-// $Id$
-//---------------------------------------------------------------------------
-// File:
-// InstrForest.cpp
-//
-// Purpose:
-// Convert SSA graph to instruction trees for instruction selection.
-//
-// Strategy:
+//===-- InstrForest.cpp - Build instruction forest for inst selection -----===//
+//
// The key goal is to group instructions into a single
// tree if one or more of them might be potentially combined into a single
// complex instruction in the target machine.
// and (2) O and I are part of the same basic block,
// and (3) O has only a single use, viz., I.
//
-// History:
-// 6/28/01 - Vikram Adve - Created
-//
-//---------------------------------------------------------------------------
-
-//*************************** User Include Files ***************************/
+//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/InstrForest.h"
-#include "llvm/Method.h"
+#include "llvm/CodeGen/MachineCodeForInstruction.h"
+#include "llvm/Function.h"
#include "llvm/iTerminators.h"
#include "llvm/iMemory.h"
-#include "llvm/ConstPoolVals.h"
-#include "llvm/BasicBlock.h"
+#include "llvm/Constant.h"
+#include "llvm/Type.h"
#include "llvm/CodeGen/MachineInstr.h"
-
+#include "Support/STLExtras.h"
+#include <alloca.h>
+using std::cerr;
+using std::vector;
//------------------------------------------------------------------------
// class InstrTreeNode
//------------------------------------------------------------------------
-
-InstrTreeNode::InstrTreeNode(InstrTreeNodeType nodeType,
- Value* _val)
- : treeNodeType(nodeType),
- val(_val)
-{
- basicNode.leftChild = NULL;
- basicNode.rightChild = NULL;
- basicNode.parent = NULL;
- basicNode.opLabel = InvalidOp;
- basicNode.treeNodePtr = this;
-}
-
void
-InstrTreeNode::dump(int dumpChildren,
- int indent) const
+InstrTreeNode::dump(int dumpChildren, int indent) const
{
- this->dumpNode(indent);
+ dumpNode(indent);
if (dumpChildren)
{
- if (leftChild())
- leftChild()->dump(dumpChildren, indent+1);
- if (rightChild())
- rightChild()->dump(dumpChildren, indent+1);
+ if (LeftChild)
+ LeftChild->dump(dumpChildren, indent+1);
+ if (RightChild)
+ RightChild->dump(dumpChildren, indent+1);
}
}
-InstructionNode::InstructionNode(Instruction* _instr)
- : InstrTreeNode(NTInstructionNode, _instr)
+InstructionNode::InstructionNode(Instruction* I)
+ : InstrTreeNode(NTInstructionNode, I),
+ codeIsFoldedIntoParent(false)
{
- OpLabel opLabel = _instr->getOpcode();
+ opLabel = I->getOpcode();
// Distinguish special cases of some instructions such as Ret and Br
//
- if (opLabel == Instruction::Ret && ((ReturnInst*) _instr)->getReturnValue())
+ if (opLabel == Instruction::Ret && cast<ReturnInst>(I)->getReturnValue())
{
- opLabel = RetValueOp; // ret(value) operation
+ opLabel = RetValueOp; // ret(value) operation
}
- else if (opLabel == Instruction::Br && ! ((BranchInst*) _instr)->isUnconditional())
+ else if (opLabel ==Instruction::Br && !cast<BranchInst>(I)->isUnconditional())
{
opLabel = BrCondOp; // br(cond) operation
}
{
opLabel = SetCCOp; // common label for all SetCC ops
}
- else if (opLabel == Instruction::Alloca && _instr->getNumOperands() > 0)
+ else if (opLabel == Instruction::Alloca && I->getNumOperands() > 0)
{
opLabel = AllocaN; // Alloca(ptr, N) operation
}
- else if ((opLabel == Instruction::Load ||
- opLabel == Instruction::GetElementPtr)
- && ((MemAccessInst*)_instr)->getFirstOffsetIdx() > 0)
+ else if (opLabel == Instruction::GetElementPtr &&
+ cast<GetElementPtrInst>(I)->hasIndices())
+ {
+ opLabel = opLabel + 100; // getElem with index vector
+ }
+ else if (opLabel == Instruction::Xor &&
+ BinaryOperator::isNot(I))
{
- opLabel = opLabel + 100; // load/getElem with index vector
+ opLabel = (I->getType() == Type::BoolTy)? NotOp // boolean Not operator
+ : BNotOp; // bitwise Not operator
+ }
+ else if (opLabel == Instruction::And ||
+ opLabel == Instruction::Or ||
+ opLabel == Instruction::Xor)
+ {
+ // Distinguish bitwise operators from logical operators!
