[llvm] r272182 - [SCEV] Break out of loop if there is no more work to do

[Sanjoy Das via llvm-commits]

Author: sanjoy
Date: Wed Jun  8 12:48:46 2016
New Revision: 272182

URL: http://llvm.org/viewvc/llvm-project?rev=272182&view=rev
Log:
[SCEV] Break out of loop if there is no more work to do

This is NFC as far as externally visible behavior is concerned, but will
keep us from spinning in the worklist traversal algorithm unnecessarily.

Modified:
    llvm/trunk/lib/Analysis/ScalarEvolution.cpp

Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=272182&r1=272181&r2=272182&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Wed Jun  8 12:48:46 2016
@@ -4889,7 +4889,7 @@ bool ScalarEvolution::isAddRecNeverPoiso
   PoisonStack.push_back(I);
 
   bool LatchControlDependentOnPoison = false;
-  while (!PoisonStack.empty()) {
+  while (!PoisonStack.empty() && !LatchControlDependentOnPoison) {
     const Instruction *Poison = PoisonStack.pop_back_val();
 
     for (auto *PoisonUser : Poison->users()) {