[IPT] Add a statistic to track instructions scanned to answer queries

I'm planning some changes to the invalidation mechanism here, and having a concrete mechanism to track progress is key.

1 files changed, 7 insertions, 1 deletions

diff --git a/llvm/lib/Analysis/InstructionPrecedenceTracking.cpp b/llvm/lib/Analysis/InstructionPrecedenceTracking.cpp
index e226555..9fee57c 100644
--- a/llvm/lib/Analysis/InstructionPrecedenceTracking.cpp
+++ b/llvm/lib/Analysis/InstructionPrecedenceTracking.cpp
@@ -19,11 +19,15 @@
 
 #include "llvm/Analysis/InstructionPrecedenceTracking.h"
 #include "llvm/Analysis/ValueTracking.h"
+#include "llvm/ADT/Statistic.h"
 #include "llvm/IR/PatternMatch.h"
 #include "llvm/Support/CommandLine.h"
 
 using namespace llvm;
 
+#define DEBUG_TYPE "ipt"
+STATISTIC(NumInstScanned, "Number of insts scanned while updating ibt");
+
 #ifndef NDEBUG
 static cl::opt<bool> ExpensiveAsserts(
     "ipt-expensive-asserts",
@@ -64,11 +68,13 @@ bool InstructionPrecedenceTracking::isPreceededBySpecialInstruction(
 
 void InstructionPrecedenceTracking::fill(const BasicBlock *BB) {
   FirstSpecialInsts.erase(BB);
-  for (auto &I : *BB)
+  for (auto &I : *BB) {
+    NumInstScanned++;
     if (isSpecialInstruction(&I)) {
       FirstSpecialInsts[BB] = &I;
       return;
     }
+  }
 
   // Mark this block as having no special instructions.
   FirstSpecialInsts[BB] = nullptr;