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|
//===- TableGen.cpp - Top-Level TableGen implementation -------------------===//
//
// TableGen is a tool which can be used to build up a description of something,
// then invoke one or more "tablegen backends" to emit information about the
// description in some predefined format. In practice, this is used by the LLVM
// code generators to automate generation of a code generator through a
// high-level description of the target.
//
//===----------------------------------------------------------------------===//
#include "Record.h"
#include "Support/CommandLine.h"
#include "Support/Signals.h"
#include "Support/FileUtilities.h"
#include "CodeEmitterGen.h"
#include "RegisterInfoEmitter.h"
#include <algorithm>
#include <fstream>
enum ActionType {
PrintRecords,
GenEmitter,
GenRegisterEnums, GenRegister, GenRegisterHeader,
PrintEnums,
Parse,
};
namespace {
cl::opt<ActionType>
Action(cl::desc("Action to perform:"),
cl::values(clEnumValN(PrintRecords, "print-records",
"Print all records to stdout (default)"),
clEnumValN(GenEmitter, "gen-emitter",
"Generate machine code emitter"),
clEnumValN(GenRegisterEnums, "gen-register-enums",
"Generate enum values for registers"),
clEnumValN(GenRegister, "gen-register-desc",
"Generate a register info description"),
clEnumValN(GenRegisterHeader, "gen-register-desc-header",
"Generate a register info description header"),
clEnumValN(PrintEnums, "print-enums",
"Print enum values for a class"),
clEnumValN(Parse, "parse",
"Interpret machine code (testing only)"),
0));
cl::opt<std::string>
Class("class", cl::desc("Print Enum list for this class"),
cl::value_desc("class name"));
cl::opt<std::string>
OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"),
cl::init("-"));
cl::opt<std::string>
InputFilename(cl::Positional, cl::desc("<input file>"), cl::init("-"));
}
void ParseFile(const std::string &Filename);
RecordKeeper Records;
static Init *getBit(Record *R, unsigned BitNo) {
const std::vector<RecordVal> &V = R->getValues();
for (unsigned i = 0, e = V.size(); i != e; ++i)
if (V[i].getPrefix()) {
assert(dynamic_cast<BitsInit*>(V[i].getValue()) &&
"Can only handle fields of bits<> type!");
BitsInit *I = (BitsInit*)V[i].getValue();
if (BitNo < I->getNumBits())
return I->getBit(BitNo);
BitNo -= I->getNumBits();
}
std::cerr << "Cannot find requested bit!\n";
abort();
return 0;
}
static unsigned getNumBits(Record *R) {
const std::vector<RecordVal> &V = R->getValues();
unsigned Num = 0;
for (unsigned i = 0, e = V.size(); i != e; ++i)
if (V[i].getPrefix()) {
assert(dynamic_cast<BitsInit*>(V[i].getValue()) &&
"Can only handle fields of bits<> type!");
Num += ((BitsInit*)V[i].getValue())->getNumBits();
}
return Num;
}
static bool BitsAreFixed(Record *I1, Record *I2, unsigned BitNo) {
return dynamic_cast<BitInit*>(getBit(I1, BitNo)) &&
dynamic_cast<BitInit*>(getBit(I2, BitNo));
}
static bool BitsAreEqual(Record *I1, Record *I2, unsigned BitNo) {
BitInit *Bit1 = dynamic_cast<BitInit*>(getBit(I1, BitNo));
BitInit *Bit2 = dynamic_cast<BitInit*>(getBit(I2, BitNo));
return Bit1 && Bit2 && Bit1->getValue() == Bit2->getValue();
}
static bool BitRangesEqual(Record *I1, Record *I2,
unsigned Start, unsigned End) {
for (unsigned i = Start; i != End; ++i)
if (!BitsAreEqual(I1, I2, i))
return false;
return true;
}
static unsigned getFirstFixedBit(Record *R, unsigned FirstFixedBit) {
// Look for the first bit of the pair that are required to be 0 or 1.
while (!dynamic_cast<BitInit*>(getBit(R, FirstFixedBit)))
++FirstFixedBit;
return FirstFixedBit;
}
static void FindInstDifferences(Record *I1, Record *I2,
unsigned FirstFixedBit, unsigned MaxBits,
unsigned &FirstVaryingBitOverall,
unsigned &LastFixedBitOverall) {
// Compare the first instruction to the rest of the instructions, looking for
// fields that differ.