+ if (I->getType() != Type::BoolTy)
+ opLabel = opLabel + 100; // bitwise operator
}
else if (opLabel == Instruction::Cast)
{
- const Type* instrValueType = _instr->getType();
- switch(instrValueType->getPrimitiveID())
+ const Type *ITy = I->getType();
+ switch(ITy->getPrimitiveID())
{
- case Type::BoolTyID: opLabel = ToBoolTy; break;
- case Type::UByteTyID: opLabel = ToUByteTy; break;
- case Type::SByteTyID: opLabel = ToSByteTy; break;
- case Type::UShortTyID: opLabel = ToUShortTy; break;
- case Type::ShortTyID: opLabel = ToShortTy; break;
- case Type::UIntTyID: opLabel = ToUIntTy; break;
- case Type::IntTyID: opLabel = ToIntTy; break;
- case Type::ULongTyID: opLabel = ToULongTy; break;
- case Type::LongTyID: opLabel = ToLongTy; break;
- case Type::FloatTyID: opLabel = ToFloatTy; break;
- case Type::DoubleTyID: opLabel = ToDoubleTy; break;
+ case Type::BoolTyID: opLabel = ToBoolTy; break;
+ case Type::UByteTyID: opLabel = ToUByteTy; break;
+ case Type::SByteTyID: opLabel = ToSByteTy; break;
+ case Type::UShortTyID: opLabel = ToUShortTy; break;
+ case Type::ShortTyID: opLabel = ToShortTy; break;
+ case Type::UIntTyID: opLabel = ToUIntTy; break;
+ case Type::IntTyID: opLabel = ToIntTy; break;
+ case Type::ULongTyID: opLabel = ToULongTy; break;
+ case Type::LongTyID: opLabel = ToLongTy; break;
+ case Type::FloatTyID: opLabel = ToFloatTy; break;
+ case Type::DoubleTyID: opLabel = ToDoubleTy; break;
+ case Type::ArrayTyID: opLabel = ToArrayTy; break;
+ case Type::PointerTyID: opLabel = ToPointerTy; break;
default:
- if (instrValueType->isArrayType())
- opLabel = ToArrayTy;
- else if (instrValueType->isPointerType())
- opLabel = ToPointerTy;
- else
- ; // Just use `Cast' opcode otherwise. It's probably ignored.
+ // Just use `Cast' opcode otherwise. It's probably ignored.
