Eliminate the first have of the optimization which eliminates BRCOND

when the condition is constant. This optimization shouldn't be
necessary, because codegen shouldn't be able to find dead control
paths that the IR-level optimizer can't find. And it's undesirable,
because it encourages bugpoint to leave "br i1 false" branches
in its output. And it wasn't updating the CFG.

I updated all the tests I could, but some tests are too reduced
and I wasn't able to meaningfully preserve them.

llvm-svn: 106748

1 files changed, 1 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 4cbfaed87fc..5719cefb42e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3047,9 +3047,7 @@ SDValue SelectionDAG::getNode(unsigned Opcode, DebugLoc DL, EVT VT,
     break;
   case ISD::BRCOND:
     if (N2C) {
-      if (N2C->getZExtValue()) // Unconditional branch
-        return getNode(ISD::BR, DL, MVT::Other, N1, N3);
-      else
+      if (!N2C->getZExtValue()) // Unconditional branch
         return N1;         // Never-taken branch
     }
     break;