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llvm-mirror/utils/TableGen/AsmWriterEmitter.cpp
Cullen Rhodes c219487139 [TableGen] Fix non-standard escape warnings for braces in InstAlias 
Summary:
TableGen interprets braces ('{}') in the asm string of instruction aliases as
variants but when defining aliases with literal braces they have to be escaped
to prevent them being removed.

Braces are escaped with '\\', for example:

  def FooBraces : InstAlias<"foo \\{$imm\\}", (foo IntOperand:$imm)>;

Although when TableGen is emitting the assembly writer (-gen-asm-writer)
the AsmString that gets emitted is:

  AsmString = "foo \{$\x01\}";

In c/c++ braces don't need to be escaped which causes compilation
warnings:

  warning: use of non-standard escape character '\{' [-Wpedantic]

This patch fixes the issue by unescaping the flattened alias asm string
in the asm writer, by replacing '\{\}' with '{}'.

Reviewed By: hfinkel

Differential Revision: https://reviews.llvm.org/D79991
2020-05-28 09:36:24 +00:00

1278 lines
46 KiB
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//===- AsmWriterEmitter.cpp - Generate an assembly writer -----------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This tablegen backend emits an assembly printer for the current target.
// Note that this is currently fairly skeletal, but will grow over time.
//
//===----------------------------------------------------------------------===//
#include "AsmWriterInst.h"
#include "CodeGenInstruction.h"
#include "CodeGenRegisters.h"
#include "CodeGenTarget.h"
#include "SequenceToOffsetTable.h"
#include "Types.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/TableGen/Error.h"
#include "llvm/TableGen/Record.h"
#include "llvm/TableGen/TableGenBackend.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <deque>
#include <iterator>
#include <map>
#include <set>
#include <string>
#include <tuple>
#include <utility>
#include <vector>
using namespace llvm;
#define DEBUG_TYPE "asm-writer-emitter"
namespace {
class AsmWriterEmitter {
RecordKeeper &Records;
CodeGenTarget Target;
ArrayRef<const CodeGenInstruction *> NumberedInstructions;
std::vector<AsmWriterInst> Instructions;
public:
AsmWriterEmitter(RecordKeeper &R);
void run(raw_ostream &o);
private:
void EmitPrintInstruction(raw_ostream &o);
void EmitGetRegisterName(raw_ostream &o);
void EmitPrintAliasInstruction(raw_ostream &O);
void FindUniqueOperandCommands(std::vector<std::string> &UOC,
std::vector<std::vector<unsigned>> &InstIdxs,
std::vector<unsigned> &InstOpsUsed,
bool PassSubtarget) const;
};
} // end anonymous namespace
static void PrintCases(std::vector<std::pair<std::string,
AsmWriterOperand>> &OpsToPrint, raw_ostream &O,
bool PassSubtarget) {
O << " case " << OpsToPrint.back().first << ":";
AsmWriterOperand TheOp = OpsToPrint.back().second;
OpsToPrint.pop_back();
// Check to see if any other operands are identical in this list, and if so,
// emit a case label for them.
for (unsigned i = OpsToPrint.size(); i != 0; --i)
if (OpsToPrint[i-1].second == TheOp) {
O << "\n case " << OpsToPrint[i-1].first << ":";
OpsToPrint.erase(OpsToPrint.begin()+i-1);
}
// Finally, emit the code.
O << "\n " << TheOp.getCode(PassSubtarget);
O << "\n break;\n";
}
/// EmitInstructions - Emit the last instruction in the vector and any other
/// instructions that are suitably similar to it.
static void EmitInstructions(std::vector<AsmWriterInst> &Insts,
raw_ostream &O, bool PassSubtarget) {
AsmWriterInst FirstInst = Insts.back();
Insts.pop_back();
std::vector<AsmWriterInst> SimilarInsts;
unsigned DifferingOperand = ~0;
for (unsigned i = Insts.size(); i != 0; --i) {
unsigned DiffOp = Insts[i-1].MatchesAllButOneOp(FirstInst);
if (DiffOp != ~1U) {
if (DifferingOperand == ~0U) // First match!
DifferingOperand = DiffOp;
// If this differs in the same operand as the rest of the instructions in
// this class, move it to the SimilarInsts list.
if (DifferingOperand == DiffOp || DiffOp == ~0U) {
SimilarInsts.push_back(Insts[i-1]);
Insts.erase(Insts.begin()+i-1);
}
}
}
O << " case " << FirstInst.CGI->Namespace << "::"
<< FirstInst.CGI->TheDef->getName() << ":\n";
for (const AsmWriterInst &AWI : SimilarInsts)
O << " case " << AWI.CGI->Namespace << "::"
<< AWI.CGI->TheDef->getName() << ":\n";
for (unsigned i = 0, e = FirstInst.Operands.size(); i != e; ++i) {
if (i != DifferingOperand) {
// If the operand is the same for all instructions, just print it.
O << " " << FirstInst.Operands[i].getCode(PassSubtarget);
} else {
// If this is the operand that varies between all of the instructions,
// emit a switch for just this operand now.
O << " switch (MI->getOpcode()) {\n";
O << " default: llvm_unreachable(\"Unexpected opcode.\");\n";
std::vector<std::pair<std::string, AsmWriterOperand>> OpsToPrint;
OpsToPrint.push_back(std::make_pair(FirstInst.CGI->Namespace.str() + "::" +
FirstInst.CGI->TheDef->getName().str(),
FirstInst.Operands[i]));
for (const AsmWriterInst &AWI : SimilarInsts) {
OpsToPrint.push_back(std::make_pair(AWI.CGI->Namespace.str()+"::" +
AWI.CGI->TheDef->getName().str(),
AWI.Operands[i]));
}
std::reverse(OpsToPrint.begin(), OpsToPrint.end());
while (!OpsToPrint.empty())
PrintCases(OpsToPrint, O, PassSubtarget);
O << " }";
}
O << "\n";
}
O << " break;\n";
}
void AsmWriterEmitter::
FindUniqueOperandCommands(std::vector<std::string> &UniqueOperandCommands,
std::vector<std::vector<unsigned>> &InstIdxs,
std::vector<unsigned> &InstOpsUsed,
bool PassSubtarget) const {
// This vector parallels UniqueOperandCommands, keeping track of which
// instructions each case are used for. It is a comma separated string of
// enums.
std::vector<std::string> InstrsForCase;
InstrsForCase.resize(UniqueOperandCommands.size());
InstOpsUsed.assign(UniqueOperandCommands.size(), 0);
for (size_t i = 0, e = Instructions.size(); i != e; ++i) {
const AsmWriterInst &Inst = Instructions[i];
if (Inst.Operands.empty())
continue; // Instruction already done.
std::string Command = " "+Inst.Operands[0].getCode(PassSubtarget)+"\n";
// Check to see if we already have 'Command' in UniqueOperandCommands.
