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+//===- PseudoLoweringEmitter.cpp - PseudoLowering Generator -----*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "pseudo-lowering"
+#include "Error.h"
+#include "CodeGenInstruction.h"
+#include "PseudoLoweringEmitter.h"
+#include "Record.h"
+#include "llvm/ADT/IndexedMap.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Debug.h"
+#include <vector>
+using namespace llvm;
+
+// FIXME: This pass currently can only expand a pseudo to a single instruction.
+// The pseudo expansion really should take a list of dags, not just
+// a single dag, so we can do fancier things.
+
+unsigned PseudoLoweringEmitter::
+addDagOperandMapping(Record *Rec, DagInit *Dag, CodeGenInstruction &Insn,
+ IndexedMap<OpData> &OperandMap, unsigned BaseIdx) {
+ unsigned OpsAdded = 0;
+ for (unsigned i = 0, e = Dag->getNumArgs(); i != e; ++i) {
+ if (DefInit *DI = dynamic_cast<DefInit*>(Dag->getArg(i))) {
+ // Physical register reference. Explicit check for the special case
+ // "zero_reg" definition.
+ if (DI->getDef()->isSubClassOf("Register") ||
+ DI->getDef()->getName() == "zero_reg") {
+ OperandMap[BaseIdx + i].Kind = OpData::Reg;
+ OperandMap[BaseIdx + i].Data.Reg = DI->getDef();
+ ++OpsAdded;
+ continue;
+ }
+
+ // Normal operands should always have the same type, or we have a
+ // problem.
+ // FIXME: We probably shouldn't ever get a non-zero BaseIdx here.
+ assert(BaseIdx == 0 && "Named subargument in pseudo expansion?!");
+ if (DI->getDef() != Insn.Operands[BaseIdx + i].Rec)
+ throw TGError(Rec->getLoc(),
+ "Pseudo operand type '" + DI->getDef()->getName() +
+ "' does not match expansion operand type '" +
+ Insn.Operands[BaseIdx + i].Rec->getName() + "'");
+ // Source operand maps to destination operand. The Data element
+ // will be filled in later, just set the Kind for now. Do it
+ // for each corresponding MachineInstr operand, not just the first.
+ for (unsigned I = 0, E = Insn.Operands[i].MINumOperands; I != E; ++I)
+ OperandMap[BaseIdx + i + I].Kind = OpData::Operand;
+ OpsAdded += Insn.Operands[i].MINumOperands;
+ } else if (IntInit *II = dynamic_cast<IntInit*>(Dag->getArg(i))) {
+ OperandMap[BaseIdx + i].Kind = OpData::Imm;
+ OperandMap[BaseIdx + i].Data.Imm = II->getValue();
+ ++OpsAdded;
+ } else if (DagInit *SubDag = dynamic_cast<DagInit*>(Dag->getArg(i))) {
+ // Just add the operands recursively. This is almost certainly
+ // a constant value for a complex operand (> 1 MI operand).
+ unsigned NewOps =
+ addDagOperandMapping(Rec, SubDag, Insn, OperandMap, BaseIdx + i);
+ OpsAdded += NewOps;
+ // Since we added more than one, we also need to adjust the base.
+ BaseIdx += NewOps - 1;
+ } else
+ assert(0 && "Unhandled pseudo-expansion argument type!");
+ }
+ return OpsAdded;
+}
+
+void PseudoLoweringEmitter::evaluateExpansion(Record *Rec) {
+ DEBUG(dbgs() << "Pseudo definition: " << Rec->getName() << "\n");
+
+ // Validate that the result pattern has the corrent number and types
+ // of arguments for the instruction it references.
+ DagInit *Dag = Rec->getValueAsDag("ResultInst");
+ assert(Dag && "Missing result instruction in pseudo expansion!");
+ DEBUG(dbgs() << " Result: " << *Dag << "\n");
+
+ DefInit *OpDef = dynamic_cast<DefInit*>(Dag->getOperator());
+ if (!OpDef)
+ throw TGError(Rec->getLoc(), Rec->getName() +
+ " has unexpected operator type!");
+ Record *Operator = OpDef->getDef();
+ if (!Operator->isSubClassOf("Instruction"))
+ throw TGError(Rec->getLoc(), "Pseudo result '" + Operator->getName() +
+ "' is not an instruction!");
+
+ CodeGenInstruction Insn(Operator);
+
+ if (Insn.isCodeGenOnly || Insn.isPseudo)
+ throw TGError(Rec->getLoc(), "Pseudo result '" + Operator->getName() +
+ "' cannot be another pseudo instruction!");
+
+ if (Insn.Operands.size() != Dag->getNumArgs())
+ throw TGError(Rec->getLoc(), "Pseudo result '" + Operator->getName() +
+ "' operand count mismatch");
+
+ IndexedMap<OpData> OperandMap;
+ OperandMap.grow(Insn.Operands.size());
+
+ addDagOperandMapping(Rec, Dag, Insn, OperandMap, 0);
+
+ // If there are more operands that weren't in the DAG, they have to
+ // be operands that have default values, or we have an error. Currently,
+ // PredicateOperand and OptionalDefOperand both have default values.
+
+
+ // Validate that each result pattern argument has a matching (by name)
+ // argument in the source instruction, in either the (outs) or (ins) list.
+ // Also check that the type of the arguments match.
+ //
+ // Record the mapping of the source to result arguments for use by
+ // the lowering emitter.
+ CodeGenInstruction SourceInsn(Rec);
+ StringMap<unsigned> SourceOperands;
+ for (unsigned i = 0, e = SourceInsn.Operands.size(); i != e; ++i)
+ SourceOperands[SourceInsn.Operands[i].Name] = i;
+
+ DEBUG(dbgs() << " Operand mapping:\n");
+ for (unsigned i = 0, e = Insn.Operands.size(); i != e; ++i) {
+ // We've already handled constant values. Just map instruction operands
+ // here.
