_OP_mul, DW_OP_deref,
 823                          DW_OP_LLVM_convert, 32, DW_ATE_signed,
 824                          DW_OP_LLVM_convert, 64, DW_ATE_signed,
 825                          DW_OP_stack_value}));
 826
 827   // Case 3: Insert the sign-extension logic before the DW_OP_stack_value.
 828   EXPECT_TRUE(hasADbgVal({DW_OP_lit0, DW_OP_mul, DW_OP_LLVM_convert, 32,
 829                          DW_ATE_signed, DW_OP_LLVM_convert, 64, DW_ATE_signed,
 830                          DW_OP_stack_value}));
 831
 832   // Cases 4-6: Just like cases 1-3, but preserve the fragment at the end.
 833   EXPECT_TRUE(hasADbgVal({DW_OP_LLVM_convert, 32, DW_ATE_signed,
 834                          DW_OP_LLVM_convert, 64, DW_ATE_signed,
 835                          DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 8}));
 836
 837   EXPECT_TRUE(hasADbgVal({DW_OP_lit0, DW_OP_mul, DW_OP_deref,
 838                          DW_OP_LLVM_convert, 32, DW_ATE_signed,
 839                          DW_OP_LLVM_convert, 64, DW_ATE_signed,
 840                          DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 8}));
 841
 842   EXPECT_TRUE(hasADbgVal({DW_OP_lit0, DW_OP_mul, DW_OP_LLVM_convert, 32,
 843                          DW_ATE_signed, DW_OP_LLVM_convert, 64, DW_ATE_signed,
 844                          DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 8}));
 845
 846   verifyModule(*M, &errs(), &BrokenDebugInfo);
 847   ASSERT_FALSE(BrokenDebugInfo);
 848 }
 849
 850 TEST(Local, RemoveUnreachableBlocks) {
 851   LLVMContext C;
 852
 853   std::unique_ptr<Module> M = parseIR(C,
 854                                       R"(
 855       define void @br_simple() {
 856       entry:
 857         br label %bb0
 858       bb0:
 859         ret void
 860       bb1:
 861         ret void
 862       }
 863
 864       define void @br_self_loop() {
 865       entry:
 866         br label %bb0
 867       bb0:
 868         br i1 true, label %bb1, label %bb0
 869       bb1:
 870         br i1 true, label %bb0, label %bb2
 871       bb2:
 872         br label %bb2
 873       }
 874
 875       define void @br_constant() {
 876       entry:
 877         br label %bb0
 878       bb0:
 879         br i1 true, label %bb1, label %bb2
 880       bb1:
 881         br i1 true, label %bb0, label %bb2
 882       bb2:
 883         br label %bb2
 884       }
 885
 886       define void @br_loop() {
 887       entry:
 888         br label %bb0
 889       bb0:
 890         br label %bb0
 891       bb1:
 892         br label %bb2
 893       bb2:
 894         br label %bb1
 895       }
 896
 897       declare i32 @__gxx_personality_v0(...)
 898
 899       define void @invoke_terminator() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
 900       entry:
 901         br i1 undef, label %invoke.block, label %exit
 902
 903       invoke.block:
 904         %cond = invoke zeroext i1 @invokable()
 905                 to label %continue.block unwind label %lpad.block
 906
 907       continue.block:
 908         br i1 %cond, label %if.then, label %if.end
 909
 910       if.then:
 911         unreachable
 912
 913       if.end:
 914         unreachable
 915
 916       lpad.block:
 917         %lp = landingpad { i8*, i32 }
 918                 catch i8* null
 919         br label %exit
 920
 921       exit:
 922         ret void
 923       }
 924
 925       declare i1 @invokable()
 926       )");
 927
 928   auto runEager = [&](Function &F, DominatorTree *DT) {
 929     PostDominatorTree PDT = PostDominatorTree(F);
 930     DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Eager);
 931     removeUnreachableBlocks(F, &DTU);
 932     EXPECT_TRUE(DTU.getDomTree().verify());
 933     EXPECT_TRUE(DTU.getPostDomTree().verify());
 934   };
 935
 936   auto runLazy = [&](Function &F, DominatorTree *DT) {
 937     PostDominatorTree PDT = PostDominatorTree(F);
 938     DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Lazy);
 939     removeUnreachableBlocks(F, &DTU);
 940     EXPECT_TRUE(DTU.getDomTree().verify());
 941     EXPECT_TRUE(DTU.getPostDomTree().verify());
 942   };
 943
 944   // Test removeUnreachableBlocks under Eager UpdateStrategy.
