llvm-6502/utils/TableGen/InstrInfoEmitter.cpp
Evan Cheng c4af4638df Remove ARM isel hacks that fold large immediates into a pair of add, sub, and,
and xor. The 32-bit move immediates can be hoisted out of loops by machine
LICM but the isel hacks were preventing them.

Instead, let peephole optimization pass recognize registers that are defined by
immediates and the ARM target hook will fold the immediates in.

Other changes include 1) do not fold and / xor into cmp to isel TST / TEQ
instructions if there are multiple uses. This happens when the 'and' is live
out, machine sink would have sinked the computation and that ends up pessimizing
code. The peephole pass would recognize situations where the 'and' can be
toggled to define CPSR and eliminate the comparison anyway.

2) Move peephole pass to after machine LICM, sink, and CSE to avoid blocking
important optimizations.

rdar://8663787, rdar://8241368


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119548 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-17 20:13:28 +00:00

337 lines
13 KiB
C++

//===- InstrInfoEmitter.cpp - Generate a Instruction Set Desc. ------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This tablegen backend is responsible for emitting a description of the target
// instruction set for the code generator.
//
//===----------------------------------------------------------------------===//
#include "InstrInfoEmitter.h"
#include "CodeGenTarget.h"
#include "Record.h"
#include "llvm/ADT/StringExtras.h"
#include <algorithm>
using namespace llvm;
static void PrintDefList(const std::vector<Record*> &Uses,
unsigned Num, raw_ostream &OS) {
OS << "static const unsigned ImplicitList" << Num << "[] = { ";
for (unsigned i = 0, e = Uses.size(); i != e; ++i)
OS << getQualifiedName(Uses[i]) << ", ";
OS << "0 };\n";
}
static void PrintBarriers(std::vector<Record*> &Barriers,
unsigned Num, raw_ostream &OS) {
OS << "static const TargetRegisterClass* Barriers" << Num << "[] = { ";
for (unsigned i = 0, e = Barriers.size(); i != e; ++i)
OS << "&" << getQualifiedName(Barriers[i]) << "RegClass, ";
OS << "NULL };\n";
}
//===----------------------------------------------------------------------===//
// Instruction Itinerary Information.
//===----------------------------------------------------------------------===//
void InstrInfoEmitter::GatherItinClasses() {
std::vector<Record*> DefList =
Records.getAllDerivedDefinitions("InstrItinClass");
std::sort(DefList.begin(), DefList.end(), LessRecord());
for (unsigned i = 0, N = DefList.size(); i < N; i++)
ItinClassMap[DefList[i]->getName()] = i;
}
unsigned InstrInfoEmitter::getItinClassNumber(const Record *InstRec) {
return ItinClassMap[InstRec->getValueAsDef("Itinerary")->getName()];
}
//===----------------------------------------------------------------------===//
// Operand Info Emission.
//===----------------------------------------------------------------------===//
std::vector<std::string>
InstrInfoEmitter::GetOperandInfo(const CodeGenInstruction &Inst) {
std::vector<std::string> Result;
for (unsigned i = 0, e = Inst.Operands.size(); i != e; ++i) {
// Handle aggregate operands and normal operands the same way by expanding
// either case into a list of operands for this op.
std::vector<CGIOperandList::OperandInfo> OperandList;
// This might be a multiple operand thing. Targets like X86 have
// registers in their multi-operand operands. It may also be an anonymous
// operand, which has a single operand, but no declared class for the
// operand.
DagInit *MIOI = Inst.Operands[i].MIOperandInfo;
if (!MIOI || MIOI->getNumArgs() == 0) {
// Single, anonymous, operand.
OperandList.push_back(Inst.Operands[i]);
} else {
for (unsigned j = 0, e = Inst.Operands[i].MINumOperands; j != e; ++j) {
OperandList.push_back(Inst.Operands[i]);
Record *OpR = dynamic_cast<DefInit*>(MIOI->getArg(j))->getDef();
OperandList.back().Rec = OpR;
}
}
for (unsigned j = 0, e = OperandList.size(); j != e; ++j) {
Record *OpR = OperandList[j].Rec;
std::string Res;
if (OpR->isSubClassOf("RegisterClass"))
