[llvm] f3d8a5c - [IPT] Remove ipt.NumInstScanned statistic (#168515)

[via llvm-commits]

Author: Luke Lau
Date: 2025-11-20T00:14:50+08:00
New Revision: f3d8a5cf5bc058328004bd0905ab4974f09fc131

URL: https://github.com/llvm/llvm-project/commit/f3d8a5cf5bc058328004bd0905ab4974f09fc131
DIFF: https://github.com/llvm/llvm-project/commit/f3d8a5cf5bc058328004bd0905ab4974f09fc131.diff

LOG: [IPT] Remove ipt.NumInstScanned statistic (#168515)

The NumInstScanned statistic is non-determinstic across multiple
identical invocations of LLVM, and leads to noise when trying to diff
LLVM statistics with e.g. ./utils/tdiff.py in llvm-test-suite.

My understanding is that it's non-deterministic because the users of
IPT's hasSpecialInstructions/isPreceededBySpecialInstruction API aren't
deterministic themselves.

This PR removes it and fixes #157598. This is just a small
quality-of-life improvement for the ./utils/tdiff.py workflow, but happy
to leave the statistic in if others are using it.

Added: 
    

Modified: 
    llvm/lib/Analysis/InstructionPrecedenceTracking.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/InstructionPrecedenceTracking.cpp b/llvm/lib/Analysis/InstructionPrecedenceTracking.cpp
index a2a9c94c14ae8..8bebd465ff7d3 100644
--- a/llvm/lib/Analysis/InstructionPrecedenceTracking.cpp
+++ b/llvm/lib/Analysis/InstructionPrecedenceTracking.cpp
@@ -19,15 +19,11 @@
 
 #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",
@@ -50,7 +46,6 @@ const Instruction *InstructionPrecedenceTracking::getFirstSpecialInstruction(
   auto [It, Inserted] = FirstSpecialInsts.try_emplace(BB);
   if (Inserted) {
     for (const auto &I : *BB) {
-      NumInstScanned++;
       if (isSpecialInstruction(&I)) {
         It->second = &I;
         break;