Fold conditional branches on constants away.

llvm-svn: 19360

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 6ab1d459575..e917350f8c9 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -727,6 +727,12 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
     }
 
     break;
+  case ISD::BRCOND:
+    if (N2C)
+      if (N2C->getValue()) // Unconditional branch
+        return getNode(ISD::BR, MVT::Other, N1, N3);
+      else
+        return N1;         // Never-taken branch
   }
 
   SDNode *N = new SDNode(Opcode, N1, N2, N3);