//
unsigned FirstVaryingBit = FirstFixedBit;
while (FirstVaryingBit < MaxBits && BitsAreEqual(I1, I2, FirstVaryingBit))
++FirstVaryingBit;
unsigned LastFixedBit = FirstVaryingBit;
while (LastFixedBit < MaxBits && BitsAreFixed(I1, I2, LastFixedBit))
++LastFixedBit;
if (FirstVaryingBit < FirstVaryingBitOverall)
FirstVaryingBitOverall = FirstVaryingBit;
if (LastFixedBit < LastFixedBitOverall)
LastFixedBitOverall = LastFixedBit;
}
static bool getBitValue(Record *R, unsigned BitNo) {
Init *I = getBit(R, BitNo);
assert(dynamic_cast<BitInit*>(I) && "Bit should be fixed!");
return ((BitInit*)I)->getValue();
}
struct BitComparator {
unsigned BitBegin, BitEnd;
BitComparator(unsigned B, unsigned E) : BitBegin(B), BitEnd(E) {}
bool operator()(Record *R1, Record *R2) { // Return true if R1 is less than R2
for (unsigned i = BitBegin; i != BitEnd; ++i) {
bool V1 = getBitValue(R1, i), V2 = getBitValue(R2, i);
if (V1 < V2)
return true;
else if (V2 < V1)
return false;
}
return false;
}
};
static void PrintRange(std::vector<Record*>::iterator I,
std::vector<Record*>::iterator E) {
while (I != E) std::cerr << **I++;
}
static bool getMemoryBit(unsigned char *M, unsigned i) {
return (M[i/8] & (1 << (i&7))) != 0;
}
static unsigned getFirstFixedBitInSequence(std::vector<Record*>::iterator IB,
std::vector<Record*>::iterator IE,
unsigned StartBit) {
unsigned FirstFixedBit = 0;
for (std::vector<Record*>::iterator I = IB; I != IE; ++I)
FirstFixedBit = std::max(FirstFixedBit, getFirstFixedBit(*I, StartBit));
return FirstFixedBit;
}
// ParseMachineCode - Try to split the vector of instructions (which is
// intentially taken by-copy) in half, narrowing down the possible instructions
// that we may have found. Eventually, this list will get pared down to zero or
// one instruction, in which case we have a match or failure.
//
static Record *ParseMachineCode(std::vector<Record*>::iterator InstsB,
std::vector<Record*>::iterator InstsE,
unsigned char *M) {
assert(InstsB != InstsE && "Empty range?");
if (InstsB+1 == InstsE) {
// Only a single instruction, see if we match it...
Record *Inst = *InstsB;
for (unsigned i = 0, e = getNumBits(Inst); i != e; ++i)
if (BitInit *BI = dynamic_cast<BitInit*>(getBit(Inst, i)))
if (getMemoryBit(M, i) != BI->getValue())
throw std::string("Parse failed!\n");
return Inst;
}
unsigned MaxBits = ~0;
for (std::vector<Record*>::iterator I = InstsB; I != InstsE; ++I)
MaxBits = std::min(MaxBits, getNumBits(*I));
unsigned FirstFixedBit = getFirstFixedBitInSequence(InstsB, InstsE, 0);
unsigned FirstVaryingBit, LastFixedBit;
do {
FirstVaryingBit = ~0;
LastFixedBit = ~0;
for (std::vector<Record*>::iterator I = InstsB+1; I != InstsE; ++I)
FindInstDifferences(*InstsB, *I, FirstFixedBit, MaxBits,
FirstVaryingBit, LastFixedBit);
if (FirstVaryingBit == MaxBits) {
std::cerr << "ERROR: Could not find bit to distinguish between "
<< "the following entries!\n";
PrintRange(InstsB, InstsE);
}
#if 0
std::cerr << "FVB: " << FirstVaryingBit << " - " << LastFixedBit
<< ": " << InstsE-InstsB << "\n";
#endif
FirstFixedBit = getFirstFixedBitInSequence(InstsB, InstsE, FirstVaryingBit);
} while (FirstVaryingBit != FirstFixedBit);
//std::cerr << "\n\nXXXXXXXXXXXXXXXXX\n\n";
//PrintRange(InstsB, InstsE);
// Sort the Insts list so that the entries have all of the bits in the range
// [FirstVaryingBit,LastFixedBit) sorted. These bits are all guaranteed to be
// set to either 0 or 1 (BitInit values), which simplifies things.
