[llvm-commits] [llvm] r94990 - in /llvm/trunk/lib/CodeGen/SelectionDAG: DAGCombiner.cpp SelectionDAG.cpp

[Mon P Wang]

Author: wangmp
Date: Mon Feb  1 13:03:18 2010
New Revision: 94990

URL: http://llvm.org/viewvc/llvm-project?rev=94990&view=rev
Log:
Fixed a couple of optimization with EXTRACT_VECTOR_ELT that assumes the result
type is the same as the element type of the vector.  EXTRACT_VECTOR_ELT can
be used to extended the width of an integer type.  This fixes a bug for
Generic/vector-casts.ll on a ppc750.

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

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=94990&r1=94989&r2=94990&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Mon Feb  1 13:03:18 2010
@@ -5403,12 +5403,19 @@
   SDValue InVec = N->getOperand(0);
 
  if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR) {
-   // If the operand is wider than the vector element type then it is implicitly
-   // truncated.  Make that explicit here.
+   // Check if the result type doesn't match the inserted element type. A
+   // SCALAR_TO_VECTOR may truncate the inserted element and the
+   // EXTRACT_VECTOR_ELT may widen the extracted vector.
    EVT EltVT = InVec.getValueType().getVectorElementType();
    SDValue InOp = InVec.getOperand(0);
-   if (InOp.getValueType() != EltVT)
-     return DAG.getNode(ISD::TRUNCATE, InVec.getDebugLoc(), EltVT, InOp);
+   EVT NVT = N->getValueType(0);
+   if (InOp.getValueType() != NVT) {
+     assert(InOp.getValueType().isInteger() && NVT.isInteger());
+     if (NVT.getSizeInBits() > InOp.getValueType().getSizeInBits())
+       return DAG.getNode(ISD::SIGN_EXTEND, InVec.getDebugLoc(), NVT, InOp);
+     else
+       return DAG.getNode(ISD::TRUNCATE, InVec.getDebugLoc(), NVT, InOp);
+   }
    return InOp;
  }
 

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=94990&r1=94989&r2=94990&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Mon Feb  1 13:03:18 2010
@@ -2765,7 +2765,7 @@
     // operations are lowered to scalars.
     if (N1.getOpcode() == ISD::INSERT_VECTOR_ELT) {
       // If the indices are the same, return the inserted element.
-      if (N1.getOperand(2) == N2)
+      if (N1.getOperand(2) == N2 && VT == N1.getOperand(1).getValueType())
         return N1.getOperand(1);
       // If the indices are known different, extract the element from
       // the original vector.