-// $Id$ -*-c++-*-
-//***************************************************************************
-// File:
-// InstrSelection.cpp
+//===- InstrSelection.cpp - Machine Independent Inst Selection Driver -----===//
//
-// Purpose:
-// Machine-independent driver file for instruction selection.
-// This file constructs a forest of BURG instruction trees and then
-// uses the BURG-generated tree grammar (BURM) to find the optimal
-// instruction sequences for a given machine.
+// 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.
+//
+//===----------------------------------------------------------------------===//
+//
+// Machine-independent driver file for instruction selection. This file
+// constructs a forest of BURG instruction trees and then uses the
+// BURG-generated tree grammar (BURM) to find the optimal instruction sequences
+// for a given machine.
//
-// History:
-// 7/02/01 - Vikram Adve - Created
-//**************************************************************************/
-
+//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/InstrSelection.h"
#include "llvm/CodeGen/InstrSelectionSupport.h"
#include "llvm/CodeGen/InstrForest.h"
#include "llvm/CodeGen/MachineCodeForInstruction.h"
-#include "llvm/CodeGen/MachineCodeForMethod.h"
-#include "llvm/Target/MachineRegInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/Target/TargetRegInfo.h"
#include "llvm/Target/TargetMachine.h"
-#include "llvm/BasicBlock.h"
#include "llvm/Function.h"
#include "llvm/iPHINode.h"
+#include "llvm/Pass.h"
#include "Support/CommandLine.h"
-#include <iostream>
-using std::cerr;
-
-//******************** Internal Data Declarations ************************/
-
-
-enum SelectDebugLevel_t {
- Select_NoDebugInfo,
- Select_PrintMachineCode,
- Select_DebugInstTrees,
- Select_DebugBurgTrees,
-};
-
-// Enable Debug Options to be specified on the command line
-cl::Enum<enum SelectDebugLevel_t> SelectDebugLevel("dselect", cl::Hidden,
- "enable instruction selection debugging information",
- clEnumValN(Select_NoDebugInfo, "n", "disable debug output"),
- clEnumValN(Select_PrintMachineCode, "y", "print generated machine code"),
- clEnumValN(Select_DebugInstTrees, "i", "print debugging info for instruction selection "),
- clEnumValN(Select_DebugBurgTrees, "b", "print burg trees"), 0);
+#include "Support/LeakDetector.h"
+using std::vector;
+std::vector<MachineInstr*>
+FixConstantOperandsForInstr(Instruction* vmInstr, MachineInstr* minstr,
+ TargetMachine& target);
-//******************** Forward Function Declarations ***********************/
-
-
-static bool SelectInstructionsForTree (InstrTreeNode* treeRoot,
- int goalnt,
- TargetMachine &target);
-
-static void PostprocessMachineCodeForTree(InstructionNode* instrNode,
- int ruleForNode,
- short* nts,
- TargetMachine &target);
+namespace {
+ //===--------------------------------------------------------------------===//
+ // SelectDebugLevel - Allow command line control over debugging.
+ //
+ enum SelectDebugLevel_t {
+ Select_NoDebugInfo,
+ Select_PrintMachineCode,
+ Select_DebugInstTrees,
+ Select_DebugBurgTrees,
+ };
+
+ // Enable Debug Options to be specified on the command line
+ cl::opt<SelectDebugLevel_t>
+ SelectDebugLevel("dselect", cl::Hidden,
+ cl::desc("enable instruction selection debug information"),
+ cl::values(
+ clEnumValN(Select_NoDebugInfo, "n", "disable debug output"),
+ clEnumValN(Select_PrintMachineCode, "y", "print generated machine code"),
+ clEnumValN(Select_DebugInstTrees, "i",
+ "print debugging info for instruction selection"),
+ clEnumValN(Select_DebugBurgTrees, "b", "print burg trees"),
+ 0));
+
+
+ //===--------------------------------------------------------------------===//
+ // InstructionSelection Pass
+ //
+ // This is the actual pass object that drives the instruction selection
+ // process.
