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factor string table generation out to its own class. This changes

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the encoding of the AsmStrs table saving a byte or two.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81739 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2009-09-14 01:16:36 +00:00
parent adc3142fdd
commit 3200fc9bad
1 changed files with 73 additions and 50 deletions
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123
utils/TableGen/AsmWriterEmitter.cpp
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@ -16,13 +16,68 @@
#include "CodeGenTarget.h"
#include "Record.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include <algorithm>
#include <sstream>
#include <iostream>
using namespace llvm;
/// StringToOffsetTable - This class uniques a bunch of nul-terminated strings
/// and keeps track of their offset in a massive contiguous string allocation.
/// It can then output this string blob and use indexes into the string to
/// reference each piece.
class StringToOffsetTable {
StringMap<unsigned> StringOffset;
std::string AggregateString;
public:
unsigned GetOrAddStringOffset(StringRef Str) {
unsigned &Entry = StringOffset[Str];
if (Entry == 0) {
// Add the string to the aggregate if this is the first time found.
Entry = AggregateString.size();
AggregateString.append(Str.begin(), Str.end());
AggregateString += '\0';
}
return Entry;
}
void EmitString(raw_ostream &O) {
O << " \"";
unsigned CharsPrinted = 0;
EscapeString(AggregateString);
for (unsigned i = 0, e = AggregateString.size(); i != e; ++i) {
if (CharsPrinted > 70) {
O << "\"\n \"";
CharsPrinted = 0;
}
O << AggregateString[i];
++CharsPrinted;
// Print escape sequences all together.
if (AggregateString[i] != '\\')
continue;
assert(i+1 < AggregateString.size() && "Incomplete escape sequence!");
if (isdigit(AggregateString[i+1])) {
assert(isdigit(AggregateString[i+2]) &&
isdigit(AggregateString[i+3]) &&
"Expected 3 digit octal escape!");
O << AggregateString[++i];
O << AggregateString[++i];
O << AggregateString[++i];
CharsPrinted += 3;
} else {
O << AggregateString[++i];
++CharsPrinted;
}
}
O << "\"";
}
};
static bool isIdentChar(char C) {
return (C >= 'a' && C <= 'z') ||
(C >= 'A' && C <= 'Z') ||
@ -569,10 +624,7 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) {
CGIAWIMap.insert(std::make_pair(Instructions[i].CGI, &Instructions[i]));
// Build an aggregate string, and build a table of offsets into it.
std::map<std::string, unsigned> StringOffset;
std::string AggregateString;
AggregateString.push_back(0); // "\0"
AggregateString.push_back(0); // "\0"
StringToOffsetTable 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.
@ -584,32 +636,28 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) {
unsigned Idx;
if (AWI == 0) {
// Something not handled by the asmwriter printer.
Idx = 0;
Idx = ~0U;
} else if (AWI->Operands[0].OperandType !=
AsmWriterOperand::isLiteralTextOperand ||
AWI->Operands[0].Str.empty()) {
// Something handled by the asmwriter printer, but with no leading string.
Idx = 1;
Idx = StringTable.GetOrAddStringOffset("");
} else {
unsigned &Entry = StringOffset[AWI->Operands[0].Str];
if (Entry == 0) {
// Add the string to the aggregate if this is the first time found.
MaxStringIdx = Entry = AggregateString.size();
std::string Str = AWI->Operands[0].Str;
UnescapeString(Str);
AggregateString += Str;
AggregateString += '\0';
}
Idx = Entry;
std::string Str = AWI->Operands[0].Str;
UnescapeString(Str);
Idx = StringTable.GetOrAddStringOffset(Str);
MaxStringIdx = std::max(MaxStringIdx, Idx);
// Nuke the string from the operand list. It is now handled!
AWI->Operands.erase(AWI->Operands.begin());
}
OpcodeInfo.push_back(Idx);
// Bias offset by one since we want 0 as a sentinel.
OpcodeInfo.push_back(Idx+1);
}
// Figure out how many bits we used for the string index.
unsigned AsmStrBits = Log2_32_Ceil(MaxStringIdx+1);
unsigned AsmStrBits = Log2_32_Ceil(MaxStringIdx+2);
// To reduce code size, we compactify common instructions into a few bits
// in the opcode-indexed table.
@ -672,34 +720,9 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) {
O << " };\n\n";
// Emit the string itself.
O << " const char *AsmStrs = \n \"";
unsigned CharsPrinted = 0;
EscapeString(AggregateString);
for (unsigned i = 0, e = AggregateString.size(); i != e; ++i) {
if (CharsPrinted > 70) {
O << "\"\n \"";
CharsPrinted = 0;
}
O << AggregateString[i];
++CharsPrinted;
// Print escape sequences all together.
if (AggregateString[i] == '\\') {
assert(i+1 < AggregateString.size() && "Incomplete escape sequence!");
if (isdigit(AggregateString[i+1])) {
assert(isdigit(AggregateString[i+2]) && isdigit(AggregateString[i+3]) &&
"Expected 3 digit octal escape!");
O << AggregateString[++i];
O << AggregateString[++i];
O << AggregateString[++i];
CharsPrinted += 3;
} else {
O << AggregateString[++i];
++CharsPrinted;
}
}
}
O << "\";\n\n";
O << " const char *AsmStrs = \n";
StringTable.EmitString(O);
O << ";\n\n";
O << "\n#ifndef NO_ASM_WRITER_BOILERPLATE\n";
@ -722,7 +745,7 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) {
O << " // Emit the opcode for the instruction.\n"
<< " unsigned Bits = OpInfo[MI->getOpcode()];\n"
<< " assert(Bits != 0 && \"Cannot print this instruction.\");\n"
<< " O << AsmStrs+(Bits & " << (1 << AsmStrBits)-1 << ");\n\n";
<< " O << AsmStrs+(Bits & " << (1 << AsmStrBits)-1 << ")-1;\n\n";
// Output the table driven operand information.
BitsLeft = 32-AsmStrBits;