Initial check in

Bug: 137197907
diff --git a/src/llvm-project/llvm/unittests/Analysis/UnrollAnalyzerTest.cpp b/src/llvm-project/llvm/unittests/Analysis/UnrollAnalyzerTest.cpp
new file mode 100644
index 0000000..937e69f
--- /dev/null
+++ b/src/llvm-project/llvm/unittests/Analysis/UnrollAnalyzerTest.cpp
@@ -0,0 +1,330 @@
+//===- UnrollAnalyzerTest.cpp - UnrollAnalyzer unit tests -----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/LoopUnrollAnalyzer.h"
+#include "llvm/AsmParser/Parser.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/Support/SourceMgr.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+namespace llvm {
+void initializeUnrollAnalyzerTestPass(PassRegistry &);
+
+static SmallVector<DenseMap<Value *, Constant *>, 16> SimplifiedValuesVector;
+static unsigned TripCount = 0;
+
+namespace {
+struct UnrollAnalyzerTest : public FunctionPass {
+  static char ID;
+  bool runOnFunction(Function &F) override {
+    LoopInfo *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+    ScalarEvolution *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
+
+    Function::iterator FI = F.begin();
+    FI++; // First basic block is entry - skip it.
+    BasicBlock *Header = &*FI++;
+    Loop *L = LI->getLoopFor(Header);
+    BasicBlock *Exiting = L->getExitingBlock();
+
+    SimplifiedValuesVector.clear();
+    TripCount = SE->getSmallConstantTripCount(L, Exiting);
+    for (unsigned Iteration = 0; Iteration < TripCount; Iteration++) {
+      DenseMap<Value *, Constant *> SimplifiedValues;
+      UnrolledInstAnalyzer Analyzer(Iteration, SimplifiedValues, *SE, L);
+      for (auto *BB : L->getBlocks())
+        for (Instruction &I : *BB)
+          Analyzer.visit(I);
+      SimplifiedValuesVector.push_back(SimplifiedValues);
+    }
+    return false;
+  }
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.addRequired<DominatorTreeWrapperPass>();
+    AU.addRequired<LoopInfoWrapperPass>();
+    AU.addRequired<ScalarEvolutionWrapperPass>();
+    AU.setPreservesAll();
+  }
+  UnrollAnalyzerTest() : FunctionPass(ID) {
+    initializeUnrollAnalyzerTestPass(*PassRegistry::getPassRegistry());
+  }
+};
+}
+
+char UnrollAnalyzerTest::ID = 0;
+
+std::unique_ptr<Module> makeLLVMModule(LLVMContext &Context,
+                                       const char *ModuleStr) {
+  SMDiagnostic Err;
+  return parseAssemblyString(ModuleStr, Err, Context);
+}
+
+TEST(UnrollAnalyzerTest, BasicSimplifications) {
+  const char *ModuleStr =
+      "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
+      "define i64 @propagate_loop_phis() {\n"
+      "entry:\n"
+      "  br label %loop\n"
+      "loop:\n"
+      "  %iv = phi i64 [ 0, %entry ], [ %inc, %loop ]\n"
+      "  %x0 = phi i64 [ 0, %entry ], [ %x2, %loop ]\n"
+      "  %x1 = or i64 %x0, 1\n"
+      "  %x2 = or i64 %x1, 2\n"
+      "  %inc = add nuw nsw i64 %iv, 1\n"
+      "  %cond = icmp sge i64 %inc, 8\n"
+      "  br i1 %cond, label %loop.end, label %loop\n"
+      "loop.end:\n"
+      "  %x.lcssa = phi i64 [ %x2, %loop ]\n"
+      "  ret i64 %x.lcssa\n"
+      "}\n";
+  UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
+  LLVMContext Context;
+  std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
+  legacy::PassManager Passes;
+  Passes.add(P);
+  Passes.run(*M);
+
+  // Perform checks
+  Module::iterator MI = M->begin();
+  Function *F = &*MI++;
+  Function::iterator FI = F->begin();
+  FI++; // First basic block is entry - skip it.
