-// $Id$
-//---------------------------------------------------------------------------
-// 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
-//
-//---------------------------------------------------------------------------
+//===----------------------------------------------------------------------===//
#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 "llvm/Support/STLExtras.h"
+#include "Support/STLExtras.h"
+#include <alloca.h>
+using std::cerr;
+using std::vector;
//------------------------------------------------------------------------
// class InstrTreeNode
//------------------------------------------------------------------------
-void InstrTreeNode::dump(int dumpChildren, int indent) const {
+void
+InstrTreeNode::dump(int dumpChildren, int indent) const
+{
dumpNode(indent);
- if (dumpChildren) {
- if (leftChild())
- leftChild()->dump(dumpChildren, indent+1);
- if (rightChild())
- rightChild()->dump(dumpChildren, indent+1);
- }
+ if (dumpChildren)
+ {
+ if (LeftChild)
+ LeftChild->dump(dumpChildren, indent+1);
+ if (RightChild)
+ RightChild->dump(dumpChildren, indent+1);
+ }
}
InstructionNode::InstructionNode(Instruction* I)
- : InstrTreeNode(NTInstructionNode, I) {
+ : InstrTreeNode(NTInstructionNode, I),
+ codeIsFoldedIntoParent(false)
+{
opLabel = I->getOpcode();
// Distinguish special cases of some instructions such as Ret and Br
//
- if (opLabel == Instruction::Ret && ((ReturnInst*)I)->getReturnValue()) {
- opLabel = RetValueOp; // ret(value) operation
- } else if (opLabel == Instruction::Br &&
- !((BranchInst*)I)->isUnconditional()) {
- opLabel = BrCondOp; // br(cond) operation
- } else if (opLabel >= Instruction::SetEQ && opLabel <= Instruction::SetGT) {
- opLabel = SetCCOp; // common label for all SetCC ops
- } else if (opLabel == Instruction::Alloca && I->getNumOperands() > 0) {
- opLabel = AllocaN; // Alloca(ptr, N) operation
- } else if ((opLabel == Instruction::Load ||
- opLabel == Instruction::GetElementPtr) &&
- ((MemAccessInst*)I)->getFirstOffsetIdx() > 0) {
- opLabel = opLabel + 100; // load/getElem with index vector
- } else if (opLabel == Instruction::Cast) {
- 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::ArrayTyID: opLabel = ToArrayTy; break;
- case Type::PointerTyID: opLabel = ToPointerTy; break;
- default:
- // Just use `Cast' opcode otherwise. It's probably ignored.
- break;
+ if (opLabel == Instruction::Ret && cast<ReturnInst>(I)->getReturnValue())
+ {
+ opLabel = RetValueOp; // ret(value) operation
+ }
+ else if (opLabel ==Instruction::Br && !cast<BranchInst>(I)->isUnconditional())
+ {
+ opLabel = BrCondOp; // br(cond) operation
+ }
+ else if (opLabel >= Instruction::SetEQ && opLabel <= Instruction::SetGT)
+ {
+ opLabel = SetCCOp; // common label for all SetCC ops
+ }
+ else if (opLabel == Instruction::Alloca && I->getNumOperands() > 0)
+ {
+ opLabel = AllocaN; // Alloca(ptr, N) operation
+ }
+ 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 = (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 *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::ArrayTyID: opLabel = ToArrayTy; break;
+ case Type::PointerTyID: opLabel = ToPointerTy; break;
+ default:
+ // Just use `Cast' opcode otherwise. It's probably ignored.
