1 files changed, 63 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Analysis/LazyBranchProbabilityInfo.cpp b/contrib/llvm/lib/Analysis/LazyBranchProbabilityInfo.cpp
new file mode 100644
index 000000000000..b51c6beb7959
--- /dev/null
+++ b/contrib/llvm/lib/Analysis/LazyBranchProbabilityInfo.cpp
@@ -0,0 +1,63 @@
+//===- LazyBranchProbabilityInfo.cpp - Lazy Branch Probability Analysis ---===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This is an alternative analysis pass to BranchProbabilityInfoWrapperPass.
+// The difference is that with this pass the branch probabilities are not
+// computed when the analysis pass is executed but rather when the BPI results
+// is explicitly requested by the analysis client.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/LazyBranchProbabilityInfo.h"
+#include "llvm/Analysis/LoopInfo.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "lazy-branch-prob"
+
+INITIALIZE_PASS_BEGIN(LazyBranchProbabilityInfoPass, DEBUG_TYPE,
+                      "Lazy Branch Probability Analysis", true, true)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
+INITIALIZE_PASS_END(LazyBranchProbabilityInfoPass, DEBUG_TYPE,
+                    "Lazy Branch Probability Analysis", true, true)
+
+char LazyBranchProbabilityInfoPass::ID = 0;
+
+LazyBranchProbabilityInfoPass::LazyBranchProbabilityInfoPass()
+    : FunctionPass(ID) {
+  initializeLazyBranchProbabilityInfoPassPass(*PassRegistry::getPassRegistry());
+}
+
+void LazyBranchProbabilityInfoPass::print(raw_ostream &OS,
+                                          const Module *) const {
+  LBPI->getCalculated().print(OS);
+}
+
+void LazyBranchProbabilityInfoPass::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.addRequired<LoopInfoWrapperPass>();
+  AU.setPreservesAll();
+}
+
+void LazyBranchProbabilityInfoPass::releaseMemory() { LBPI.reset(); }
+
+bool LazyBranchProbabilityInfoPass::runOnFunction(Function &F) {
+  LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+  LBPI = llvm::make_unique<LazyBranchProbabilityInfo>(&F, &LI);
+  return false;
+}
+
+void LazyBranchProbabilityInfoPass::getLazyBPIAnalysisUsage(AnalysisUsage &AU) {
+  AU.addRequired<LazyBranchProbabilityInfoPass>();
+  AU.addRequired<LoopInfoWrapperPass>();
+}
+
+void llvm::initializeLazyBPIPassPass(PassRegistry &Registry) {
+  INITIALIZE_PASS_DEPENDENCY(LazyBranchProbabilityInfoPass);
+  INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass);
+}