[llvm-commits] [llvm] r70715 - in /llvm/trunk/lib/Target/MSP430: MSP430ISelLowering.cpp MSP430ISelLowering.h MSP430InstrInfo.td

[Anton Korobeynikov]

Author: asl
Date: Sun May  3 08:03:33 2009
New Revision: 70715

URL: http://llvm.org/viewvc/llvm-project?rev=70715&view=rev
Log:
Add dummy lowering for shifts

Modified:
    llvm/trunk/lib/Target/MSP430/MSP430ISelLowering.cpp
    llvm/trunk/lib/Target/MSP430/MSP430ISelLowering.h
    llvm/trunk/lib/Target/MSP430/MSP430InstrInfo.td

Modified: llvm/trunk/lib/Target/MSP430/MSP430ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/MSP430/MSP430ISelLowering.cpp?rev=70715&r1=70714&r2=70715&view=diff

==============================================================================
--- llvm/trunk/lib/Target/MSP430/MSP430ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/MSP430/MSP430ISelLowering.cpp Sun May  3 08:03:33 2009
@@ -49,6 +49,12 @@
   // Division is expensive
   setIntDivIsCheap(false);
 
+  // Even if we have only 1 bit shift here, we can perform
+  // shifts of the whole bitwidth 1 bit per step.
+  setShiftAmountType(MVT::i8);
+
+  setOperationAction(ISD::SRA, MVT::i16, Custom);
+
   setOperationAction(ISD::RET, MVT::Other, Custom);
 }
 
@@ -56,6 +62,7 @@
 LowerOperation(SDValue Op, SelectionDAG &DAG) {
   switch (Op.getOpcode()) {
   case ISD::FORMAL_ARGUMENTS: return LowerFORMAL_ARGUMENTS(Op, DAG);
+  case ISD::SRA: return LowerShifts(Op, DAG);
   case ISD::RET: return LowerRET(Op, DAG);
   default:
     assert(0 && "unimplemented operand");
@@ -210,10 +217,34 @@
   return DAG.getNode(MSP430ISD::RET_FLAG, dl, MVT::Other, Chain);
 }
 
+SDValue MSP430TargetLowering::LowerShifts(SDValue Op,
+                                          SelectionDAG &DAG) {
+  assert(Op.getOpcode() == ISD::SRA && "Only SRA is currently supported.");
+  SDNode* N = Op.getNode();
+  MVT VT = Op.getValueType();
+  DebugLoc dl = N->getDebugLoc();
+
+  // We currently only lower SRA of constant argument.
+  if (!isa<ConstantSDNode>(N->getOperand(1)))
+    return SDValue();
+
+  uint64_t ShiftAmount = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
+
+  // Expand the stuff into sequence of shifts.
+  // FIXME: for some shift amounts this might be done better!
+  // E.g.: foo >> (8 + N) => sxt(swpb(foo)) >> N
+  SDValue Victim = N->getOperand(0);
+  while (ShiftAmount--)
+    Victim = DAG.getNode(MSP430ISD::RRA, dl, VT, Victim);
+
+  return Victim;
+}
+
 const char *MSP430TargetLowering::getTargetNodeName(unsigned Opcode) const {
   switch (Opcode) {
   default: return NULL;
   case MSP430ISD::RET_FLAG:           return "MSP430ISD::RET_FLAG";
+  case MSP430ISD::RRA:                return "MSP430ISD::RRA";
   }
 }
 

Modified: llvm/trunk/lib/Target/MSP430/MSP430ISelLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/MSP430/MSP430ISelLowering.h?rev=70715&r1=70714&r2=70715&view=diff

==============================================================================
--- llvm/trunk/lib/Target/MSP430/MSP430ISelLowering.h (original)
+++ llvm/trunk/lib/Target/MSP430/MSP430ISelLowering.h Sun May  3 08:03:33 2009
@@ -25,7 +25,10 @@
       FIRST_NUMBER = ISD::BUILTIN_OP_END,
 
       /// Return with a flag operand. Operand 0 is the chain operand.
-      RET_FLAG
+      RET_FLAG,
+
+      /// Y = RRA X, rotate right arithmetically
+      RRA
     };
   }
 
@@ -46,6 +49,7 @@
     SDValue LowerFORMAL_ARGUMENTS(SDValue Op, SelectionDAG &DAG);
     SDValue LowerRET(SDValue Op, SelectionDAG &DAG);
     SDValue LowerCCCArguments(SDValue Op, SelectionDAG &DAG);
+    SDValue LowerShifts(SDValue Op, SelectionDAG &DAG);
 
   private:
     const MSP430Subtarget &Subtarget;

Modified: llvm/trunk/lib/Target/MSP430/MSP430InstrInfo.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/MSP430/MSP430InstrInfo.td?rev=70715&r1=70714&r2=70715&view=diff

==============================================================================
--- llvm/trunk/lib/Target/MSP430/MSP430InstrInfo.td (original)
+++ llvm/trunk/lib/Target/MSP430/MSP430InstrInfo.td Sun May  3 08:03:33 2009
@@ -26,9 +26,11 @@
 //===----------------------------------------------------------------------===//
 // MSP430 Specific Node Definitions.
 //===----------------------------------------------------------------------===//
-def retflag : SDNode<"MSP430ISD::RET_FLAG", SDTNone,
+def MSP430retflag : SDNode<"MSP430ISD::RET_FLAG", SDTNone,
                      [SDNPHasChain, SDNPOptInFlag]>;
 
+def MSP430rra     : SDNode<"MSP430ISD::RRA", SDTIntUnaryOp, []>;
+
 //===----------------------------------------------------------------------===//
 // Pseudo Instructions
 //===----------------------------------------------------------------------===//
@@ -41,7 +43,7 @@
 
 // FIXME: Provide proper encoding!
 let isReturn = 1, isTerminator = 1 in {
-  def RETI : Pseudo<(outs), (ins), "ret", [(retflag)]>;
+  def RETI : Pseudo<(outs), (ins), "ret", [(MSP430retflag)]>;
 }
 
 //===----------------------------------------------------------------------===//
@@ -73,4 +75,13 @@
                      [(set GR16:$dst, (add GR16:$src1, GR16:$src2)),
                       (implicit SR)]>;
 }
+
+// FIXME: Provide proper encoding!
+let isTwoAddress = 1 in {
+def SAR16r1 : Pseudo<(outs GR16:$dst), (ins GR16:$src),
+                     "rra.w\t$dst",
+                     [(set GR16:$dst, (MSP430rra GR16:$src)),
+                      (implicit SR)]>;
 }
+
+} // Defs = [SR]