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llvm-mirror/utils/TableGen/FastISelEmitter.cpp
Bill Schmidt 66f498a584 Change order of tablegen generated fast-isel instruction code to be 
based on instruction complexity

The order that tablegen fast-isel instruction code is generated is
currently based on the text of the predicate (using string
less-than). This patch changes this to instead use the instruction
complexity. Because the complexities are not unique a C++ multimap is
used instead of a map.

This fixes the problem where code with no predicate always comes out
first (the empty string always compares as less than all other
strings) thus making the code with predicates dead code. See the FMUL
code in PPCFastISel.cpp for an example. It also more closely matches
the normal codegen ordering. Some error checking in the tablegen
fast-isel code is fixed as well.

Patch by Bill Seurer.

llvm-svn: 222038
2014-11-14 21:05:45 +00:00

892 lines
30 KiB
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//===- FastISelEmitter.cpp - Generate an instruction selector -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This tablegen backend emits code for use by the "fast" instruction
// selection algorithm. See the comments at the top of
// lib/CodeGen/SelectionDAG/FastISel.cpp for background.
//
// This file scans through the target's tablegen instruction-info files
// and extracts instructions with obvious-looking patterns, and it emits
// code to look up these instructions by type and operator.
//
//===----------------------------------------------------------------------===//
#include "CodeGenDAGPatterns.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/TableGen/Error.h"
#include "llvm/TableGen/Record.h"
#include "llvm/TableGen/TableGenBackend.h"
using namespace llvm;
/// InstructionMemo - This class holds additional information about an
/// instruction needed to emit code for it.
///
namespace {
struct InstructionMemo {
std::string Name;
const CodeGenRegisterClass *RC;
std::string SubRegNo;
std::vector<std::string>* PhysRegs;
std::string PredicateCheck;
};
} // End anonymous namespace
/// ImmPredicateSet - This uniques predicates (represented as a string) and
/// gives them unique (small) integer ID's that start at 0.
namespace {
class ImmPredicateSet {
DenseMap<TreePattern *, unsigned> ImmIDs;
std::vector<TreePredicateFn> PredsByName;
public:
unsigned getIDFor(TreePredicateFn Pred) {
unsigned &Entry = ImmIDs[Pred.getOrigPatFragRecord()];
if (Entry == 0) {
PredsByName.push_back(Pred);
Entry = PredsByName.size();
}
return Entry-1;
}
const TreePredicateFn &getPredicate(unsigned i) {
assert(i < PredsByName.size());
return PredsByName[i];
}
typedef std::vector<TreePredicateFn>::const_iterator iterator;
iterator begin() const { return PredsByName.begin(); }
iterator end() const { return PredsByName.end(); }
};
} // End anonymous namespace
/// OperandsSignature - This class holds a description of a list of operand
/// types. It has utility methods for emitting text based on the operands.
///
namespace {
struct OperandsSignature {
class OpKind {
enum { OK_Reg, OK_FP, OK_Imm, OK_Invalid = -1 };
char Repr;
public:
OpKind() : Repr(OK_Invalid) {}
bool operator<(OpKind RHS) const { return Repr < RHS.Repr; }
bool operator==(OpKind RHS) const { return Repr == RHS.Repr; }
static OpKind getReg() { OpKind K; K.Repr = OK_Reg; return K; }
static OpKind getFP() { OpKind K; K.Repr = OK_FP; return K; }
static OpKind getImm(unsigned V) {
assert((unsigned)OK_Imm+V < 128 &&
"Too many integer predicates for the 'Repr' char");
OpKind K; K.Repr = OK_Imm+V; return K;
}
bool isReg() const { return Repr == OK_Reg; }
bool isFP() const { return Repr == OK_FP; }
bool isImm() const { return Repr >= OK_Imm; }
unsigned getImmCode() const { assert(isImm()); return Repr-OK_Imm; }
void printManglingSuffix(raw_ostream &OS, ImmPredicateSet &ImmPredicates,
bool StripImmCodes) const {
if (isReg())
OS << 'r';
else if (isFP())
OS << 'f';
else {
OS << 'i';
if (!StripImmCodes)
if (unsigned Code = getImmCode())
OS << "_" << ImmPredicates.getPredicate(Code-1).getFnName();
}
}
};
SmallVector<OpKind, 3> Operands;
bool operator<(const OperandsSignature &O) const {
return Operands < O.Operands;
}
bool operator==(const OperandsSignature &O) const {
return Operands == O.Operands;
}
bool empty() const { return Operands.empty(); }
bool hasAnyImmediateCodes() const {
for (unsigned i = 0, e = Operands.size(); i != e; ++i)
if (Operands[i].isImm() && Operands[i].getImmCode() != 0)
return true;
return false;
}
/// getWithoutImmCodes - Return a copy of this with any immediate codes forced
/// to zero.
