From: Xin Tong <trent.xin.tong@gmail.com>
Date: Sat, 17 Jun 2017 16:55:12 +0000 (+0000)
Subject: [TRE] Add assertion for folding trivial return block
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9bca842196de4664bdc2b2e94ba512b0668b4ff7;p=llvm

[TRE] Add assertion for folding trivial return block

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305637 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/TailRecursionElimination.cpp b/lib/Transforms/Scalar/TailRecursionElimination.cpp
index 93c4b57514c..365566c07f4 100644
--- a/lib/Transforms/Scalar/TailRecursionElimination.cpp
+++ b/lib/Transforms/Scalar/TailRecursionElimination.cpp
@@ -677,6 +677,10 @@ static bool foldReturnAndProcessPred(BasicBlock *BB, ReturnInst *Ret,
                                      const TargetTransformInfo *TTI) {
   bool Change = false;
 
+  // Make sure this block is a trivial return block.
+  assert(BB->getFirstNonPHIOrDbg() == Ret &&
+         "Trying to fold non-trivial return block");
+
   // If the return block contains nothing but the return and PHI's,
   // there might be an opportunity to duplicate the return in its
   // predecessors and perform TRE there. Look for predecessors that end