Move SHL,SHR i64 -> legalizer

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23178 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 57 insertions, 2 deletions

diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index c6511e8f5c..987ffe1612 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -72,7 +72,9 @@ PPC32TargetLowering::PPC32TargetLowering(TargetMachine &TM)
   setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
   setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
   
-  // PowerPC wants to expand SRA_PARTS into SELECT_CC and stuff.
+  // PowerPC wants to expand i64 shifts itself.
+  setOperationAction(ISD::SHL, MVT::i64, Custom);
+  setOperationAction(ISD::SRL, MVT::i64, Custom);
   setOperationAction(ISD::SRA, MVT::i64, Custom);
 
   // PowerPC does not have BRCOND* which requires SetCC
@@ -164,7 +166,59 @@ SDOperand PPC32TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
       }
     }
     break;    
-  case ISD::SRA:
+  case ISD::SHL: {
+    assert(Op.getValueType() == MVT::i64 &&
+           Op.getOperand(1).getValueType() == MVT::i32 && "Unexpected SHL!");
+    // The generic code does a fine job expanding shift by a constant.
+    if (isa<ConstantSDNode>(Op.getOperand(1))) break;
+    
+    // Otherwise, expand into a bunch of logical ops.  Note that these ops
+    // depend on the PPC behavior for oversized shift amounts.
+    SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op.getOperand(0),
+                               DAG.getConstant(0, MVT::i32));
+    SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op.getOperand(0),
+                               DAG.getConstant(1, MVT::i32));
+    SDOperand Amt = Op.getOperand(1);
+    
+    SDOperand Tmp1 = DAG.getNode(ISD::SUB, MVT::i32,
+                                 DAG.getConstant(32, MVT::i32), Amt);
+    SDOperand Tmp2 = DAG.getNode(ISD::SHL, MVT::i32, Hi, Amt);
+    SDOperand Tmp3 = DAG.getNode(ISD::SRL, MVT::i32, Lo, Tmp1);
+    SDOperand Tmp4 = DAG.getNode(ISD::OR , MVT::i32, Tmp2, Tmp3);
+    SDOperand Tmp5 = DAG.getNode(ISD::ADD, MVT::i32, Amt,
+                                 DAG.getConstant(-32U, MVT::i32));
+    SDOperand Tmp6 = DAG.getNode(ISD::SHL, MVT::i32, Lo, Tmp5);
+    SDOperand OutHi = DAG.getNode(ISD::OR, MVT::i32, Tmp4, Tmp6);
+    SDOperand OutLo = DAG.getNode(ISD::SHL, MVT::i32, Lo, Amt);
+    return DAG.getNode(ISD::BUILD_PAIR, MVT::i64, OutLo, OutHi);
+  }
+  case ISD::SRL: {
+    assert(Op.getValueType() == MVT::i64 &&
+           Op.getOperand(1).getValueType() == MVT::i32 && "Unexpected SHL!");
+    // The generic code does a fine job expanding shift by a constant.
+    if (isa<ConstantSDNode>(Op.getOperand(1))) break;
+    
+    // Otherwise, expand into a bunch of logical ops.  Note that these ops
+    // depend on the PPC behavior for oversized shift amounts.
+    SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op.getOperand(0),
+                               DAG.getConstant(0, MVT::i32));
+    SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op.getOperand(0),
+                               DAG.getConstant(1, MVT::i32));
+    SDOperand Amt = Op.getOperand(1);
+    
+    SDOperand Tmp1 = DAG.getNode(ISD::SUB, MVT::i32,
+                                 DAG.getConstant(32, MVT::i32), Amt);
+    SDOperand Tmp2 = DAG.getNode(ISD::SRL, MVT::i32, Lo, Amt);
+    SDOperand Tmp3 = DAG.getNode(ISD::SHL, MVT::i32, Hi, Tmp1);
+    SDOperand Tmp4 = DAG.getNode(ISD::OR , MVT::i32, Tmp2, Tmp3);
+    SDOperand Tmp5 = DAG.getNode(ISD::ADD, MVT::i32, Amt,
+                                 DAG.getConstant(-32U, MVT::i32));
+    SDOperand Tmp6 = DAG.getNode(ISD::SRL, MVT::i32, Hi, Tmp5);
+    SDOperand OutLo = DAG.getNode(ISD::OR, MVT::i32, Tmp4, Tmp6);
+    SDOperand OutHi = DAG.getNode(ISD::SRL, MVT::i32, Hi, Amt);
+    return DAG.getNode(ISD::BUILD_PAIR, MVT::i64, OutLo, OutHi);
+  }    
+  case ISD::SRA: {
     assert(Op.getValueType() == MVT::i64 &&
            Op.getOperand(1).getValueType() == MVT::i32 && "Unexpected SRA!");
     // The generic code does a fine job expanding shift by a constant.
@@ -190,6 +244,7 @@ SDOperand PPC32TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
                                       Tmp4, Tmp6, ISD::SETLE);
     return DAG.getNode(ISD::BUILD_PAIR, MVT::i64, OutLo, OutHi);
   }
+  }
   return SDOperand();
 }