// If not, add it.
auto I = llvm::find(UniqueOperandCommands, Command);
if (I != UniqueOperandCommands.end()) {
size_t idx = I - UniqueOperandCommands.begin();
InstrsForCase[idx] += ", ";
InstrsForCase[idx] += Inst.CGI->TheDef->getName();
InstIdxs[idx].push_back(i);
} else {
UniqueOperandCommands.push_back(std::move(Command));
InstrsForCase.push_back(std::string(Inst.CGI->TheDef->getName()));
InstIdxs.emplace_back();
InstIdxs.back().push_back(i);
// This command matches one operand so far.
InstOpsUsed.push_back(1);
}
}
// For each entry of UniqueOperandCommands, there is a set of instructions
// that uses it. If the next command of all instructions in the set are
// identical, fold it into the command.
for (size_t CommandIdx = 0, e = UniqueOperandCommands.size();
CommandIdx != e; ++CommandIdx) {
const auto &Idxs = InstIdxs[CommandIdx];
for (unsigned Op = 1; ; ++Op) {
// Find the first instruction in the set.
const AsmWriterInst &FirstInst = Instructions[Idxs.front()];
// If this instruction has no more operands, we isn't anything to merge
// into this command.
if (FirstInst.Operands.size() == Op)
break;
// Otherwise, scan to see if all of the other instructions in this command
// set share the operand.
if (std::any_of(Idxs.begin()+1, Idxs.end(),
[&](unsigned Idx) {
const AsmWriterInst &OtherInst = Instructions[Idx];
return OtherInst.Operands.size() == Op ||
OtherInst.Operands[Op] != FirstInst.Operands[Op];
}))
break;
// Okay, everything in this command set has the same next operand. Add it
// to UniqueOperandCommands and remember that it was consumed.
std::string Command = " " +
FirstInst.Operands[Op].getCode(PassSubtarget) + "\n";
UniqueOperandCommands[CommandIdx] += Command;
InstOpsUsed[CommandIdx]++;
}
}
// Prepend some of the instructions each case is used for onto the case val.
for (unsigned i = 0, e = InstrsForCase.size(); i != e; ++i) {
std::string Instrs = InstrsForCase[i];
if (Instrs.size() > 70) {
Instrs.erase(Instrs.begin()+70, Instrs.end());
Instrs += "...";
}
if (!Instrs.empty())
UniqueOperandCommands[i] = " // " + Instrs + "\n" +
UniqueOperandCommands[i];
}
}
static void UnescapeString(std::string &Str) {
for (unsigned i = 0; i != Str.size(); ++i) {
if (Str[i] == '\\' && i != Str.size()-1) {
switch (Str[i+1]) {
default: continue; // Don't execute the code after the switch.
case 'a': Str[i] = '\a'; break;
case 'b': Str[i] = '\b'; break;
case 'e': Str[i] = 27; break;
case 'f': Str[i] = '\f'; break;
case 'n': Str[i] = '\n'; break;
case 'r': Str[i] = '\r'; break;
case 't': Str[i] = '\t'; break;
case 'v': Str[i] = '\v'; break;
case '"': Str[i] = '\"'; break;
case '\'': Str[i] = '\''; break;
case '\\': Str[i] = '\\'; break;
}
// Nuke the second character.
Str.erase(Str.begin()+i+1);
}
}
}
/// UnescapeAliasString - Supports literal braces in InstAlias asm string which
/// are escaped with '\\' to avoid being interpreted as variants. Braces must
/// be unescaped before c++ code is generated as (e.g.):
///
/// AsmString = "foo \{$\x01\}";
///
/// causes non-standard escape character warnings.
static void UnescapeAliasString(std::string &Str) {
for (unsigned i = 0; i != Str.size(); ++i) {
if (Str[i] == '\\' && i != Str.size()-1) {
switch (Str[i+1]) {
default: continue; // Don't execute the code after the switch.
case '{': Str[i] = '{'; break;
case '}': Str[i] = '}'; break;
}
// Nuke the second character.
Str.erase(Str.begin()+i+1);
}
}
}
/// EmitPrintInstruction - Generate the code for the "printInstruction" method
/// implementation. Destroys all instances of AsmWriterInst information, by
/// clearing the Instructions vector.
void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) {
Record *AsmWriter = Target.getAsmWriter();
StringRef ClassName = AsmWriter->getValueAsString("AsmWriterClassName");
bool PassSubtarget = AsmWriter->getValueAsInt("PassSubtarget");
O << "/// printInstruction - This method is automatically generated by "
"tablegen\n"
"/// from the instruction set description.\n"
"void "
<< Target.getName() << ClassName
<< "::printInstruction(const MCInst *MI, uint64_t Address, "
<< (PassSubtarget ? "const MCSubtargetInfo &STI, " : "")
<< "raw_ostream &O) {\n";
// Build an aggregate string, and build a table of offsets into it.