OperandsSignature getWithoutImmCodes() const {
OperandsSignature Result;
for (unsigned i = 0, e = Operands.size(); i != e; ++i)
if (!Operands[i].isImm())
Result.Operands.push_back(Operands[i]);
else
Result.Operands.push_back(OpKind::getImm(0));
return Result;
}
void emitImmediatePredicate(raw_ostream &OS, ImmPredicateSet &ImmPredicates) {
bool EmittedAnything = false;
for (unsigned i = 0, e = Operands.size(); i != e; ++i) {
if (!Operands[i].isImm()) continue;
unsigned Code = Operands[i].getImmCode();
if (Code == 0) continue;
if (EmittedAnything)
OS << " &&\n ";
TreePredicateFn PredFn = ImmPredicates.getPredicate(Code-1);
// Emit the type check.
OS << "VT == "
<< getEnumName(PredFn.getOrigPatFragRecord()->getTree(0)->getType(0))
<< " && ";
OS << PredFn.getFnName() << "(imm" << i <<')';
EmittedAnything = true;
}
}
/// initialize - Examine the given pattern and initialize the contents
/// of the Operands array accordingly. Return true if all the operands
/// are supported, false otherwise.
///
bool initialize(TreePatternNode *InstPatNode, const CodeGenTarget &Target,
MVT::SimpleValueType VT,
ImmPredicateSet &ImmediatePredicates,
const CodeGenRegisterClass *OrigDstRC) {
if (InstPatNode->isLeaf())
return false;
if (InstPatNode->getOperator()->getName() == "imm") {
Operands.push_back(OpKind::getImm(0));
return true;
}
if (InstPatNode->getOperator()->getName() == "fpimm") {
Operands.push_back(OpKind::getFP());
return true;
}
const CodeGenRegisterClass *DstRC = nullptr;
for (unsigned i = 0, e = InstPatNode->getNumChildren(); i != e; ++i) {
TreePatternNode *Op = InstPatNode->getChild(i);
// Handle imm operands specially.
if (!Op->isLeaf() && Op->getOperator()->getName() == "imm") {
unsigned PredNo = 0;
if (!Op->getPredicateFns().empty()) {
TreePredicateFn PredFn = Op->getPredicateFns()[0];
// If there is more than one predicate weighing in on this operand
// then we don't handle it. This doesn't typically happen for
// immediates anyway.
if (Op->getPredicateFns().size() > 1 ||
!PredFn.isImmediatePattern())
return false;
// Ignore any instruction with 'FastIselShouldIgnore', these are
// not needed and just bloat the fast instruction selector. For
// example, X86 doesn't need to generate code to match ADD16ri8 since
// ADD16ri will do just fine.
Record *Rec = PredFn.getOrigPatFragRecord()->getRecord();
if (Rec->getValueAsBit("FastIselShouldIgnore"))
return false;
PredNo = ImmediatePredicates.getIDFor(PredFn)+1;
}
// Handle unmatched immediate sizes here.
//if (Op->getType(0) != VT)
// return false;
Operands.push_back(OpKind::getImm(PredNo));
continue;
}
// For now, filter out any operand with a predicate.
