[llvm-commits] CVS: llvm/include/llvm/CodeGen/SelectionDAG.h
Chris Lattner
lattner at cs.uiuc.edu
Thu Jan 6 23:46:21 PST 2005
Changes in directory llvm/include/llvm/CodeGen:
SelectionDAG.h updated: 1.6 -> 1.7
---
Log message:
Complete rewrite of the SelectionDAG class.
---
Diffs of the changes: (+103 -316)
Index: llvm/include/llvm/CodeGen/SelectionDAG.h
diff -u llvm/include/llvm/CodeGen/SelectionDAG.h:1.6 llvm/include/llvm/CodeGen/SelectionDAG.h:1.7
--- llvm/include/llvm/CodeGen/SelectionDAG.h:1.6 Wed Sep 1 17:55:34 2004
+++ llvm/include/llvm/CodeGen/SelectionDAG.h Fri Jan 7 01:45:38 2005
@@ -1,4 +1,4 @@
-//===-- llvm/CodeGen/SelectionDAG.h - InstSelection DAG Rep. ----*- C++ -*-===//
+//===-- llvm/CodeGen/SelectionDAG.h - InstSelection DAG ---------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
@@ -7,364 +7,151 @@
//
//===----------------------------------------------------------------------===//
//
-// This file declares the SelectionDAG class, which is used to represent an LLVM
-// function in a low-level representation suitable for instruction selection.
-// This DAG is constructed as the first step of instruction selection in order
-// to allow implementation of machine specific optimizations and code
-// simplifications.
-//
-// The representation used by the SelectionDAG is a target-independent
-// representation, which is loosly modeled after the GCC RTL representation, but
-// is significantly simpler.
+// This file declares the SelectionDAG class, and transitively defines the
+// SDNode class and subclasses.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_SELECTIONDAG_H
#define LLVM_CODEGEN_SELECTIONDAG_H
-#include "llvm/CodeGen/ValueTypes.h"
-#include "llvm/Support/DataTypes.h"
+#include "llvm/CodeGen/SelectionDAGNodes.h"
#include <map>
-#include <vector>
-#include <cassert>
+#include <string> // FIXME remove eventually, turning map into const char* map.
namespace llvm {
-
-class Value;
-class Type;
-class Instruction;
-class CallInst;
-class BasicBlock;
-class MachineBasicBlock;
-class MachineFunction;
-class TargetMachine;
-class SelectionDAGNode;
-class SelectionDAGBlock;
-class SelectionDAGBuilder;
-class SelectionDAGTargetBuilder;
-
-/// ISD namespace - This namespace contains an enum which represents all of the
-/// SelectionDAG node types and value types.
+ class TargetLowering;
+ class TargetMachine;
+ class MachineFunction;
+
+/// SelectionDAG class - This is used to represent a portion of an LLVM function
+/// in a low-level Data Dependence DAG representation suitable for instruction
+/// selection. This DAG is constructed as the first step of instruction
+/// selection in order to allow implementation of machine specific optimizations
+/// and code simplifications.
+///
+/// The representation used by the SelectionDAG is a target-independent
+/// representation, which has some similarities to the GCC RTL representation,
+/// but is significantly more simple, powerful, and is a graph form instead of a
+/// linear form.
///
-namespace ISD {
- enum NodeType {
- // ChainNode nodes are used to sequence operations within a basic block
- // which cannot be reordered (such as loads, stores, calls, etc).
- // BlockChainNodes are used to connect the DAG's for different basic blocks
- // into one big DAG.
- ChainNode, BlockChainNode,
-
- // ProtoNodes are nodes that are only half way constructed.
- ProtoNode,
-
- // Leaf nodes
- Constant, FrameIndex, BasicBlock,
-
- // Simple binary arithmetic operators
- Plus, Minus, Times, SDiv, UDiv, SRem, URem,
-
- // Bitwise operators
- And, Or, Xor,
-
- // Comparisons
- SetEQ, SetNE, SetLT, SetLE, SetGT, SetGE,
-
- // Control flow instructions
- Br, BrCond, Switch, Ret, RetVoid,
-
- // Other operators
- Load, Store, PHI, Call,
-
- // Unknown operators, of a specified arity
- Unspec1, Unspec2
- };
-}
-
class SelectionDAG {
- friend class SelectionDAGBuilder;
- MachineFunction &F;
const TargetMachine &TM;
- MVT::ValueType PointerType; // The ValueType the target uses for pointers
-
- // ValueMap - The SelectionDAGNode for each LLVM value in the function.
