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llvm-project/llvm/utils/TableGen/RISCVCompressInstEmitter.cpp

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//===- RISCVCompressInstEmitter.cpp - Generator for RISCV Compression -===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
// RISCVCompressInstEmitter implements a tablegen-driven CompressPat based
// RISCV Instruction Compression mechanism.
//
//===--------------------------------------------------------------===//
//
// RISCVCompressInstEmitter implements a tablegen-driven CompressPat Instruction
// Compression mechanism for generating RISCV compressed instructions
// (C ISA Extension) from the expanded instruction form.
// This tablegen backend processes CompressPat declarations in a
// td file and generates all the required checks to validate the pattern
// declarations; validate the input and output operands to generate the correct
// compressed instructions. The checks include validating different types of
// operands; register operands, immediate operands, fixed register and fixed
// immediate inputs.
//
// Example:
// class CompressPat<dag input, dag output> {
// dag Input = input;
// dag Output = output;
// list<Predicate> Predicates = [];
// }
//
// let Predicates = [HasStdExtC] in {
// def : CompressPat<(ADD GPRNoX0:$rs1, GPRNoX0:$rs1, GPRNoX0:$rs2),
// (C_ADD GPRNoX0:$rs1, GPRNoX0:$rs2)>;
// }
//
// The result is an auto-generated header file
// 'RISCVGenCompressInstEmitter.inc' which exports two functions for
// compressing/uncompressing MCInst instructions, plus
// some helper functions:
//
// bool compressInst(MCInst& OutInst, const MCInst &MI,
// const MCSubtargetInfo &STI,
// MCContext &Context);
//
// bool uncompressInst(MCInst& OutInst, const MCInst &MI,
// const MCRegisterInfo &MRI,
// const MCSubtargetInfo &STI);
//
// In addition, it exports a function for checking whether
// an instruction is compressable:
//
// bool isCompressibleInst(const MachineInstr& MI,
// const RISCVSubtarget *Subtarget,
// const MCRegisterInfo &MRI,
// const MCSubtargetInfo &STI);
//
// The clients that include this auto-generated header file and
// invoke these functions can compress an instruction before emitting
// it in the target-specific ASM or ELF streamer or can uncompress
// an instruction before printing it when the expanded instruction
// format aliases is favored.
//===----------------------------------------------------------------------===//
#include "CodeGenInstruction.h"
#include "CodeGenTarget.h"
#include "llvm/ADT/IndexedMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringMap.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"
#include <set>
#include <vector>
using namespace llvm;
#define DEBUG_TYPE "compress-inst-emitter"
namespace {
class RISCVCompressInstEmitter {
struct OpData {
enum MapKind { Operand, Imm, Reg };
MapKind Kind;
union {
unsigned Operand; // Operand number mapped to.
uint64_t Imm; // Integer immediate value.
Record *Reg; // Physical register.
} Data;
int TiedOpIdx = -1; // Tied operand index within the instruction.
};
struct CompressPat {
CodeGenInstruction Source; // The source instruction definition.
CodeGenInstruction Dest; // The destination instruction to transform to.
std::vector<Record *>
PatReqFeatures; // Required target features to enable pattern.
IndexedMap<OpData>
SourceOperandMap; // Maps operands in the Source Instruction to
// the corresponding Dest instruction operand.
IndexedMap<OpData>
DestOperandMap; // Maps operands in the Dest Instruction
// to the corresponding Source instruction operand.
CompressPat(CodeGenInstruction &S, CodeGenInstruction &D,
std::vector<Record *> RF, IndexedMap<OpData> &SourceMap,
IndexedMap<OpData> &DestMap)
: Source(S), Dest(D), PatReqFeatures(RF), SourceOperandMap(SourceMap),
DestOperandMap(DestMap) {}
};
enum EmitterType { Compress, Uncompress, CheckCompress };
RecordKeeper &Records;
CodeGenTarget Target;
SmallVector<CompressPat, 4> CompressPatterns;
void addDagOperandMapping(Record *Rec, DagInit *Dag, CodeGenInstruction &Inst,
IndexedMap<OpData> &OperandMap, bool IsSourceInst);
void evaluateCompressPat(Record *Compress);
void emitCompressInstEmitter(raw_ostream &o, EmitterType EType);
bool validateTypes(Record *SubType, Record *Type, bool IsSourceInst);
bool validateRegister(Record *Reg, Record *RegClass);
void createDagOperandMapping(Record *Rec, StringMap<unsigned> &SourceOperands,
StringMap<unsigned> &DestOperands,
DagInit *SourceDag, DagInit *DestDag,
IndexedMap<OpData> &SourceOperandMap);
void createInstOperandMapping(Record *Rec, DagInit *SourceDag,
DagInit *DestDag,
IndexedMap<OpData> &SourceOperandMap,
IndexedMap<OpData> &DestOperandMap,
StringMap<unsigned> &SourceOperands,
CodeGenInstruction &DestInst);
public:
RISCVCompressInstEmitter(RecordKeeper &R) : Records(R), Target(R) {}
void run(raw_ostream &o);
};
} // End anonymous namespace.