// For now, filter out any operand with multiple values.
if (!Op->getPredicateFns().empty() || Op->getNumTypes() != 1)
return false;
if (!Op->isLeaf()) {
if (Op->getOperator()->getName() == "fpimm") {
Operands.push_back(OpKind::getFP());
continue;
}
// For now, ignore other non-leaf nodes.
return false;
}
assert(Op->hasTypeSet(0) && "Type infererence not done?");
// For now, all the operands must have the same type (if they aren't
// immediates). Note that this causes us to reject variable sized shifts
// on X86.
if (Op->getType(0) != VT)
return false;
DefInit *OpDI = dyn_cast<DefInit>(Op->getLeafValue());
if (!OpDI)
return false;
Record *OpLeafRec = OpDI->getDef();
// For now, the only other thing we accept is register operands.
const CodeGenRegisterClass *RC = nullptr;
if (OpLeafRec->isSubClassOf("RegisterOperand"))
OpLeafRec = OpLeafRec->getValueAsDef("RegClass");
if (OpLeafRec->isSubClassOf("RegisterClass"))
RC = &Target.getRegisterClass(OpLeafRec);
else if (OpLeafRec->isSubClassOf("Register"))
RC = Target.getRegBank().getRegClassForRegister(OpLeafRec);
else if (OpLeafRec->isSubClassOf("ValueType")) {
RC = OrigDstRC;
} else
return false;
// For now, this needs to be a register class of some sort.
if (!RC)
return false;
// For now, all the operands must have the same register class or be
// a strict subclass of the destination.
if (DstRC) {
if (DstRC != RC && !DstRC->hasSubClass(RC))
return false;
} else
DstRC = RC;
Operands.push_back(OpKind::getReg());
}
return true;
}
void PrintParameters(raw_ostream &OS) const {
for (unsigned i = 0, e = Operands.size(); i != e; ++i) {
if (Operands[i].isReg()) {
OS << "unsigned Op" << i << ", bool Op" << i << "IsKill";
} else if (Operands[i].isImm()) {
OS << "uint64_t imm" << i;
} else if (Operands[i].isFP()) {
OS << "const ConstantFP *f" << i;
} else {
llvm_unreachable("Unknown operand kind!");
}
if (i + 1 != e)
OS << ", ";
}
}
void PrintArguments(raw_ostream &OS,
const std::vector<std::string> &PR) const {
assert(PR.size() == Operands.size());
bool PrintedArg = false;
for (unsigned i = 0, e = Operands.size(); i != e; ++i) {
if (PR[i] != "")
// Implicit physical register operand.
continue;
if (PrintedArg)
OS << ", ";
if (Operands[i].isReg()) {
OS << "Op" << i << ", Op" << i << "IsKill";
PrintedArg = true;
} else if (Operands[i].isImm()) {
OS << "imm" << i;
PrintedArg = true;
} else if (Operands[i].isFP()) {
OS << "f" << i;
PrintedArg = true;
} else {
llvm_unreachable("Unknown operand kind!");
}
}
}
void PrintArguments(raw_ostream &OS) const {
for (unsigned i = 0, e = Operands.size(); i != e; ++i) {
if (Operands[i].isReg()) {
OS << "Op" << i << ", Op" << i << "IsKill";
} else if (Operands[i].isImm()) {
OS << "imm" << i;
} else if (Operands[i].isFP()) {
OS << "f" << i;
} else {
llvm_unreachable("Unknown operand kind!");
}
if (i + 1 != e)
OS << ", ";
}
}
void PrintManglingSuffix(raw_ostream &OS, const std::vector<std::string> &PR,
ImmPredicateSet &ImmPredicates,
bool StripImmCodes = false) const {
for (unsigned i = 0, e = Operands.size(); i != e; ++i) {
if (PR[i] != "")
// Implicit physical register operand. e.g. Instruction::Mul expect to
// select to a binary op. On x86, mul may take a single operand with
// the other operand being implicit. We must emit something that looks
// like a binary instruction except for the very inner fastEmitInst_*
// call.