Res += getQualifiedName(OpR) + "RegClassID, ";
else if (OpR->isSubClassOf("PointerLikeRegClass"))
Res += utostr(OpR->getValueAsInt("RegClassKind")) + ", ";
else
// -1 means the operand does not have a fixed register class.
Res += "-1, ";
// Fill in applicable flags.
Res += "0";
// Ptr value whose register class is resolved via callback.
if (OpR->isSubClassOf("PointerLikeRegClass"))
Res += "|(1<<TOI::LookupPtrRegClass)";
// Predicate operands. Check to see if the original unexpanded operand
// was of type PredicateOperand.
if (Inst.Operands[i].Rec->isSubClassOf("PredicateOperand"))
Res += "|(1<<TOI::Predicate)";
// Optional def operands. Check to see if the original unexpanded operand
// was of type OptionalDefOperand.
if (Inst.Operands[i].Rec->isSubClassOf("OptionalDefOperand"))
Res += "|(1<<TOI::OptionalDef)";
// Fill in constraint info.
Res += ", ";
const CGIOperandList::ConstraintInfo &Constraint =
Inst.Operands[i].Constraints[j];
if (Constraint.isNone())
Res += "0";
else if (Constraint.isEarlyClobber())
Res += "(1 << TOI::EARLY_CLOBBER)";
else {
assert(Constraint.isTied());
Res += "((" + utostr(Constraint.getTiedOperand()) +
" << 16) | (1 << TOI::TIED_TO))";
}
Result.push_back(Res);
}
}
return Result;
}
void InstrInfoEmitter::EmitOperandInfo(raw_ostream &OS,
OperandInfoMapTy &OperandInfoIDs) {
// ID #0 is for no operand info.
unsigned OperandListNum = 0;
OperandInfoIDs[std::vector<std::string>()] = ++OperandListNum;
OS << "\n";
const CodeGenTarget &Target = CDP.getTargetInfo();
for (CodeGenTarget::inst_iterator II = Target.inst_begin(),
E = Target.inst_end(); II != E; ++II) {
std::vector<std::string> OperandInfo = GetOperandInfo(**II);
unsigned &N = OperandInfoIDs[OperandInfo];
if (N != 0) continue;
N = ++OperandListNum;
OS << "static const TargetOperandInfo OperandInfo" << N << "[] = { ";
for (unsigned i = 0, e = OperandInfo.size(); i != e; ++i)
OS << "{ " << OperandInfo[i] << " }, ";
OS << "};\n";
}
}
void InstrInfoEmitter::DetectRegisterClassBarriers(std::vector<Record*> &Defs,
const std::vector<CodeGenRegisterClass> &RCs,
std::vector<Record*> &Barriers) {
std::set<Record*> DefSet;
unsigned NumDefs = Defs.size();
for (unsigned i = 0; i < NumDefs; ++i)
DefSet.insert(Defs[i]);
for (unsigned i = 0, e = RCs.size(); i != e; ++i) {
const CodeGenRegisterClass &RC = RCs[i];
unsigned NumRegs = RC.Elements.size();
if (NumRegs > NumDefs)
continue; // Can't possibly clobber this RC.
bool Clobber = true;
for (unsigned j = 0; j < NumRegs; ++j) {
Record *Reg = RC.Elements[j];
if (!DefSet.count(Reg)) {
Clobber = false;
break;
}
}
if (Clobber)
Barriers.push_back(RC.TheDef);
}
}
//===----------------------------------------------------------------------===//
// Main Output.
//===----------------------------------------------------------------------===//
// run - Emit the main instruction description records for the target...
void InstrInfoEmitter::run(raw_ostream &OS) {
GatherItinClasses();
EmitSourceFileHeader("Target Instruction Descriptors", OS);
OS << "namespace llvm {\n\n";
CodeGenTarget &Target = CDP.getTargetInfo();
const std::string &TargetName = Target.getName();
Record *InstrInfo = Target.getInstructionSet();
const std::vector<CodeGenRegisterClass> &RCs = Target.getRegisterClasses();
// Keep track of all of the def lists we have emitted already.
std::map<std::vector<Record*>, unsigned> EmittedLists;
unsigned ListNumber = 0;
std::map<std::vector<Record*>, unsigned> EmittedBarriers;
unsigned BarrierNumber = 0;
std::map<Record*, unsigned> BarriersMap;
// Emit all of the instruction's implicit uses and defs.
for (CodeGenTarget::inst_iterator II = Target.inst_begin(),
E = Target.inst_end(); II != E; ++II) {
Record *Inst = (*II)->TheDef;
std::vector<Record*> Uses = Inst->getValueAsListOfDefs("Uses");
if (!Uses.empty()) {
unsigned &IL = EmittedLists[Uses];
if (!IL) PrintDefList(Uses, IL = ++ListNumber, OS);
}
std::vector<Record*> Defs = Inst->getValueAsListOfDefs("Defs");
if (!Defs.empty()) {
std::vector<Record*> RCBarriers;
DetectRegisterClassBarriers(Defs, RCs, RCBarriers);
if (!RCBarriers.empty()) {
