|  | //===- UnrollAnalyzerTest.cpp - UnrollAnalyzer unit tests -----------------===// | 
|  | // | 
|  | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | 
|  | // See https://llvm.org/LICENSE.txt for license information. | 
|  | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #include "llvm/Analysis/AssumptionCache.h" | 
|  | #include "llvm/Analysis/LoopInfo.h" | 
|  | #include "llvm/Analysis/LoopUnrollAnalyzer.h" | 
|  | #include "llvm/Analysis/ScalarEvolution.h" | 
|  | #include "llvm/Analysis/TargetLibraryInfo.h" | 
|  | #include "llvm/AsmParser/Parser.h" | 
|  | #include "llvm/IR/Dominators.h" | 
|  | #include "llvm/Support/SourceMgr.h" | 
|  | #include "gtest/gtest.h" | 
|  |  | 
|  | using namespace llvm; | 
|  |  | 
|  | typedef SmallVector<DenseMap<Value *, Value *>, 16> SimplifiedValuesVectorTy; | 
|  |  | 
|  | /// Build loop info and scalar evolution for the function and run the analysis. | 
|  | static void | 
|  | runUnrollAnalyzer(Module &M, StringRef FuncName, | 
|  | SimplifiedValuesVectorTy &SimplifiedValuesVector) { | 
|  | auto *F = M.getFunction(FuncName); | 
|  | ASSERT_NE(F, nullptr) << "Could not find " << FuncName; | 
|  |  | 
|  | TargetLibraryInfoImpl TLII; | 
|  | TargetLibraryInfo TLI(TLII); | 
|  | AssumptionCache AC(*F); | 
|  | DominatorTree DT(*F); | 
|  | LoopInfo LI(DT); | 
|  | ScalarEvolution SE(*F, TLI, AC, DT, LI); | 
|  |  | 
|  | 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(); | 
|  | unsigned TripCount = SE.getSmallConstantTripCount(L, Exiting); | 
|  | for (unsigned Iteration = 0; Iteration < TripCount; Iteration++) { | 
|  | DenseMap<Value *, Value *> SimplifiedValues; | 
|  | UnrolledInstAnalyzer Analyzer(Iteration, SimplifiedValues, SE, L); | 
|  | for (auto *BB : L->getBlocks()) | 
|  | for (Instruction &I : *BB) | 
|  | Analyzer.visit(I); | 
|  | SimplifiedValuesVector.push_back(SimplifiedValues); | 
|  | } | 
|  | } | 
|  |  | 
|  | 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"; | 
|  | LLVMContext Context; | 
|  | std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr); | 
|  | SimplifiedValuesVectorTy SimplifiedValuesVector; | 
|  | runUnrollAnalyzer(*M, "propagate_loop_phis", SimplifiedValuesVector); | 
|  | unsigned TripCount = SimplifiedValuesVector.size(); | 
|  |  | 
|  | // 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"; | 
|  |  | 
|  | LLVMContext Context; | 
|  | std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr); | 
|  | SimplifiedValuesVectorTy SimplifiedValuesVector; | 
|  | runUnrollAnalyzer(*M, "foo", SimplifiedValuesVector); | 
|  |  | 
|  | 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"; | 
|  | LLVMContext Context; | 
|  | std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr); | 
|  | SimplifiedValuesVectorTy SimplifiedValuesVector; | 
|  | runUnrollAnalyzer(*M, "branch_iv_trunc", SimplifiedValuesVector); | 
|  |  | 
|  | // 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" | 
|  | "  %cmp2 = icmp slt i8* %iv2.0, %iv.0\n" | 
|  | "  %cmp3 = icmp ult 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"; | 
|  | LLVMContext Context; | 
|  | std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr); | 
|  | SimplifiedValuesVectorTy SimplifiedValuesVector; | 
|  | runUnrollAnalyzer(*M, "ptr_cmp", SimplifiedValuesVector); | 
|  |  | 
|  | // 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 *Cmp1 = &*BBI++; | 
|  | Instruction *Cmp2 = &*BBI++; | 
|  | Instruction *Cmp3 = &*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(Cmp1); | 
|  | EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end()); | 
|  | EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 0U); | 
|  | // Check that "%cmp2 = icmp slt i8* %iv2.0, %iv.0" does not simplify | 
|  | auto I2 = SimplifiedValuesVector[5].find(Cmp2); | 
|  | EXPECT_TRUE(I2 == SimplifiedValuesVector[5].end()); | 
|  | // Check that "%cmp3 = icmp ult i8* %iv2.0, %iv.0" is simplified to 0. | 
|  | auto I3 = SimplifiedValuesVector[5].find(Cmp3); | 
|  | EXPECT_TRUE(I3 != 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"; | 
|  |  | 
|  | LLVMContext Context; | 
|  | std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr); | 
|  | SimplifiedValuesVectorTy SimplifiedValuesVector; | 
|  | runUnrollAnalyzer(*M, "const_load_cast", SimplifiedValuesVector); | 
|  |  | 
|  | // 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); | 
|  | } |