unittests/Analysis/ProfileSummaryInfoTest.cpp

   1 //===- ProfileSummaryInfoTest.cpp - ProfileSummaryInfo unit tests ---------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/Analysis/BlockFrequencyInfo.h"
  11 #include "llvm/Analysis/BlockFrequencyInfoImpl.h"
  12 #include "llvm/Analysis/BranchProbabilityInfo.h"
  13 #include "llvm/Analysis/LoopInfo.h"
  14 #include "llvm/Analysis/ProfileSummaryInfo.h"
  15 #include "llvm/AsmParser/Parser.h"
  16 #include "llvm/IR/BasicBlock.h"
  17 #include "llvm/IR/CallSite.h"
  18 #include "llvm/IR/Dominators.h"
  19 #include "llvm/IR/Function.h"
  20 #include "llvm/IR/LLVMContext.h"
  21 #include "llvm/IR/MDBuilder.h"
  22 #include "llvm/IR/Module.h"
  23 #include "llvm/Support/DataTypes.h"
  24 #include "llvm/Support/FormatVariadic.h"
  25 #include "llvm/Support/SourceMgr.h"
  26 #include "llvm/Support/raw_ostream.h"
  27 #include "gtest/gtest.h"
  28
  29 namespace llvm {
  30 namespace {
  31
  32 class ProfileSummaryInfoTest : public testing::Test {
  33 protected:
  34   LLVMContext C;
  35   std::unique_ptr<BranchProbabilityInfo> BPI;
  36   std::unique_ptr<DominatorTree> DT;
  37   std::unique_ptr<LoopInfo> LI;
  38
  39   ProfileSummaryInfo buildPSI(Module *M) {
  40     return ProfileSummaryInfo(*M);
  41   }
  42   BlockFrequencyInfo buildBFI(Function &F) {
  43     DT.reset(new DominatorTree(F));
  44     LI.reset(new LoopInfo(*DT));
  45     BPI.reset(new BranchProbabilityInfo(F, *LI));
  46     return BlockFrequencyInfo(F, *BPI, *LI);
  47   }
  48   std::unique_ptr<Module> makeLLVMModule(const char *ProfKind = nullptr) {
  49     const char *ModuleString =
  50         "define i32 @g(i32 %x) !prof !21 {{\n"
  51         "  ret i32 0\n"
  52         "}\n"
  53         "define i32 @h(i32 %x) !prof !22 {{\n"
  54         "  ret i32 0\n"
  55         "}\n"
  56         "define i32 @f(i32 %x) !prof !20 {{\n"
  57         "bb0:\n"
  58         "  %y1 = icmp eq i32 %x, 0 \n"
  59         "  br i1 %y1, label %bb1, label %bb2, !prof !23 \n"
  60         "bb1:\n"
  61         "  %z1 = call i32 @g(i32 %x)\n"
  62         "  br label %bb3\n"
  63         "bb2:\n"
  64         "  %z2 = call i32 @h(i32 %x)\n"
  65         "  br label %bb3\n"
  66         "bb3:\n"
  67         "  %y2 = phi i32 [0, %bb1], [1, %bb2] \n"
  68         "  ret i32 %y2\n"
  69         "}\n"
  70         "!20 = !{{!\"function_entry_count\", i64 400}\n"
  71         "!21 = !{{!\"function_entry_count\", i64 1}\n"
  72         "!22 = !{{!\"function_entry_count\", i64 100}\n"
  73         "!23 = !{{!\"branch_weights\", i32 64, i32 4}\n"
  74         "{0}";
  75     const char *SummaryString = "!llvm.module.flags = !{{!1}"
  76                                 "!1 = !{{i32 1, !\"ProfileSummary\", !2}"
  77                                 "!2 = !{{!3, !4, !5, !6, !7, !8, !9, !10}"
  78                                 "!3 = !{{!\"ProfileFormat\", !\"{0}\"}"
  79                                 "!4 = !{{!\"TotalCount\", i64 10000}"
  80                                 "!5 = !{{!\"MaxCount\", i64 10}"
  81                                 "!6 = !{{!\"MaxInternalCount\", i64 1}"
  82                                 "!7 = !{{!\"MaxFunctionCount\", i64 1000}"
  83                                 "!8 = !{{!\"NumCounts\", i64 3}"
  84                                 "!9 = !{{!\"NumFunctions\", i64 3}"
  85                                 "!10 = !{{!\"DetailedSummary\", !11}"
  86                                 "!11 = !{{!12, !13, !14}"
  87                                 "!12 = !{{i32 10000, i64 1000, i32 1}"
  88                                 "!13 = !{{i32 999000, i64 300, i32 3}"
  89                                 "!14 = !{{i32 999999, i64 5, i32 10}";
  90     SMDiagnostic Err;
  91     if (ProfKind)
  92       return parseAssemblyString(
  93           formatv(ModuleString, formatv(SummaryString, ProfKind).str()).str(),
  94           Err, C);
  95     else
  96       return parseAssemblyString(formatv(ModuleString, "").str(), Err, C);
  97   }
  98 };
  99
 100 TEST_F(ProfileSummaryInfoTest, TestNoProfile) {
 101   auto M = makeLLVMModule(/*ProfKind=*/nullptr);
 102   Function *F = M->getFunction("f");
 103
 104   ProfileSummaryInfo PSI = buildPSI(M.get());
 105   // In the absence of profiles, is{Hot|Cold}X methods should always return
 106   // false.