+  BasicBlock *Header = &*FI++;
+
+  BasicBlock::iterator BBI = Header->begin();
+  std::advance(BBI, 4);
+  Instruction *Y1 = &*BBI++;
+  Instruction *Y2 = &*BBI++;
+  // Check simplification expected on the 1st iteration.
+  // Check that "%inc = add nuw nsw i64 %iv, 1" is simplified to 1
+  auto I1 = SimplifiedValuesVector[0].find(Y1);
+  EXPECT_TRUE(I1 != SimplifiedValuesVector[0].end());
+  EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 1U);
+
+  // Check that "%cond = icmp sge i64 %inc, 10" is simplified to false
+  auto I2 = SimplifiedValuesVector[0].find(Y2);
+  EXPECT_TRUE(I2 != SimplifiedValuesVector[0].end());
+  EXPECT_FALSE(cast<ConstantInt>((*I2).second)->getZExtValue());
+
+  // Check simplification expected on the last iteration.
+  // Check that "%inc = add nuw nsw i64 %iv, 1" is simplified to 8
+  I1 = SimplifiedValuesVector[TripCount - 1].find(Y1);
+  EXPECT_TRUE(I1 != SimplifiedValuesVector[TripCount - 1].end());
+  EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), TripCount);
+
+  // Check that "%cond = icmp sge i64 %inc, 10" is simplified to false
+  I2 = SimplifiedValuesVector[TripCount - 1].find(Y2);
+  EXPECT_TRUE(I2 != SimplifiedValuesVector[TripCount - 1].end());
+  EXPECT_TRUE(cast<ConstantInt>((*I2).second)->getZExtValue());
+}
+
+TEST(UnrollAnalyzerTest, OuterLoopSimplification) {
+  const char *ModuleStr =
+      "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
+      "define void @foo() {\n"
+      "entry:\n"
+      "  br label %outer.loop\n"
+      "outer.loop:\n"
+      "  %iv.outer = phi i64 [ 0, %entry ], [ %iv.outer.next, %outer.loop.latch ]\n"
+      "  %iv.outer.next = add nuw nsw i64 %iv.outer, 1\n"
+      "  br label %inner.loop\n"
+      "inner.loop:\n"
+      "  %iv.inner = phi i64 [ 0, %outer.loop ], [ %iv.inner.next, %inner.loop ]\n"
+      "  %iv.inner.next = add nuw nsw i64 %iv.inner, 1\n"
+      "  %exitcond.inner = icmp eq i64 %iv.inner.next, 1000\n"
+      "  br i1 %exitcond.inner, label %outer.loop.latch, label %inner.loop\n"
+      "outer.loop.latch:\n"
+      "  %exitcond.outer = icmp eq i64 %iv.outer.next, 40\n"
+      "  br i1 %exitcond.outer, label %exit, label %outer.loop\n"
+      "exit:\n"
+      "  ret void\n"
+      "}\n";
+
+  UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
+  LLVMContext Context;
+  std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
+  legacy::PassManager Passes;
+  Passes.add(P);
+  Passes.run(*M);
+
+  Module::iterator MI = M->begin();
+  Function *F = &*MI++;
+  Function::iterator FI = F->begin();
+  FI++;
+  BasicBlock *Header = &*FI++;
+  BasicBlock *InnerBody = &*FI++;
+
+  BasicBlock::iterator BBI = Header->begin();
+  BBI++;
+  Instruction *Y1 = &*BBI;
+  BBI = InnerBody->begin();
+  BBI++;
+  Instruction *Y2 = &*BBI;
+  // Check that we can simplify IV of the outer loop, but can't simplify the IV
+  // of the inner loop if we only know the iteration number of the outer loop.
