improve a comment


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36464 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 654eafe..53431dd 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -572,8 +572,9 @@
   // Emit constants.
   WriteModuleConstants(VE, Stream);
   
-  // FIXME: Purge aggregate values from the VE, emit a record that indicates how
-  // many to purge.
+  // If we have any aggregate values in the value table, purge them - these can
+  // only be used to initialize global variables.  Doing so makes the value
+  // namespace smaller for code in functions.
   int NumNonAggregates = VE.PurgeAggregateValues();
   if (NumNonAggregates != -1) {
     SmallVector<unsigned, 1> Vals;
@@ -583,7 +584,8 @@
   
   // Emit function bodies.
   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
-    WriteFunction(*I, VE, Stream);
+    if (!I->isDeclaration())
+      WriteFunction(*I, VE, Stream);
   
   // Emit the type symbol table information.
   WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);