continue;
Operands[i].printManglingSuffix(OS, ImmPredicates, StripImmCodes);
}
}
void PrintManglingSuffix(raw_ostream &OS, ImmPredicateSet &ImmPredicates,
bool StripImmCodes = false) const {
for (unsigned i = 0, e = Operands.size(); i != e; ++i)
Operands[i].printManglingSuffix(OS, ImmPredicates, StripImmCodes);
}
};
} // End anonymous namespace
namespace {
class FastISelMap {
// A multimap is needed instead of a "plain" map because the key is
// the instruction's complexity (an int) and they are not unique.
typedef std::multimap<int, InstructionMemo> PredMap;
typedef std::map<MVT::SimpleValueType, PredMap> RetPredMap;
typedef std::map<MVT::SimpleValueType, RetPredMap> TypeRetPredMap;
typedef std::map<std::string, TypeRetPredMap> OpcodeTypeRetPredMap;
typedef std::map<OperandsSignature, OpcodeTypeRetPredMap>
OperandsOpcodeTypeRetPredMap;
OperandsOpcodeTypeRetPredMap SimplePatterns;
// This is used to check that there are no duplicate predicates
typedef std::multimap<std::string, bool> PredCheckMap;
typedef std::map<MVT::SimpleValueType, PredCheckMap> RetPredCheckMap;
typedef std::map<MVT::SimpleValueType, RetPredCheckMap> TypeRetPredCheckMap;
typedef std::map<std::string, TypeRetPredCheckMap> OpcodeTypeRetPredCheckMap;
typedef std::map<OperandsSignature, OpcodeTypeRetPredCheckMap>
OperandsOpcodeTypeRetPredCheckMap;
OperandsOpcodeTypeRetPredCheckMap SimplePatternsCheck;
std::map<OperandsSignature, std::vector<OperandsSignature> >
SignaturesWithConstantForms;
std::string InstNS;
ImmPredicateSet ImmediatePredicates;
public:
explicit FastISelMap(std::string InstNS);
void collectPatterns(CodeGenDAGPatterns &CGP);
void printImmediatePredicates(raw_ostream &OS);
void printFunctionDefinitions(raw_ostream &OS);
private:
void emitInstructionCode(raw_ostream &OS,
const OperandsSignature &Operands,
const PredMap &PM,
const std::string &RetVTName);
};
} // End anonymous namespace
static std::string getOpcodeName(Record *Op, CodeGenDAGPatterns &CGP) {
return CGP.getSDNodeInfo(Op).getEnumName();
}
static std::string getLegalCName(std::string OpName) {
std::string::size_type pos = OpName.find("::");
if (pos != std::string::npos)
OpName.replace(pos, 2, "_");
return OpName;
}
FastISelMap::FastISelMap(std::string instns)
: InstNS(instns) {
}
static std::string PhyRegForNode(TreePatternNode *Op,
const CodeGenTarget &Target) {
std::string PhysReg;
if (!Op->isLeaf())
return PhysReg;
Record *OpLeafRec = cast<DefInit>(Op->getLeafValue())->getDef();
if (!OpLeafRec->isSubClassOf("Register"))
return PhysReg;
PhysReg += cast<StringInit>(OpLeafRec->getValue("Namespace")->getValue())
->getValue();
PhysReg += "::";
PhysReg += Target.getRegBank().getReg(OpLeafRec)->getName();
return PhysReg;
}
void FastISelMap::collectPatterns(CodeGenDAGPatterns &CGP) {
const CodeGenTarget &Target = CGP.getTargetInfo();
// Determine the target's namespace name.
InstNS = Target.getInstNamespace() + "::";
assert(InstNS.size() > 2 && "Can't determine target-specific namespace!");
// Scan through all the patterns and record the simple ones.
for (CodeGenDAGPatterns::ptm_iterator I = CGP.ptm_begin(),
E = CGP.ptm_end(); I != E; ++I) {
const PatternToMatch &Pattern = *I;
// For now, just look at Instructions, so that we don't have to worry
// about emitting multiple instructions for a pattern.