SequenceToOffsetTable<std::string> StringTable;
/// OpcodeInfo - This encodes the index of the string to use for the first
/// chunk of the output as well as indices used for operand printing.
std::vector<uint64_t> OpcodeInfo(NumberedInstructions.size());
const unsigned OpcodeInfoBits = 64;
// Add all strings to the string table upfront so it can generate an optimized
// representation.
for (AsmWriterInst &AWI : Instructions) {
if (AWI.Operands[0].OperandType ==
AsmWriterOperand::isLiteralTextOperand &&
!AWI.Operands[0].Str.empty()) {
std::string Str = AWI.Operands[0].Str;
UnescapeString(Str);
StringTable.add(Str);
}
}
StringTable.layout();
unsigned MaxStringIdx = 0;
for (AsmWriterInst &AWI : Instructions) {
unsigned Idx;
if (AWI.Operands[0].OperandType != AsmWriterOperand::isLiteralTextOperand ||
AWI.Operands[0].Str.empty()) {
// Something handled by the asmwriter printer, but with no leading string.
Idx = StringTable.get("");
} else {
std::string Str = AWI.Operands[0].Str;
UnescapeString(Str);
Idx = StringTable.get(Str);
MaxStringIdx = std::max(MaxStringIdx, Idx);
// Nuke the string from the operand list. It is now handled!
AWI.Operands.erase(AWI.Operands.begin());
}
// Bias offset by one since we want 0 as a sentinel.
OpcodeInfo[AWI.CGIIndex] = Idx+1;
}
// Figure out how many bits we used for the string index.
unsigned AsmStrBits = Log2_32_Ceil(MaxStringIdx+2);
// To reduce code size, we compactify common instructions into a few bits
// in the opcode-indexed table.
unsigned BitsLeft = OpcodeInfoBits-AsmStrBits;
std::vector<std::vector<std::string>> TableDrivenOperandPrinters;
while (true) {
std::vector<std::string> UniqueOperandCommands;
std::vector<std::vector<unsigned>> InstIdxs;
std::vector<unsigned> NumInstOpsHandled;
FindUniqueOperandCommands(UniqueOperandCommands, InstIdxs,
NumInstOpsHandled, PassSubtarget);
// If we ran out of operands to print, we're done.
if (UniqueOperandCommands.empty()) break;
// Compute the number of bits we need to represent these cases, this is
// ceil(log2(numentries)).
unsigned NumBits = Log2_32_Ceil(UniqueOperandCommands.size());
// If we don't have enough bits for this operand, don't include it.
if (NumBits > BitsLeft) {
LLVM_DEBUG(errs() << "Not enough bits to densely encode " << NumBits
<< " more bits\n");
break;
}
// Otherwise, we can include this in the initial lookup table. Add it in.
for (size_t i = 0, e = InstIdxs.size(); i != e; ++i) {
unsigned NumOps = NumInstOpsHandled[i];
for (unsigned Idx : InstIdxs[i]) {
OpcodeInfo[Instructions[Idx].CGIIndex] |=
(uint64_t)i << (OpcodeInfoBits-BitsLeft);
// Remove the info about this operand from the instruction.
AsmWriterInst &Inst = Instructions[Idx];
if (!Inst.Operands.empty()) {
assert(NumOps <= Inst.Operands.size() &&
"Can't remove this many ops!");
Inst.Operands.erase(Inst.Operands.begin(),
Inst.Operands.begin()+NumOps);
}
}
}
BitsLeft -= NumBits;
// Remember the handlers for this set of operands.
TableDrivenOperandPrinters.push_back(std::move(UniqueOperandCommands));
}
// Emit the string table itself.
StringTable.emitStringLiteralDef(O, " static const char AsmStrs[]");
// Emit the lookup tables in pieces to minimize wasted bytes.
unsigned BytesNeeded = ((OpcodeInfoBits - BitsLeft) + 7) / 8;
unsigned Table = 0, Shift = 0;
SmallString<128> BitsString;
raw_svector_ostream BitsOS(BitsString);
// If the total bits is more than 32-bits we need to use a 64-bit type.
BitsOS << " uint" << ((BitsLeft < (OpcodeInfoBits - 32)) ? 64 : 32)
<< "_t Bits = 0;\n";
while (BytesNeeded != 0) {
// Figure out how big this table section needs to be, but no bigger than 4.
unsigned TableSize = std::min(1 << Log2_32(BytesNeeded), 4);
BytesNeeded -= TableSize;
TableSize *= 8; // Convert to bits;
uint64_t Mask = (1ULL << TableSize) - 1;
O << " static const uint" << TableSize << "_t OpInfo" << Table
<< "[] = {\n";
for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i) {
O << " " << ((OpcodeInfo[i] >> Shift) & Mask) << "U,\t// "
<< NumberedInstructions[i]->TheDef->getName() << "\n";
}
O << " };\n\n";
// Emit string to combine the individual table lookups.
BitsOS << " Bits |= ";
// If the total bits is more than 32-bits we need to use a 64-bit type.
if (BitsLeft < (OpcodeInfoBits - 32))
BitsOS << "(uint64_t)";
BitsOS << "OpInfo" << Table << "[MI->getOpcode()] << " << Shift << ";\n";
// Prepare the shift for the next iteration and increment the table count.
Shift += TableSize;
++Table;
}
// Emit the initial tab character.
O << " O << \"\\t\";\n\n";
O << " // Emit the opcode for the instruction.\n";
O << BitsString;
// Emit the starting string.
O << " assert(Bits != 0 && \"Cannot print this instruction.\");\n"
<< " O << AsmStrs+(Bits & " << (1 << AsmStrBits)-1 << ")-1;\n\n";
// Output the table driven operand information.
BitsLeft = OpcodeInfoBits-AsmStrBits;
for (unsigned i = 0, e = TableDrivenOperandPrinters.size(); i != e; ++i) {
std::vector<std::string> &Commands = TableDrivenOperandPrinters[i];
// Compute the number of bits we need to represent these cases, this is
// ceil(log2(numentries)).
unsigned NumBits = Log2_32_Ceil(Commands.size());
assert(NumBits <= BitsLeft && "consistency error");
// Emit code to extract this field from Bits.
O << "\n // Fragment " << i << " encoded into " << NumBits
<< " bits for " << Commands.size() << " unique commands.\n";
if (Commands.size() == 2) {
// Emit two possibilitys with if/else.