 945   runWithDomTree(*M, "br_simple", runEager);
 946   runWithDomTree(*M, "br_self_loop", runEager);
 947   runWithDomTree(*M, "br_constant", runEager);
 948   runWithDomTree(*M, "br_loop", runEager);
 949   runWithDomTree(*M, "invoke_terminator", runEager);
 950
 951   // Test removeUnreachableBlocks under Lazy UpdateStrategy.
 952   runWithDomTree(*M, "br_simple", runLazy);
 953   runWithDomTree(*M, "br_self_loop", runLazy);
 954   runWithDomTree(*M, "br_constant", runLazy);
 955   runWithDomTree(*M, "br_loop", runLazy);
 956   runWithDomTree(*M, "invoke_terminator", runLazy);
 957
 958   M = parseIR(C,
 959               R"(
 960       define void @f() {
 961       entry:
 962         ret void
 963       bb0:
 964         ret void
 965       }
 966         )");
 967
 968   auto checkRUBlocksRetVal = [&](Function &F, DominatorTree *DT) {
 969     DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Lazy);
 970     EXPECT_TRUE(removeUnreachableBlocks(F, &DTU));
 971     EXPECT_FALSE(removeUnreachableBlocks(F, &DTU));
 972     EXPECT_TRUE(DTU.getDomTree().verify());
 973   };
 974
 975   runWithDomTree(*M, "f", checkRUBlocksRetVal);
 976 }
 977
 978 TEST(Local, SimplifyCFGWithNullAC) {
 979   LLVMContext Ctx;
 980
 981   std::unique_ptr<Module> M = parseIR(Ctx, R"(
 982     declare void @true_path()
 983     declare void @false_path()
 984     declare void @llvm.assume(i1 %cond);
 985
 986     define i32 @foo(i1, i32) {
 987     entry:
 988       %cmp = icmp sgt i32 %1, 0
 989       br i1 %cmp, label %if.bb1, label %then.bb1
 990     if.bb1:
 991       call void @true_path()
 992       br label %test.bb
 993     then.bb1:
 994       call void @false_path()
 995       br label %test.bb
 996     test.bb:
 997       %phi = phi i1 [1, %if.bb1], [%0, %then.bb1]
 998       call void @llvm.assume(i1 %0)
 999       br i1 %phi, label %if.bb2, label %then.bb2
1000     if.bb2:
1001       ret i32 %1
1002     then.bb2:
1003       ret i32 0
1004     }
1005   )");
1006
1007   Function &F = *cast<Function>(M->getNamedValue("foo"));
1008   TargetTransformInfo TTI(M->getDataLayout());
1009
1010   SimplifyCFGOptions Options{};
1011   Options.setAssumptionCache(nullptr);
1012
1013   // Obtain BasicBlock of interest to this test, %test.bb.
1014   BasicBlock *TestBB = nullptr;
1015   for (BasicBlock &BB : F) {
1016     if (BB.getName().equals("test.bb")) {
1017       TestBB = &BB;
1018       break;
1019     }
1020   }
1021   ASSERT_TRUE(TestBB);
1022
1023   DominatorTree DT(F);
1024   DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Eager);
1025
1026   // %test.bb is expected to be simplified by FoldCondBranchOnPHI.