+ break;
+ }
}
- }
}
-void InstructionNode::dumpNode(int indent) const {
+void
+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";
}
-void VRegListNode::dumpNode(int indent) const {
+void
+VRegListNode::dumpNode(int indent) const
+{
for (int i=0; i < indent; i++)
- cout << " ";
+ cerr << " ";
- cout << "List" << endl;
+ cerr << "List" << "\n";
}
-void VRegNode::dumpNode(int indent) const {
+void
+VRegNode::dumpNode(int indent) const
+{
for (int i=0; i < indent; i++)
- cout << " ";
+ cerr << " ";
- cout << "VReg " << getValue() << "\t(type "
- << (int) getValue()->getValueType() << ")" << endl;
+ cerr << "VReg " << getValue() << "\t(type "
+ << (int) getValue()->getValueType() << ")" << "\n";
}
-void ConstantNode::dumpNode(int indent) const {
+void
+ConstantNode::dumpNode(int indent) const
+{
for (int i=0; i < indent; i++)
- cout << " ";
+ cerr << " ";
- cout << "Constant " << getValue() << "\t(type "
- << (int) getValue()->getValueType() << ")" << endl;
+ cerr << "Constant " << getValue() << "\t(type "
+ << (int) getValue()->getValueType() << ")" << "\n";
}
-void LabelNode::dumpNode(int indent) const {
+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::dump() const {
- for (hash_set<InstructionNode*>::const_iterator I = treeRoots.begin();
- I != treeRoots.end(); ++I)
+InstrForest::InstrForest(Function *F)
+{
+ 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 (const_root_iterator I = roots_begin(); I != roots_end(); ++I)
(*I)->dump(/*dumpChildren*/ 1, /*indent*/ 0);
}
-inline void InstrForest::noteTreeNodeForInstr(Instruction *instr,
- InstructionNode *treeNode) {
- assert(treeNode->getNodeType() == InstrTreeNode::NTInstructionNode);
+inline void
+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)
+{
(*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 *Par, InstrTreeNode *Chld) {
- Par->LeftChild = Chld;
- Chld->Parent = Par;
- if (Chld->getNodeType() == InstrTreeNode::NTInstructionNode)
- treeRoots.erase((InstructionNode*)Chld); // no longer a tree root
+inline void
+InstrForest::setLeftChild(InstrTreeNode *parent, InstrTreeNode *child)
+{
+ 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 *Par, InstrTreeNode *Chld){
- Par->RightChild = Chld;
- Chld->Parent = Par;
- if (Chld->getNodeType() == InstrTreeNode::NTInstructionNode)
- treeRoots.erase((InstructionNode*)Chld); // no longer a tree root
+inline void
+InstrForest::setRightChild(InstrTreeNode *parent, InstrTreeNode *child)
+{
+ parent->RightChild = child;
+ child->Parent = parent;
+ if (InstructionNode* instrNode = dyn_cast<InstructionNode>(child))
+ eraseRoot(instrNode); // no longer a tree root
}
-InstructionNode *InstrForest::buildTreeForInstruction(Instruction *Inst) {
- InstructionNode *treeNode = getTreeNodeForInstr(Inst);
- if (treeNode) {
- // treeNode has already been constructed for this instruction
- assert(treeNode->getInstruction() == Inst);
- return treeNode;
- }
+InstructionNode*
+InstrForest::buildTreeForInstruction(Instruction *instr)
+{
+ 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(Inst);
- noteTreeNodeForInstr(Inst, treeNode);
+ treeNode = new InstructionNode(instr);
+ 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 need to create artificial list nodes to hold them.
- // (Note that we only not count operands that get tree nodes, and not
+ // (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
// if a fixed array is too small.
//
int numChildren = 0;
- const unsigned int MAX_CHILD = 8;
- static InstrTreeNode *fixedChildArray[MAX_CHILD];
InstrTreeNode **childArray =
- (Inst->getNumOperands() > MAX_CHILD)
- ? new (InstrTreeNode*)[Inst->getNumOperands()] : fixedChildArray;
+ (InstrTreeNode **)alloca(instr->getNumOperands()*sizeof(InstrTreeNode *));
//
// Walk the operands of the instruction
//
- for (Instruction::op_iterator O = Inst->op_begin(); O != Inst->op_end(); ++O){
- Value* operand = *O;
+ for (Instruction::op_iterator O = instr->op_begin(); O!=instr->op_end(); ++O)
+ {
+ 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 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->isBasicBlock() || operand->isMethod())
- && !Inst->isTerminator();
+ // Check latter condition here just to simplify the next IF.