O << " if ((Bits >> "
<< (OpcodeInfoBits-BitsLeft) << ") & "
<< ((1 << NumBits)-1) << ") {\n"
<< Commands[1]
<< " } else {\n"
<< Commands[0]
<< " }\n\n";
} else if (Commands.size() == 1) {
// Emit a single possibility.
O << Commands[0] << "\n\n";
} else {
O << " switch ((Bits >> "
<< (OpcodeInfoBits-BitsLeft) << ") & "
<< ((1 << NumBits)-1) << ") {\n"
<< " default: llvm_unreachable(\"Invalid command number.\");\n";
// Print out all the cases.
for (unsigned j = 0, e = Commands.size(); j != e; ++j) {
O << " case " << j << ":\n";
O << Commands[j];
O << " break;\n";
}
O << " }\n\n";
}
BitsLeft -= NumBits;
}
// Okay, delete instructions with no operand info left.
auto I = llvm::remove_if(Instructions,
[](AsmWriterInst &Inst) { return Inst.Operands.empty(); });
Instructions.erase(I, Instructions.end());
// Because this is a vector, we want to emit from the end. Reverse all of the
// elements in the vector.
std::reverse(Instructions.begin(), Instructions.end());
// Now that we've emitted all of the operand info that fit into 64 bits, emit
// information for those instructions that are left. This is a less dense
// encoding, but we expect the main 64-bit table to handle the majority of
// instructions.
if (!Instructions.empty()) {
// Find the opcode # of inline asm.
O << " switch (MI->getOpcode()) {\n";
O << " default: llvm_unreachable(\"Unexpected opcode.\");\n";
while (!Instructions.empty())
EmitInstructions(Instructions, O, PassSubtarget);
O << " }\n";
}
O << "}\n";
}
static void
emitRegisterNameString(raw_ostream &O, StringRef AltName,
const std::deque<CodeGenRegister> &Registers) {
SequenceToOffsetTable<std::string> StringTable;
SmallVector<std::string, 4> AsmNames(Registers.size());
unsigned i = 0;
for (const auto &Reg : Registers) {
std::string &AsmName = AsmNames[i++];
// "NoRegAltName" is special. We don't need to do a lookup for that,
// as it's just a reference to the default register name.
if (AltName == "" || AltName == "NoRegAltName") {
AsmName = std::string(Reg.TheDef->getValueAsString("AsmName"));
if (AsmName.empty())
AsmName = std::string(Reg.getName());
} else {
// Make sure the register has an alternate name for this index.
std::vector<Record*> AltNameList =
Reg.TheDef->getValueAsListOfDefs("RegAltNameIndices");
unsigned Idx = 0, e;
for (e = AltNameList.size();
Idx < e && (AltNameList[Idx]->getName() != AltName);
++Idx)
;
// If the register has an alternate name for this index, use it.
// Otherwise, leave it empty as an error flag.
if (Idx < e) {
std::vector<StringRef> AltNames =
Reg.TheDef->getValueAsListOfStrings("AltNames");
if (AltNames.size() <= Idx)
PrintFatalError(Reg.TheDef->getLoc(),
"Register definition missing alt name for '" +
AltName + "'.");
AsmName = std::string(AltNames[Idx]);
}
}
StringTable.add(AsmName);
}
StringTable.layout();
StringTable.emitStringLiteralDef(O, Twine(" static const char AsmStrs") +
AltName + "[]");
O << " static const " << getMinimalTypeForRange(StringTable.size() - 1, 32)
<< " RegAsmOffset" << AltName << "[] = {";
for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
if ((i % 14) == 0)
O << "\n ";
O << StringTable.get(AsmNames[i]) << ", ";
}
O << "\n };\n"
<< "\n";
}
void AsmWriterEmitter::EmitGetRegisterName(raw_ostream &O) {
Record *AsmWriter = Target.getAsmWriter();
StringRef ClassName = AsmWriter->getValueAsString("AsmWriterClassName");
const auto &Registers = Target.getRegBank().getRegisters();
const std::vector<Record*> &AltNameIndices = Target.getRegAltNameIndices();
bool hasAltNames = AltNameIndices.size() > 1;
StringRef Namespace = Registers.front().TheDef->getValueAsString("Namespace");
O <<
"\n\n/// getRegisterName - This method is automatically generated by tblgen\n"
"/// from the register set description. This returns the assembler name\n"
"/// for the specified register.\n"
"const char *" << Target.getName() << ClassName << "::";
if (hasAltNames)
O << "\ngetRegisterName(unsigned RegNo, unsigned AltIdx) {\n";
else
O << "getRegisterName(unsigned RegNo) {\n";
O << " assert(RegNo && RegNo < " << (Registers.size()+1)
<< " && \"Invalid register number!\");\n"
<< "\n";
if (hasAltNames) {
for (const Record *R : AltNameIndices)
emitRegisterNameString(O, R->getName(), Registers);
} else
emitRegisterNameString(O, "", Registers);
if (hasAltNames) {
O << " switch(AltIdx) {\n"
<< " default: llvm_unreachable(\"Invalid register alt name index!\");\n";
for (const Record *R : AltNameIndices) {
StringRef AltName = R->getName();
O << " case ";
if (!Namespace.empty())
O << Namespace << "::";
O << AltName << ":\n";
if (R->isValueUnset("FallbackRegAltNameIndex"))
O << " assert(*(AsmStrs" << AltName << "+RegAsmOffset" << AltName
<< "[RegNo-1]) &&\n"
<< " \"Invalid alt name index for register!\");\n";
else {
O << " if (!*(AsmStrs" << AltName << "+RegAsmOffset" << AltName
<< "[RegNo-1]))\n"
<< " return getRegisterName(RegNo, ";
if (!Namespace.empty())
O << Namespace << "::";
O << R->getValueAsDef("FallbackRegAltNameIndex")->getName() << ");\n";
}
O << " return AsmStrs" << AltName << "+RegAsmOffset" << AltName
<< "[RegNo-1];\n";
}
O << " }\n";
} else {
O << " assert (*(AsmStrs+RegAsmOffset[RegNo-1]) &&\n"
<< " \"Invalid alt name index for register!\");\n"
<< " return AsmStrs+RegAsmOffset[RegNo-1];\n";
}
O << "}\n";
}
namespace {
// IAPrinter - Holds information about an InstAlias. Two InstAliases match if
// they both have the same conditionals. In which case, we cannot print out the
// alias for that pattern.