- std::map<const Value*, SelectionDAGNode*> ValueMap;
+ MachineFunction &MF;
- // BlockMap - The MachineBasicBlock created for each LLVM BasicBlock
- std::map<const BasicBlock*, MachineBasicBlock*> BlockMap;
-
- // Root - The root of the entire DAG
- SelectionDAGNode *Root;
+ // Root - The root of the entire DAG. EntryNode - The starting token.
+ SDOperand Root, EntryNode;
// AllNodes - All of the nodes in the DAG
- std::vector<SelectionDAGNode*> AllNodes;
+ std::vector<SDNode*> AllNodes;
+
+ // Maps to auto-CSE operations.
+ std::map<std::pair<unsigned, std::pair<SDOperand, MVT::ValueType> >,
+ SDNode *> UnaryOps;
+ std::map<std::pair<unsigned, std::pair<SDOperand, SDOperand> >,
+ SDNode *> BinaryOps;
+
+ std::map<std::pair<std::pair<SDOperand, SDOperand>, ISD::CondCode>,
+ SetCCSDNode*> SetCCs;
+
+ std::map<std::pair<SDOperand, std::pair<SDOperand, MVT::ValueType> >,
+ SDNode *> Loads;
+
+ std::map<const GlobalValue*, SDNode*> GlobalValues;
+ std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> Constants;
+ std::map<std::pair<double, MVT::ValueType>, SDNode*> ConstantFPs;
+ std::map<int, SDNode*> FrameIndices;
+ std::map<unsigned, SDNode*> ConstantPoolIndices;
+ std::map<MachineBasicBlock *, SDNode*> BBNodes;
+ std::map<std::string, SDNode*> ExternalSymbols;
public:
- /// SelectionDAG constructor - Build a SelectionDAG for the specified
- /// function. Implemented in DAGBuilder.cpp
- ///
- SelectionDAG(MachineFunction &F, const TargetMachine &TM,
- SelectionDAGTargetBuilder &SDTB);
+ SelectionDAG(const TargetMachine &tm, MachineFunction &mf) : TM(tm), MF(mf) {
+ EntryNode = Root = getNode(ISD::EntryToken, MVT::Other);
+ }
~SelectionDAG();
- /// getValueType - Return the ValueType for the specified LLVM type. This
- /// method works on all scalar LLVM types.
- ///
- MVT::ValueType getValueType(const Type *Ty) const;
-
- /// getRoot - Return the root of the current SelectionDAG.
- ///
- SelectionDAGNode *getRoot() const { return Root; }
+ MachineFunction &getMachineFunction() const { return MF; }
+ const TargetMachine &getTarget() { return TM; }
- /// getMachineFunction - Return the MachineFunction object that this
- /// SelectionDAG corresponds to.
+ /// getRoot - Return the root tag of the SelectionDAG.
///
- MachineFunction &getMachineFunction() const { return F; }
+ const SDOperand &getRoot() const { return Root; }
- //===--------------------------------------------------------------------===//
- // Addition and updating methods
- //
+ /// getEntryNode - Return the token chain corresponding to the entry of the
+ /// function.
+ const SDOperand &getEntryNode() const { return EntryNode; }
- /// addNode - Add the specified node to the SelectionDAG so that it will be
- /// deleted when the DAG is...
+ /// setRoot - Set the current root tag of the SelectionDAG.
///
- SelectionDAGNode *addNode(SelectionDAGNode *N) {
- AllNodes.push_back(N);
- return N;
- }
-
- /// addNodeForValue - Add the specified node to the SelectionDAG so that it
- /// will be deleted when the DAG is... and update the value map to indicate
- /// that the specified DAG node computes the value. Note that it is an error
- /// to specify multiple DAG nodes that compute the same value.