+ bool includeAddressOperand =
+ (isa<BasicBlock>(operand) || isa<Function>(operand))
+ && !instr->isTerminator();
- if (includeAddressOperand || operand->isInstruction() ||
- operand->isConstant() || operand->isMethodArgument()) {
- // This operand is a data value
+ 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.
- //
- // (Note that if the value has only a single use (viz., `instr'),
- // the def of the value can be safely moved just before instr
- // and therefore it is safe to combine these two instructions.)
- //
- // In all other cases, the virtual register holding the value
- // is used directly, i.e., made a child of the instruction node.
- //
- InstrTreeNode* opTreeNode;
- if (operand->isInstruction() && operand->use_size() == 1 &&
- ((Instruction*)operand)->getParent() == Inst->getParent()) {
- // Recursively create a treeNode for it.
- opTreeNode = buildTreeForInstruction((Instruction*)operand);
- } else if (ConstPoolVal *CPV = operand->castConstant()) {
- // Create a leaf node for a constant
- opTreeNode = new ConstantNode(CPV);
- } else {
- // Create a leaf node for the virtual register
- opTreeNode = new VRegNode(operand);
- }
+ // 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 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
+ // and therefore it is safe to combine these two instructions.)
+ //
+ // In all other cases, the virtual register holding the value
+ // is used directly, i.e., made a child of the instruction node.
+ //
+ InstrTreeNode* opTreeNode;
+ 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 = buildTreeForInstruction((Instruction*)operand);
+ }
+ else if (Constant *CPV = dyn_cast<Constant>(operand))
+ {
+ // Create a leaf node for a constant
+ opTreeNode = new ConstantNode(CPV);
+ }
+ else
+ {
+ // Create a leaf node for the virtual register
+ opTreeNode = new VRegNode(operand);
+ }
- childArray[numChildren++] = opTreeNode;
+ childArray[numChildren++] = opTreeNode;
+ }
}
- }
//--------------------------------------------------------------------
// Add any selected operands as children in the tree.
InstrTreeNode *parent = treeNode;
- if (numChildren > 2) {
- unsigned instrOpcode = treeNode->getInstruction()->getOpcode();
- assert(instrOpcode == Instruction::PHINode ||
- instrOpcode == Instruction::Call ||
- instrOpcode == Instruction::Load ||
- instrOpcode == Instruction::Store ||
- instrOpcode == Instruction::GetElementPtr);
- }
+ if (numChildren > 2)
+ {
+ unsigned instrOpcode = treeNode->getInstruction()->getOpcode();
+ 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)
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();
- setRightChild(parent, listNode);
- setLeftChild(listNode, childArray[numChildren - n]);
- parent = listNode;
- }
+ for (n = numChildren-1; n >= 2; n--)
+ {
+ // We have more than two children
+ InstrTreeNode *listNode = new VRegListNode();
+ setRightChild(parent, listNode);
+ setLeftChild(listNode, childArray[numChildren - n]);
+ parent = listNode;
+ }
// Now insert the last remaining child (if any).
- if (numChildren >= 2) {
- assert(n == 1);
- setRightChild(parent, childArray[numChildren - 1]);
- }
-
- if (childArray != fixedChildArray)
- delete [] childArray;
+ if (numChildren >= 2)
+ {
+ assert(n == 1);
+ setRightChild(parent, childArray[numChildren - 1]);
+ }
return treeNode;
}
-
-
-InstrForest::InstrForest(Method *M) {
- for_each(M->inst_begin(), M->inst_end(),
- bind_obj(this, &InstrForest::buildTreeForInstruction));
-}
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