class IAPrinter {
std::map<StringRef, std::pair<int, int>> OpMap;
std::vector<std::string> Conds;
std::string Result;
std::string AsmString;
unsigned NumMIOps;
public:
IAPrinter(std::string R, std::string AS, unsigned NumMIOps)
: Result(std::move(R)), AsmString(std::move(AS)), NumMIOps(NumMIOps) {}
void addCond(std::string C) { Conds.push_back(std::move(C)); }
ArrayRef<std::string> getConds() const { return Conds; }
size_t getCondCount() const { return Conds.size(); }
void addOperand(StringRef Op, int OpIdx, int PrintMethodIdx = -1) {
assert(OpIdx >= 0 && OpIdx < 0xFE && "Idx out of range");
assert(PrintMethodIdx >= -1 && PrintMethodIdx < 0xFF &&
"Idx out of range");
OpMap[Op] = std::make_pair(OpIdx, PrintMethodIdx);
}
unsigned getNumMIOps() { return NumMIOps; }
StringRef getResult() { return Result; }
bool isOpMapped(StringRef Op) { return OpMap.find(Op) != OpMap.end(); }
int getOpIndex(StringRef Op) { return OpMap[Op].first; }
std::pair<int, int> &getOpData(StringRef Op) { return OpMap[Op]; }
std::pair<StringRef, StringRef::iterator> parseName(StringRef::iterator Start,
StringRef::iterator End) {
StringRef::iterator I = Start;
StringRef::iterator Next;
if (*I == '{') {
// ${some_name}
Start = ++I;
while (I != End && *I != '}')
++I;
Next = I;
// eat the final '}'
if (Next != End)
++Next;
} else {
// $name, just eat the usual suspects.
while (I != End &&
((*I >= 'a' && *I <= 'z') || (*I >= 'A' && *I <= 'Z') ||
(*I >= '0' && *I <= '9') || *I == '_'))
++I;
Next = I;
}
return std::make_pair(StringRef(Start, I - Start), Next);
}
std::string formatAliasString(uint32_t &UnescapedSize) {
// Directly mangle mapped operands into the string. Each operand is
// identified by a '$' sign followed by a byte identifying the number of the
// operand. We add one to the index to avoid zero bytes.
StringRef ASM(AsmString);
std::string OutString;
raw_string_ostream OS(OutString);
for (StringRef::iterator I = ASM.begin(), E = ASM.end(); I != E;) {
OS << *I;
++UnescapedSize;
if (*I == '$') {
StringRef Name;
std::tie(Name, I) = parseName(++I, E);
assert(isOpMapped(Name) && "Unmapped operand!");
int OpIndex, PrintIndex;
std::tie(OpIndex, PrintIndex) = getOpData(Name);
if (PrintIndex == -1) {
// Can use the default printOperand route.
OS << format("\\x%02X", (unsigned char)OpIndex + 1);
++UnescapedSize;
} else {
// 3 bytes if a PrintMethod is needed: 0xFF, the MCInst operand
// number, and which of our pre-detected Methods to call.
OS << format("\\xFF\\x%02X\\x%02X", OpIndex + 1, PrintIndex + 1);
UnescapedSize += 3;
}
} else {
++I;
}
}
OS.flush();
return OutString;
}
bool operator==(const IAPrinter &RHS) const {
if (NumMIOps != RHS.NumMIOps)
return false;
if (Conds.size() != RHS.Conds.size())
return false;
unsigned Idx = 0;
for (const auto &str : Conds)
if (str != RHS.Conds[Idx++])
return false;
return true;
}
};
} // end anonymous namespace
static unsigned CountNumOperands(StringRef AsmString, unsigned Variant) {
return AsmString.count(' ') + AsmString.count('\t');
}
namespace {
struct AliasPriorityComparator {
typedef std::pair<CodeGenInstAlias, int> ValueType;
bool operator()(const ValueType &LHS, const ValueType &RHS) const {
if (LHS.second == RHS.second) {
// We don't actually care about the order, but for consistency it
// shouldn't depend on pointer comparisons.
return LessRecordByID()(LHS.first.TheDef, RHS.first.TheDef);
}
// Aliases with larger priorities should be considered first.
return LHS.second > RHS.second;
}
};
} // end anonymous namespace
void AsmWriterEmitter::EmitPrintAliasInstruction(raw_ostream &O) {
Record *AsmWriter = Target.getAsmWriter();
O << "\n#ifdef PRINT_ALIAS_INSTR\n";
O << "#undef PRINT_ALIAS_INSTR\n\n";
//////////////////////////////
// Gather information about aliases we need to print
//////////////////////////////
// Emit the method that prints the alias instruction.
StringRef ClassName = AsmWriter->getValueAsString("AsmWriterClassName");
unsigned Variant = AsmWriter->getValueAsInt("Variant");
bool PassSubtarget = AsmWriter->getValueAsInt("PassSubtarget");
std::vector<Record*> AllInstAliases =
Records.getAllDerivedDefinitions("InstAlias");
// Create a map from the qualified name to a list of potential matches.
typedef std::set<std::pair<CodeGenInstAlias, int>, AliasPriorityComparator>
AliasWithPriority;
std::map<std::string, AliasWithPriority> AliasMap;
for (Record *R : AllInstAliases) {
int Priority = R->getValueAsInt("EmitPriority");
if (Priority < 1)
continue; // Aliases with priority 0 are never emitted.
