AMDGPU: change a redundant if () to an assert(). NFC

Summary:
I've been carrying this change around with me for a while, because the if ()
managed to confuse me while following the code. All callers ensure that the
assertion holds.

Reviewers: arsenm, tstellarAMD

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D19042

llvm-svn: 266344

diff --git a/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp b/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
index 563beba..3009564 100644 (file)
--- a/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
+++ b/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
@@ -341,8 +341,7 @@ void SIAnnotateControlFlow::handleLoop(BranchInst *Term) {
 void SIAnnotateControlFlow::closeControlFlow(BasicBlock *BB) {
   llvm::Loop *L = LI->getLoopFor(BB);
 
-  if (Stack.back().first != BB)
-    return;
+  assert(Stack.back().first == BB);
 
   if (L && L->getHeader() == BB) {
     // We can't insert an EndCF call into a loop header, because it will