//
std::sort(InstsB, InstsE, BitComparator(FirstVaryingBit, LastFixedBit));
// Once the list is sorted by these bits, split the bit list into smaller
// lists, and recurse on each one.
//
std::vector<Record*>::iterator RangeBegin = InstsB;
Record *Match = 0;
while (RangeBegin != InstsE) {
std::vector<Record*>::iterator RangeEnd = RangeBegin+1;
while (RangeEnd != InstsE &&
BitRangesEqual(*RangeBegin, *RangeEnd, FirstVaryingBit, LastFixedBit))
++RangeEnd;
// We just identified a range of equal instructions. If this range is the
// input range, we were not able to distinguish between the instructions in
// the set. Print an error and exit!
//
if (RangeBegin == InstsB && RangeEnd == InstsE) {
std::cerr << "Error: Could not distinguish among the following insts!:\n";
PrintRange(InstsB, InstsE);
abort();
}
#if 0
std::cerr << "FVB: " << FirstVaryingBit << " - " << LastFixedBit
<< ": [" << RangeEnd-RangeBegin << "] - ";
for (int i = LastFixedBit-1; i >= (int)FirstVaryingBit; --i)
std::cerr << (int)((BitInit*)getBit(*RangeBegin, i))->getValue() << " ";
std::cerr << "\n";
#endif
if (Record *R = ParseMachineCode(RangeBegin, RangeEnd, M)) {
if (Match) {
std::cerr << "Error: Multiple matches found:\n";
PrintRange(InstsB, InstsE);
}
assert(Match == 0 && "Multiple matches??");
Match = R;
}
RangeBegin = RangeEnd;
}
return Match;
}
static void PrintValue(Record *I, unsigned char *Ptr, const RecordVal &Val) {
assert(dynamic_cast<BitsInit*>(Val.getValue()) &&
"Can only handle undefined bits<> types!");
BitsInit *BI = (BitsInit*)Val.getValue();
assert(BI->getNumBits() <= 32 && "Can only handle fields up to 32 bits!");
unsigned Value = 0;
const std::vector<RecordVal> &Vals = I->getValues();
// Start by filling in fixed values...
for (unsigned i = 0, e = BI->getNumBits(); i != e; ++i)
if (BitInit *B = dynamic_cast<BitInit*>(BI->getBit(i)))
Value |= B->getValue() << i;
// Loop over all of the fields in the instruction adding in any
// contributions to this value (due to bit references).
//
unsigned Offset = 0;
for (unsigned f = 0, e = Vals.size(); f != e; ++f)
if (Vals[f].getPrefix()) {
BitsInit *FieldInitializer = (BitsInit*)Vals[f].getValue();
if (&Vals[f] == &Val) {
// Read the bits directly now...
for (unsigned i = 0, e = BI->getNumBits(); i != e; ++i)
Value |= getMemoryBit(Ptr, Offset+i) << i;
break;
}
// Scan through the field looking for bit initializers of the current
// variable...
for (unsigned i = 0, e = FieldInitializer->getNumBits(); i != e; ++i)
if (VarBitInit *VBI =
dynamic_cast<VarBitInit*>(FieldInitializer->getBit(i))) {
TypedInit *TI = VBI->getVariable();
if (VarInit *VI = dynamic_cast<VarInit*>(TI)) {
if (VI->getName() == Val.getName())
Value |= getMemoryBit(Ptr, Offset+i) << VBI->getBitNum();
} else if (FieldInit *FI = dynamic_cast<FieldInit*>(TI)) {
// FIXME: implement this!