- ///
- SelectionDAGNode *addNodeForValue(SelectionDAGNode *N, const Value *V) {
- assert(ValueMap.count(V) == 0 && "Value already has a DAG node!");
- return addNode(ValueMap[V] = N);
- }
-
- void dump() const;
-private:
- void addInstructionToDAG(const Instruction &I, const BasicBlock &BB);
-};
+ const SDOperand &setRoot(SDOperand N) { return Root = N; }
-
-/// SelectionDAGReducedValue - During the reducer pass we need the ability to
-/// add an arbitrary (but usually 1 or 0) number of arbitrarily sized values to
-/// the selection DAG. Because of this, we represent these values as a singly
-/// linked list of values attached to the DAGNode. We end up putting the
-/// arbitrary state for the value in subclasses of this node.
-///
-/// Note that this class does not have a virtual dtor, this is because we know
-/// that the subclasses will not hold state that needs to be destroyed.
-///
-class SelectionDAGReducedValue {
- unsigned Code;
- SelectionDAGReducedValue *Next;
-public:
- SelectionDAGReducedValue(unsigned C) : Code(C), Next(0) {}
-
- /// getValueCode - Return the code for this reducer value...
- ///
- unsigned getValueCode() const { return Code; }
-
- /// getNext - Return the next value in the list
+ /// Legalize - This transforms the SelectionDAG into a SelectionDAG that is
+ /// compatible with the target instruction selector, as indicated by the
+ /// TargetLowering object.
///
- const SelectionDAGReducedValue *getNext() const { return Next; }
- void setNext(SelectionDAGReducedValue *N) { Next = N; }
+ /// Note that this is an involved process that may invalidate pointers into
+ /// the graph.
+ void Legalize(TargetLowering &TLI);
- SelectionDAGReducedValue *getNext() { return Next; }
-};
+ SDOperand getConstant(uint64_t Val, MVT::ValueType VT);
+ SDOperand getConstantFP(double Val, MVT::ValueType VT);
+ SDOperand getGlobalAddress(const GlobalValue *GV, MVT::ValueType VT);
+ SDOperand getFrameIndex(int FI, MVT::ValueType VT);
+ SDOperand getConstantPool(unsigned CPIdx, MVT::ValueType VT);
+ SDOperand getBasicBlock(MachineBasicBlock *MBB);
+ SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT);
-
-
-/// SelectionDAGNode - Represents one node in the selection DAG.
-///
-class SelectionDAGNode {
- std::vector<SelectionDAGNode*> Uses;
- ISD::NodeType NodeType;
- MVT::ValueType ValueType;
- MachineBasicBlock *BB;
- SelectionDAGReducedValue *ValList;
-
- /// Costs - Each pair of elements of 'Costs' contains the cost of producing
- /// the value with the target specific slot number and the production number
- /// to use to produce it. A zero value for the production number indicates
- /// that the cost has not yet been computed.
- unsigned *Costs;
-public:
- SelectionDAGNode(ISD::NodeType NT, MVT::ValueType VT,
- MachineBasicBlock *bb = 0)
- : NodeType(NT), ValueType(VT), BB(bb), ValList(0), Costs(0) {}
-
- SelectionDAGNode(ISD::NodeType NT, MVT::ValueType VT, MachineBasicBlock *bb,
- SelectionDAGNode *N)
- : NodeType(NT), ValueType(VT), BB(bb), ValList(0), Costs(0) {
- assert(NT != ISD::ProtoNode && "Cannot specify uses for a protonode!");
- Uses.reserve(1); Uses.push_back(N);
- }
- SelectionDAGNode(ISD::NodeType NT, MVT::ValueType VT, MachineBasicBlock *bb,
- SelectionDAGNode *N1, SelectionDAGNode *N2)
- : NodeType(NT), ValueType(VT), BB(bb), ValList(0), Costs(0) {
- assert(NT != ISD::ProtoNode && "Cannot specify uses for a protonode!");
- Uses.reserve(2); Uses.push_back(N1); Uses.push_back(N2);
- }
- SelectionDAGNode(ISD::NodeType NT, MVT::ValueType VT, MachineBasicBlock *bb,
- SelectionDAGNode *N1, SelectionDAGNode *N2,
- SelectionDAGNode *N3)
- : NodeType(NT), ValueType(VT), BB(bb), ValList(0), Costs(0) {
