Create a wrapper pass for BlockFrequencyInfo.

This is useful when we want to do block frequency analysis
conditionally (e.g. only in PGO mode) but don't want to add
one more pass dependence.

Patch by congh.
Approved by dexonsmith.
Differential Revision: http://reviews.llvm.org/D11196

llvm-svn: 242248

1 files changed, 48 insertions, 32 deletions

diff --git a/llvm/lib/Analysis/BlockFrequencyInfo.cpp b/llvm/lib/Analysis/BlockFrequencyInfo.cpp
index 3d819eb596d..7be33658518 100644
--- a/llvm/lib/Analysis/BlockFrequencyInfo.cpp
+++ b/llvm/lib/Analysis/BlockFrequencyInfo.cpp
@@ -105,31 +105,9 @@ struct DOTGraphTraits<BlockFrequencyInfo*> : public DefaultDOTGraphTraits {
 } // end namespace llvm
 #endif
 
-INITIALIZE_PASS_BEGIN(BlockFrequencyInfo, "block-freq",
-                      "Block Frequency Analysis", true, true)
-INITIALIZE_PASS_DEPENDENCY(BranchProbabilityInfo)
-INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
-INITIALIZE_PASS_END(BlockFrequencyInfo, "block-freq",
-                    "Block Frequency Analysis", true, true)
-
-char BlockFrequencyInfo::ID = 0;
-
-
-BlockFrequencyInfo::BlockFrequencyInfo() : FunctionPass(ID) {
-  initializeBlockFrequencyInfoPass(*PassRegistry::getPassRegistry());
-}
-
-BlockFrequencyInfo::~BlockFrequencyInfo() {}
-
-void BlockFrequencyInfo::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.addRequired<BranchProbabilityInfo>();
-  AU.addRequired<LoopInfoWrapperPass>();
-  AU.setPreservesAll();
-}
-
-bool BlockFrequencyInfo::runOnFunction(Function &F) {
-  BranchProbabilityInfo &BPI = getAnalysis<BranchProbabilityInfo>();
-  LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+void BlockFrequencyInfo::calculate(const Function &F,
+                                   const BranchProbabilityInfo &BPI,
+                                   const LoopInfo &LI) {
   if (!BFI)
     BFI.reset(new ImplType);
   BFI->doFunction(&F, &BPI, &LI);
@@ -137,13 +115,6 @@ bool BlockFrequencyInfo::runOnFunction(Function &F) {
   if (ViewBlockFreqPropagationDAG != GVDT_None)
     view();
 #endif
-  return false;
-}
-
-void BlockFrequencyInfo::releaseMemory() { BFI.reset(); }
-
-void BlockFrequencyInfo::print(raw_ostream &O, const Module *) const {
-  if (BFI) BFI->print(O);
 }
 
 BlockFrequency BlockFrequencyInfo::getBlockFreq(const BasicBlock *BB) const {
@@ -180,3 +151,48 @@ BlockFrequencyInfo::printBlockFreq(raw_ostream &OS,
 uint64_t BlockFrequencyInfo::getEntryFreq() const {
   return BFI ? BFI->getEntryFreq() : 0;
 }
+
+void BlockFrequencyInfo::releaseMemory() { BFI.reset(); }
+
+void BlockFrequencyInfo::print(raw_ostream &OS) const {
+  if (BFI)
+    BFI->print(OS);
+}
+
+
+INITIALIZE_PASS_BEGIN(BlockFrequencyInfoWrapperPass, "block-freq",
+                      "Block Frequency Analysis", true, true)
+INITIALIZE_PASS_DEPENDENCY(BranchProbabilityInfo)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
+INITIALIZE_PASS_END(BlockFrequencyInfoWrapperPass, "block-freq",
+                    "Block Frequency Analysis", true, true)
+
+char BlockFrequencyInfoWrapperPass::ID = 0;
+
+
+BlockFrequencyInfoWrapperPass::BlockFrequencyInfoWrapperPass()
+    : FunctionPass(ID) {
+  initializeBlockFrequencyInfoWrapperPassPass(*PassRegistry::getPassRegistry());
+}
+
+BlockFrequencyInfoWrapperPass::~BlockFrequencyInfoWrapperPass() {}
+
+void BlockFrequencyInfoWrapperPass::print(raw_ostream &OS,
+                                          const Module *) const {
+  BFI.print(OS);
+}
+
+void BlockFrequencyInfoWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.addRequired<BranchProbabilityInfo>();
+  AU.addRequired<LoopInfoWrapperPass>();
+  AU.setPreservesAll();
+}
+
+void BlockFrequencyInfoWrapperPass::releaseMemory() { BFI.releaseMemory(); }
+
+bool BlockFrequencyInfoWrapperPass::runOnFunction(Function &F) {
+  BranchProbabilityInfo &BPI = getAnalysis<BranchProbabilityInfo>();
+  LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+  BFI.calculate(F, BPI, LI);
+  return false;
+}