[DAGCombiner] Added BSWAP(BSWAP(x)) -> x combine pattern.

[oota-llvm.git] / lib / CodeGen / SelectionDAG / SelectionDAG.cpp

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index f72bfc6ceaa1e8a8e9df98258dfb00266a2168dd..20cec6ebad1ad1498ba6f36ebf02a081554a4d80 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2432,6 +2432,19 @@ void SelectionDAG::computeKnownBits(SDValue Op, APInt &KnownZero,
     KnownOne = KnownOne.trunc(BitWidth);
     break;
   }
+  case ISD::SMIN:
+  case ISD::SMAX:
+  case ISD::UMIN:
+  case ISD::UMAX: {
+    APInt Op0Zero, Op0One;
+    APInt Op1Zero, Op1One;
+    computeKnownBits(Op.getOperand(0), Op0Zero, Op0One, Depth);
+    computeKnownBits(Op.getOperand(1), Op1Zero, Op1One, Depth);
+
+    KnownZero = Op0Zero & Op1Zero;
+    KnownOne = Op0One & Op1One;
+    break;
+  }
   case ISD::FrameIndex:
   case ISD::TargetFrameIndex:
     if (unsigned Align = InferPtrAlignment(Op)) {
@@ -2535,7 +2548,15 @@ unsigned SelectionDAG::ComputeNumSignBits(SDValue Op, unsigned Depth) const{
     if (Tmp == 1) return 1;  // Early out.
     Tmp2 = ComputeNumSignBits(Op.getOperand(2), Depth+1);
     return std::min(Tmp, Tmp2);
-
+  case ISD::SMIN:
+  case ISD::SMAX:
+  case ISD::UMIN:
+  case ISD::UMAX:
+    Tmp = ComputeNumSignBits(Op.getOperand(0), Depth + 1);
+    if (Tmp == 1)
+      return 1;  // Early out.
+    Tmp2 = ComputeNumSignBits(Op.getOperand(1), Depth + 1);
+    return std::min(Tmp, Tmp2);
   case ISD::SADDO:
   case ISD::UADDO:
   case ISD::SSUBO:
@@ -2911,6 +2932,11 @@ SDValue SelectionDAG::getNode(unsigned Opcode, SDLoc DL,
       case ISD::TRUNCATE:
       case ISD::UINT_TO_FP:
       case ISD::SINT_TO_FP:
+      case ISD::BSWAP:
+      case ISD::CTLZ:
+      case ISD::CTLZ_ZERO_UNDEF:
+      case ISD::CTTZ:
+      case ISD::CTTZ_ZERO_UNDEF:
       case ISD::CTPOP: {
         EVT SVT = VT.getScalarType();
         EVT InVT = BV->getValueType(0);
@@ -3056,6 +3082,14 @@ SDValue SelectionDAG::getNode(unsigned Opcode, SDLoc DL,
     if (OpOpcode == ISD::UNDEF)
       return getUNDEF(VT);
     break;
+  case ISD::BSWAP:
+    assert(VT.isInteger() && VT == Operand.getValueType() &&
+           "Invalid BSWAP!");
+    assert((VT.getScalarSizeInBits() % 16 == 0) &&
+           "BSWAP types must be a multiple of 16 bits!");
+    if (OpOpcode == ISD::UNDEF)
+      return getUNDEF(VT);
+    break;
   case ISD::BITCAST:
     // Basic sanity checking.
     assert(VT.getSizeInBits() == Operand.getValueType().getSizeInBits()