bool RISCVCompressInstEmitter::validateRegister(Record *Reg, Record *RegClass) {
assert(Reg->isSubClassOf("Register") && "Reg record should be a Register\n");
assert(RegClass->isSubClassOf("RegisterClass") && "RegClass record should be"
" a RegisterClass\n");
const CodeGenRegisterClass &RC = Target.getRegisterClass(RegClass);
const CodeGenRegister *R = Target.getRegisterByName(Reg->getName().lower());
assert((R != nullptr) &&
("Register" + Reg->getName().str() + " not defined!!\n").c_str());
return RC.contains(R);
}
bool RISCVCompressInstEmitter::validateTypes(Record *DagOpType,
Record *InstOpType,
bool IsSourceInst) {
if (DagOpType == InstOpType)
return true;
// Only source instruction operands are allowed to not match Input Dag
// operands.
if (!IsSourceInst)
return false;
if (DagOpType->isSubClassOf("RegisterClass") &&
InstOpType->isSubClassOf("RegisterClass")) {
const CodeGenRegisterClass &RC = Target.getRegisterClass(InstOpType);
const CodeGenRegisterClass &SubRC = Target.getRegisterClass(DagOpType);
return RC.hasSubClass(&SubRC);
}
// At this point either or both types are not registers, reject the pattern.
if (DagOpType->isSubClassOf("RegisterClass") ||
InstOpType->isSubClassOf("RegisterClass"))
return false;
// Let further validation happen when compress()/uncompress() functions are
// invoked.
LLVM_DEBUG(dbgs() << (IsSourceInst ? "Input" : "Output")
<< " Dag Operand Type: '" << DagOpType->getName()
<< "' and "
<< "Instruction Operand Type: '" << InstOpType->getName()
<< "' can't be checked at pattern validation time!\n");
return true;
}
/// The patterns in the Dag contain different types of operands:
/// Register operands, e.g.: GPRC:$rs1; Fixed registers, e.g: X1; Immediate
/// operands, e.g.: simm6:$imm; Fixed immediate operands, e.g.: 0. This function
/// maps Dag operands to its corresponding instruction operands. For register
/// operands and fixed registers it expects the Dag operand type to be contained
/// in the instantiated instruction operand type. For immediate operands and
/// immediates no validation checks are enforced at pattern validation time.
void RISCVCompressInstEmitter::addDagOperandMapping(
Record *Rec, DagInit *Dag, CodeGenInstruction &Inst,
IndexedMap<OpData> &OperandMap, bool IsSourceInst) {
// TiedCount keeps track of the number of operands skipped in Inst
// operands list to get to the corresponding Dag operand. This is
// necessary because the number of operands in Inst might be greater
// than number of operands in the Dag due to how tied operands
// are represented.
unsigned TiedCount = 0;
for (unsigned i = 0, e = Inst.Operands.size(); i != e; ++i) {
int TiedOpIdx = Inst.Operands[i].getTiedRegister();
if (-1 != TiedOpIdx) {
// Set the entry in OperandMap for the tied operand we're skipping.
OperandMap[i].Kind = OperandMap[TiedOpIdx].Kind;
OperandMap[i].Data = OperandMap[TiedOpIdx].Data;
TiedCount++;
continue;
}
if (DefInit *DI = dyn_cast<DefInit>(Dag->getArg(i - TiedCount))) {
if (DI->getDef()->isSubClassOf("Register")) {
// Check if the fixed register belongs to the Register class.
if (!validateRegister(DI->getDef(), Inst.Operands[i].Rec))
PrintFatalError(Rec->getLoc(),
"Error in Dag '" + Dag->getAsString() +
"'Register: '" + DI->getDef()->getName() +
"' is not in register class '" +
Inst.Operands[i].Rec->getName() + "'");
OperandMap[i].Kind = OpData::Reg;
OperandMap[i].Data.Reg = DI->getDef();
continue;
}
// Validate that Dag operand type matches the type defined in the
// corresponding instruction. Operands in the input Dag pattern are
// allowed to be a subclass of the type specified in corresponding
// instruction operand instead of being an exact match.
if (!validateTypes(DI->getDef(), Inst.Operands[i].Rec, IsSourceInst))
PrintFatalError(Rec->getLoc(),
"Error in Dag '" + Dag->getAsString() + "'. Operand '" +
Dag->getArgNameStr(i - TiedCount) + "' has type '" +
DI->getDef()->getName() +
"' which does not match the type '" +
Inst.Operands[i].Rec->getName() +
"' in the corresponding instruction operand!");
OperandMap[i].Kind = OpData::Operand;
} else if (IntInit *II = dyn_cast<IntInit>(Dag->getArg(i - TiedCount))) {
// Validate that corresponding instruction operand expects an immediate.
if (Inst.Operands[i].Rec->isSubClassOf("RegisterClass"))
PrintFatalError(
Rec->getLoc(),
("Error in Dag '" + Dag->getAsString() + "' Found immediate: '" +
II->getAsString() +
"' but corresponding instruction operand expected a register!"));
// No pattern validation check possible for values of fixed immediate.
