[ORE] Move loop invariant ORE checks outside the PM loop.

Summary:
This takes 22ms out of ~20s compiling sqlite3.c because we call it
for every unit of compilation and every pass.

Reviewers: paquette, anemet

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D49586

llvm-svn: 337654

1 files changed, 6 insertions, 2 deletions

diff --git a/llvm/lib/Analysis/LoopPass.cpp b/llvm/lib/Analysis/LoopPass.cpp
index c5ced03cfa8..07a151ce0fc 100644
--- a/llvm/lib/Analysis/LoopPass.cpp
+++ b/llvm/lib/Analysis/LoopPass.cpp
@@ -193,6 +193,8 @@ bool LPPassManager::runOnFunction(Function &F) {
   }
 
   // Walk Loops
+  unsigned InstrCount = 0;
+  bool EmitICRemark = M.shouldEmitInstrCountChangedRemark();
   while (!LQ.empty()) {
     CurrentLoopDeleted = false;
     CurrentLoop = LQ.back();
@@ -210,9 +212,11 @@ bool LPPassManager::runOnFunction(Function &F) {
       {
         PassManagerPrettyStackEntry X(P, *CurrentLoop->getHeader());
         TimeRegion PassTimer(getPassTimer(P));
-        unsigned InstrCount = initSizeRemarkInfo(M);
+        if (EmitICRemark)
+          InstrCount = initSizeRemarkInfo(M);
         Changed |= P->runOnLoop(CurrentLoop, *this);
-        emitInstrCountChangedRemark(P, M, InstrCount);
+        if (EmitICRemark)
+          emitInstrCountChangedRemark(P, M, InstrCount);
       }
 
       if (Changed)