Add a statistic to track number of times we rebuild instruction ordering

The goal here is to assist some future tuning work both on instruction ordering invalidation, and on some client code which uses it.

diff --git a/llvm/lib/IR/BasicBlock.cpp b/llvm/lib/IR/BasicBlock.cpp
index d14abaf..ed1956e 100644 (file)
--- a/llvm/lib/IR/BasicBlock.cpp
+++ b/llvm/lib/IR/BasicBlock.cpp
@@ -12,6 +12,7 @@
 
 #include "llvm/IR/BasicBlock.h"
 #include "SymbolTableListTraitsImpl.h"
+#include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/IR/CFG.h"
 #include "llvm/IR/Constants.h"
@@ -23,6 +24,9 @@
 
 using namespace llvm;
 
+#define DEBUG_TYPE "ir"
+STATISTIC(NumInstrRenumberings, "Number of renumberings across all blocks");
+
 ValueSymbolTable *BasicBlock::getValueSymbolTable() {
   if (Function *F = getParent())
     return F->getValueSymbolTable();
@@ -505,6 +509,8 @@ void BasicBlock::renumberInstructions() {
   BasicBlockBits Bits = getBasicBlockBits();
   Bits.InstrOrderValid = true;
   setBasicBlockBits(Bits);
+
+  NumInstrRenumberings++;
 }
 
 #ifndef NDEBUG