OperandMap[i].Kind = OpData::Imm;
OperandMap[i].Data.Imm = II->getValue();
LLVM_DEBUG(
dbgs() << " Found immediate '" << II->getValue() << "' at "
<< (IsSourceInst ? "input " : "output ")
<< "Dag. No validation time check possible for values of "
"fixed immediate.\n");
} else
llvm_unreachable("Unhandled CompressPat argument type!");
}
}
// Verify the Dag operand count is enough to build an instruction.
static bool verifyDagOpCount(CodeGenInstruction &Inst, DagInit *Dag,
bool IsSource) {
if (Dag->getNumArgs() == Inst.Operands.size())
return true;
// Source instructions are non compressed instructions and don't have tied
// operands.
if (IsSource)
PrintFatalError(Inst.TheDef->getLoc(),
"Input operands for Inst '" + Inst.TheDef->getName() +
"' and input Dag operand count mismatch");
// The Dag can't have more arguments than the Instruction.
if (Dag->getNumArgs() > Inst.Operands.size())
PrintFatalError(Inst.TheDef->getLoc(),
"Inst '" + Inst.TheDef->getName() +
"' and Dag operand count mismatch");
// The Instruction might have tied operands so the Dag might have
// a fewer operand count.
unsigned RealCount = Inst.Operands.size();
for (unsigned i = 0; i < Inst.Operands.size(); i++)
if (Inst.Operands[i].getTiedRegister() != -1)
--RealCount;
if (Dag->getNumArgs() != RealCount)
PrintFatalError(Inst.TheDef->getLoc(),
"Inst '" + Inst.TheDef->getName() +
"' and Dag operand count mismatch");
return true;
}
static bool validateArgsTypes(Init *Arg1, Init *Arg2) {
DefInit *Type1 = dyn_cast<DefInit>(Arg1);
DefInit *Type2 = dyn_cast<DefInit>(Arg2);
assert(Type1 && ("Arg1 type not found\n"));
assert(Type2 && ("Arg2 type not found\n"));
return Type1->getDef() == Type2->getDef();
}
// Creates a mapping between the operand name in the Dag (e.g. $rs1) and
// its index in the list of Dag operands and checks that operands with the same
// name have the same types. For example in 'C_ADD $rs1, $rs2' we generate the
// mapping $rs1 --> 0, $rs2 ---> 1. If the operand appears twice in the (tied)
// same Dag we use the last occurrence for indexing.
void RISCVCompressInstEmitter::createDagOperandMapping(
Record *Rec, StringMap<unsigned> &SourceOperands,
StringMap<unsigned> &DestOperands, DagInit *SourceDag, DagInit *DestDag,
IndexedMap<OpData> &SourceOperandMap) {
for (unsigned i = 0; i < DestDag->getNumArgs(); ++i) {
// Skip fixed immediates and registers, they were handled in
// addDagOperandMapping.
if ("" == DestDag->getArgNameStr(i))
continue;
DestOperands[DestDag->getArgNameStr(i)] = i;
}
for (unsigned i = 0; i < SourceDag->getNumArgs(); ++i) {
// Skip fixed immediates and registers, they were handled in
// addDagOperandMapping.
if ("" == SourceDag->getArgNameStr(i))
continue;
StringMap<unsigned>::iterator it =
SourceOperands.find(SourceDag->getArgNameStr(i));
if (it != SourceOperands.end()) {
// Operand sharing the same name in the Dag should be mapped as tied.
SourceOperandMap[i].TiedOpIdx = it->getValue();
if (!validateArgsTypes(SourceDag->getArg(it->getValue()),
SourceDag->getArg(i)))
PrintFatalError(Rec->getLoc(),
"Input Operand '" + SourceDag->getArgNameStr(i) +
"' has a mismatched tied operand!\n");
}
it = DestOperands.find(SourceDag->getArgNameStr(i));
if (it == DestOperands.end())
PrintFatalError(Rec->getLoc(), "Operand " + SourceDag->getArgNameStr(i) +
" defined in Input Dag but not used in"
" Output Dag!\n");
// Input Dag operand types must match output Dag operand type.
if (!validateArgsTypes(DestDag->getArg(it->getValue()),
SourceDag->getArg(i)))
PrintFatalError(Rec->getLoc(), "Type mismatch between Input and "
"Output Dag operand '" +
SourceDag->getArgNameStr(i) + "'!");
SourceOperands[SourceDag->getArgNameStr(i)] = i;
}
}
/// Map operand names in the Dag to their index in both corresponding input and
/// output instructions. Validate that operands defined in the input are
/// used in the output pattern while populating the maps.
void RISCVCompressInstEmitter::createInstOperandMapping(
Record *Rec, DagInit *SourceDag, DagInit *DestDag,
IndexedMap<OpData> &SourceOperandMap, IndexedMap<OpData> &DestOperandMap,
StringMap<unsigned> &SourceOperands, CodeGenInstruction &DestInst) {
// TiedCount keeps track of the number of operands skipped in Inst
// operands list to get to the corresponding Dag operand.