+ if (OperandMap[Insn.Operands[i].MIOperandNo].Kind != OpData::Operand)
+ continue;
+ StringMap<unsigned>::iterator SourceOp =
+ SourceOperands.find(Dag->getArgName(i));
+ if (SourceOp == SourceOperands.end())
+ throw TGError(Rec->getLoc(),
+ "Pseudo output operand '" + Dag->getArgName(i) +
+ "' has no matching source operand.");
+ // Map the source operand to the destination operand index for each
+ // MachineInstr operand.
+ for (unsigned I = 0, E = Insn.Operands[i].MINumOperands; I != E; ++I)
+ OperandMap[Insn.Operands[i].MIOperandNo + I].Data.Operand =
+ SourceOp->getValue();
+
+ DEBUG(dbgs() << " " << SourceOp->getValue() << " ==> " << i << "\n");
+ }
+
+ Expansions.push_back(PseudoExpansion(SourceInsn, Insn, OperandMap));
+}
+
+void PseudoLoweringEmitter::emitLoweringEmitter(raw_ostream &o) {
+ // Emit file header.
+ EmitSourceFileHeader("Pseudo-instruction MC lowering Source Fragment", o);
+
+ o << "bool " << Target.getName() + "AsmPrinter" << "::\n"
+ << "emitPseudoExpansionLowering(MCStreamer &OutStreamer,\n"
+ << " const MachineInstr *MI) {\n"
+ << " switch (MI->getOpcode()) {\n"
+ << " default: return false;\n";
+ for (unsigned i = 0, e = Expansions.size(); i != e; ++i) {
+ PseudoExpansion &Expansion = Expansions[i];
+ CodeGenInstruction &Source = Expansion.Source;
+ CodeGenInstruction &Dest = Expansion.Dest;
+ o << " case " << Source.Namespace << "::"
+ << Source.TheDef->getName() << ": {\n"
+ << " MCInst TmpInst;\n"
+ << " MCOperand MCOp;\n"
+ << " TmpInst.setOpcode(" << Dest.Namespace << "::"
+ << Dest.TheDef->getName() << ");\n";
+
+ // Copy the operands from the source instruction.
+ // FIXME: Instruction operands with defaults values (predicates and cc_out
+ // in ARM, for example shouldn't need explicit values in the
+ // expansion DAG.
+ unsigned MIOpNo = 0;
+ for (unsigned OpNo = 0, E = Dest.Operands.size(); OpNo != E;
+ ++OpNo) {
+ o << " // Operand: " << Dest.Operands[OpNo].Name << "\n";
+ for (unsigned i = 0, e = Dest.Operands[OpNo].MINumOperands;
+ i != e; ++i) {
+ switch (Expansion.OperandMap[MIOpNo + i].Kind) {
+ default:
+ llvm_unreachable("Unknown operand type?!");
+ case OpData::Operand:
+ o << " lowerOperand(MI->getOperand("
+ << Source.Operands[Expansion.OperandMap[MIOpNo].Data
+ .Operand].MIOperandNo + i
+ << "), MCOp);\n"
+ << " TmpInst.addOperand(MCOp);\n";
+ break;
+ case OpData::Imm:
+ o << " TmpInst.addOperand(MCOperand::CreateImm("
+ << Expansion.OperandMap[MIOpNo + i].Data.Imm << "));\n";
+ break;
+ case OpData::Reg: {
+ Record *Reg = Expansion.OperandMap[MIOpNo + i].Data.Reg;
+ o << " TmpInst.addOperand(MCOperand::CreateReg(";
+ // "zero_reg" is special.
+ if (Reg->getName() == "zero_reg")
+ o << "0";
+ else
+ o << Reg->getValueAsString("Namespace") << "::" << Reg->getName();
+ o << "));\n";
+ break;
+ }
+ }
+ }
+ MIOpNo += Dest.Operands[OpNo].MINumOperands;
+ }
+ if (Dest.Operands.isVariadic) {
+ o << " // variable_ops\n";
+ o << " for (unsigned i = " << MIOpNo
+ << ", e = MI->getNumOperands(); i != e; ++i)\n"
+ << " if (lowerOperand(MI->getOperand(i), MCOp))\n"
+ << " TmpInst.addOperand(MCOp);\n";
+ }
+ o << " OutStreamer.EmitInstruction(TmpInst);\n"
+ << " break;\n"
+ << " }\n";
+ }
+ o << " }\n return true;\n}\n\n";
+}
+
+void PseudoLoweringEmitter::run(raw_ostream &o) {
+ Record *ExpansionClass = Records.getClass("PseudoInstExpansion");
+ Record *InstructionClass = Records.getClass("PseudoInstExpansion");
+ assert(ExpansionClass && "PseudoInstExpansion class definition missing!");
+ assert(InstructionClass && "Instruction class definition missing!");
+
+ std::vector<Record*> Insts;
+ for (std::map<std::string, Record*>::const_iterator I =
+ Records.getDefs().begin(), E = Records.getDefs().end(); I != E; ++I) {
+ if (I->second->isSubClassOf(ExpansionClass) &&
+ I->second->isSubClassOf(InstructionClass))
+ Insts.push_back(I->second);
+ }
+
+ // Process the pseudo expansion definitions, validating them as we do so.
+ for (unsigned i = 0, e = Insts.size(); i != e; ++i)
+ evaluateExpansion(Insts[i]);
+
+ // Generate expansion code to lower the pseudo to an MCInst of the real
+ // instruction.
+ emitLoweringEmitter(o);
+}
+
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