const DagInit *DI = R->getValueAsDag("ResultInst");
AliasMap[getQualifiedName(DI->getOperatorAsDef(R->getLoc()))].insert(
std::make_pair(CodeGenInstAlias(R, Target), Priority));
}
// A map of which conditions need to be met for each instruction operand
// before it can be matched to the mnemonic.
std::map<std::string, std::vector<IAPrinter>> IAPrinterMap;
std::vector<std::pair<std::string, bool>> PrintMethods;
// A list of MCOperandPredicates for all operands in use, and the reverse map
std::vector<const Record*> MCOpPredicates;
DenseMap<const Record*, unsigned> MCOpPredicateMap;
for (auto &Aliases : AliasMap) {
// Collection of instruction alias rules. May contain ambiguous rules.
std::vector<IAPrinter> IAPs;
for (auto &Alias : Aliases.second) {
const CodeGenInstAlias &CGA = Alias.first;
unsigned LastOpNo = CGA.ResultInstOperandIndex.size();
std::string FlatInstAsmString =
CodeGenInstruction::FlattenAsmStringVariants(CGA.ResultInst->AsmString,
Variant);
unsigned NumResultOps = CountNumOperands(FlatInstAsmString, Variant);
std::string FlatAliasAsmString =
CodeGenInstruction::FlattenAsmStringVariants(CGA.AsmString, Variant);
UnescapeAliasString(FlatAliasAsmString);
// Don't emit the alias if it has more operands than what it's aliasing.
if (NumResultOps < CountNumOperands(FlatAliasAsmString, Variant))
continue;
StringRef Namespace = Target.getName();
unsigned NumMIOps = 0;
for (auto &ResultInstOpnd : CGA.ResultInst->Operands)
NumMIOps += ResultInstOpnd.MINumOperands;
IAPrinter IAP(CGA.Result->getAsString(), FlatAliasAsmString, NumMIOps);
bool CantHandle = false;
unsigned MIOpNum = 0;
for (unsigned i = 0, e = LastOpNo; i != e; ++i) {
// Skip over tied operands as they're not part of an alias declaration.
auto &Operands = CGA.ResultInst->Operands;
while (true) {
unsigned OpNum = Operands.getSubOperandNumber(MIOpNum).first;
if (Operands[OpNum].MINumOperands == 1 &&
Operands[OpNum].getTiedRegister() != -1) {
// Tied operands of different RegisterClass should be explicit within
// an instruction's syntax and so cannot be skipped.
int TiedOpNum = Operands[OpNum].getTiedRegister();
if (Operands[OpNum].Rec->getName() ==
Operands[TiedOpNum].Rec->getName()) {
++MIOpNum;
continue;
}
}
break;
}
// Ignore unchecked result operands.
while (IAP.getCondCount() < MIOpNum)
IAP.addCond("AliasPatternCond::K_Ignore, 0");
const CodeGenInstAlias::ResultOperand &RO = CGA.ResultOperands[i];
switch (RO.Kind) {
case CodeGenInstAlias::ResultOperand::K_Record: {
const Record *Rec = RO.getRecord();
StringRef ROName = RO.getName();
int PrintMethodIdx = -1;
// These two may have a PrintMethod, which we want to record (if it's
// the first time we've seen it) and provide an index for the aliasing
// code to use.
if (Rec->isSubClassOf("RegisterOperand") ||
Rec->isSubClassOf("Operand")) {
StringRef PrintMethod = Rec->getValueAsString("PrintMethod");
bool IsPCRel =
Rec->getValueAsString("OperandType") == "OPERAND_PCREL";
if (PrintMethod != "" && PrintMethod != "printOperand") {
PrintMethodIdx = llvm::find_if(PrintMethods,
[&](auto &X) {
return X.first == PrintMethod;
}) -
PrintMethods.begin();
if (static_cast<unsigned>(PrintMethodIdx) == PrintMethods.size())
PrintMethods.emplace_back(std::string(PrintMethod), IsPCRel);
}
}
if (Rec->isSubClassOf("RegisterOperand"))
Rec = Rec->getValueAsDef("RegClass");
if (Rec->isSubClassOf("RegisterClass")) {
if (!IAP.isOpMapped(ROName)) {
IAP.addOperand(ROName, MIOpNum, PrintMethodIdx);
Record *R = CGA.ResultOperands[i].getRecord();
if (R->isSubClassOf("RegisterOperand"))
R = R->getValueAsDef("RegClass");
IAP.addCond(std::string(
formatv("AliasPatternCond::K_RegClass, {0}::{1}RegClassID",
Namespace, R->getName())));
} else {
IAP.addCond(std::string(formatv(
"AliasPatternCond::K_TiedReg, {0}", IAP.getOpIndex(ROName))));
}
} else {
// Assume all printable operands are desired for now. This can be
// overridden in the InstAlias instantiation if necessary.
IAP.addOperand(ROName, MIOpNum, PrintMethodIdx);
// There might be an additional predicate on the MCOperand
unsigned Entry = MCOpPredicateMap[Rec];
if (!Entry) {
if (!Rec->isValueUnset("MCOperandPredicate")) {
MCOpPredicates.push_back(Rec);
Entry = MCOpPredicates.size();
MCOpPredicateMap[Rec] = Entry;
} else
break; // No conditions on this operand at all
}
IAP.addCond(
std::string(formatv("AliasPatternCond::K_Custom, {0}", Entry)));
}
break;
}
case CodeGenInstAlias::ResultOperand::K_Imm: {
// Just because the alias has an immediate result, doesn't mean the
// MCInst will. An MCExpr could be present, for example.
auto Imm = CGA.ResultOperands[i].getImm();
int32_t Imm32 = int32_t(Imm);
if (Imm != Imm32)
PrintFatalError("Matching an alias with an immediate out of the "
"range of int32_t is not supported");
IAP.addCond(std::string(
formatv("AliasPatternCond::K_Imm, uint32_t({0})", Imm32)));
break;
}
case CodeGenInstAlias::ResultOperand::K_Reg:
// If this is zero_reg, something's playing tricks we're not
// equipped to handle.
