Pull DAG ISel generation nodes out of the PowerPC backend to where they
can be used by other targets.  For those targets that want to use it,
have at.  :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23680 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/TargetSelectionDAG.td b/lib/Target/TargetSelectionDAG.td
new file mode 100644
index 0000000..ed63fcb
--- /dev/null
+++ b/lib/Target/TargetSelectionDAG.td
@@ -0,0 +1,214 @@
+//===- TargetSelectionDAG.td - Common code for DAG isels ---*- tablegen -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file defines the target-independent interfaces used by SelectionDAG
+// instruction selection generators.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// Selection DAG Type Constraint definitions.
+//
+// Note that the semantics of these constraints are hard coded into tblgen.  To
+// modify or add constraints, you have to hack tblgen.
+//
+
+class SDTypeConstraint<int opnum> {
+  int OperandNum = opnum;
+}
+
+// SDTCisVT - The specified operand has exactly this VT.
+class SDTCisVT <int OpNum, ValueType vt> : SDTypeConstraint<OpNum> {
+  ValueType VT = vt;
+}
+
+// SDTCisInt - The specified operand is has integer type.
+class SDTCisInt<int OpNum> : SDTypeConstraint<OpNum>;
+
+// SDTCisFP - The specified operand is has floating point type.
+class SDTCisFP <int OpNum> : SDTypeConstraint<OpNum>;
+
+// SDTCisSameAs - The two specified operands have identical types.
+class SDTCisSameAs<int OpNum, int OtherOp> : SDTypeConstraint<OpNum> {
+  int OtherOperandNum = OtherOp;
+}
+
+// SDTCisVTSmallerThanOp - The specified operand is a VT SDNode, and its type is
+// smaller than the 'Other' operand.
+class SDTCisVTSmallerThanOp<int OpNum, int OtherOp> : SDTypeConstraint<OpNum> {
+  int OtherOperandNum = OtherOp;
+}
+
+//===----------------------------------------------------------------------===//
+// Selection DAG Type Profile definitions.
+//
+// These use the constraints defined above to describe the type requirements of
+// the various nodes.  These are not hard coded into tblgen, allowing targets to
+// add their own if needed.
+//
+
+// SDTypeProfile - This profile describes the type requirements of a Selection
+// DAG node.
+class SDTypeProfile<int numresults, int numoperands,
+                    list<SDTypeConstraint> constraints> {
+  int NumResults = numresults;
+  int NumOperands = numoperands;
+  list<SDTypeConstraint> Constraints = constraints;
+}
+
+// Builtin profiles.
+def SDTImm    : SDTypeProfile<1, 0, [SDTCisInt<0>]>;      // for 'imm'.
+def SDTVT     : SDTypeProfile<1, 0, [SDTCisVT<0, OtherVT>]>; // for 'vt'
+def SDTIntBinOp : SDTypeProfile<1, 2, [   // add, and, or, xor, udiv, etc.
+  SDTCisSameAs<0, 1>, SDTCisSameAs<0, 2>, SDTCisInt<0>
+]>;
+def SDTFPBinOp : SDTypeProfile<1, 2, [      // fadd, fmul, etc.
+  SDTCisSameAs<0, 1>, SDTCisSameAs<0, 2>, SDTCisFP<0>
+]>;
+def SDTIntUnaryOp : SDTypeProfile<1, 1, [   // ctlz
+  SDTCisSameAs<0, 1>, SDTCisInt<0>
+]>;
+def SDTFPUnaryOp  : SDTypeProfile<1, 1, [   // fneg, fsqrt, etc
+  SDTCisSameAs<0, 1>, SDTCisFP<0>
+]>;
+def SDTExtInreg : SDTypeProfile<1, 2, [   // sext_inreg
+  SDTCisSameAs<0, 1>, SDTCisInt<0>, SDTCisVT<2, OtherVT>,
+  SDTCisVTSmallerThanOp<2, 1>
+]>;
+
+//===----------------------------------------------------------------------===//
+// Selection DAG Node Properties.
+//
+// Note: These are hard coded into tblgen.
+//
+class SDNodeProperty;
+def SDNPCommutative : SDNodeProperty;   // X op Y == Y op X
+def SDNPAssociative : SDNodeProperty;   // (X op Y) op Z == X op (Y op Z)
+
+//===----------------------------------------------------------------------===//
+// Selection DAG Node definitions.