unsigned &IB = EmittedBarriers[RCBarriers];
if (!IB) PrintBarriers(RCBarriers, IB = ++BarrierNumber, OS);
BarriersMap.insert(std::make_pair(Inst, IB));
}
unsigned &IL = EmittedLists[Defs];
if (!IL) PrintDefList(Defs, IL = ++ListNumber, OS);
}
}
OperandInfoMapTy OperandInfoIDs;
// Emit all of the operand info records.
EmitOperandInfo(OS, OperandInfoIDs);
// Emit all of the TargetInstrDesc records in their ENUM ordering.
//
OS << "\nstatic const TargetInstrDesc " << TargetName
<< "Insts[] = {\n";
const std::vector<const CodeGenInstruction*> &NumberedInstructions =
Target.getInstructionsByEnumValue();
for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i)
emitRecord(*NumberedInstructions[i], i, InstrInfo, EmittedLists,
BarriersMap, OperandInfoIDs, OS);
OS << "};\n";
OS << "} // End llvm namespace \n";
}
void InstrInfoEmitter::emitRecord(const CodeGenInstruction &Inst, unsigned Num,
Record *InstrInfo,
std::map<std::vector<Record*>, unsigned> &EmittedLists,
std::map<Record*, unsigned> &BarriersMap,
const OperandInfoMapTy &OpInfo,
raw_ostream &OS) {
int MinOperands = 0;
if (!Inst.Operands.size() == 0)
// Each logical operand can be multiple MI operands.
MinOperands = Inst.Operands.back().MIOperandNo +
Inst.Operands.back().MINumOperands;
OS << " { ";
OS << Num << ",\t" << MinOperands << ",\t"
<< Inst.Operands.NumDefs << ",\t" << getItinClassNumber(Inst.TheDef)
<< ",\t\"" << Inst.TheDef->getName() << "\", 0";
// Emit all of the target indepedent flags...
if (Inst.isReturn) OS << "|(1<<TID::Return)";
if (Inst.isBranch) OS << "|(1<<TID::Branch)";
if (Inst.isIndirectBranch) OS << "|(1<<TID::IndirectBranch)";
if (Inst.isCompare) OS << "|(1<<TID::Compare)";
if (Inst.isMoveImm) OS << "|(1<<TID::MoveImm)";
if (Inst.isBarrier) OS << "|(1<<TID::Barrier)";
if (Inst.hasDelaySlot) OS << "|(1<<TID::DelaySlot)";
if (Inst.isCall) OS << "|(1<<TID::Call)";
if (Inst.canFoldAsLoad) OS << "|(1<<TID::FoldableAsLoad)";
if (Inst.mayLoad) OS << "|(1<<TID::MayLoad)";
if (Inst.mayStore) OS << "|(1<<TID::MayStore)";
if (Inst.isPredicable) OS << "|(1<<TID::Predicable)";
if (Inst.isConvertibleToThreeAddress) OS << "|(1<<TID::ConvertibleTo3Addr)";
if (Inst.isCommutable) OS << "|(1<<TID::Commutable)";
if (Inst.isTerminator) OS << "|(1<<TID::Terminator)";
if (Inst.isReMaterializable) OS << "|(1<<TID::Rematerializable)";
if (Inst.isNotDuplicable) OS << "|(1<<TID::NotDuplicable)";
if (Inst.Operands.hasOptionalDef) OS << "|(1<<TID::HasOptionalDef)";
if (Inst.usesCustomInserter) OS << "|(1<<TID::UsesCustomInserter)";
if (Inst.Operands.isVariadic)OS << "|(1<<TID::Variadic)";
if (Inst.hasSideEffects) OS << "|(1<<TID::UnmodeledSideEffects)";
if (Inst.isAsCheapAsAMove) OS << "|(1<<TID::CheapAsAMove)";
if (Inst.hasExtraSrcRegAllocReq) OS << "|(1<<TID::ExtraSrcRegAllocReq)";
if (Inst.hasExtraDefRegAllocReq) OS << "|(1<<TID::ExtraDefRegAllocReq)";
// Emit all of the target-specific flags...
BitsInit *TSF = Inst.TheDef->getValueAsBitsInit("TSFlags");
if (!TSF) throw "no TSFlags?";
uint64_t Value = 0;
for (unsigned i = 0, e = TSF->getNumBits(); i != e; ++i) {
if (BitInit *Bit = dynamic_cast<BitInit*>(TSF->getBit(i)))
Value |= uint64_t(Bit->getValue()) << i;
else
throw "Invalid TSFlags bit in " + Inst.TheDef->getName();
}
OS << ", 0x";
OS.write_hex(Value);
OS << "ULL, ";
// Emit the implicit uses and defs lists...
std::vector<Record*> UseList = Inst.TheDef->getValueAsListOfDefs("Uses");
if (UseList.empty())
OS << "NULL, ";
else
OS << "ImplicitList" << EmittedLists[UseList] << ", ";
std::vector<Record*> DefList = Inst.TheDef->getValueAsListOfDefs("Defs");
if (DefList.empty())
OS << "NULL, ";
else
OS << "ImplicitList" << EmittedLists[DefList] << ", ";
std::map<Record*, unsigned>::iterator BI = BarriersMap.find(Inst.TheDef);
if (BI == BarriersMap.end())
OS << "NULL, ";
else
OS << "Barriers" << BI->second << ", ";
// Emit the operand info.
std::vector<std::string> OperandInfo = GetOperandInfo(Inst);
if (OperandInfo.empty())
OS << "0";
else
OS << "OperandInfo" << OpInfo.find(OperandInfo)->second;
OS << " }, // Inst #" << Num << " = " << Inst.TheDef->getName() << "\n";
}