std::cerr << "FIELD INIT not implemented yet!\n";
}
}
Offset += FieldInitializer->getNumBits();
}
std::cout << "0x" << std::hex << Value << std::dec;
}
static void PrintInstruction(Record *I, unsigned char *Ptr) {
std::cout << "Inst " << getNumBits(I)/8 << " bytes: "
<< "\t" << I->getName() << "\t" << *I->getValue("Name")->getValue()
<< "\t";
const std::vector<RecordVal> &Vals = I->getValues();
for (unsigned i = 0, e = Vals.size(); i != e; ++i)
if (!Vals[i].getValue()->isComplete()) {
std::cout << Vals[i].getName() << "=";
PrintValue(I, Ptr, Vals[i]);
std::cout << "\t";
}
std::cout << "\n";// << *I;
}
static void ParseMachineCode() {
// X86 code
unsigned char Buffer[] = {
0x55, // push EBP
0x89, 0xE5, // mov EBP, ESP
//0x83, 0xEC, 0x08, // sub ESP, 0x8
0xE8, 1, 2, 3, 4, // call +0x04030201
0x89, 0xEC, // mov ESP, EBP
0x5D, // pop EBP
0xC3, // ret
0x90, // nop
0xC9, // leave
0x89, 0xF6, // mov ESI, ESI
0x68, 1, 2, 3, 4, // push 0x04030201
0x5e, // pop ESI
0xFF, 0xD0, // call EAX
0xB8, 1, 2, 3, 4, // mov EAX, 0x04030201
0x85, 0xC0, // test EAX, EAX
0xF4, // hlt
};
#if 0
// SparcV9 code
unsigned char Buffer[] = { 0xbf, 0xe0, 0x20, 0x1f, 0x1, 0x0, 0x0, 0x1,
0x0, 0x0, 0x0, 0x0, 0xc1, 0x0, 0x20, 0x1, 0x1,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x40, 0x0, 0x0, 0x0, 0x1,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0xaf, 0xe8, 0x20, 0x17
};
#endif
std::vector<Record*> Insts = Records.getAllDerivedDefinitions("Instruction");
unsigned char *BuffPtr = Buffer;
while (1) {
Record *R = ParseMachineCode(Insts.begin(), Insts.end(), BuffPtr);
PrintInstruction(R, BuffPtr);
unsigned Bits = getNumBits(R);
assert((Bits & 7) == 0 && "Instruction is not an even number of bytes!");
BuffPtr += Bits/8;
}
}
int main(int argc, char **argv) {
cl::ParseCommandLineOptions(argc, argv);
ParseFile(InputFilename);
std::ostream *Out = &std::cout;
if (OutputFilename != "-") {
// Output to a .tmp file, because we don't actually want to overwrite the
// output file unless the generated file is different or the specified file
// does not exist.
Out = new std::ofstream((OutputFilename+".tmp").c_str());
if (!Out->good()) {
std::cerr << argv[0] << ": error opening " << OutputFilename << ".tmp!\n";
return 1;
}
// Make sure the file gets removed if *gasp* tablegen crashes...
RemoveFileOnSignal(OutputFilename+".tmp");
}
try {
switch (Action) {
case PrintRecords:
*Out << Records; // No argument, dump all contents
break;
case Parse:
ParseMachineCode();
break;
case GenEmitter:
CodeEmitterGen(Records).run(*Out);
break;
case GenRegisterEnums:
RegisterInfoEmitter(Records).runEnums(*Out);
break;
case GenRegister:
RegisterInfoEmitter(Records).run(*Out);
break;
case GenRegisterHeader:
RegisterInfoEmitter(Records).runHeader(*Out);
break;
case PrintEnums:
std::vector<Record*> Recs = Records.getAllDerivedDefinitions(Class);
for (unsigned i = 0, e = Recs.size(); i != e; ++i)
*Out << Recs[i] << ", ";
*Out << "\n";
break;
}
} catch (const std::string &Error) {
std::cerr << Error << "\n";
if (Out != &std::cout) {
delete Out; // Close the file
std::remove(OutputFilename.c_str()); // Remove the file, it's broken
}
return 1;
}
if (Out != &std::cout) {
delete Out; // Close the file
// Now that we have generated the result, check to see if we either don't
// have the requested file, or if the requested file is different than the
// file we generated. If so, move the generated file over the requested
// file. Otherwise, just remove the file we just generated, so 'make'
// doesn't try to regenerate tons of dependencies.
//
MoveFileOverIfUpdated(OutputFilename+".tmp", OutputFilename);
}
return 0;
}
|