1 files changed, 7 insertions, 1 deletions
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 9d9fe7d376d..0cd24633499 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -3397,8 +3397,14 @@ void Verifier::verifyDominatesUse(Instruction &I, unsigned i) {
       return;
   }
 
+  // Quick check whether the def has already been encountered in the same block.
+  // PHI nodes are not checked to prevent accepting preceeding PHIs, because PHI
+  // uses are defined to happen on the incoming edge, not at the instruction.
+  if (!isa<PHINode>(I) && InstsInThisBlock.count(Op))
+    return;
+
   const Use &U = I.getOperandUse(i);
-  Assert(InstsInThisBlock.count(Op) || DT.dominates(Op, U),
+  Assert(DT.dominates(Op, U),
          "Instruction does not dominate all uses!", Op, &I);
 }