+  //
+  //  Y1 is %iv.outer.next, Y2 is %iv.inner.next
+  auto I1 = SimplifiedValuesVector[0].find(Y1);
+  EXPECT_TRUE(I1 != SimplifiedValuesVector[0].end());
+  auto I2 = SimplifiedValuesVector[0].find(Y2);
+  EXPECT_TRUE(I2 == SimplifiedValuesVector[0].end());
+}
+TEST(UnrollAnalyzerTest, CmpSimplifications) {
+  const char *ModuleStr =
+      "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
+      "define void @branch_iv_trunc() {\n"
+      "entry:\n"
+      "  br label %for.body\n"
+      "for.body:\n"
+      "  %indvars.iv = phi i64 [ 0, %entry ], [ %tmp3, %for.body ]\n"
+      "  %tmp2 = trunc i64 %indvars.iv to i32\n"
+      "  %cmp3 = icmp eq i32 %tmp2, 5\n"
+      "  %tmp3 = add nuw nsw i64 %indvars.iv, 1\n"
+      "  %exitcond = icmp eq i64 %tmp3, 10\n"
+      "  br i1 %exitcond, label %for.end, label %for.body\n"
+      "for.end:\n"
+      "  ret void\n"
+      "}\n";
+  UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
+  LLVMContext Context;
+  std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
+  legacy::PassManager Passes;
+  Passes.add(P);
+  Passes.run(*M);
+
+  // Perform checks
+  Module::iterator MI = M->begin();
+  Function *F = &*MI++;
+  Function::iterator FI = F->begin();
+  FI++; // First basic block is entry - skip it.
+  BasicBlock *Header = &*FI++;
+
+  BasicBlock::iterator BBI = Header->begin();
+  BBI++;
+  Instruction *Y1 = &*BBI++;
+  Instruction *Y2 = &*BBI++;
+  // Check simplification expected on the 5th iteration.
+  // Check that "%tmp2 = trunc i64 %indvars.iv to i32" is simplified to 5
+  // and "%cmp3 = icmp eq i32 %tmp2, 5" is simplified to 1 (i.e. true).
+  auto I1 = SimplifiedValuesVector[5].find(Y1);
+  EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end());
+  EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 5U);
+  auto I2 = SimplifiedValuesVector[5].find(Y2);
+  EXPECT_TRUE(I2 != SimplifiedValuesVector[5].end());
+  EXPECT_EQ(cast<ConstantInt>((*I2).second)->getZExtValue(), 1U);
+}
+TEST(UnrollAnalyzerTest, PtrCmpSimplifications) {
+  const char *ModuleStr =
+      "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
+      "define void @ptr_cmp(i8 *%a) {\n"
+      "entry:\n"
+      "  %limit = getelementptr i8, i8* %a, i64 40\n"
+      "  %start.iv2 = getelementptr i8, i8* %a, i64 7\n"
+      "  br label %loop.body\n"
+      "loop.body:\n"
+      "  %iv.0 = phi i8* [ %a, %entry ], [ %iv.1, %loop.body ]\n"
+      "  %iv2.0 = phi i8* [ %start.iv2, %entry ], [ %iv2.1, %loop.body ]\n"
+      "  %cmp = icmp eq i8* %iv2.0, %iv.0\n"
+      "  %iv.1 = getelementptr inbounds i8, i8* %iv.0, i64 1\n"
+      "  %iv2.1 = getelementptr inbounds i8, i8* %iv2.0, i64 1\n"
+      "  %exitcond = icmp ne i8* %iv.1, %limit\n"
+      "  br i1 %exitcond, label %loop.body, label %loop.exit\n"
+      "loop.exit:\n"
+      "  ret void\n"
+      "}\n";
+  UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
+  LLVMContext Context;
+  std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
+  legacy::PassManager Passes;
+  Passes.add(P);
+  Passes.run(*M);
+
+  // Perform checks
+  Module::iterator MI = M->begin();
+  Function *F = &*MI++;
+  Function::iterator FI = F->begin();
+  FI++; // First basic block is entry - skip it.
