MC: Sprinkle in some more interesting statistics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99350 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCExpr.cpp b/lib/MC/MCExpr.cpp
index d0025f3..a9256b6 100644
--- a/lib/MC/MCExpr.cpp
+++ b/lib/MC/MCExpr.cpp
@@ -7,7 +7,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+#define DEBUG_TYPE "mcexpr"
 #include "llvm/MC/MCExpr.h"
+#include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/MC/MCAsmLayout.h"
 #include "llvm/MC/MCAssembler.h"
@@ -19,6 +21,12 @@
 #include "llvm/Target/TargetAsmBackend.h"
 using namespace llvm;
 
+namespace {
+namespace stats {
+STATISTIC(MCExprEvaluate, "Number of MCExpr evaluations");
+}
+}
+
 void MCExpr::print(raw_ostream &OS) const {
   switch (getKind()) {
   case MCExpr::Target:
@@ -231,6 +239,8 @@
 
 bool MCExpr::EvaluateAsRelocatable(MCValue &Res,
                                    const MCAsmLayout *Layout) const {
+  ++stats::MCExprEvaluate;
+
   switch (getKind()) {
   case Target:
     return cast<MCTargetExpr>(this)->EvaluateAsRelocatableImpl(Res, Layout);