[PATCH] Debug info: Support fragmented variables.

[David Blaikie]

I'm curious why there are both SROA and SelDAG changes in this together - I assume the SelDAG (and any other LLVM CodeGen) changes could be separated/tested with raw IR inputs and the SROA changes should be implemented/tested as standalone IR->IR behavior, right?

So is there more separation to do in this patch, or are these changes somehow inextricably linked?

================
Comment at: lib/CodeGen/AsmPrinter/DwarfDebug.cpp:1285
@@ -1283,1 +1284,3 @@
 
+//    // Attempt to merge the last two entries.
+//    auto LastLoc = DebugLoc.rbegin();
----------------
Remove commented out code (& unrelated whitespace changes) - then this file shouldn't be included in the diff at all.

Ideally this whole change shouldn't have any changes to core debug info APIs/IR APIs - those changes have already been committed. This change is now just about teaching certain optimizations to preserve/create the IR necessary to describe the variable location fragments, right?

http://reviews.llvm.org/D2680