diff --git a/llvm/lib/Transforms/Utils/PetarCountCttz.cpp b/llvm/lib/Transforms/Utils/PetarCountCttz.cpp
index 33a7af390d32e..93ad2457cac3b 100644
--- a/llvm/lib/Transforms/Utils/PetarCountCttz.cpp
+++ b/llvm/lib/Transforms/Utils/PetarCountCttz.cpp
@@ -8,18 +8,18 @@ int countCttzIntrinsicAppearance=0;
 PreservedAnalyses PetarCountCttzPass::run(Function &F, FunctionAnalysisManager &AM) {
 
   errs() << "Function name: " << F.getName() << "\n";
-  errs() << "\n-------------------------------\n";
-  errs() << "Instructions within this function!\n";
+  //errs() << "\n-------------------------------\n";
+  //errs() << "Instructions within this function!\n";
   for(BasicBlock& BB: F){
     for(Instruction& I: BB){
-       errs()<< I.getName() << "\n";
+       //errs()<< I.getName() << "\n";
        IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I);
        
        if(II && (II->getIntrinsicID() == Intrinsic::cttz))
          countCttzIntrinsicAppearance++;
     }
   }
-  errs() << "\n-------------------------------\n";
+  //errs() << "\n-------------------------------\n";
   errs() << "Total number of cttz intrinsic appearances is equal to: " << countCttzIntrinsicAppearance << ".\n";
 
   return PreservedAnalyses::all();
diff --git a/llvm/test/Transforms/Util/petar-count-cttz.ll b/llvm/test/Transforms/Util/petar-count-cttz.ll
new file mode 100644
index 0000000000000..941cffca4587a
--- /dev/null
+++ b/llvm/test/Transforms/Util/petar-count-cttz.ll
@@ -0,0 +1,48 @@
+; RUN: opt -disable-output -passes=petarcountcttz %s 2>&1 | FileCheck %s
+
+; CHECK: Function name: cttz_64_eq_select
+; CHECK-NEXT: Total number of cttz intrinsic appearances is equal to: 1.
+declare i64 @llvm.cttz.i64(i64, i1)
+define i64 @cttz_64_eq_select(i64 %v) nounwind {
+
+  %cnt = tail call i64 @llvm.cttz.i64(i64 %v, i1 true)
+  %tobool = icmp eq i64 %v, 0
+  %.op = add nuw nsw i64 %cnt, 6
+  %add = select i1 %tobool, i64 5, i64 %.op
+  ret i64 %add
+}
+
+; CHECK-NEXT: Function name: cttz_64_ne_select
+; CHECK-NEXT: Total number of cttz intrinsic appearances is equal to: 2.
+define i64 @cttz_64_ne_select(i64 %v) nounwind {
+
+  %cnt = tail call i64 @llvm.cttz.i64(i64 %v, i1 true)
+  %tobool = icmp ne i64 %v, 0
+  %.op = add nuw nsw i64 %cnt, 6
+  %add = select i1 %tobool, i64 %.op, i64 5
+  ret i64 %add
+}
+
+; CHECK-NEXT: Function name: cttz_32_eq_select
+; CHECK-NEXT: Total number of cttz intrinsic appearances is equal to: 3.
+declare i32 @llvm.cttz.i32(i32, i1)
+define i32 @cttz_32_eq_select(i32 %v) nounwind {
+
+  %cnt = tail call i32 @llvm.cttz.i32(i32 %v, i1 true)
+  %tobool = icmp eq i32 %v, 0
+  %.op = add nuw nsw i32 %cnt, 6
+  %add = select i1 %tobool, i32 5, i32 %.op
+  ret i32 %add
+}
+
+; CHECK-NEXT: Function name: cttz_32_ne_select
+; CHECK-NEXT: Total number of cttz intrinsic appearances is equal to: 4.
+define i32 @cttz_32_ne_select(i32 %v) nounwind {
+
+  %cnt = tail call i32 @llvm.cttz.i32(i32 %v, i1 true)
+  %tobool = icmp ne i32 %v, 0
+  %.op = add nuw nsw i32 %cnt, 6
+  %add = select i1 %tobool, i32 %.op, i32 5
+  ret i32 %add
+}
+
diff --git a/petar_notes.txt b/petar_notes.txt
new file mode 100644
index 0000000000000..e4afaf2f2e203
--- /dev/null
+++ b/petar_notes.txt
@@ -0,0 +1,6 @@
+LLVM project
+Author: Chris Lattner
+Master thesis title: Semantic detection of a CRC function for RISCV in LLVM
+
+What have I learned so far?
+