if (!CGA.ResultOperands[i].getRegister()) {
CantHandle = true;
break;
}
StringRef Reg = CGA.ResultOperands[i].getRegister()->getName();
IAP.addCond(std::string(
formatv("AliasPatternCond::K_Reg, {0}::{1}", Namespace, Reg)));
break;
}
MIOpNum += RO.getMINumOperands();
}
if (CantHandle) continue;
std::vector<Record *> ReqFeatures;
if (PassSubtarget) {
// We only consider ReqFeatures predicates if PassSubtarget
std::vector<Record *> RF =
CGA.TheDef->getValueAsListOfDefs("Predicates");
copy_if(RF, std::back_inserter(ReqFeatures), [](Record *R) {
return R->getValueAsBit("AssemblerMatcherPredicate");
});
}
for (auto I = ReqFeatures.cbegin(); I != ReqFeatures.cend(); I++) {
Record *R = *I;
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";
for (auto *Arg : D->getArgs()) {
bool IsNeg = 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);
IsNeg = true;
}
if (!isa<DefInit>(Arg) ||
!cast<DefInit>(Arg)->getDef()->isSubClassOf("SubtargetFeature"))
PrintFatalError(R->getLoc(), "Invalid AssemblerCondDag!");
IAP.addCond(std::string(formatv(
"AliasPatternCond::K_{0}{1}Feature, {2}::{3}", IsOr ? "Or" : "",
IsNeg ? "Neg" : "", Namespace, Arg->getAsString())));
}
// If an AssemblerPredicate with ors is used, note end of list should
// these be combined.
if (IsOr)
IAP.addCond("AliasPatternCond::K_EndOrFeatures, 0");
}
IAPrinterMap[Aliases.first].push_back(std::move(IAP));
}
}
//////////////////////////////
// Write out the printAliasInstr function
//////////////////////////////
std::string Header;
raw_string_ostream HeaderO(Header);
HeaderO << "bool " << Target.getName() << ClassName
<< "::printAliasInstr(const MCInst"
<< " *MI, uint64_t Address, "
<< (PassSubtarget ? "const MCSubtargetInfo &STI, " : "")
<< "raw_ostream &OS) {\n";
std::string PatternsForOpcode;
raw_string_ostream OpcodeO(PatternsForOpcode);
unsigned PatternCount = 0;
std::string Patterns;
raw_string_ostream PatternO(Patterns);
unsigned CondCount = 0;
std::string Conds;
raw_string_ostream CondO(Conds);
// All flattened alias strings.
std::map<std::string, uint32_t> AsmStringOffsets;
std::vector<std::pair<uint32_t, std::string>> AsmStrings;
size_t AsmStringsSize = 0;
// Iterate over the opcodes in enum order so they are sorted by opcode for
// binary search.
for (const CodeGenInstruction *Inst : NumberedInstructions) {
auto It = IAPrinterMap.find(getQualifiedName(Inst->TheDef));
if (It == IAPrinterMap.end())
continue;
std::vector<IAPrinter> &IAPs = It->second;
std::vector<IAPrinter*> UniqueIAPs;
// Remove any ambiguous alias rules.
for (auto &LHS : IAPs) {
bool IsDup = false;
for (const auto &RHS : IAPs) {
if (&LHS != &RHS && LHS == RHS) {
IsDup = true;
break;
}
}
if (!IsDup)
UniqueIAPs.push_back(&LHS);
}
if (UniqueIAPs.empty()) continue;
unsigned PatternStart = PatternCount;
// Insert the pattern start and opcode in the pattern list for debugging.
PatternO << formatv(" // {0} - {1}\n", It->first, PatternStart);
for (IAPrinter *IAP : UniqueIAPs) {
// Start each condition list with a comment of the resulting pattern that
// we're trying to match.
unsigned CondStart = CondCount;
CondO << formatv(" // {0} - {1}\n", IAP->getResult(), CondStart);
for (const auto &Cond : IAP->getConds())
CondO << " {" << Cond << "},\n";
CondCount += IAP->getCondCount();
// After operands have been examined, re-encode the alias string with
// escapes indicating how operands should be printed.
uint32_t UnescapedSize = 0;
std::string EncodedAsmString = IAP->formatAliasString(UnescapedSize);
auto Insertion =
AsmStringOffsets.insert({EncodedAsmString, AsmStringsSize});
if (Insertion.second) {
// If the string is new, add it to the vector.
AsmStrings.push_back({AsmStringsSize, EncodedAsmString});
AsmStringsSize += UnescapedSize + 1;
}
unsigned AsmStrOffset = Insertion.first->second;
PatternO << formatv(" {{{0}, {1}, {2}, {3} },\n", AsmStrOffset,
CondStart, IAP->getNumMIOps(), IAP->getCondCount());
++PatternCount;
}
OpcodeO << formatv(" {{{0}, {1}, {2} },\n", It->first, PatternStart,
PatternCount - PatternStart);
}
if (OpcodeO.str().empty()) {
O << HeaderO.str();
O << " return false;\n";
O << "}\n\n";
O << "#endif // PRINT_ALIAS_INSTR\n";
return;
}
// Forward declare the validation method if needed.
if (!MCOpPredicates.empty())
O << "static bool " << Target.getName() << ClassName
<< "ValidateMCOperand(const MCOperand &MCOp,\n"
<< " const MCSubtargetInfo &STI,\n"
<< " unsigned PredicateIndex);\n";
O << HeaderO.str();
O.indent(2) << "static const PatternsForOpcode OpToPatterns[] = {\n";
O << OpcodeO.str();
O.indent(2) << "};\n\n";
O.indent(2) << "static const AliasPattern Patterns[] = {\n";
O << PatternO.str();
O.indent(2) << "};\n\n";
O.indent(2) << "static const AliasPatternCond Conds[] = {\n";
O << CondO.str();
O.indent(2) << "};\n\n";
O.indent(2) << "static const char AsmStrings[] =\n";
for (const auto &P : AsmStrings) {
O.indent(4) << "/* " << P.first << " */ \"" << P.second << "\\0\"\n";
}
O.indent(2) << ";\n\n";
// Assert that the opcode table is sorted. Use a static local constructor to
// ensure that the check only happens once on first run.