+ //
+ class InstructionSelection : public FunctionPass {
+ TargetMachine &Target;
+ void InsertCodeForPhis(Function &F);
+ void InsertPhiElimInstructions(BasicBlock *BB,
+ const vector<MachineInstr*>& CpVec);
+ void SelectInstructionsForTree(InstrTreeNode* treeRoot, int goalnt);
+ void PostprocessMachineCodeForTree(InstructionNode* instrNode,
+ int ruleForNode, short* nts);
+ public:
+ InstructionSelection(TargetMachine &T) : Target(T) {}
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesCFG();
+ }
+
+ bool runOnFunction(Function &F);
+ virtual const char *getPassName() const { return "Instruction Selection"; }
+ };
+}
-static void InsertCode4AllPhisInMeth(Function *F, TargetMachine &target);
+TmpInstruction::TmpInstruction(MachineCodeForInstruction& mcfi,
+ Value *s1, Value *s2, const std::string &name)
+ : Instruction(s1->getType(), Instruction::UserOp1, name)
+{
+ mcfi.addTemp(this);
+ Operands.push_back(Use(s1, this)); // s1 must be non-null
+ if (s2) {
+ Operands.push_back(Use(s2, this));
+ }
+ // TmpInstructions should not be garbage checked.
+ LeakDetector::removeGarbageObject(this);
+}
+
+// Constructor that requires the type of the temporary to be specified.
+// Both S1 and S2 may be NULL.(
+TmpInstruction::TmpInstruction(MachineCodeForInstruction& mcfi,
+ const Type *Ty, Value *s1, Value* s2,
+ const std::string &name)
+ : Instruction(Ty, Instruction::UserOp1, name)
+{
+ mcfi.addTemp(this);
-//******************* Externally Visible Functions *************************/
+ if (s1) { Operands.push_back(Use(s1, this)); }
+ if (s2) { Operands.push_back(Use(s2, this)); }
+ // TmpInstructions should not be garbage checked.
+ LeakDetector::removeGarbageObject(this);
+}
-//---------------------------------------------------------------------------
-// Entry point for instruction selection using BURG.
-// Returns true if instruction selection failed, false otherwise.
-//---------------------------------------------------------------------------
-bool
-SelectInstructionsForMethod(Function *F, TargetMachine &target)
+bool InstructionSelection::runOnFunction(Function &F)
{
- bool failed = false;
-
//
// Build the instruction trees to be given as inputs to BURG.
//
- InstrForest instrForest(F);
+ InstrForest instrForest(&F);
if (SelectDebugLevel >= Select_DebugInstTrees)
{
- cerr << "\n\n*** Input to instruction selection for function "
- << F->getName() << "\n\n";
- F->dump();
-
- cerr << "\n\n*** Instruction trees for function "
- << F->getName() << "\n\n";
+ std::cerr << "\n\n*** Input to instruction selection for function "
+ << F.getName() << "\n\n" << F
+ << "\n\n*** Instruction trees for function "
+ << F.getName() << "\n\n";
instrForest.dump();
}
if (SelectDebugLevel >= Select_DebugBurgTrees)
{
printcover(basicNode, 1, 0);
- cerr << "\nCover cost == " << treecost(basicNode, 1, 0) << "\n\n";
+ std::cerr << "\nCover cost == " << treecost(basicNode, 1, 0) <<"\n\n";
printMatches(basicNode);
}
// Then recursively walk the tree to select instructions
- if (SelectInstructionsForTree(basicNode, /*goalnt*/1, target))
- {
- failed = true;
- break;
- }
+ SelectInstructionsForTree(basicNode, /*goalnt*/1);
}
//
- // Record instructions in the vector for each basic block
+ // Create the MachineBasicBlock records and add all of the MachineInstrs
+ // defined in the MachineCodeForInstruction objects to also live in the
+ // MachineBasicBlock objects.
