[BPI] Apply invoke heuristic before loop branch heuristic

Currently the loop branch heuristic is applied before the invoke heuristic which makes us overestimate the probability of the unwind destination of invokes inside loops. This in turn makes us grossly underestimate the frequencies of loops with invokes.

Reviewed By: skatkov, vsk

Differential Revision: https://reviews.llvm.org/D47371

llvm-svn: 334285

1 files changed, 8 insertions, 11 deletions

diff --git a/llvm/lib/Analysis/BranchProbabilityInfo.cpp b/llvm/lib/Analysis/BranchProbabilityInfo.cpp
index ed4dc9031ab..1a4fc0465bb 100644
--- a/llvm/lib/Analysis/BranchProbabilityInfo.cpp
+++ b/llvm/lib/Analysis/BranchProbabilityInfo.cpp
@@ -203,12 +203,10 @@ BranchProbabilityInfo::updatePostDominatedByColdCall(const BasicBlock *BB) {
 /// unreachable-terminated block as extremely unlikely.
 bool BranchProbabilityInfo::calcUnreachableHeuristics(const BasicBlock *BB) {
   const TerminatorInst *TI = BB->getTerminator();
+  (void) TI;
   assert(TI->getNumSuccessors() > 1 && "expected more than one successor!");
-
-  // Return false here so that edge weights for InvokeInst could be decided
-  // in calcInvokeHeuristics().
-  if (isa<InvokeInst>(TI))
-    return false;
+  assert(!isa<InvokeInst>(TI) &&
+         "Invokes should have already been handled by calcInvokeHeuristics");
 
   SmallVector<unsigned, 4> UnreachableEdges;
   SmallVector<unsigned, 4> ReachableEdges;
@@ -351,12 +349,10 @@ bool BranchProbabilityInfo::calcMetadataWeights(const BasicBlock *BB) {
 /// Return false, otherwise.
 bool BranchProbabilityInfo::calcColdCallHeuristics(const BasicBlock *BB) {
   const TerminatorInst *TI = BB->getTerminator();
+  (void) TI;
   assert(TI->getNumSuccessors() > 1 && "expected more than one successor!");
-
-  // Return false here so that edge weights for InvokeInst could be decided
-  // in calcInvokeHeuristics().
-  if (isa<InvokeInst>(TI))
-    return false;
+  assert(!isa<InvokeInst>(TI) &&
+         "Invokes should have already been handled by calcInvokeHeuristics");
 
   // Determine which successors are post-dominated by a cold block.
   SmallVector<unsigned, 4> ColdEdges;
@@ -975,6 +971,8 @@ void BranchProbabilityInfo::calculate(const Function &F, const LoopInfo &LI,
       continue;
     if (calcMetadataWeights(BB))
       continue;
+    if (calcInvokeHeuristics(BB))
+      continue;
     if (calcUnreachableHeuristics(BB))
       continue;
     if (calcColdCallHeuristics(BB))
@@ -987,7 +985,6 @@ void BranchProbabilityInfo::calculate(const Function &F, const LoopInfo &LI,
       continue;
     if (calcFloatingPointHeuristics(BB))
       continue;
-    calcInvokeHeuristics(BB);
   }
 
   PostDominatedByUnreachable.clear();