- assert(NT != ISD::ProtoNode && "Cannot specify uses for a protonode!");
- Uses.reserve(3); Uses.push_back(N1); Uses.push_back(N2); Uses.push_back(N3);
- }
-
- ~SelectionDAGNode() { delete [] Costs; delete ValList; }
-
- void setNode(ISD::NodeType NT, MachineBasicBlock *bb) {
- assert(NodeType == ISD::ProtoNode && NT != ISD::ProtoNode);
- NodeType = NT; BB = bb;
- }
- void setNode(ISD::NodeType NT, MachineBasicBlock *bb, SelectionDAGNode *N) {
- assert(NodeType == ISD::ProtoNode && NT != ISD::ProtoNode);
- NodeType = NT; BB = bb; Uses.reserve(1); Uses.push_back(N);
- }
- void setNode(ISD::NodeType NT, MachineBasicBlock *bb,
- SelectionDAGNode *N1, SelectionDAGNode *N2) {
- assert(NodeType == ISD::ProtoNode && NT != ISD::ProtoNode);
- NodeType = NT; BB = bb;
- Uses.reserve(1); Uses.push_back(N1); Uses.push_back(N2);
+ SDOperand getCopyToReg(SDOperand Chain, SDOperand N, unsigned VReg) {
+ // Note: these are auto-CSE'd because the caller doesn't make requests that
+ // could cause duplicates to occur.
+ SDNode *NN = new CopyRegSDNode(Chain, N, VReg);
+ AllNodes.push_back(NN);
+ return SDOperand(NN, 0);
}
- //===--------------------------------------------------------------------===//
- // Accessors
- //
- ISD::NodeType getNodeType() const { return NodeType; }
- MVT::ValueType getValueType() const { return ValueType; }
- MachineBasicBlock *getBB() const { return BB; }
-
- SelectionDAGNode *getUse(unsigned Num) {
- assert(Num < Uses.size() && "Invalid child # of SelectionDAGNode!");
- return Uses[Num];
+ SDOperand getCopyFromReg(unsigned VReg, MVT::ValueType VT) {
+ // Note: These nodes are auto-CSE'd by the caller of this method.
+ SDNode *NN = new CopyRegSDNode(VReg, VT);
+ AllNodes.push_back(NN);
+ return SDOperand(NN, 0);
}
- template<class Type>
- Type *getValue(unsigned Code) const {
- SelectionDAGReducedValue *Vals = ValList;
- while (1) {
- assert(Vals && "Code does not exist in this list!");
- if (Vals->getValueCode() == Code)
- return (Type*)Vals;
- Vals = Vals->getNext();
- }
- }
-
- template<class Type>
- Type *hasValue(unsigned Code) const {
- SelectionDAGReducedValue *Vals = ValList;
- while (Vals) {
- if (Vals->getValueCode() == Code)
- return (Type*)Vals;
- Vals = Vals->getNext();
- }
- return false;
- }
-
- void addValue(SelectionDAGReducedValue *New) {
- assert(New->getNext() == 0);
- New->setNext(ValList);
- ValList = New;
+ /// getCall - Note that this destroys the vector of RetVals passed in.
+ ///
+ SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain,
+ SDOperand Callee) {
+ SDNode *NN = new SDNode(ISD::CALL, Chain, Callee);
+ NN->setValueTypes(RetVals);
+ AllNodes.push_back(NN);
+ return NN;
}
- //===--------------------------------------------------------------------===//
- // Utility methods used by the pattern matching instruction selector
- //
+ SDOperand getSetCC(ISD::CondCode, SDOperand LHS, SDOperand RHS);
- /// getPatternFor - Return the pattern selected to compute the specified slot,
- /// or zero if there is no pattern yet.
+ /// getNode - Gets or creates the specified node.
///
- unsigned getPatternFor(unsigned Slot) const {
- return Costs ? Costs[Slot*2] : 0;
- }
+ SDOperand getNode(unsigned Opcode, MVT::ValueType VT);
+ SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N);
+ SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
+ SDOperand N1, SDOperand N2);
+ SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
+ SDOperand N1, SDOperand N2, SDOperand N3);
+ SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
+ std::vector<SDOperand> &Children);
- /// getCostFor - Return the cost to compute the value corresponding to Slot.