//
- for (Function::iterator BI = F->begin(), BE = F->end(); BI != BE; ++BI)
+ MachineFunction &MF = MachineFunction::get(&F);
+ for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
+ MachineBasicBlock *MCBB = new MachineBasicBlock(BI);
+ MF.getBasicBlockList().push_back(MCBB);
+
for (BasicBlock::iterator II = BI->begin(); II != BI->end(); ++II) {
- MachineCodeForInstruction &mvec =MachineCodeForInstruction::get(II);
- for (unsigned i=0; i < mvec.size(); i++)
- BI->getMachineInstrVec().push_back(mvec[i]);
+ MachineCodeForInstruction &mvec = MachineCodeForInstruction::get(II);
+ MCBB->insert(MCBB->end(), mvec.begin(), mvec.end());
}
+ }
- // Insert phi elimination code -- added by Ruchira
- InsertCode4AllPhisInMeth(F, target);
-
+ // Insert phi elimination code
+ InsertCodeForPhis(F);
if (SelectDebugLevel >= Select_PrintMachineCode)
{
- cerr << "\n*** Machine instructions after INSTRUCTION SELECTION\n";
- MachineCodeForMethod::get(F).dump();
+ std::cerr << "\n*** Machine instructions after INSTRUCTION SELECTION\n";
+ MachineFunction::get(&F).dump();
}
- return false;
-}
-
-
-//*********************** Private Functions *****************************/
-
-
-//-------------------------------------------------------------------------
-// Thid method inserts a copy instruction to a predecessor BB as a result
-// of phi elimination.
-//-------------------------------------------------------------------------
-
-void
-InsertPhiElimInstructions(BasicBlock *BB, const vector<MachineInstr*>& CpVec)
-{
- Instruction *TermInst = (Instruction*)BB->getTerminator();
- MachineCodeForInstruction &MC4Term =MachineCodeForInstruction::get(TermInst);
- MachineInstr *FirstMIOfTerm = *( MC4Term.begin() );
-
- assert( FirstMIOfTerm && "No Machine Instrs for terminator" );
-
- // get an iterator to machine instructions in the BB
- MachineCodeForBasicBlock& bbMvec = BB->getMachineInstrVec();
- MachineCodeForBasicBlock::iterator MCIt = bbMvec.begin();
-
- // find the position of first machine instruction generated by the
- // terminator of this BB
- for( ; (MCIt != bbMvec.end()) && (*MCIt != FirstMIOfTerm) ; ++MCIt )
- ;
- assert( MCIt != bbMvec.end() && "Start inst of terminator not found");
-
- // insert the copy instructions just before the first machine instruction
- // generated for the terminator
- bbMvec.insert(MCIt, CpVec.begin(), CpVec.end());
-
- //cerr << "\nPhiElimination copy inst: " << *CopyInstVec[0];
+ return true;
}
//-------------------------------------------------------------------------
void
-InsertCode4AllPhisInMeth(Function *F, TargetMachine &target)
+InstructionSelection::InsertCodeForPhis(Function &F)
{
// for all basic blocks in function
//
- for (Function::iterator BB = F->begin(); BB != F->end(); ++BB) {
- BasicBlock::InstListType &InstList = BB->getInstList();
- for (BasicBlock::iterator IIt = InstList.begin();
- PHINode *PN = dyn_cast<PHINode>(&*IIt); ++IIt) {
+ MachineFunction &MF = MachineFunction::get(&F);
+ for (MachineFunction::iterator BB = MF.begin(); BB != MF.end(); ++BB) {
+ for (BasicBlock::const_iterator IIt = BB->getBasicBlock()->begin();
+ const PHINode *PN = dyn_cast<PHINode>(IIt); ++IIt) {
// FIXME: This is probably wrong...
Value *PhiCpRes = new PHINode(PN->getType(), "PhiCp:");
-
+
+ // The leak detector shouldn't track these nodes. They are not garbage,
+ // even though their parent field is never filled in.
