[llvm-commits] [llvm] r58820 - in /llvm/trunk/lib: CodeGen/SelectionDAG/LegalizeDAG.cpp Transforms/Scalar/InstructionCombining.cpp

[Mon P Wang]

Author: wangmp
Date: Thu Nov  6 16:52:21 2008
New Revision: 58820

URL: http://llvm.org/viewvc/llvm-project?rev=58820&view=rev
Log:
Fixed scalarizing an extract subvector and prevent an infinite loop
when simplify a vector. 

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
    llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp?rev=58820&r1=58819&r2=58820&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp Thu Nov  6 16:52:21 2008
@@ -7516,8 +7516,8 @@
     break;
   }
   case ISD::EXTRACT_SUBVECTOR:
-    Result = Node->getOperand(0);
-    assert(Result.getValueType() == NewVT);
+    Result = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, NewVT, Node->getOperand(0),
+                          Node->getOperand(1));
     break;
   case ISD::BIT_CONVERT: {
     SDValue Op0 = Op.getOperand(0);
@@ -8174,7 +8174,7 @@
 
   SDValue VecOp = DAG.getNode(ISD::BIT_CONVERT, VecEVT, ValOp);
   SDValue EOp = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, EVT, VecOp,
-                                  DAG.getIntPtrConstant(0));
+                            DAG.getIntPtrConstant(0));
   SDValue StOp = DAG.getStore(Chain, EOp, BasePtr, SV, SVOffset,
                                isVolatile, Alignment);
   StChain.push_back(StOp);

Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=58820&r1=58819&r2=58820&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Thu Nov  6 16:52:21 2008
@@ -1410,6 +1410,12 @@
   } else if (isa<ConstantAggregateZero>(V)) {
     // Simplify the CAZ to a ConstantVector where the non-demanded elements are
     // set to undef.
+    
+    // Check if this is identity. If so, return 0 since we are not simplifying
+    // anything.
+    if (DemandedElts == ((1ULL << VWidth) -1))
+      return 0;
+    
     const Type *EltTy = cast<VectorType>(V->getType())->getElementType();
     Constant *Zero = Constant::getNullValue(EltTy);
     Constant *Undef = UndefValue::get(EltTy);