Version 1.2 now supports encoding strings as a special case, to avoid having

to emit all of those sbyte constants.

llvm-svn: 10863
This commit is contained in:
Chris Lattner 2004-01-14 23:35:21 +00:00
parent de36304453
commit 394afe0f90
3 changed files with 47 additions and 2 deletions

View File

@ -298,6 +298,42 @@ void BytecodeParser::ParseGlobalTypes(const unsigned char *&Buf,
ParseConstantPool(Buf, EndBuf, T, ModuleTypeValues);
}
void BytecodeParser::parseStringConstants(const unsigned char *&Buf,
const unsigned char *EndBuf,
unsigned NumEntries, ValueTable &Tab){
unsigned Typ;
for (; NumEntries; --NumEntries) {
if (read_vbr(Buf, EndBuf, Typ)) throw Error_readvbr;
const Type *Ty = getType(Typ);
if (!isa<ArrayType>(Ty))
throw std::string("String constant data invalid!");
const ArrayType *ATy = cast<ArrayType>(Ty);
if (ATy->getElementType() != Type::SByteTy &&
ATy->getElementType() != Type::UByteTy)
throw std::string("String constant data invalid!");
// Read character data. The type tells us how long the string is.
char Data[ATy->getNumElements()];
if (input_data(Buf, EndBuf, Data, Data+ATy->getNumElements()))
throw Error_inputdata;
std::vector<Constant*> Elements(ATy->getNumElements());
if (ATy->getElementType() == Type::SByteTy)
for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i)
Elements[i] = ConstantSInt::get(Type::SByteTy, Data[i]);
else
for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i)
Elements[i] = ConstantSInt::get(Type::UByteTy, Data[i]);
// Create the constant, inserting it as needed.
Constant *C = ConstantArray::get(ATy, Elements);
unsigned Slot = insertValue(C, Typ, Tab);
ResolveReferencesToConstant(C, Slot);
}
}
void BytecodeParser::ParseConstantPool(const unsigned char *&Buf,
const unsigned char *EndBuf,
ValueTable &Tab,
@ -310,6 +346,9 @@ void BytecodeParser::ParseConstantPool(const unsigned char *&Buf,
if (Typ == Type::TypeTyID) {
BCR_TRACE(3, "Type: 'type' NumEntries: " << NumEntries << "\n");
parseTypeConstants(Buf, EndBuf, TypeTab, NumEntries);
} else if (Typ == Type::VoidTyID) {
assert(&Tab == &ModuleValues && "Cannot read strings in functions!");
parseStringConstants(Buf, EndBuf, NumEntries, Tab);
} else {
BCR_TRACE(3, "Type: '" << *getType(Typ) << "' NumEntries: "
<< NumEntries << "\n");

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@ -552,8 +552,8 @@ void BytecodeParser::ParseVersionInfo(const unsigned char *&Buf,
switch (RevisionNum) {
case 2: // LLVM pre-1.0 release: will be deleted on the next rev
// Version #2 added information about all 4 linkage types instead of just
// having internal and external.
// Version #2 only supported 4 linkage types. It didn't support weak
// linkage.
hasExtendedLinkageSpecs = false;
hasOldStyleVarargs = true;
hasVarArgCallPadding = true;
@ -561,8 +561,11 @@ void BytecodeParser::ParseVersionInfo(const unsigned char *&Buf,
case 0: // LLVM 1.0, 1.1 release version
// Compared to rev #2, we added support for weak linkage, a more dense
// encoding, and better varargs support.
// Base LLVM 1.0 bytecode format.
break;
case 1: // LLVM 1.2 release version
// LLVM 1.2 added explicit support for emitting strings efficiently.
break;
default:

View File

@ -177,6 +177,9 @@ private:
TypeValuesListTy &Tab, unsigned NumEntries);
const Type *parseTypeConstant(const unsigned char *&Buf,
const unsigned char *EndBuf);
void parseStringConstants(const unsigned char *&Buf,
const unsigned char *EndBuf,
unsigned NumEntries, ValueTable &Tab);
Value *getValue(unsigned TypeID, unsigned num, bool Create = true);
const Type *getType(unsigned ID);