+ //
+ LeakDetector::removeGarbageObject(PhiCpRes);
+
// for each incoming value of the phi, insert phi elimination
//
for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i) {
// insert the copy instruction to the predecessor BB
vector<MachineInstr*> mvec, CpVec;
- target.getRegInfo().cpValue2Value(PN->getIncomingValue(i), PhiCpRes,
+ Target.getRegInfo().cpValue2Value(PN->getIncomingValue(i), PhiCpRes,
mvec);
for (vector<MachineInstr*>::iterator MI=mvec.begin();
MI != mvec.end(); ++MI) {
vector<MachineInstr*> CpVec2 =
- FixConstantOperandsForInstr(PN, *MI, target);
+ FixConstantOperandsForInstr(const_cast<PHINode*>(PN), *MI, Target);
CpVec2.push_back(*MI);
CpVec.insert(CpVec.end(), CpVec2.begin(), CpVec2.end());
}
}
vector<MachineInstr*> mvec;
- target.getRegInfo().cpValue2Value(PhiCpRes, PN, mvec);
-
- // get an iterator to machine instructions in the BB
- MachineCodeForBasicBlock& bbMvec = BB->getMachineInstrVec();
-
- bbMvec.insert(bbMvec.begin(), mvec.begin(), mvec.end());
+ Target.getRegInfo().cpValue2Value(PhiCpRes, const_cast<PHINode*>(PN),
+ mvec);
+ BB->insert(BB->begin(), mvec.begin(), mvec.end());
} // for each Phi Instr in BB
} // for all BBs in function
}
+//-------------------------------------------------------------------------
+// Thid method inserts a copy instruction to a predecessor BB as a result
+// of phi elimination.
+//-------------------------------------------------------------------------
-//---------------------------------------------------------------------------
-// Function PostprocessMachineCodeForTree
-//
-// Apply any final cleanups to machine code for the root of a subtree
-// after selection for all its children has been completed.
-//---------------------------------------------------------------------------
-
-static void
-PostprocessMachineCodeForTree(InstructionNode* instrNode,
- int ruleForNode,
- short* nts,
- TargetMachine &target)
-{
- // Fix up any constant operands in the machine instructions to either
- // use an immediate field or to load the constant into a register
- // Walk backwards and use direct indexes to allow insertion before current
- //
- Instruction* vmInstr = instrNode->getInstruction();
- MachineCodeForInstruction &mvec = MachineCodeForInstruction::get(vmInstr);
- for (int i = (int) mvec.size()-1; i >= 0; i--)
- {
- std::vector<MachineInstr*> loadConstVec =
- FixConstantOperandsForInstr(vmInstr, mvec[i], target);
-
- if (loadConstVec.size() > 0)
- mvec.insert(mvec.begin()+i, loadConstVec.begin(), loadConstVec.end());
+void
+InstructionSelection::InsertPhiElimInstructions(BasicBlock *BB,
+ const vector<MachineInstr*>& CpVec)
+{
+ Instruction *TermInst = (Instruction*)BB->getTerminator();
+ MachineCodeForInstruction &MC4Term = MachineCodeForInstruction::get(TermInst);
+ MachineInstr *FirstMIOfTerm = MC4Term.front();
+ assert (FirstMIOfTerm && "No Machine Instrs for terminator");
+
+ MachineFunction &MF = MachineFunction::get(BB->getParent());
+
+ // FIXME: if PHI instructions existed in the machine code, this would be
+ // unnecessary.
+ MachineBasicBlock *MBB = 0;
+ for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)
+ if (I->getBasicBlock() == BB) {
+ MBB = I;
+ break;
}
+
+ // find the position of first machine instruction generated by the
+ // terminator of this BB
+ MachineBasicBlock::iterator MCIt =
+ std::find(MBB->begin(), MBB->end(), FirstMIOfTerm);
+
+ assert(MCIt != MBB->end() && "Start inst of terminator not found");
+
+ // insert the copy instructions just before the first machine instruction
+ // generated for the terminator
+ MBB->insert(MCIt, CpVec.begin(), CpVec.end());
}
+
//---------------------------------------------------------------------------
// Function SelectInstructionsForTree
//
// may be used by multiple instructions).
