LLVM  10.0.0svn
LazyBranchProbabilityInfo.cpp
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1 //===- LazyBranchProbabilityInfo.cpp - Lazy Branch Probability Analysis ---===//
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 // This is an alternative analysis pass to BranchProbabilityInfoWrapperPass.
10 // The difference is that with this pass the branch probabilities are not
11 // computed when the analysis pass is executed but rather when the BPI results
12 // is explicitly requested by the analysis client.
13 //
14 //===----------------------------------------------------------------------===//
15 
17 #include "llvm/Analysis/LoopInfo.h"
19 #include "llvm/IR/Dominators.h"
20 
21 using namespace llvm;
22 
23 #define DEBUG_TYPE "lazy-branch-prob"
24 
26  "Lazy Branch Probability Analysis", true, true)
30  "Lazy Branch Probability Analysis", true, true)
31 
32 char LazyBranchProbabilityInfoPass::ID = 0;
33 
34 LazyBranchProbabilityInfoPass::LazyBranchProbabilityInfoPass()
35  : FunctionPass(ID) {
37 }
38 
40  const Module *) const {
41  LBPI->getCalculated().print(OS);
42 }
43 
45  // We require DT so it's available when LI is available. The LI updating code
46  // asserts that DT is also present so if we don't make sure that we have DT
47  // here, that assert will trigger.
51  AU.setPreservesAll();
52 }
53 
55 
57  LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
58  TargetLibraryInfo &TLI =
59  getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F);
60  LBPI = std::make_unique<LazyBranchProbabilityInfo>(&F, &LI, &TLI);
61  return false;
62 }
63 
68 }
69 
74 }
static PassRegistry * getPassRegistry()
getPassRegistry - Access the global registry object, which is automatically initialized at applicatio...
This class represents lattice values for constants.
Definition: AllocatorList.h:23
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:66
A global registry used in conjunction with static constructors to make pluggable components (like tar...
Definition: Registry.h:44
void releaseMemory() override
releaseMemory() - This member can be implemented by a pass if it wants to be able to release its memo...
static void getLazyBPIAnalysisUsage(AnalysisUsage &AU)
Helper for client passes to set up the analysis usage on behalf of this pass.
F(f)
AnalysisUsage & addRequired()
#define INITIALIZE_PASS_DEPENDENCY(depName)
Definition: PassSupport.h:50
This is an alternative analysis pass to BranchProbabilityInfoWrapperPass.
void getAnalysisUsage(AnalysisUsage &AU) const override
getAnalysisUsage - This function should be overriden by passes that need analysis information to do t...
#define DEBUG_TYPE
void initializeLazyBPIPassPass(PassRegistry &Registry)
Helper for client passes to initialize dependent passes for LBPI.
void initializeLazyBranchProbabilityInfoPassPass(PassRegistry &)
bool runOnFunction(Function &F) override
runOnFunction - Virtual method overriden by subclasses to do the per-function processing of the pass...
Represent the analysis usage information of a pass.
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:284
INITIALIZE_PASS_BEGIN(LazyBranchProbabilityInfoPass, DEBUG_TYPE, "Lazy Branch Probability Analysis", true, true) INITIALIZE_PASS_END(LazyBranchProbabilityInfoPass
INITIALIZE_PASS_END(RegBankSelect, DEBUG_TYPE, "Assign register bank of generic virtual registers", false, false) RegBankSelect
Provides information about what library functions are available for the current target.
void print(raw_ostream &OS, const Module *M) const override
print - Print out the internal state of the pass.
void setPreservesAll()
Set by analyses that do not transform their input at all.
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:45
The legacy pass manager&#39;s analysis pass to compute loop information.
Definition: LoopInfo.h:1208
PassRegistry - This class manages the registration and intitialization of the pass subsystem as appli...
Definition: PassRegistry.h:38
Legacy analysis pass which computes a DominatorTree.
Definition: Dominators.h:259
Lazy Branch Probability true