Revert 122353-122355 for the moment, they broke stuff.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122360 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 29 deletions

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 35f4a76b68..75d6013ff2 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -2967,37 +2967,11 @@ SDValue DAGCombiner::visitSHL(SDNode *N) {
       N0.getOperand(1).getOpcode() == ISD::Constant) {
     uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
     uint64_t c2 = N1C->getZExtValue();
-    if (c1 + c2 >= OpSizeInBits)
+    if (c1 + c2 > OpSizeInBits)
       return DAG.getConstant(0, VT);
     return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0.getOperand(0),
                        DAG.getConstant(c1 + c2, N1.getValueType()));
   }
-
-  // fold (shl (ext (shl x, c1)), c2) -> (ext (shl x, (add c1, c2)))
-  // For this to be valid, the second form must not preserve any of the bits
-  // that are shifted out by the inner shift in the first form.  This means
-  // the outer shift size must be >= the number of bits added by the ext.
-  // As a corollary, we don't care what kind of ext it is.
-  if (N1C && (N0.getOpcode() == ISD::ZERO_EXTEND ||
-              N0.getOpcode() == ISD::ANY_EXTEND ||
-              N0.getOpcode() == ISD::SIGN_EXTEND) &&
-      N0.getOperand(0).getOpcode() == ISD::SHL &&
-      isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
-    uint64_t c1 = 
-      cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
-    uint64_t c2 = N1C->getZExtValue();
-    EVT InnerShiftVT = N0.getOperand(0).getValueType();
-    uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
-    if (c2 >= OpSizeInBits - InnerShiftSize) {
-      if (c1 + c2 >= OpSizeInBits)
-        return DAG.getConstant(0, VT);
-      return DAG.getNode(ISD::SHL, N0->getDebugLoc(), VT,
-                         DAG.getNode(N0.getOpcode(), N0->getDebugLoc(), VT,
-                                     N0.getOperand(0)->getOperand(0)),
-                         DAG.getConstant(c1 + c2, VT));
-    }
-  }
-
   // fold (shl (srl x, c1), c2) -> (shl (and x, (shl -1, c1)), (sub c2, c1)) or
   //                               (srl (and x, (shl -1, c1)), (sub c1, c2))
   if (N1C && N0.getOpcode() == ISD::SRL &&
@@ -3191,7 +3165,7 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
       N0.getOperand(1).getOpcode() == ISD::Constant) {
     uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
     uint64_t c2 = N1C->getZExtValue();
-    if (c1 + c2 >= OpSizeInBits)
+    if (c1 + c2 > OpSizeInBits)
       return DAG.getConstant(0, VT);
     return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0),
                        DAG.getConstant(c1 + c2, N1.getValueType()));
@@ -3204,7 +3178,7 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
     uint64_t c1 = 
       cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
     uint64_t c2 = N1C->getZExtValue();
-    EVT InnerShiftVT = N0.getOperand(0).getValueType();
+    EVT InnerShiftVT = N0.getOperand(0)->getOperand(1).getValueType();
     uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
     // This is only valid if the OpSizeInBits + c1 = size of inner shift.
     if (c1 + OpSizeInBits == InnerShiftSize) {