//---------------------------------------------------------------------------
-bool
-SelectInstructionsForTree(InstrTreeNode* treeRoot, int goalnt,
- TargetMachine &target)
+void
+InstructionSelection::SelectInstructionsForTree(InstrTreeNode* treeRoot,
+ int goalnt)
{
// Get the rule that matches this node.
//
int ruleForNode = burm_rule(treeRoot->state, goalnt);
- if (ruleForNode == 0)
- {
- cerr << "Could not match instruction tree for instr selection\n";
- assert(0);
- return true;
- }
+ if (ruleForNode == 0) {
+ std::cerr << "Could not match instruction tree for instr selection\n";
+ abort();
+ }
// Get this rule's non-terminals and the corresponding child nodes (if any)
//
InstructionNode* instrNode = (InstructionNode*)treeRoot;
assert(instrNode->getNodeType() == InstrTreeNode::NTInstructionNode);
- GetInstructionsByRule(instrNode, ruleForNode, nts, target, minstrVec);
+ GetInstructionsByRule(instrNode, ruleForNode, nts, Target, minstrVec);
MachineCodeForInstruction &mvec =
MachineCodeForInstruction::get(instrNode->getInstruction());
// Now we have the first non-chain rule so we have found
// the actual child nodes. Recursively compile them.
//
- for (int i = 0; nts[i]; i++)
+ for (unsigned i = 0; nts[i]; i++)
{
assert(i < 2);
InstrTreeNode::InstrTreeNodeType nodeType = kids[i]->getNodeType();
if (nodeType == InstrTreeNode::NTVRegListNode ||
nodeType == InstrTreeNode::NTInstructionNode)
- {
- if (SelectInstructionsForTree(kids[i], nts[i], target))
- return true; // failure
- }
+ SelectInstructionsForTree(kids[i], nts[i]);
}
}
- // Finally, do any postprocessing on this node after its children
+ // Finally, do any post-processing on this node after its children
// have been translated
//
if (treeRoot->opLabel != VRegListOp)
+ PostprocessMachineCodeForTree((InstructionNode*)treeRoot, ruleForNode, nts);
+}
+
+//---------------------------------------------------------------------------
+// Function PostprocessMachineCodeForTree
+//
+// Apply any final cleanups to machine code for the root of a subtree
+// after selection for all its children has been completed.
+//
+void
+InstructionSelection::PostprocessMachineCodeForTree(InstructionNode* instrNode,
+ int ruleForNode,
+ short* nts)
+{
+ // Fix up any constant operands in the machine instructions to either
+ // use an immediate field or to load the constant into a register
+ // Walk backwards and use direct indexes to allow insertion before current
+ //
+ Instruction* vmInstr = instrNode->getInstruction();
+ MachineCodeForInstruction &mvec = MachineCodeForInstruction::get(vmInstr);
+ for (unsigned i = mvec.size(); i != 0; --i)
{
- InstructionNode* instrNode = (InstructionNode*)treeRoot;
- PostprocessMachineCodeForTree(instrNode, ruleForNode, nts, target);
+ vector<MachineInstr*> loadConstVec =
+ FixConstantOperandsForInstr(vmInstr, mvec[i-1], Target);
+
+ mvec.insert(mvec.begin()+i-1, loadConstVec.begin(), loadConstVec.end());
}
-
- return false; // success
}
+
+
+//===----------------------------------------------------------------------===//
+// createInstructionSelectionPass - Public entrypoint for instruction selection
+// and this file as a whole...
+//
+FunctionPass *createInstructionSelectionPass(TargetMachine &T) {
+ return new InstructionSelection(T);
+}
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