1027   EXPECT_TRUE(simplifyCFG(TestBB, TTI,
1028                           RequireAndPreserveDomTree ? &DTU : nullptr, Options));
1029 }
1030
1031 TEST(Local, CanReplaceOperandWithVariable) {
1032   LLVMContext Ctx;
1033   Module M("test_module", Ctx);
1034   IRBuilder<> B(Ctx);
1035
1036   FunctionType *FnType =
1037     FunctionType::get(Type::getVoidTy(Ctx), {}, false);
1038
1039   FunctionType *VarArgFnType =
1040     FunctionType::get(Type::getVoidTy(Ctx), {B.getInt32Ty()}, true);
1041
1042   Function *TestBody = Function::Create(FnType, GlobalValue::ExternalLinkage,
1043                                         0, "", &M);
1044
1045   BasicBlock *BB0 = BasicBlock::Create(Ctx, "", TestBody);
1046   B.SetInsertPoint(BB0);
1047
1048   FunctionCallee Intrin = M.getOrInsertFunction("llvm.foo", FnType);
1049   FunctionCallee Func = M.getOrInsertFunction("foo", FnType);
1050   FunctionCallee VarArgFunc
1051     = M.getOrInsertFunction("foo.vararg", VarArgFnType);
1052   FunctionCallee VarArgIntrin
1053     = M.getOrInsertFunction("llvm.foo.vararg", VarArgFnType);
1054
1055   auto *CallToIntrin = B.CreateCall(Intrin);
1056   auto *CallToFunc = B.CreateCall(Func);
1057
1058   // Test if it's valid to replace the callee operand.
1059   EXPECT_FALSE(canReplaceOperandWithVariable(CallToIntrin, 0));
1060   EXPECT_TRUE(canReplaceOperandWithVariable(CallToFunc, 0));
1061
1062   // That it's invalid to replace an argument in the variadic argument list for
1063   // an intrinsic, but OK for a normal function.
1064   auto *CallToVarArgFunc = B.CreateCall(
1065     VarArgFunc, {B.getInt32(0), B.getInt32(1), B.getInt32(2)});
1066   EXPECT_TRUE(canReplaceOperandWithVariable(CallToVarArgFunc, 0));
1067   EXPECT_TRUE(canReplaceOperandWithVariable(CallToVarArgFunc, 1));
1068   EXPECT_TRUE(canReplaceOperandWithVariable(CallToVarArgFunc, 2));
1069   EXPECT_TRUE(canReplaceOperandWithVariable(CallToVarArgFunc, 3));
1070
1071   auto *CallToVarArgIntrin = B.CreateCall(
1072     VarArgIntrin, {B.getInt32(0), B.getInt32(1), B.getInt32(2)});
1073   EXPECT_TRUE(canReplaceOperandWithVariable(CallToVarArgIntrin, 0));
1074   EXPECT_FALSE(canReplaceOperandWithVariable(CallToVarArgIntrin, 1));
1075   EXPECT_FALSE(canReplaceOperandWithVariable(CallToVarArgIntrin, 2));
1076   EXPECT_FALSE(canReplaceOperandWithVariable(CallToVarArgIntrin, 3));
1077
1078   // Test that it's invalid to replace gcroot operands, even though it can't use
1079   // immarg.
1080   Type *PtrPtr = B.getInt8Ty()->getPointerTo(0);
1081   Value *Alloca = B.CreateAlloca(PtrPtr, (unsigned)0);
1082   CallInst *GCRoot = B.CreateIntrinsic(Intrinsic::gcroot, {},
1083     {Alloca, Constant::getNullValue(PtrPtr)});
1084   EXPECT_TRUE(canReplaceOperandWithVariable(GCRoot, 0)); // Alloca
1085   EXPECT_FALSE(canReplaceOperandWithVariable(GCRoot, 1));
1086   EXPECT_FALSE(canReplaceOperandWithVariable(GCRoot, 2));
1087
1088   BB0->dropAllReferences();
1089 }