unsigned TiedCount = 0;
LLVM_DEBUG(dbgs() << " Operand mapping:\n Source Dest\n");
for (unsigned i = 0, e = DestInst.Operands.size(); i != e; ++i) {
int TiedInstOpIdx = DestInst.Operands[i].getTiedRegister();
if (TiedInstOpIdx != -1) {
++TiedCount;
DestOperandMap[i].Data = DestOperandMap[TiedInstOpIdx].Data;
DestOperandMap[i].Kind = DestOperandMap[TiedInstOpIdx].Kind;
if (DestOperandMap[i].Kind == OpData::Operand)
// No need to fill the SourceOperandMap here since it was mapped to
// destination operand 'TiedInstOpIdx' in a previous iteration.
LLVM_DEBUG(dbgs() << " " << DestOperandMap[i].Data.Operand
<< " ====> " << i
<< " Dest operand tied with operand '"
<< TiedInstOpIdx << "'\n");
continue;
}
// Skip fixed immediates and registers, they were handled in
// addDagOperandMapping.
if (DestOperandMap[i].Kind != OpData::Operand)
continue;
unsigned DagArgIdx = i - TiedCount;
StringMap<unsigned>::iterator SourceOp =
SourceOperands.find(DestDag->getArgNameStr(DagArgIdx));
if (SourceOp == SourceOperands.end())
PrintFatalError(Rec->getLoc(),
"Output Dag operand '" +
DestDag->getArgNameStr(DagArgIdx) +
"' has no matching input Dag operand.");
assert(DestDag->getArgNameStr(DagArgIdx) ==
SourceDag->getArgNameStr(SourceOp->getValue()) &&
"Incorrect operand mapping detected!\n");
DestOperandMap[i].Data.Operand = SourceOp->getValue();
SourceOperandMap[SourceOp->getValue()].Data.Operand = i;
LLVM_DEBUG(dbgs() << " " << SourceOp->getValue() << " ====> " << i
<< "\n");
}
}
/// Validates the CompressPattern and create operand mapping.
/// These are the checks to validate a CompressPat pattern declarations.
/// Error out with message under these conditions:
/// - Dag Input opcode is an expanded instruction and Dag Output opcode is a
/// compressed instruction.
/// - Operands in Dag Input must be all used in Dag Output.
/// Register Operand type in Dag Input Type must be contained in the
/// corresponding Source Instruction type.
/// - Register Operand type in Dag Input must be the same as in Dag Ouput.
/// - Register Operand type in Dag Output must be the same as the
/// corresponding Destination Inst type.
/// - Immediate Operand type in Dag Input must be the same as in Dag Ouput.
/// - Immediate Operand type in Dag Ouput must be the same as the corresponding
/// Destination Instruction type.
/// - Fixed register must be contained in the corresponding Source Instruction
/// type.
/// - Fixed register must be contained in the corresponding Destination
/// Instruction type. Warning message printed under these conditions:
/// - Fixed immediate in Dag Input or Dag Ouput cannot be checked at this time
/// and generate warning.
/// - Immediate operand type in Dag Input differs from the corresponding Source
/// Instruction type and generate a warning.
void RISCVCompressInstEmitter::evaluateCompressPat(Record *Rec) {
// Validate input Dag operands.
DagInit *SourceDag = Rec->getValueAsDag("Input");
assert(SourceDag && "Missing 'Input' in compress pattern!");
LLVM_DEBUG(dbgs() << "Input: " << *SourceDag << "\n");
// Checking we are transforming from compressed to uncompressed instructions.
Record *Operator = SourceDag->getOperatorAsDef(Rec->getLoc());
if (!Operator->isSubClassOf("RVInst"))
PrintFatalError(Rec->getLoc(), "Input instruction '" + Operator->getName() +
"' is not a 32 bit wide instruction!");
CodeGenInstruction SourceInst(Operator);
verifyDagOpCount(SourceInst, SourceDag, true);
// Validate output Dag operands.
DagInit *DestDag = Rec->getValueAsDag("Output");
assert(DestDag && "Missing 'Output' in compress pattern!");
LLVM_DEBUG(dbgs() << "Output: " << *DestDag << "\n");
Record *DestOperator = DestDag->getOperatorAsDef(Rec->getLoc());
if (!DestOperator->isSubClassOf("RVInst16"))
PrintFatalError(Rec->getLoc(), "Output instruction '" +
DestOperator->getName() +
"' is not a 16 bit wide instruction!");
CodeGenInstruction DestInst(DestOperator);
verifyDagOpCount(DestInst, DestDag, false);
// Fill the mapping from the source to destination instructions.