O << "#ifndef NDEBUG\n";
O.indent(2) << "static struct SortCheck {\n";
O.indent(2) << " SortCheck(ArrayRef<PatternsForOpcode> OpToPatterns) {\n";
O.indent(2) << " assert(std::is_sorted(\n";
O.indent(2) << " OpToPatterns.begin(), OpToPatterns.end(),\n";
O.indent(2) << " [](const PatternsForOpcode &L, const "
"PatternsForOpcode &R) {\n";
O.indent(2) << " return L.Opcode < R.Opcode;\n";
O.indent(2) << " }) &&\n";
O.indent(2) << " \"tablegen failed to sort opcode patterns\");\n";
O.indent(2) << " }\n";
O.indent(2) << "} sortCheckVar(OpToPatterns);\n";
O << "#endif\n\n";
O.indent(2) << "AliasMatchingData M {\n";
O.indent(2) << " makeArrayRef(OpToPatterns),\n";
O.indent(2) << " makeArrayRef(Patterns),\n";
O.indent(2) << " makeArrayRef(Conds),\n";
O.indent(2) << " StringRef(AsmStrings, array_lengthof(AsmStrings)),\n";
if (MCOpPredicates.empty())
O.indent(2) << " nullptr,\n";
else
O.indent(2) << " &" << Target.getName() << ClassName << "ValidateMCOperand,\n";
O.indent(2) << "};\n";
O.indent(2) << "const char *AsmString = matchAliasPatterns(MI, "
<< (PassSubtarget ? "&STI" : "nullptr") << ", M);\n";
O.indent(2) << "if (!AsmString) return false;\n\n";
// Code that prints the alias, replacing the operands with the ones from the
// MCInst.
O << " unsigned I = 0;\n";
O << " while (AsmString[I] != ' ' && AsmString[I] != '\\t' &&\n";
O << " AsmString[I] != '$' && AsmString[I] != '\\0')\n";
O << " ++I;\n";
O << " OS << '\\t' << StringRef(AsmString, I);\n";
O << " if (AsmString[I] != '\\0') {\n";
O << " if (AsmString[I] == ' ' || AsmString[I] == '\\t') {\n";
O << " OS << '\\t';\n";
O << " ++I;\n";
O << " }\n";
O << " do {\n";
O << " if (AsmString[I] == '$') {\n";
O << " ++I;\n";
O << " if (AsmString[I] == (char)0xff) {\n";
O << " ++I;\n";
O << " int OpIdx = AsmString[I++] - 1;\n";
O << " int PrintMethodIdx = AsmString[I++] - 1;\n";
O << " printCustomAliasOperand(MI, Address, OpIdx, PrintMethodIdx, ";
O << (PassSubtarget ? "STI, " : "");
O << "OS);\n";
O << " } else\n";
O << " printOperand(MI, unsigned(AsmString[I++]) - 1, ";
O << (PassSubtarget ? "STI, " : "");
O << "OS);\n";
O << " } else {\n";
O << " OS << AsmString[I++];\n";
O << " }\n";
O << " } while (AsmString[I] != '\\0');\n";
O << " }\n\n";
O << " return true;\n";
O << "}\n\n";
//////////////////////////////
// Write out the printCustomAliasOperand function
//////////////////////////////
O << "void " << Target.getName() << ClassName << "::"
<< "printCustomAliasOperand(\n"
<< " const MCInst *MI, uint64_t Address, unsigned OpIdx,\n"
<< " unsigned PrintMethodIdx,\n"
<< (PassSubtarget ? " const MCSubtargetInfo &STI,\n" : "")
<< " raw_ostream &OS) {\n";
if (PrintMethods.empty())
O << " llvm_unreachable(\"Unknown PrintMethod kind\");\n";
else {
O << " switch (PrintMethodIdx) {\n"
<< " default:\n"
<< " llvm_unreachable(\"Unknown PrintMethod kind\");\n"
<< " break;\n";
for (unsigned i = 0; i < PrintMethods.size(); ++i) {
O << " case " << i << ":\n"
<< " " << PrintMethods[i].first << "(MI, "
<< (PrintMethods[i].second ? "Address, " : "") << "OpIdx, "
<< (PassSubtarget ? "STI, " : "") << "OS);\n"
<< " break;\n";
}
O << " }\n";
}
O << "}\n\n";
if (!MCOpPredicates.empty()) {
O << "static bool " << Target.getName() << ClassName
<< "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";
for (unsigned i = 0; i < MCOpPredicates.size(); ++i) {
Init *MCOpPred = MCOpPredicates[i]->getValueInit("MCOperandPredicate");
if (CodeInit *SI = dyn_cast<CodeInit>(MCOpPred)) {
O << " case " << i + 1 << ": {\n"
<< SI->getValue() << "\n"
<< " }\n";
} else
llvm_unreachable("Unexpected MCOperandPredicate field!");
}
O << " }\n"
<< "}\n\n";
}
O << "#endif // PRINT_ALIAS_INSTR\n";
}
AsmWriterEmitter::AsmWriterEmitter(RecordKeeper &R) : Records(R), Target(R) {
Record *AsmWriter = Target.getAsmWriter();
unsigned Variant = AsmWriter->getValueAsInt("Variant");
// Get the instruction numbering.
NumberedInstructions = Target.getInstructionsByEnumValue();
for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i) {
const CodeGenInstruction *I = NumberedInstructions[i];
if (!I->AsmString.empty() && I->TheDef->getName() != "PHI")
Instructions.emplace_back(*I, i, Variant);
}
}
void AsmWriterEmitter::run(raw_ostream &O) {
EmitPrintInstruction(O);
EmitGetRegisterName(O);
EmitPrintAliasInstruction(O);
}
namespace llvm {
void EmitAsmWriter(RecordKeeper &RK, raw_ostream &OS) {
emitSourceFileHeader("Assembly Writer Source Fragment", OS);
AsmWriterEmitter(RK).run(OS);
}
} // end namespace llvm
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