[ThinLTO] Support for reference graph in per-module and combined summary.

Summary:
This patch adds support for including a full reference graph including
call graph edges and other GV references in the summary.

The reference graph edges can be used to make importing decisions
without materializing any source modules, can be used in the plugin
to make file staging decisions for distributed build systems, and is
expected to have other uses.

The call graph edges are recorded in each function summary in the
bitcode via a list of <CalleeValueIds, StaticCount> tuples when no PGO
data exists, or <CalleeValueId, StaticCount, ProfileCount> pairs when
there is PGO, where the ValueId can be mapped to the function GUID via
the ValueSymbolTable. In the function index in memory, the call graph
edges reference the target via the CalleeGUID instead of the
CalleeValueId.

The reference graph edges are recorded in each summary record with a
list of referenced value IDs, which can be mapped to value GUID via the
ValueSymbolTable.

Addtionally, a new summary record type is added to record references
from global variable initializers. A number of bitcode records and data
structures have been renamed to reflect the newly expanded scope of the
summary beyond functions. More cleanup will follow.

Reviewers: joker.eph, davidxl

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D17212

llvm-svn: 263275

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/Object/FunctionIndexObjectFile.cpp b/llvm/lib/Object/FunctionIndexObjectFile.cpp
index 927fd1409a6..9347988cf3d 100644
--- a/llvm/lib/Object/FunctionIndexObjectFile.cpp
+++ b/llvm/lib/Object/FunctionIndexObjectFile.cpp
@@ -66,15 +66,15 @@ FunctionIndexObjectFile::findBitcodeInMemBuffer(MemoryBufferRef Object) {
   }
 }
 
-// Looks for function index in the given memory buffer.
+// Looks for module summary index in the given memory buffer.
 // returns true if found, else false.
-bool FunctionIndexObjectFile::hasFunctionSummaryInMemBuffer(
+bool FunctionIndexObjectFile::hasGlobalValueSummaryInMemBuffer(
     MemoryBufferRef Object, DiagnosticHandlerFunction DiagnosticHandler) {
   ErrorOr<MemoryBufferRef> BCOrErr = findBitcodeInMemBuffer(Object);
   if (!BCOrErr)
     return false;
 
-  return hasFunctionSummary(BCOrErr.get(), DiagnosticHandler);
+  return hasGlobalValueSummary(BCOrErr.get(), DiagnosticHandler);
 }
 
 // Parse function index in the given memory buffer.