 107   EXPECT_FALSE(PSI.isHotCount(1000));
 108   EXPECT_FALSE(PSI.isHotCount(0));
 109   EXPECT_FALSE(PSI.isColdCount(1000));
 110   EXPECT_FALSE(PSI.isColdCount(0));
 111
 112   EXPECT_FALSE(PSI.isFunctionEntryHot(F));
 113   EXPECT_FALSE(PSI.isFunctionEntryCold(F));
 114
 115   BasicBlock &BB0 = F->getEntryBlock();
 116   BasicBlock *BB1 = BB0.getTerminator()->getSuccessor(0);
 117
 118   BlockFrequencyInfo BFI = buildBFI(*F);
 119   EXPECT_FALSE(PSI.isHotBB(&BB0, &BFI));
 120   EXPECT_FALSE(PSI.isColdBB(&BB0, &BFI));
 121
 122   CallSite CS1(BB1->getFirstNonPHI());
 123   EXPECT_FALSE(PSI.isHotCallSite(CS1, &BFI));
 124   EXPECT_FALSE(PSI.isColdCallSite(CS1, &BFI));
 125 }
 126 TEST_F(ProfileSummaryInfoTest, TestCommon) {
 127   auto M = makeLLVMModule("InstrProf");
 128   Function *F = M->getFunction("f");
 129   Function *G = M->getFunction("g");
 130   Function *H = M->getFunction("h");
 131
 132   ProfileSummaryInfo PSI = buildPSI(M.get());
 133   EXPECT_TRUE(PSI.isHotCount(400));
 134   EXPECT_TRUE(PSI.isColdCount(2));
 135   EXPECT_FALSE(PSI.isColdCount(100));
 136   EXPECT_FALSE(PSI.isHotCount(100));
 137
 138   EXPECT_TRUE(PSI.isFunctionEntryHot(F));
 139   EXPECT_FALSE(PSI.isFunctionEntryHot(G));
 140   EXPECT_FALSE(PSI.isFunctionEntryHot(H));
 141 }
 142
 143 TEST_F(ProfileSummaryInfoTest, InstrProf) {
 144   auto M = makeLLVMModule("InstrProf");
 145   Function *F = M->getFunction("f");
 146   ProfileSummaryInfo PSI = buildPSI(M.get());
 147
 148   BasicBlock &BB0 = F->getEntryBlock();
 149   BasicBlock *BB1 = BB0.getTerminator()->getSuccessor(0);
 150   BasicBlock *BB2 = BB0.getTerminator()->getSuccessor(1);
 151   BasicBlock *BB3 = BB1->getSingleSuccessor();
 152
 153   BlockFrequencyInfo BFI = buildBFI(*F);
 154   EXPECT_TRUE(PSI.isHotBB(&BB0, &BFI));
 155   EXPECT_TRUE(PSI.isHotBB(BB1, &BFI));
 156   EXPECT_FALSE(PSI.isHotBB(BB2, &BFI));
 157   EXPECT_TRUE(PSI.isHotBB(BB3, &BFI));
 158
 159   CallSite CS1(BB1->getFirstNonPHI());
 160   auto *CI2 = BB2->getFirstNonPHI();
 161   CallSite CS2(CI2);
 162
 163   EXPECT_TRUE(PSI.isHotCallSite(CS1, &BFI));
 164   EXPECT_FALSE(PSI.isHotCallSite(CS2, &BFI));
 165 }
 166
 167 TEST_F(ProfileSummaryInfoTest, SampleProf) {
 168   auto M = makeLLVMModule("SampleProfile");
 169   Function *F = M->getFunction("f");
 170   ProfileSummaryInfo PSI = buildPSI(M.get());
 171
 172   BasicBlock &BB0 = F->getEntryBlock();
 173   BasicBlock *BB1 = BB0.getTerminator()->getSuccessor(0);
 174   BasicBlock *BB2 = BB0.getTerminator()->getSuccessor(1);
 175   BasicBlock *BB3 = BB1->getSingleSuccessor();
 176
 177   BlockFrequencyInfo BFI = buildBFI(*F);
 178   EXPECT_TRUE(PSI.isHotBB(&BB0, &BFI));
 179   EXPECT_TRUE(PSI.isHotBB(BB1, &BFI));
 180   EXPECT_FALSE(PSI.isHotBB(BB2, &BFI));
 181   EXPECT_TRUE(PSI.isHotBB(BB3, &BFI));
 182
 183   CallSite CS1(BB1->getFirstNonPHI());
 184   auto *CI2 = BB2->getFirstNonPHI();
 185   CallSite CS2(CI2);
 186
 187   EXPECT_TRUE(PSI.isHotCallSite(CS1, &BFI));
 188   EXPECT_FALSE(PSI.isHotCallSite(CS2, &BFI));
 189
 190   // Test that CS2 is considered hot when it gets an MD_prof metadata with
 191   // weights that exceed the hot count threshold.
 192   MDBuilder MDB(M->getContext());
 193   CI2->setMetadata(llvm::LLVMContext::MD_prof, MDB.createBranchWeights({400}));
 194   EXPECT_TRUE(PSI.isHotCallSite(CS2, &BFI));
 195 }
 196
 197 } // end anonymous namespace
 198 } // end namespace llvm