+//
+class SDNode<string opcode, SDTypeProfile typeprof,
+             list<SDNodeProperty> props = [], string sdclass = "SDNode"> {
+  string Opcode  = opcode;
+  string SDClass = sdclass;
+  list<SDNodeProperty> Properties = props;
+  SDTypeProfile TypeProfile = typeprof;
+}
+
+def set;
+def node;
+
+def imm        : SDNode<"ISD::Constant"  , SDTImm     , [], "ConstantSDNode">;
+def vt         : SDNode<"ISD::VALUETYPE" , SDTVT      , [], "VTSDNode">;
+def add        : SDNode<"ISD::ADD"       , SDTIntBinOp   ,
+                        [SDNPCommutative, SDNPAssociative]>;
+def sub        : SDNode<"ISD::SUB"       , SDTIntBinOp>;
+def mul        : SDNode<"ISD::MUL"       , SDTIntBinOp,
+                        [SDNPCommutative, SDNPAssociative]>;
+def mulhs      : SDNode<"ISD::MULHS"     , SDTIntBinOp, [SDNPCommutative]>;
+def mulhu      : SDNode<"ISD::MULHU"     , SDTIntBinOp, [SDNPCommutative]>;
+def sdiv       : SDNode<"ISD::SDIV"      , SDTIntBinOp>;
+def udiv       : SDNode<"ISD::UDIV"      , SDTIntBinOp>;
+def srem       : SDNode<"ISD::SREM"      , SDTIntBinOp>;
+def urem       : SDNode<"ISD::UREM"      , SDTIntBinOp>;
+def srl        : SDNode<"ISD::SRL"       , SDTIntBinOp>;
+def sra        : SDNode<"ISD::SRA"       , SDTIntBinOp>;
+def shl        : SDNode<"ISD::SHL"       , SDTIntBinOp>;
+def and        : SDNode<"ISD::AND"       , SDTIntBinOp,
+                        [SDNPCommutative, SDNPAssociative]>;
+def or         : SDNode<"ISD::OR"        , SDTIntBinOp,
+                        [SDNPCommutative, SDNPAssociative]>;
+def xor        : SDNode<"ISD::XOR"       , SDTIntBinOp,
+                        [SDNPCommutative, SDNPAssociative]>;
+def fadd       : SDNode<"ISD::FADD"       , SDTFPBinOp, [SDNPCommutative]>;
+def fsub       : SDNode<"ISD::FSUB"       , SDTFPBinOp>;
+def fmul       : SDNode<"ISD::FMUL"       , SDTFPBinOp, [SDNPCommutative]>;
+def fdiv       : SDNode<"ISD::FDIV"       , SDTFPBinOp>;
+def frem       : SDNode<"ISD::FREM"       , SDTFPBinOp>;
+def fabs       : SDNode<"ISD::FABS"       , SDTFPUnaryOp>;
+def fneg       : SDNode<"ISD::FNEG"       , SDTFPUnaryOp>;
+def fsqrt      : SDNode<"ISD::FSQRT"      , SDTFPUnaryOp>;
+
+def sext_inreg : SDNode<"ISD::SIGN_EXTEND_INREG", SDTExtInreg>;
+def ctlz       : SDNode<"ISD::CTLZ"      , SDTIntUnaryOp>;
+
+//===----------------------------------------------------------------------===//
+// Selection DAG Node Transformation Functions.
+//
+// This mechanism allows targets to manipulate nodes in the output DAG once a
+// match has been formed.  This is typically used to manipulate immediate
+// values.
+//
+class SDNodeXForm<SDNode opc, code xformFunction> {
+  SDNode Opcode = opc;
+  code XFormFunction = xformFunction;
+}
+
+def NOOP_SDNodeXForm : SDNodeXForm<imm, [{}]>;
+
+
+//===----------------------------------------------------------------------===//
+// Selection DAG Pattern Fragments.
+//
+// Pattern fragments are reusable chunks of dags that match specific things.
+// They can take arguments and have C++ predicates that control whether they
+// match.  They are intended to make the patterns for common instructions more
+// compact and readable.
+//
+
+/// PatFrag - Represents a pattern fragment.  This can match something on the
+/// DAG, frame a single node to multiply nested other fragments.
+///
+class PatFrag<dag ops, dag frag, code pred = [{}],
+              SDNodeXForm xform = NOOP_SDNodeXForm> {
+  dag Operands = ops;
+  dag Fragment = frag;
+  code Predicate = pred;
+  SDNodeXForm OperandTransform = xform;
+}
+
+// PatLeaf's are pattern fragments that have no operands.  This is just a helper
+// to define immediates and other common things concisely.
+class PatLeaf<dag frag, code pred = [{}], SDNodeXForm xform = NOOP_SDNodeXForm>
+ : PatFrag<(ops), frag, pred, xform>;
+
+// Leaf fragments.
+
+def immAllOnes : PatLeaf<(imm), [{ return N->isAllOnesValue(); }]>;
+def immZero    : PatLeaf<(imm), [{ return N->isNullValue();    }]>;
+
+def vtInt      : PatLeaf<(vt),  [{ return MVT::isInteger(N->getVT()); }]>;
+def vtFP       : PatLeaf<(vt),  [{ return MVT::isFloatingPoint(N->getVT()); }]>;
+
+// Other helper fragments.
+
+def not  : PatFrag<(ops node:$in), (xor node:$in, immAllOnes)>;
+def ineg : PatFrag<(ops node:$in), (sub immZero, node:$in)>;
+
+//===----------------------------------------------------------------------===//
+// Selection DAG Pattern Support.
+//
+// Patterns are what are actually matched against the target-flavored
+// instruction selection DAG.  Instructions defined by the target implicitly
+// define patterns in most cases, but patterns can also be explicitly added when
+// an operation is defined by a sequence of instructions (e.g. loading a large
+// immediate value on RISC targets that do not support immediates as large as
+// their GPRs).
+//
+
+class Pattern<dag patternToMatch, list<dag> resultInstrs> {
+  dag       PatternToMatch = patternToMatch;
+  list<dag> ResultInstrs   = resultInstrs;
+}
+
+// Pat - A simple (but common) form of a pattern, which produces a simple result
+// not needing a full list.
+class Pat<dag pattern, dag result> : Pattern<pattern, [result]>;
+