[llvm] r324323 - [MergeICmps][NFC] Add more assertions.

[Clement Courbet via llvm-commits]

Author: courbet
Date: Tue Feb  6 01:14:00 2018
New Revision: 324323

URL: http://llvm.org/viewvc/llvm-project?rev=324323&view=rev
Log:
[MergeICmps][NFC] Add more assertions.

Modified:
    llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp?rev=324323&r1=324322&r2=324323&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp Tue Feb  6 01:14:00 2018
@@ -275,9 +275,11 @@ class BCECmpChain {
 
 BCECmpChain::BCECmpChain(const std::vector<BasicBlock *> &Blocks, PHINode &Phi)
     : Phi_(Phi) {
+  assert(!Blocks.empty() && "a chain should have at least one block");
   // Now look inside blocks to check for BCE comparisons.
   std::vector<BCECmpBlock> Comparisons;
   for (BasicBlock *Block : Blocks) {
+    assert(Block && "invalid block");
     BCECmpBlock Comparison = visitCmpBlock(Phi.getIncomingValueForBlock(Block),
                                            Block, Phi.getParent());
     Comparison.BB = Block;
@@ -328,6 +330,7 @@ BCECmpChain::BCECmpChain(const std::vect
     DEBUG(dbgs() << "\n");
     Comparisons.push_back(Comparison);
   }
+  assert(!Comparisons.empty() && "chain with a single complex basic block");
   EntryBlock_ = Comparisons[0].BB;
   Comparisons_ = std::move(Comparisons);
 #ifdef MERGEICMPS_DOT_ON
@@ -507,6 +510,7 @@ std::vector<BasicBlock *> getOrderedBloc
                                            int NumBlocks) {
   // Walk up from the last block to find other blocks.
   std::vector<BasicBlock *> Blocks(NumBlocks);
+  assert(LastBlock && "invalid last block");
   BasicBlock *CurBlock = LastBlock;
   for (int BlockIndex = NumBlocks - 1; BlockIndex > 0; --BlockIndex) {
     if (CurBlock->hasAddressTaken()) {