TreePatternNode *Dst = Pattern.getDstPattern();
if (Dst->isLeaf()) continue;
Record *Op = Dst->getOperator();
if (!Op->isSubClassOf("Instruction"))
continue;
CodeGenInstruction &II = CGP.getTargetInfo().getInstruction(Op);
if (II.Operands.empty())
continue;
// For now, ignore multi-instruction patterns.
bool MultiInsts = false;
for (unsigned i = 0, e = Dst->getNumChildren(); i != e; ++i) {
TreePatternNode *ChildOp = Dst->getChild(i);
if (ChildOp->isLeaf())
continue;
if (ChildOp->getOperator()->isSubClassOf("Instruction")) {
MultiInsts = true;
break;
}
}
if (MultiInsts)
continue;
// For now, ignore instructions where the first operand is not an
// output register.
const CodeGenRegisterClass *DstRC = nullptr;
std::string SubRegNo;
if (Op->getName() != "EXTRACT_SUBREG") {
Record *Op0Rec = II.Operands[0].Rec;
if (Op0Rec->isSubClassOf("RegisterOperand"))
Op0Rec = Op0Rec->getValueAsDef("RegClass");
if (!Op0Rec->isSubClassOf("RegisterClass"))
continue;
DstRC = &Target.getRegisterClass(Op0Rec);
if (!DstRC)
continue;
} else {
// If this isn't a leaf, then continue since the register classes are
// a bit too complicated for now.
if (!Dst->getChild(1)->isLeaf()) continue;
DefInit *SR = dyn_cast<DefInit>(Dst->getChild(1)->getLeafValue());
if (SR)
SubRegNo = getQualifiedName(SR->getDef());
else
SubRegNo = Dst->getChild(1)->getLeafValue()->getAsString();
}
// Inspect the pattern.
TreePatternNode *InstPatNode = Pattern.getSrcPattern();
if (!InstPatNode) continue;
if (InstPatNode->isLeaf()) continue;
// Ignore multiple result nodes for now.
if (InstPatNode->getNumTypes() > 1) continue;
Record *InstPatOp = InstPatNode->getOperator();
std::string OpcodeName = getOpcodeName(InstPatOp, CGP);
MVT::SimpleValueType RetVT = MVT::isVoid;
if (InstPatNode->getNumTypes()) RetVT = InstPatNode->getType(0);
MVT::SimpleValueType VT = RetVT;
if (InstPatNode->getNumChildren()) {
assert(InstPatNode->getChild(0)->getNumTypes() == 1);
VT = InstPatNode->getChild(0)->getType(0);
}
// For now, filter out any instructions with predicates.
if (!InstPatNode->getPredicateFns().empty())
continue;
// Check all the operands.
OperandsSignature Operands;
if (!Operands.initialize(InstPatNode, Target, VT, ImmediatePredicates,
DstRC))
continue;
std::vector<std::string>* PhysRegInputs = new std::vector<std::string>();
if (InstPatNode->getOperator()->getName() == "imm" ||
InstPatNode->getOperator()->getName() == "fpimm")
PhysRegInputs->push_back("");
else {
// Compute the PhysRegs used by the given pattern, and check that
// the mapping from the src to dst patterns is simple.
bool FoundNonSimplePattern = false;
unsigned DstIndex = 0;
for (unsigned i = 0, e = InstPatNode->getNumChildren(); i != e; ++i) {
std::string PhysReg = PhyRegForNode(InstPatNode->getChild(i), Target);
if (PhysReg.empty()) {
if (DstIndex >= Dst->getNumChildren() ||
Dst->getChild(DstIndex)->getName() !=
InstPatNode->getChild(i)->getName()) {
FoundNonSimplePattern = true;
break;
}
++DstIndex;
}
PhysRegInputs->push_back(PhysReg);
}
if (Op->getName() != "EXTRACT_SUBREG" && DstIndex < Dst->getNumChildren())
FoundNonSimplePattern = true;
if (FoundNonSimplePattern)
continue;
}
// Check if the operands match one of the patterns handled by FastISel.
std::string ManglingSuffix;
raw_string_ostream SuffixOS(ManglingSuffix);
Operands.PrintManglingSuffix(SuffixOS, ImmediatePredicates, true);
SuffixOS.flush();
if (!StringSwitch<bool>(ManglingSuffix)
.Cases("", "r", "rr", "ri", "rf", true)
.Cases("rri", "i", "f", true)
.Default(false))
continue;
// Get the predicate that guards this pattern.
std::string PredicateCheck = Pattern.getPredicateCheck();
// Ok, we found a pattern that we can handle. Remember it.
