[LTO] Support Statistics

Summary:
I thought -Xlinker -mllvm -Xlinker -stats worked at some point but maybe
it never did.

For clang, I believe that stats are printed from cc1_main.  This patch
also prints them for LTO, specifically right after codegen happens.

I only looked at the C API for LTO briefly to see if this is a good
place.  Probably there are still cases where this wouldn't be printed
but it seems to be working for the common case.  I also experimented
putting this in the LTOCodeGenerator destructor but that didn't trigger
for me because ld64 does not destroy the LTOCodeGenerator.

Reviewers: dexonsmith, joker.eph

Subscribers: rafael, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D17302

llvm-svn: 261013

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/LTO/LTOCodeGenerator.cpp b/llvm/lib/LTO/LTOCodeGenerator.cpp
index 70626682d55..5d173b262dc 100644
--- a/llvm/lib/LTO/LTOCodeGenerator.cpp
+++ b/llvm/lib/LTO/LTOCodeGenerator.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/LTO/LTOCodeGenerator.h"
+#include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Analysis/Passes.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
@@ -553,6 +554,10 @@ bool LTOCodeGenerator::compileOptimized(ArrayRef<raw_pwrite_stream *> Out) {
                    RelocModel, CodeModel::Default, CGOptLevel, FileType,
                    ShouldRestoreGlobalsLinkage);
 
+  // If statistics were requested, print them out after codegen.
+  if (llvm::AreStatisticsEnabled())
+    llvm::PrintStatistics();
+
   return true;
 }