IndexedMap<OpData> SourceOperandMap;
SourceOperandMap.grow(SourceInst.Operands.size());
// Create a mapping between source Dag operands and source Inst operands.
addDagOperandMapping(Rec, SourceDag, SourceInst, SourceOperandMap,
/*IsSourceInst*/ true);
IndexedMap<OpData> DestOperandMap;
DestOperandMap.grow(DestInst.Operands.size());
// Create a mapping between destination Dag operands and destination Inst
// operands.
addDagOperandMapping(Rec, DestDag, DestInst, DestOperandMap,
/*IsSourceInst*/ false);
StringMap<unsigned> SourceOperands;
StringMap<unsigned> DestOperands;
createDagOperandMapping(Rec, SourceOperands, DestOperands, SourceDag, DestDag,
SourceOperandMap);
// Create operand mapping between the source and destination instructions.
createInstOperandMapping(Rec, SourceDag, DestDag, SourceOperandMap,
DestOperandMap, SourceOperands, DestInst);
// Get the target features for the CompressPat.
std::vector<Record *> PatReqFeatures;
std::vector<Record *> RF = Rec->getValueAsListOfDefs("Predicates");
copy_if(RF, std::back_inserter(PatReqFeatures), [](Record *R) {
return R->getValueAsBit("AssemblerMatcherPredicate");
});
CompressPatterns.push_back(CompressPat(SourceInst, DestInst, PatReqFeatures,
SourceOperandMap, DestOperandMap));
}
static void
getReqFeatures(std::set<std::pair<bool, StringRef>> &FeaturesSet,
std::set<std::set<std::pair<bool, StringRef>>> &AnyOfFeatureSets,
const std::vector<Record *> &ReqFeatures) {
for (auto &R : ReqFeatures) {
const DagInit *D = R->getValueAsDag("AssemblerCondDag");
std::string CombineType = D->getOperator()->getAsString();
if (CombineType != "any_of" && CombineType != "all_of")
PrintFatalError(R->getLoc(), "Invalid AssemblerCondDag!");
if (D->getNumArgs() == 0)
PrintFatalError(R->getLoc(), "Invalid AssemblerCondDag!");
bool IsOr = CombineType == "any_of";
std::set<std::pair<bool, StringRef>> AnyOfSet;
for (auto *Arg : D->getArgs()) {
bool IsNot = false;
if (auto *NotArg = dyn_cast<DagInit>(Arg)) {
if (NotArg->getOperator()->getAsString() != "not" ||
NotArg->getNumArgs() != 1)
PrintFatalError(R->getLoc(), "Invalid AssemblerCondDag!");
Arg = NotArg->getArg(0);
IsNot = true;
}
if (!isa<DefInit>(Arg) ||
!cast<DefInit>(Arg)->getDef()->isSubClassOf("SubtargetFeature"))
PrintFatalError(R->getLoc(), "Invalid AssemblerCondDag!");
if (IsOr)
AnyOfSet.insert({IsNot, cast<DefInit>(Arg)->getDef()->getName()});
else
FeaturesSet.insert({IsNot, cast<DefInit>(Arg)->getDef()->getName()});
}
if (IsOr)
AnyOfFeatureSets.insert(AnyOfSet);
}
}
static unsigned getPredicates(DenseMap<const Record *, unsigned> &PredicateMap,
std::vector<const Record *> &Predicates,
Record *Rec, StringRef Name) {
unsigned Entry = PredicateMap[Rec];
if (Entry)
return Entry;
if (!Rec->isValueUnset(Name)) {
Predicates.push_back(Rec);
Entry = Predicates.size();
PredicateMap[Rec] = Entry;
return Entry;
}
PrintFatalError(Rec->getLoc(), "No " + Name +
" predicate on this operand at all: '" + Rec->getName().str() + "'");
return 0;
}
static void printPredicates(std::vector<const Record *> &Predicates,
StringRef Name, raw_ostream &o) {
for (unsigned i = 0; i < Predicates.size(); ++i) {
Init *Pred = Predicates[i]->getValueInit(Name);
if (CodeInit *SI = dyn_cast<CodeInit>(Pred))
o << " case " << i + 1 << ": {\n"
<< " // " << Predicates[i]->getName().str() << "\n"
<< " " << SI->getValue() << "\n"
<< " }\n";
else
llvm_unreachable("Unexpected predicate field!");
}
}
static std::string mergeCondAndCode(raw_string_ostream &CondStream,
raw_string_ostream &CodeStream) {
std::string S;
raw_string_ostream CombinedStream(S);
CombinedStream.indent(4)
<< "if ("
<< CondStream.str().substr(
6, CondStream.str().length() -
10) // remove first indentation and last '&&'.