InstructionMemo Memo = {
Pattern.getDstPattern()->getOperator()->getName(),
DstRC,
SubRegNo,
PhysRegInputs,
PredicateCheck
};
int complexity = Pattern.getPatternComplexity(CGP);
if (SimplePatternsCheck[Operands][OpcodeName][VT]
[RetVT].count(PredicateCheck)) {
PrintFatalError(Pattern.getSrcRecord()->getLoc(),
"Duplicate predicate in FastISel table!");
}
SimplePatternsCheck[Operands][OpcodeName][VT][RetVT].insert(
std::make_pair(PredicateCheck, true));
// Note: Instructions with the same complexity will appear in the order
// that they are encountered.
SimplePatterns[Operands][OpcodeName][VT][RetVT].insert(
std::make_pair(complexity, Memo));
// If any of the operands were immediates with predicates on them, strip
// them down to a signature that doesn't have predicates so that we can
// associate them with the stripped predicate version.
if (Operands.hasAnyImmediateCodes()) {
SignaturesWithConstantForms[Operands.getWithoutImmCodes()]
.push_back(Operands);
}
}
}
void FastISelMap::printImmediatePredicates(raw_ostream &OS) {
if (ImmediatePredicates.begin() == ImmediatePredicates.end())
return;
OS << "\n// FastEmit Immediate Predicate functions.\n";
for (ImmPredicateSet::iterator I = ImmediatePredicates.begin(),
E = ImmediatePredicates.end(); I != E; ++I) {
OS << "static bool " << I->getFnName() << "(int64_t Imm) {\n";
OS << I->getImmediatePredicateCode() << "\n}\n";
}
OS << "\n\n";
}
void FastISelMap::emitInstructionCode(raw_ostream &OS,
const OperandsSignature &Operands,
const PredMap &PM,
const std::string &RetVTName) {
// Emit code for each possible instruction. There may be
// multiple if there are subtarget concerns. A reverse iterator
// is used to produce the ones with highest complexity first.
bool OneHadNoPredicate = false;
for (PredMap::const_reverse_iterator PI = PM.rbegin(), PE = PM.rend();
PI != PE; ++PI) {
const InstructionMemo &Memo = PI->second;
std::string PredicateCheck = Memo.PredicateCheck;
if (PredicateCheck.empty()) {
assert(!OneHadNoPredicate &&
"Multiple instructions match and more than one had "
"no predicate!");
OneHadNoPredicate = true;
} else {
if (OneHadNoPredicate) {
// FIXME: This should be a PrintError once the x86 target
// fixes PR21575.
PrintWarning("Multiple instructions match and one with no "
"predicate came before one with a predicate! "
"name:" + Memo.Name + " predicate: " +
PredicateCheck);
}
OS << " if (" + PredicateCheck + ") {\n";
OS << " ";
}
for (unsigned i = 0; i < Memo.PhysRegs->size(); ++i) {
if ((*Memo.PhysRegs)[i] != "")
OS << " BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, "
<< "TII.get(TargetOpcode::COPY), "
<< (*Memo.PhysRegs)[i] << ").addReg(Op" << i << ");\n";
}
OS << " return fastEmitInst_";
if (Memo.SubRegNo.empty()) {
Operands.PrintManglingSuffix(OS, *Memo.PhysRegs,
ImmediatePredicates, true);
OS << "(" << InstNS << Memo.Name << ", ";
OS << "&" << InstNS << Memo.RC->getName() << "RegClass";
if (!Operands.empty())
OS << ", ";
Operands.PrintArguments(OS, *Memo.PhysRegs);
OS << ");\n";
} else {
OS << "extractsubreg(" << RetVTName
<< ", Op0, Op0IsKill, " << Memo.SubRegNo << ");\n";
}
if (!PredicateCheck.empty()) {
OS << " }\n";
}
}
// Return 0 if all of the possibilities had predicates but none
// were satisfied.