break;
}
}
-
- basicNode.opLabel = opLabel;
}
InstructionNode::dumpNode(int indent) const
{
for (int i=0; i < indent; i++)
- cout << " ";
-
- cout << getInstruction()->getOpcodeName();
-
- const vector<MachineInstr*>& mvec = getInstruction()->getMachineInstrVec();
- if (mvec.size() > 0)
- cout << "\tMachine Instructions: ";
- for (unsigned int i=0; i < mvec.size(); i++)
- {
- mvec[i]->dump(0);
- if (i < mvec.size() - 1)
- cout << "; ";
- }
-
- cout << endl;
+ cerr << " ";
+ cerr << getInstruction()->getOpcodeName()
+ << " [label " << getOpLabel() << "]" << "\n";
}
-VRegListNode::VRegListNode()
- : InstrTreeNode(NTVRegListNode, NULL)
-{
- basicNode.opLabel = VRegListOp;
-}
-
void
VRegListNode::dumpNode(int indent) const
{
for (int i=0; i < indent; i++)
- cout << " ";
+ cerr << " ";
- cout << "List" << endl;
+ cerr << "List" << "\n";
}
-VRegNode::VRegNode(Value* _val)
- : InstrTreeNode(NTVRegNode, _val)
-{
- basicNode.opLabel = VRegNodeOp;
-}
-
void
VRegNode::dumpNode(int indent) const
{
for (int i=0; i < indent; i++)
- cout << " ";
+ cerr << " ";
- cout << "VReg " << getValue() << "\t(type "
- << (int) getValue()->getValueType() << ")" << endl;
-}
-
-
-ConstantNode::ConstantNode(ConstPoolVal* constVal)
- : InstrTreeNode(NTConstNode, constVal)
-{
- basicNode.opLabel = ConstantNodeOp;
+ cerr << "VReg " << getValue() << "\t(type "
+ << (int) getValue()->getValueType() << ")" << "\n";
}
void
ConstantNode::dumpNode(int indent) const
{
for (int i=0; i < indent; i++)
- cout << " ";
+ cerr << " ";
- cout << "Constant " << getValue() << "\t(type "
- << (int) getValue()->getValueType() << ")" << endl;
-}
-
-
-LabelNode::LabelNode(BasicBlock* _bblock)
- : InstrTreeNode(NTLabelNode, _bblock)
-{
- basicNode.opLabel = LabelNodeOp;
+ cerr << "Constant " << getValue() << "\t(type "
+ << (int) getValue()->getValueType() << ")" << "\n";
}
void
LabelNode::dumpNode(int indent) const
{
for (int i=0; i < indent; i++)
- cout << " ";
+ cerr << " ";
- cout << "Label " << getValue() << endl;
+ cerr << "Label " << getValue() << "\n";
}
//------------------------------------------------------------------------
// A forest of instruction trees, usually for a single method.
//------------------------------------------------------------------------
-void
-InstrForest::buildTreesForMethod(Method *method)
+InstrForest::InstrForest(Function *F)
{
- for (Method::inst_iterator instrIter = method->inst_begin();
- instrIter != method->inst_end();
- ++instrIter)
- {
- Instruction *instr = *instrIter;
- if (! instr->isPHINode())
- (void) this->buildTreeForInstruction(instr);
- }
+ for (Function::iterator BB = F->begin(), FE = F->end(); BB != FE; ++BB) {
+ for(BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
+ buildTreeForInstruction(I);
+ }
}
+InstrForest::~InstrForest()
+{
+ for_each(treeRoots.begin(), treeRoots.end(), deleter<InstructionNode>);
+}
void
InstrForest::dump() const
{
- for (hash_set<InstructionNode*>::const_iterator
- treeRootIter = treeRoots.begin();
- treeRootIter != treeRoots.end();
- ++treeRootIter)
- {
- (*treeRootIter)->dump(/*dumpChildren*/ 1, /*indent*/ 0);
- }
+ for (const_root_iterator I = roots_begin(); I != roots_end(); ++I)
+ (*I)->dump(/*dumpChildren*/ 1, /*indent*/ 0);
}
inline void
-InstrForest::noteTreeNodeForInstr(Instruction* instr,
- InstructionNode* treeNode)
+InstrForest::eraseRoot(InstructionNode* node)
+{
+ for (RootSet::reverse_iterator RI=treeRoots.rbegin(), RE=treeRoots.rend();
+ RI != RE; ++RI)
+ if (*RI == node)
+ treeRoots.erase(RI.base()-1);
+}
+
+inline void
+InstrForest::noteTreeNodeForInstr(Instruction *instr,
+ InstructionNode *treeNode)
{
- assert(treeNode->getNodeType() == InstrTreeNode::NTInstructionNode);
(*this)[instr] = treeNode;
- treeRoots.insert(treeNode); // mark node as root of a new tree
+ treeRoots.push_back(treeNode); // mark node as root of a new tree
}
inline void