<< ") {\n";
CombinedStream << CodeStream.str();
CombinedStream.indent(4) << " return true;\n";
CombinedStream.indent(4) << "} // if\n";
return CombinedStream.str();
}
void RISCVCompressInstEmitter::emitCompressInstEmitter(raw_ostream &o,
EmitterType EType) {
Record *AsmWriter = Target.getAsmWriter();
if (!AsmWriter->getValueAsInt("PassSubtarget"))
PrintFatalError(AsmWriter->getLoc(),
"'PassSubtarget' is false. SubTargetInfo object is needed "
"for target features.\n");
std::string Namespace = std::string(Target.getName());
// Sort entries in CompressPatterns to handle instructions that can have more
// than one candidate for compression\uncompression, e.g ADD can be
// transformed to a C_ADD or a C_MV. When emitting 'uncompress()' function the
// source and destination are flipped and the sort key needs to change
// accordingly.
llvm::stable_sort(CompressPatterns,
[EType](const CompressPat &LHS, const CompressPat &RHS) {
if (EType == EmitterType::Compress ||
EType == EmitterType::CheckCompress)
return (LHS.Source.TheDef->getName().str() <
RHS.Source.TheDef->getName().str());
else
return (LHS.Dest.TheDef->getName().str() <
RHS.Dest.TheDef->getName().str());
});
// A list of MCOperandPredicates for all operands in use, and the reverse map.
std::vector<const Record *> MCOpPredicates;
DenseMap<const Record *, unsigned> MCOpPredicateMap;
// A list of ImmLeaf Predicates for all operands in use, and the reverse map.
std::vector<const Record *> ImmLeafPredicates;
DenseMap<const Record *, unsigned> ImmLeafPredicateMap;
std::string F;
std::string FH;
raw_string_ostream Func(F);
raw_string_ostream FuncH(FH);
bool NeedMRI = false;
if (EType == EmitterType::Compress)
o << "\n#ifdef GEN_COMPRESS_INSTR\n"
<< "#undef GEN_COMPRESS_INSTR\n\n";
else if (EType == EmitterType::Uncompress)
o << "\n#ifdef GEN_UNCOMPRESS_INSTR\n"
<< "#undef GEN_UNCOMPRESS_INSTR\n\n";
else if (EType == EmitterType::CheckCompress)
o << "\n#ifdef GEN_CHECK_COMPRESS_INSTR\n"
<< "#undef GEN_CHECK_COMPRESS_INSTR\n\n";
if (EType == EmitterType::Compress) {
FuncH << "static bool compressInst(MCInst& OutInst,\n";
FuncH.indent(25) << "const MCInst &MI,\n";
FuncH.indent(25) << "const MCSubtargetInfo &STI,\n";
FuncH.indent(25) << "MCContext &Context) {\n";
} else if (EType == EmitterType::Uncompress){
FuncH << "static bool uncompressInst(MCInst& OutInst,\n";
FuncH.indent(27) << "const MCInst &MI,\n";
FuncH.indent(27) << "const MCRegisterInfo &MRI,\n";
FuncH.indent(27) << "const MCSubtargetInfo &STI) {\n";
} else if (EType == EmitterType::CheckCompress) {
FuncH << "static bool isCompressibleInst(const MachineInstr& MI,\n";
FuncH.indent(27) << "const RISCVSubtarget *Subtarget,\n";
FuncH.indent(27) << "const MCRegisterInfo &MRI,\n";
FuncH.indent(27) << "const MCSubtargetInfo &STI) {\n";
}
if (CompressPatterns.empty()) {
o << FuncH.str();
o.indent(2) << "return false;\n}\n";
if (EType == EmitterType::Compress)
o << "\n#endif //GEN_COMPRESS_INSTR\n";
else if (EType == EmitterType::Uncompress)
o << "\n#endif //GEN_UNCOMPRESS_INSTR\n\n";
else if (EType == EmitterType::CheckCompress)
o << "\n#endif //GEN_CHECK_COMPRESS_INSTR\n\n";
return;
}
std::string CaseString("");
raw_string_ostream CaseStream(CaseString);
std::string PrevOp("");
std::string CurOp("");
CaseStream << " switch (MI.getOpcode()) {\n";
CaseStream << " default: return false;\n";
bool CompressOrCheck =
EType == EmitterType::Compress || EType == EmitterType::CheckCompress;
bool CompressOrUncompress =
EType == EmitterType::Compress || EType == EmitterType::Uncompress;
for (auto &CompressPat : CompressPatterns) {
std::string CondString;
std::string CodeString;
raw_string_ostream CondStream(CondString);
raw_string_ostream CodeStream(CodeString);
CodeGenInstruction &Source =
CompressOrCheck ? CompressPat.Source : CompressPat.Dest;
CodeGenInstruction &Dest =
CompressOrCheck ? CompressPat.Dest : CompressPat.Source;
IndexedMap<OpData> SourceOperandMap = CompressOrCheck ?
CompressPat.SourceOperandMap : CompressPat.DestOperandMap;
IndexedMap<OpData> &DestOperandMap = CompressOrCheck ?