if (!OneHadNoPredicate)
OS << " return 0;\n";
OS << "}\n";
OS << "\n";
}
void FastISelMap::printFunctionDefinitions(raw_ostream &OS) {
// Now emit code for all the patterns that we collected.
for (OperandsOpcodeTypeRetPredMap::const_iterator OI = SimplePatterns.begin(),
OE = SimplePatterns.end(); OI != OE; ++OI) {
const OperandsSignature &Operands = OI->first;
const OpcodeTypeRetPredMap &OTM = OI->second;
for (OpcodeTypeRetPredMap::const_iterator I = OTM.begin(), E = OTM.end();
I != E; ++I) {
const std::string &Opcode = I->first;
const TypeRetPredMap &TM = I->second;
OS << "// FastEmit functions for " << Opcode << ".\n";
OS << "\n";
// Emit one function for each opcode,type pair.
for (TypeRetPredMap::const_iterator TI = TM.begin(), TE = TM.end();
TI != TE; ++TI) {
MVT::SimpleValueType VT = TI->first;
const RetPredMap &RM = TI->second;
if (RM.size() != 1) {
for (RetPredMap::const_iterator RI = RM.begin(), RE = RM.end();
RI != RE; ++RI) {
MVT::SimpleValueType RetVT = RI->first;
const PredMap &PM = RI->second;
OS << "unsigned fastEmit_"
<< getLegalCName(Opcode)
<< "_" << getLegalCName(getName(VT))
<< "_" << getLegalCName(getName(RetVT)) << "_";
Operands.PrintManglingSuffix(OS, ImmediatePredicates);
OS << "(";
Operands.PrintParameters(OS);
OS << ") {\n";
emitInstructionCode(OS, Operands, PM, getName(RetVT));
}
// Emit one function for the type that demultiplexes on return type.
OS << "unsigned fastEmit_"
<< getLegalCName(Opcode) << "_"
<< getLegalCName(getName(VT)) << "_";
Operands.PrintManglingSuffix(OS, ImmediatePredicates);
OS << "(MVT RetVT";
if (!Operands.empty())
OS << ", ";
Operands.PrintParameters(OS);
OS << ") {\nswitch (RetVT.SimpleTy) {\n";
for (RetPredMap::const_iterator RI = RM.begin(), RE = RM.end();
RI != RE; ++RI) {
MVT::SimpleValueType RetVT = RI->first;
OS << " case " << getName(RetVT) << ": return fastEmit_"
<< getLegalCName(Opcode) << "_" << getLegalCName(getName(VT))
<< "_" << getLegalCName(getName(RetVT)) << "_";
Operands.PrintManglingSuffix(OS, ImmediatePredicates);
OS << "(";
Operands.PrintArguments(OS);
OS << ");\n";
}
OS << " default: return 0;\n}\n}\n\n";
} else {
// Non-variadic return type.
OS << "unsigned fastEmit_"
<< getLegalCName(Opcode) << "_"
<< getLegalCName(getName(VT)) << "_";
Operands.PrintManglingSuffix(OS, ImmediatePredicates);
OS << "(MVT RetVT";
if (!Operands.empty())
OS << ", ";
Operands.PrintParameters(OS);
OS << ") {\n";
OS << " if (RetVT.SimpleTy != " << getName(RM.begin()->first)
<< ")\n return 0;\n";
const PredMap &PM = RM.begin()->second;
emitInstructionCode(OS, Operands, PM, "RetVT");
}
}
// Emit one function for the opcode that demultiplexes based on the type.
