Make sure to check for a very bad class of errors: an instruction

that does not dominate all of its users, but is in the same basic block as
its users.  This class of error is what caused the mysterious CBE only
failures last night.

llvm-svn: 12979

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/VMCore/Verifier.cpp b/llvm/lib/VMCore/Verifier.cpp
index ffe2c5a5486..edd3da1a007 100644
--- a/llvm/lib/VMCore/Verifier.cpp
+++ b/llvm/lib/VMCore/Verifier.cpp
@@ -559,6 +559,12 @@ void Verifier::visitInstruction(Instruction &I) {
         // exceptional destination.
         if (InvokeInst *II = dyn_cast<InvokeInst>(Op))
           OpBlock = II->getNormalDest();
+        else if (OpBlock == BB) {
+          // If they are in the same basic block, make sure that the definition
+          // comes before the use.
+          Assert2(DS->dominates(Op, &I),
+                  "Instruction does not dominate all uses!", Op, &I);
+        }
 
         // Definition must dominate use unless use is unreachable!
         Assert2(DS->dominates(OpBlock, BB) ||