-InstrForest::setLeftChild(InstrTreeNode* parent, InstrTreeNode* child)
+InstrForest::setLeftChild(InstrTreeNode *parent, InstrTreeNode *child)
{
- parent->basicNode.leftChild = & child->basicNode;
- child->basicNode.parent = & parent->basicNode;
- if (child->getNodeType() == InstrTreeNode::NTInstructionNode)
- treeRoots.erase((InstructionNode*) child); // no longer a tree root
+ parent->LeftChild = child;
+ child->Parent = parent;
+ if (InstructionNode* instrNode = dyn_cast<InstructionNode>(child))
+ eraseRoot(instrNode); // no longer a tree root
}
-
inline void
-InstrForest::setRightChild(InstrTreeNode* parent, InstrTreeNode* child)
+InstrForest::setRightChild(InstrTreeNode *parent, InstrTreeNode *child)
{
- parent->basicNode.rightChild = & child->basicNode;
- child->basicNode.parent = & parent->basicNode;
- if (child->getNodeType() == InstrTreeNode::NTInstructionNode)
- treeRoots.erase((InstructionNode*) child); // no longer a tree root
+ parent->RightChild = child;
+ child->Parent = parent;
+ if (InstructionNode* instrNode = dyn_cast<InstructionNode>(child))
+ eraseRoot(instrNode); // no longer a tree root
}
InstructionNode*
-InstrForest::buildTreeForInstruction(Instruction* instr)
+InstrForest::buildTreeForInstruction(Instruction *instr)
{
- InstructionNode* treeNode = this->getTreeNodeForInstr(instr);
- if (treeNode != NULL)
- {// treeNode has already been constructed for this instruction
+ InstructionNode *treeNode = getTreeNodeForInstr(instr);
+ if (treeNode)
+ {
+ // treeNode has already been constructed for this instruction
assert(treeNode->getInstruction() == instr);
return treeNode;
}
// Otherwise, create a new tree node for this instruction.
//
treeNode = new InstructionNode(instr);
- this->noteTreeNodeForInstr(instr, treeNode);
+ noteTreeNodeForInstr(instr, treeNode);
+
+ if (instr->getOpcode() == Instruction::Call)
+ { // Operands of call instruction
+ return treeNode;
+ }
// If the instruction has more than 2 instruction operands,
- // then we will not add any children. This assumes that instructions
- // like 'call' that have more than 2 instruction operands do not
- // ever get combined with the instructions that compute the operands.
- // Note that we only count operands of type instruction and not other
- // values such as branch labels for a branch or switch instruction.
+ // then we need to create artificial list nodes to hold them.
+ // (Note that we only count operands that get tree nodes, and not
+ // others such as branch labels for a branch or switch instruction.)
//
// To do this efficiently, we'll walk all operands, build treeNodes
- // for all instruction operands and save them in an array, and then
- // insert children at the end if there are not more than 2.
+ // for all appropriate operands and save them in an array. We then
+ // insert children at the end, creating list nodes where needed.
// As a performance optimization, allocate a child array only
// if a fixed array is too small.
//
int numChildren = 0;
- const unsigned int MAX_CHILD = 8;
- static InstrTreeNode* fixedChildArray[MAX_CHILD];
- InstrTreeNode** childArray =
- (instr->getNumOperands() > MAX_CHILD)
- ? new (InstrTreeNode*)[instr->getNumOperands()]
- : fixedChildArray;
+ InstrTreeNode **childArray =
+ (InstrTreeNode **)alloca(instr->getNumOperands()*sizeof(InstrTreeNode *));
//
// Walk the operands of the instruction
//
- for (Instruction::op_iterator opIter = instr->op_begin();
- opIter != instr->op_end();
- ++opIter)
+ for (Instruction::op_iterator O = instr->op_begin(); O!=instr->op_end(); ++O)
{
- Value* operand = *opIter;
+ Value* operand = *O;
// Check if the operand is a data value, not an branch label, type,
// method or module. If the operand is an address type (i.e., label
// or method) that is used in an non-branching operation, e.g., `add'.
// that should be considered a data value.