OS << "unsigned fastEmit_"
<< getLegalCName(Opcode) << "_";
Operands.PrintManglingSuffix(OS, ImmediatePredicates);
OS << "(MVT VT, MVT RetVT";
if (!Operands.empty())
OS << ", ";
Operands.PrintParameters(OS);
OS << ") {\n";
OS << " switch (VT.SimpleTy) {\n";
for (TypeRetPredMap::const_iterator TI = TM.begin(), TE = TM.end();
TI != TE; ++TI) {
MVT::SimpleValueType VT = TI->first;
std::string TypeName = getName(VT);
OS << " case " << TypeName << ": return fastEmit_"
<< getLegalCName(Opcode) << "_" << getLegalCName(TypeName) << "_";
Operands.PrintManglingSuffix(OS, ImmediatePredicates);
OS << "(RetVT";
if (!Operands.empty())
OS << ", ";
Operands.PrintArguments(OS);
OS << ");\n";
}
OS << " default: return 0;\n";
OS << " }\n";
OS << "}\n";
OS << "\n";
}
OS << "// Top-level FastEmit function.\n";
OS << "\n";
// Emit one function for the operand signature that demultiplexes based
// on opcode and type.
OS << "unsigned fastEmit_";
Operands.PrintManglingSuffix(OS, ImmediatePredicates);
OS << "(MVT VT, MVT RetVT, unsigned Opcode";
if (!Operands.empty())
OS << ", ";
Operands.PrintParameters(OS);
OS << ") ";
if (!Operands.hasAnyImmediateCodes())
OS << "override ";
OS << "{\n";
// If there are any forms of this signature available that operate on
// constrained forms of the immediate (e.g., 32-bit sext immediate in a
// 64-bit operand), check them first.
std::map<OperandsSignature, std::vector<OperandsSignature> >::iterator MI
= SignaturesWithConstantForms.find(Operands);
if (MI != SignaturesWithConstantForms.end()) {
// Unique any duplicates out of the list.
std::sort(MI->second.begin(), MI->second.end());
MI->second.erase(std::unique(MI->second.begin(), MI->second.end()),
MI->second.end());
// Check each in order it was seen. It would be nice to have a good
// relative ordering between them, but we're not going for optimality
// here.
for (unsigned i = 0, e = MI->second.size(); i != e; ++i) {
OS << " if (";
MI->second[i].emitImmediatePredicate(OS, ImmediatePredicates);
OS << ")\n if (unsigned Reg = fastEmit_";
MI->second[i].PrintManglingSuffix(OS, ImmediatePredicates);
OS << "(VT, RetVT, Opcode";
if (!MI->second[i].empty())
OS << ", ";
MI->second[i].PrintArguments(OS);
OS << "))\n return Reg;\n\n";
}
// Done with this, remove it.
SignaturesWithConstantForms.erase(MI);
}
OS << " switch (Opcode) {\n";
for (OpcodeTypeRetPredMap::const_iterator I = OTM.begin(), E = OTM.end();
I != E; ++I) {
const std::string &Opcode = I->first;
OS << " case " << Opcode << ": return fastEmit_"
<< getLegalCName(Opcode) << "_";
Operands.PrintManglingSuffix(OS, ImmediatePredicates);
OS << "(VT, RetVT";
if (!Operands.empty())
OS << ", ";
Operands.PrintArguments(OS);
OS << ");\n";
}
OS << " default: return 0;\n";
OS << " }\n";
OS << "}\n";
OS << "\n";
}
// TODO: SignaturesWithConstantForms should be empty here.
}
namespace llvm {
void EmitFastISel(RecordKeeper &RK, raw_ostream &OS) {
CodeGenDAGPatterns CGP(RK);
const CodeGenTarget &Target = CGP.getTargetInfo();
emitSourceFileHeader("\"Fast\" Instruction Selector for the " +
Target.getName() + " target", OS);
// Determine the target's namespace name.
std::string InstNS = Target.getInstNamespace() + "::";
assert(InstNS.size() > 2 && "Can't determine target-specific namespace!");
FastISelMap F(InstNS);
F.collectPatterns(CGP);
F.printImmediatePredicates(OS);
F.printFunctionDefinitions(OS);
}
} // End llvm namespace
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