+ /// getLoad - Loads are not normal binary operators: their result type is not
+ /// determined by their operands, and they produce a value AND a token chain.
///
- unsigned getCostFor(unsigned Slot) const {
- return Costs ? Costs[Slot*2+1] : 0;
- }
+ SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr);
- /// setPatternCostFor - Sets the pattern and the cost for the specified slot
- /// to the specified values. This allocates the Costs vector if necessary, so
- /// you must specify the maximum number of slots that may be used.
- ///
- void setPatternCostFor(unsigned Slot, unsigned Pattern, unsigned Cost,
- unsigned NumSlots) {
- if (Costs == 0) {
- Costs = new unsigned[NumSlots*2];
- for (unsigned i = 0; i != NumSlots*2; ++i) Costs[i] = 0;
- }
- Costs[Slot*2] = Pattern;
- Costs[Slot*2+1] = Cost;
+ void replaceAllUsesWith(SDOperand Old, SDOperand New) {
+ assert(Old != New && "RAUW self!");
+ assert(0 && "Unimplemented!");
}
void dump() const;
-private:
- void printit(unsigned Offset, unsigned &LastID,
- std::map<const SelectionDAGNode*, unsigned> &NodeIDs) const;
};
-
-/// SelectionDAGTargetBuilder - This class must be implemented by the target, to
-/// indicate how to perform the extremely target-specific tasks of building DAG
-/// nodes to represent the calling convention used by the target.
-///
-struct SelectionDAGTargetBuilder {
- /// expandArguments - This method is called once by the SelectionDAG
- /// construction mechanisms to add DAG nodes for each formal argument to the
- /// current function. If any of the incoming arguments lives on the stack,
- /// this method should also create the stack slots for the arguments as
- /// necessary.
- virtual void expandArguments(SelectionDAG &SD) = 0;
-
- /// expandCall - This method is called once per function call by the
- /// SelectionDAG construction algorithm. It must add DAG nodes to the
- /// SelectionDAG specified to perform that call.
- virtual void expandCall(SelectionDAG &SD, CallInst &CI) = 0;
-};
-
-namespace ISD {
- enum { // Builtin Slot numbers
- Constant_i1_Slot,
- Constant_i8_Slot,
- Constant_i16_Slot,
- Constant_i32_Slot,
- Constant_i64_Slot,
- Constant_f32_Slot,
- Constant_f64_Slot,
-
- FrameIndex_i32_Slot,
- FrameIndex_i64_Slot,
- BasicBlock_i32_Slot,
- BasicBlock_i64_Slot,
- NumBuiltinSlots
- };
}
-template<typename ValType, unsigned NodeCode>
-struct ReducedValue : public SelectionDAGReducedValue {
- ReducedValue(const ValType &V) : SelectionDAGReducedValue(NodeCode), Val(V) {}
- ValType Val;
-};
-
-typedef ReducedValue<int, ISD::FrameIndex_i32_Slot > ReducedValue_FrameIndex_i32;
-typedef ReducedValue<int, ISD::FrameIndex_i64_Slot > ReducedValue_FrameIndex_i64;
-typedef ReducedValue<MachineBasicBlock*, ISD::BasicBlock_i32_Slot > ReducedValue_BasicBlock_i32;
-typedef ReducedValue<MachineBasicBlock*, ISD::BasicBlock_i64_Slot > ReducedValue_BasicBlock_i64;
-
-typedef ReducedValue<bool , ISD::Constant_i1_Slot > ReducedValue_Constant_i1;
-typedef ReducedValue<unsigned char , ISD::Constant_i8_Slot > ReducedValue_Constant_i8;
-typedef ReducedValue<unsigned short, ISD::Constant_i16_Slot> ReducedValue_Constant_i16;
-typedef ReducedValue<unsigned , ISD::Constant_i32_Slot> ReducedValue_Constant_i32;
-typedef ReducedValue<uint64_t , ISD::Constant_i64_Slot> ReducedValue_Constant_i64;
-typedef ReducedValue<float , ISD::Constant_f32_Slot> ReducedValue_Constant_f32;
-typedef ReducedValue<double , ISD::Constant_f64_Slot> ReducedValue_Constant_f64;
-
-} // End llvm namespace
-
#endif
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