CompressPat.DestOperandMap : CompressPat.SourceOperandMap;
CurOp = Source.TheDef->getName().str();
// Check current and previous opcode to decide to continue or end a case.
if (CurOp != PrevOp) {
if (PrevOp != "")
CaseStream.indent(6) << "break;\n } // case " + PrevOp + "\n";
CaseStream.indent(4) << "case " + Namespace + "::" + CurOp + ": {\n";
}
std::set<std::pair<bool, StringRef>> FeaturesSet;
std::set<std::set<std::pair<bool, StringRef>>> AnyOfFeatureSets;
// Add CompressPat required features.
getReqFeatures(FeaturesSet, AnyOfFeatureSets, CompressPat.PatReqFeatures);
// Add Dest instruction required features.
std::vector<Record *> ReqFeatures;
std::vector<Record *> RF = Dest.TheDef->getValueAsListOfDefs("Predicates");
copy_if(RF, std::back_inserter(ReqFeatures), [](Record *R) {
return R->getValueAsBit("AssemblerMatcherPredicate");
});
getReqFeatures(FeaturesSet, AnyOfFeatureSets, ReqFeatures);
// Emit checks for all required features.
for (auto &Op : FeaturesSet) {
StringRef Not = Op.first ? "!" : "";
CondStream.indent(6)
<< Not << ("STI.getFeatureBits()[" + Namespace + "::" + Op.second + "]").str() +
" &&\n";
}
// Emit checks for all required feature groups.
for (auto &Set : AnyOfFeatureSets) {
CondStream.indent(6) << "(";
for (auto &Op : Set) {
bool isLast = &Op == &*Set.rbegin();
StringRef Not = Op.first ? "!" : "";
CondStream << Not << ("STI.getFeatureBits()[" + Namespace + "::" + Op.second +
"]").str();
if (!isLast)
CondStream << " || ";
}
CondStream << ") &&\n";
}
// Start Source Inst operands validation.
unsigned OpNo = 0;
for (OpNo = 0; OpNo < Source.Operands.size(); ++OpNo) {
if (SourceOperandMap[OpNo].TiedOpIdx != -1) {
if (Source.Operands[OpNo].Rec->isSubClassOf("RegisterClass"))
CondStream.indent(6)
<< "(MI.getOperand("
<< std::to_string(OpNo) + ").getReg() == MI.getOperand("
<< std::to_string(SourceOperandMap[OpNo].TiedOpIdx)
<< ").getReg()) &&\n";
else
PrintFatalError("Unexpected tied operand types!\n");
}
// Check for fixed immediates\registers in the source instruction.
switch (SourceOperandMap[OpNo].Kind) {
case OpData::Operand:
// We don't need to do anything for source instruction operand checks.
break;
case OpData::Imm:
CondStream.indent(6)
<< "(MI.getOperand(" + std::to_string(OpNo) + ").isImm()) &&\n" +
" (MI.getOperand(" + std::to_string(OpNo) +
").getImm() == " +
std::to_string(SourceOperandMap[OpNo].Data.Imm) + ") &&\n";
break;
case OpData::Reg: {
Record *Reg = SourceOperandMap[OpNo].Data.Reg;
CondStream.indent(6) << "(MI.getOperand(" + std::to_string(OpNo) +
").getReg() == " + Namespace +
"::" + Reg->getName().str() + ") &&\n";
break;
}
}
}
CodeStream.indent(6) << "// " + Dest.AsmString + "\n";
if (CompressOrUncompress)
CodeStream.indent(6) << "OutInst.setOpcode(" + Namespace +
"::" + Dest.TheDef->getName().str() + ");\n";
OpNo = 0;
for (const auto &DestOperand : Dest.Operands) {
CodeStream.indent(6) << "// Operand: " + DestOperand.Name + "\n";
switch (DestOperandMap[OpNo].Kind) {
case OpData::Operand: {
unsigned OpIdx = DestOperandMap[OpNo].Data.Operand;
// Check that the operand in the Source instruction fits
// the type for the Dest instruction.
if (DestOperand.Rec->isSubClassOf("RegisterClass")) {
NeedMRI = true;
// This is a register operand. Check the register class.
// Don't check register class if this is a tied operand, it was done
// for the operand its tied to.
if (DestOperand.getTiedRegister() == -1)
CondStream.indent(6)
<< "(MRI.getRegClass(" + Namespace +
"::" + DestOperand.Rec->getName().str() +
"RegClassID).contains(" + "MI.getOperand(" +
std::to_string(OpIdx) + ").getReg())) &&\n";
if (CompressOrUncompress)
CodeStream.indent(6) << "OutInst.addOperand(MI.getOperand(" +
std::to_string(OpIdx) + "));\n";
} else {
// Handling immediate operands.
