Read/write global variable alignments if present

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24216 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-11-06 07:11:04 +00:00
parent abdf0f5327
commit 8eb52dd734
2 changed files with 37 additions and 6 deletions

View File

@ -1903,6 +1903,17 @@ void BytecodeReader::ParseModuleGlobalInfo() {
bool isConstant = VarType & 1;
bool hasInitializer = VarType & 2;
GlobalValue::LinkageTypes Linkage;
unsigned Alignment = 0;
// An extension word is present when linkage = 3 (internal) and hasinit = 0.
if (LinkageID == 3 && !hasInitializer) {
unsigned ExtWord = read_vbr_uint();
// The extension word has this format: bit 0 = has initializer, bit 1-3 =
// linkage, bit 4-8 = alignment (log2), bits 10+ = future use.
hasInitializer = ExtWord & 1;
LinkageID = (ExtWord >> 1) & 7;
Alignment = (1 << ((ExtWord >> 4) & 31)) >> 1;
}
switch (LinkageID) {
case 0: Linkage = GlobalValue::ExternalLinkage; break;
@ -1930,6 +1941,7 @@ void BytecodeReader::ParseModuleGlobalInfo() {
// Create the global variable...
GlobalVariable *GV = new GlobalVariable(ElTy, isConstant, Linkage,
0, "", TheModule);
GV->setAlignment(Alignment);
insertValue(GV, SlotNo, ModuleValues);
unsigned initSlot = 0;

View File

@ -416,7 +416,6 @@ void BytecodeWriter::outputConstantStrings() {
//===----------------------------------------------------------------------===//
//=== Instruction Output ===//
//===----------------------------------------------------------------------===//
typedef unsigned char uchar;
// outputInstructionFormat0 - Output those weird instructions that have a large
// number of operands or have large operands themselves.
@ -925,15 +924,35 @@ void BytecodeWriter::outputModuleInfoBlock(const Module *M) {
// Output the types for the global variables in the module...
for (Module::const_global_iterator I = M->global_begin(),
End = M->global_end(); I != End;++I) {
End = M->global_end(); I != End; ++I) {
int Slot = Table.getSlot(I->getType());
assert(Slot != -1 && "Module global vars is broken!");
assert((I->hasInitializer() || !I->hasInternalLinkage()) &&
"Global must have an initializer or have external linkage!");
// Fields: bit0 = isConstant, bit1 = hasInitializer, bit2-4=Linkage,
// bit5+ = Slot # for type
unsigned oSlot = ((unsigned)Slot << 5) | (getEncodedLinkage(I) << 2) |
(I->hasInitializer() << 1) | (unsigned)I->isConstant();
output_vbr(oSlot);
// bit5+ = Slot # for type.
bool HasExtensionWord = I->getAlignment() != 0;
// If we need to use the extension byte, set linkage=3(internal) and
// initializer = 0 (impossible!).
if (!HasExtensionWord) {
unsigned oSlot = ((unsigned)Slot << 5) | (getEncodedLinkage(I) << 2) |
(I->hasInitializer() << 1) | (unsigned)I->isConstant();
output_vbr(oSlot);
} else {
unsigned oSlot = ((unsigned)Slot << 5) | (3 << 2) |
(0 << 1) | (unsigned)I->isConstant();
output_vbr(oSlot);
// The extension word has this format: bit 0 = has initializer, bit 1-3 =
// linkage, bit 4-8 = alignment (log2), bits 10+ = future use.
unsigned ExtWord = I->hasInitializer() | (getEncodedLinkage(I) << 1) |
(Log2_32(I->getAlignment())+1) << 4;
output_vbr(ExtWord);
}
// If we have an initializer, output it now.
if (I->hasInitializer()) {