[llvm-commits] [llvm] r74969 - /llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

[Chris Lattner]

Author: lattner
Date: Tue Jul  7 18:28:46 2009
New Revision: 74969

URL: http://llvm.org/viewvc/llvm-project?rev=74969&view=rev
Log:
SelectionDAG::SignBitIsZero doesn't work right for vectors,
for now, conservatively return false.


Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=74969&r1=74968&r2=74969&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Tue Jul  7 18:28:46 2009
@@ -1516,6 +1516,10 @@
 /// SignBitIsZero - Return true if the sign bit of Op is known to be zero.  We
 /// use this predicate to simplify operations downstream.
 bool SelectionDAG::SignBitIsZero(SDValue Op, unsigned Depth) const {
+  // This predicate is not safe for vector operations.
+  if (Op.getValueType().isVector())
+    return false;
+  
   unsigned BitWidth = Op.getValueSizeInBits();
   return MaskedValueIsZero(Op, APInt::getSignBit(BitWidth), Depth);
 }