LLVM  10.0.0svn
LazyBlockFrequencyInfo.cpp
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1 //===- LazyBlockFrequencyInfo.cpp - Lazy Block Frequency 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 BlockFrequencyInfoWrapperPass. The
10 // difference is that with this pass the block frequencies are not computed when
11 // the analysis pass is executed but rather when the BFI result is explicitly
12 // requested by the analysis client.
13 //
14 //===----------------------------------------------------------------------===//
15 
18 #include "llvm/Analysis/LoopInfo.h"
19 #include "llvm/IR/Dominators.h"
20 
21 using namespace llvm;
22 
23 #define DEBUG_TYPE "lazy-block-freq"
24 
26  "Lazy Block Frequency Analysis", true, true)
27 INITIALIZE_PASS_DEPENDENCY(LazyBPIPass)
30  "Lazy Block Frequency Analysis", true, true)
31 
32 char LazyBlockFrequencyInfoPass::ID = 0;
33 
34 LazyBlockFrequencyInfoPass::LazyBlockFrequencyInfoPass() : FunctionPass(ID) {
36 }
37 
39  LBFI.getCalculated().print(OS);
40 }
41 
44  // We require DT so it's available when LI is available. The LI updating code
45  // asserts that DT is also present so if we don't make sure that we have DT
46  // here, that assert will trigger.
49  AU.setPreservesAll();
50 }
51 
52 void LazyBlockFrequencyInfoPass::releaseMemory() { LBFI.releaseMemory(); }
53 
55  auto &BPIPass = getAnalysis<LazyBranchProbabilityInfoPass>();
56  LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
57  LBFI.setAnalysis(&F, &BPIPass, &LI);
58  return false;
59 }
60 
65 }
66 
68  initializeLazyBPIPassPass(Registry);
71 }
static PassRegistry * getPassRegistry()
getPassRegistry - Access the global registry object, which is automatically initialized at applicatio...
This is an alternative analysis pass to BlockFrequencyInfoWrapperPass.
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:65
A global registry used in conjunction with static constructors to make pluggable components (like tar...
Definition: Registry.h:44
Lazy Block Frequency true
void initializeLazyBFIPassPass(PassRegistry &Registry)
Helper for client passes to initialize dependent passes for LBFI.
INITIALIZE_PASS_BEGIN(LazyBlockFrequencyInfoPass, DEBUG_TYPE, "Lazy Block Frequency Analysis", true, true) INITIALIZE_PASS_END(LazyBlockFrequencyInfoPass
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
void initializeLazyBPIPassPass(PassRegistry &Registry)
Helper for client passes to initialize dependent passes for LBPI.
void initializeLazyBlockFrequencyInfoPassPass(PassRegistry &)
#define DEBUG_TYPE
Represent the analysis usage information of a pass.
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:284
void releaseMemory() override
releaseMemory() - This member can be implemented by a pass if it wants to be able to release its memo...
bool runOnFunction(Function &F) override
runOnFunction - Virtual method overriden by subclasses to do the per-function processing of the pass...
INITIALIZE_PASS_END(RegBankSelect, DEBUG_TYPE, "Assign register bank of generic virtual registers", false, false) RegBankSelect
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.
static void getLazyBFIAnalysisUsage(AnalysisUsage &AU)
Helper for client passes to set up the analysis usage on behalf of this pass.
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:1177
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
void getAnalysisUsage(AnalysisUsage &AU) const override
getAnalysisUsage - This function should be overriden by passes that need analysis information to do t...