+  BasicBlock *Header = &*FI;
+
+  BasicBlock::iterator BBI = Header->begin();
+  std::advance(BBI, 2);
+  Instruction *Y1 = &*BBI;
+  // Check simplification expected on the 5th iteration.
+  // Check that "%cmp = icmp eq i8* %iv2.0, %iv.0" is simplified to 0.
+  auto I1 = SimplifiedValuesVector[5].find(Y1);
+  EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end());
+  EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 0U);
+}
+TEST(UnrollAnalyzerTest, CastSimplifications) {
+  const char *ModuleStr =
+      "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
+      "@known_constant = internal unnamed_addr constant [10 x i32] [i32 0, i32 1, i32 0, i32 1, i32 0, i32 259, i32 0, i32 1, i32 0, i32 1], align 16\n"
+      "define void @const_load_cast() {\n"
+      "entry:\n"
+      "  br label %loop\n"
+      "\n"
+      "loop:\n"
+      "  %iv = phi i64 [ 0, %entry ], [ %inc, %loop ]\n"
+      "  %array_const_idx = getelementptr inbounds [10 x i32], [10 x i32]* @known_constant, i64 0, i64 %iv\n"
+      "  %const_array_element = load i32, i32* %array_const_idx, align 4\n"
+      "  %se = sext i32 %const_array_element to i64\n"
+      "  %ze = zext i32 %const_array_element to i64\n"
+      "  %tr = trunc i32 %const_array_element to i8\n"
+      "  %inc = add nuw nsw i64 %iv, 1\n"
+      "  %exitcond86.i = icmp eq i64 %inc, 10\n"
+      "  br i1 %exitcond86.i, label %loop.end, label %loop\n"
+      "\n"
+      "loop.end:\n"
+      "  ret void\n"
+      "}\n";
+
+  UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
+  LLVMContext Context;
+  std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
+  legacy::PassManager Passes;
+  Passes.add(P);
+  Passes.run(*M);
+
+  // Perform checks
+  Module::iterator MI = M->begin();
+  Function *F = &*MI++;
+  Function::iterator FI = F->begin();
+  FI++; // First basic block is entry - skip it.
+  BasicBlock *Header = &*FI++;
+
+  BasicBlock::iterator BBI = Header->begin();
+  std::advance(BBI, 3);
+  Instruction *Y1 = &*BBI++;
+  Instruction *Y2 = &*BBI++;
+  Instruction *Y3 = &*BBI++;
+  // Check simplification expected on the 5th iteration.
+  // "%se = sext i32 %const_array_element to i64" should be simplified to 259,
+  // "%ze = zext i32 %const_array_element to i64" should be simplified to 259,
+  // "%tr = trunc i32 %const_array_element to i8" should be simplified to 3.
+  auto I1 = SimplifiedValuesVector[5].find(Y1);
+  EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end());
+  EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 259U);
+  auto I2 = SimplifiedValuesVector[5].find(Y2);
+  EXPECT_TRUE(I2 != SimplifiedValuesVector[5].end());
+  EXPECT_EQ(cast<ConstantInt>((*I2).second)->getZExtValue(), 259U);
+  auto I3 = SimplifiedValuesVector[5].find(Y3);
+  EXPECT_TRUE(I3 != SimplifiedValuesVector[5].end());
+  EXPECT_EQ(cast<ConstantInt>((*I3).second)->getZExtValue(), 3U);
+}
+
+} // end namespace llvm
+
+INITIALIZE_PASS_BEGIN(UnrollAnalyzerTest, "unrollanalyzertestpass",
+                      "unrollanalyzertestpass", false, false)
+INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
+INITIALIZE_PASS_END(UnrollAnalyzerTest, "unrollanalyzertestpass",
+                    "unrollanalyzertestpass", false, false)