if (CompressOrUncompress) {
unsigned Entry = getPredicates(MCOpPredicateMap, MCOpPredicates,
DestOperand.Rec, StringRef("MCOperandPredicate"));
CondStream.indent(6) << Namespace + "ValidateMCOperand(" +
"MI.getOperand(" + std::to_string(OpIdx) +
"), STI, " + std::to_string(Entry) +
") &&\n";
} else {
unsigned Entry = getPredicates(ImmLeafPredicateMap, ImmLeafPredicates,
DestOperand.Rec, StringRef("ImmediateCode"));
CondStream.indent(6) << "MI.getOperand(" + std::to_string(OpIdx) +
").isImm() && \n";
CondStream.indent(6) << Namespace + "ValidateMachineOperand(" +
"MI.getOperand(" + std::to_string(OpIdx) +
"), Subtarget, " + std::to_string(Entry) +
") &&\n";
}
if (CompressOrUncompress)
CodeStream.indent(6) << "OutInst.addOperand(MI.getOperand(" +
std::to_string(OpIdx) + "));\n";
}
break;
}
case OpData::Imm: {
if (CompressOrUncompress) {
unsigned Entry = getPredicates(MCOpPredicateMap, MCOpPredicates,
DestOperand.Rec, StringRef("MCOperandPredicate"));
CondStream.indent(6)
<< Namespace + "ValidateMCOperand(" + "MCOperand::createImm(" +
std::to_string(DestOperandMap[OpNo].Data.Imm) + "), STI, " +
std::to_string(Entry) + ") &&\n";
} else {
unsigned Entry = getPredicates(ImmLeafPredicateMap, ImmLeafPredicates,
DestOperand.Rec, StringRef("ImmediateCode"));
CondStream.indent(6)
<< Namespace + "ValidateMachineOperand(" + "MachineOperand::CreateImm(" +
std::to_string(DestOperandMap[OpNo].Data.Imm) + "), SubTarget, " +
std::to_string(Entry) + ") &&\n";
}
if (CompressOrUncompress)
CodeStream.indent(6)
<< "OutInst.addOperand(MCOperand::createImm(" +
std::to_string(DestOperandMap[OpNo].Data.Imm) + "));\n";
} break;
case OpData::Reg: {
if (CompressOrUncompress) {
// Fixed register has been validated at pattern validation time.
Record *Reg = DestOperandMap[OpNo].Data.Reg;
CodeStream.indent(6) << "OutInst.addOperand(MCOperand::createReg(" +
Namespace + "::" + Reg->getName().str() +
"));\n";
}
} break;
}
++OpNo;
}
if (CompressOrUncompress)
CodeStream.indent(6) << "OutInst.setLoc(MI.getLoc());\n";
CaseStream << mergeCondAndCode(CondStream, CodeStream);
PrevOp = CurOp;
}
Func << CaseStream.str() << "\n";
// Close brace for the last case.
Func.indent(4) << "} // case " + CurOp + "\n";
Func.indent(2) << "} // switch\n";
Func.indent(2) << "return false;\n}\n";
if (!MCOpPredicates.empty()) {
o << "static bool " << Namespace
<< "ValidateMCOperand(const MCOperand &MCOp,\n"
<< " const MCSubtargetInfo &STI,\n"
<< " unsigned PredicateIndex) {\n"
<< " switch (PredicateIndex) {\n"
<< " default:\n"
<< " llvm_unreachable(\"Unknown MCOperandPredicate kind\");\n"
<< " break;\n";
printPredicates(MCOpPredicates, "MCOperandPredicate", o);
o << " }\n"
<< "}\n\n";
}
if (!ImmLeafPredicates.empty()) {
o << "static bool " << Namespace
<< "ValidateMachineOperand(const MachineOperand &MO,\n"
<< " const RISCVSubtarget *Subtarget,\n"
<< " unsigned PredicateIndex) {\n"
<< " int64_t Imm = MO.getImm(); \n"
<< " switch (PredicateIndex) {\n"
<< " default:\n"
<< " llvm_unreachable(\"Unknown ImmLeaf Predicate kind\");\n"
<< " break;\n";
printPredicates(ImmLeafPredicates, "ImmediateCode", o);
o << " }\n"
<< "}\n\n";
}
o << FuncH.str();
if (NeedMRI && EType == EmitterType::Compress)
o.indent(2) << "const MCRegisterInfo &MRI = *Context.getRegisterInfo();\n";
o << Func.str();
if (EType == EmitterType::Compress)
o << "\n#endif //GEN_COMPRESS_INSTR\n";
else if (EType == EmitterType::Uncompress)
o << "\n#endif //GEN_UNCOMPRESS_INSTR\n\n";
else if (EType == EmitterType::CheckCompress)
o << "\n#endif //GEN_CHECK_COMPRESS_INSTR\n\n";
}
void RISCVCompressInstEmitter::run(raw_ostream &o) {
Record *CompressClass = Records.getClass("CompressPat");
assert(CompressClass && "Compress class definition missing!");
std::vector<Record *> Insts;
for (const auto &D : Records.getDefs()) {
if (D.second->isSubClassOf(CompressClass))
Insts.push_back(D.second.get());
}
// Process the CompressPat definitions, validating them as we do so.
for (unsigned i = 0, e = Insts.size(); i != e; ++i)
evaluateCompressPat(Insts[i]);
// Emit file header.
emitSourceFileHeader("Compress instruction Source Fragment", o);
// Generate compressInst() function.
emitCompressInstEmitter(o, EmitterType::Compress);
// Generate uncompressInst() function.
emitCompressInstEmitter(o, EmitterType::Uncompress);
// Generate isCompressibleInst() function.
emitCompressInstEmitter(o, EmitterType::CheckCompress);
}
namespace llvm {
void EmitCompressInst(RecordKeeper &RK, raw_ostream &OS) {
RISCVCompressInstEmitter(RK).run(OS);
}
} // namespace llvm
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