Handle Unary ! in EmitBranchOnBoolExpr, so that we can efficiently
codegen stuff like "if (!(X && Y))"


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59115 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index a797d75..0756de7 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -263,7 +263,12 @@
       EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
       return;
     }
-    
+  }
+  
+  if (const UnaryOperator *CondUOp = dyn_cast<UnaryOperator>(Cond)) {
+    // br(!x, t, f) -> br(x, f, t)
+    if (CondUOp->getOpcode() == UnaryOperator::LNot)
+      return EmitBranchOnBoolExpr(CondUOp->getSubExpr(), FalseBlock, TrueBlock);
   }
   
   // Emit the code with the fully general case.