-
+
// Check latter condition here just to simplify the next IF.
bool includeAddressOperand =
- ((operand->getValueType() == Value::BasicBlockVal
- || operand->getValueType() == Value::MethodVal)
- && ! instr->isTerminator());
-
- if (/* (*opIter) != NULL
- &&*/ includeAddressOperand
- || operand->getValueType() == Value::InstructionVal
- || operand->getValueType() == Value::ConstantVal
- || operand->getValueType() == Value::MethodArgumentVal)
- {// This operand is a data value
-
+ (isa<BasicBlock>(operand) || isa<Function>(operand))
+ && !instr->isTerminator();
+
+ if (includeAddressOperand || isa<Instruction>(operand) ||
+ isa<Constant>(operand) || isa<Argument>(operand) ||
+ isa<GlobalVariable>(operand))
+ {
+ // This operand is a data value
+
// An instruction that computes the incoming value is added as a
// child of the current instruction if:
// the value has only a single use
- // AND both instructions are in the same basic block
- // AND the instruction is not a PHI
+ // AND both instructions are in the same basic block.
+ // AND the current instruction is not a PHI (because the incoming
+ // value is conceptually in a predecessor block,
+ // even though it may be in the same static block)
//
// (Note that if the value has only a single use (viz., `instr'),
// the def of the value can be safely moved just before instr
// is used directly, i.e., made a child of the instruction node.
//
InstrTreeNode* opTreeNode;
- if (operand->getValueType() == Value::InstructionVal
- && operand->use_size() == 1
- && ((Instruction*)operand)->getParent() == instr->getParent()
- && ! ((Instruction*)operand)->isPHINode())
+ if (isa<Instruction>(operand) && operand->use_size() == 1 &&
+ cast<Instruction>(operand)->getParent() == instr->getParent() &&
+ instr->getOpcode() != Instruction::PHINode &&
+ instr->getOpcode() != Instruction::Call)
{
// Recursively create a treeNode for it.
- opTreeNode =this->buildTreeForInstruction((Instruction*)operand);
+ opTreeNode = buildTreeForInstruction((Instruction*)operand);
}
- else if (operand->getValueType() == Value::ConstantVal)
+ else if (Constant *CPV = dyn_cast<Constant>(operand))
{
// Create a leaf node for a constant
- opTreeNode = new ConstantNode((ConstPoolVal*) operand);
+ opTreeNode = new ConstantNode(CPV);
}
else
{
// Create a leaf node for the virtual register
opTreeNode = new VRegNode(operand);
}
-
- childArray[numChildren] = opTreeNode;
- numChildren++;
+
+ childArray[numChildren++] = opTreeNode;
}
}
// and VRegList nodes as internal nodes.
//--------------------------------------------------------------------
- InstrTreeNode* parent = treeNode; // new VRegListNode();
- int n;
+ InstrTreeNode *parent = treeNode;
if (numChildren > 2)
{
unsigned instrOpcode = treeNode->getInstruction()->getOpcode();
- assert(instrOpcode == Instruction::Call ||
+ assert(instrOpcode == Instruction::PHINode ||
+ instrOpcode == Instruction::Call ||
instrOpcode == Instruction::Load ||
instrOpcode == Instruction::Store ||
instrOpcode == Instruction::GetElementPtr);
// Insert the first child as a direct child
if (numChildren >= 1)
- this->setLeftChild(parent, childArray[0]);
+ setLeftChild(parent, childArray[0]);
+
+ int n;
// Create a list node for children 2 .. N-1, if any
for (n = numChildren-1; n >= 2; n--)
- { // We have more than two children
- InstrTreeNode* listNode = new VRegListNode();
- this->setRightChild(parent, listNode);
- this->setLeftChild(listNode, childArray[numChildren - n]);
+ {
+ // We have more than two children
+ InstrTreeNode *listNode = new VRegListNode();
+ setRightChild(parent, listNode);
+ setLeftChild(listNode, childArray[numChildren - n]);
parent = listNode;
}
if (numChildren >= 2)
{
assert(n == 1);
- this->setRightChild(parent, childArray[numChildren - 1]);
- }
-
- if (childArray != fixedChildArray)
- {
- delete[] childArray;
+ setRightChild(parent, childArray[numChildren - 1]);
}
return treeNode;
}
-