Add special case bitcode support for DebugLoc. This avoids
having the bitcode writer materialize mdnodes for all the
debug location tuples when writing out the bc file and
stores the information in a more compact form. For example,
the -O0 -g bc file for combine.c in 176.gcc shrinks from
739392 to 512096 bytes.
This concludes my planned short-term debug info work.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100261 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 1f69e16..9bda6dc 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -596,7 +596,8 @@
static void WriteMetadataAttachment(const Function &F,
const ValueEnumerator &VE,
BitstreamWriter &Stream) {
- bool StartedMetadataBlock = false;
+ Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
+
SmallVector<uint64_t, 64> Record;
// Write metadata attachments
@@ -607,7 +608,7 @@
for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
I != E; ++I) {
MDs.clear();
- I->getAllMetadata(MDs);
+ I->getAllMetadataOtherThanDebugLoc(MDs);
// If no metadata, ignore instruction.
if (MDs.empty()) continue;
@@ -618,16 +619,11 @@
Record.push_back(MDs[i].first);
Record.push_back(VE.getValueID(MDs[i].second));
}
- if (!StartedMetadataBlock) {
- Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
- StartedMetadataBlock = true;
- }
Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
Record.clear();
}
- if (StartedMetadataBlock)
- Stream.ExitBlock();
+ Stream.ExitBlock();
}
static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
@@ -1256,19 +1252,49 @@
// Keep a running idea of what the instruction ID is.
unsigned InstID = CstEnd;
+ bool NeedsMetadataAttachment = false;
+
+ DebugLoc LastDL;
+
// Finally, emit all the instructions, in order.
for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
I != E; ++I) {
WriteInstruction(*I, InstID, VE, Stream, Vals);
+
if (!I->getType()->isVoidTy())
++InstID;
+
+ // If the instruction has metadata, write a metadata attachment later.
+ NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
+
+ // If the instruction has a debug location, emit it.
+ DebugLoc DL = I->getDebugLoc();
+ if (DL.isUnknown()) {
+ // nothing todo.
+ } else if (DL == LastDL) {
+ // Just repeat the same debug loc as last time.
+ Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
+ } else {
+ MDNode *Scope, *IA;
+ DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
+
+ Vals.push_back(DL.getLine());
+ Vals.push_back(DL.getCol());
+ Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
+ Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
+ Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
+ Vals.clear();
+
+ LastDL = DL;
+ }
}
// Emit names for all the instructions etc.
WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
- WriteMetadataAttachment(F, VE, Stream);
+ if (NeedsMetadataAttachment)
+ WriteMetadataAttachment(F, VE, Stream);
VE.purgeFunction();
Stream.ExitBlock();
}
diff --git a/lib/Bitcode/Writer/ValueEnumerator.cpp b/lib/Bitcode/Writer/ValueEnumerator.cpp
index aa4c3af..d2baec7 100644
--- a/lib/Bitcode/Writer/ValueEnumerator.cpp
+++ b/lib/Bitcode/Writer/ValueEnumerator.cpp
@@ -104,9 +104,16 @@
// Enumerate metadata attached with this instruction.
MDs.clear();
- I->getAllMetadata(MDs);
+ I->getAllMetadataOtherThanDebugLoc(MDs);
for (unsigned i = 0, e = MDs.size(); i != e; ++i)
EnumerateMetadata(MDs[i].second);
+
+ if (!I->getDebugLoc().isUnknown()) {
+ MDNode *Scope, *IA;
+ I->getDebugLoc().getScopeAndInlinedAt(Scope, IA, I->getContext());
+ if (Scope) EnumerateMetadata(Scope);
+ if (IA) EnumerateMetadata(IA);
+ }
}
}