; LLVM IR from ravireddy07/cpp-book :: src/Recursion (RecursionTwins)

; Unoptimized IR (clang -disable-llvm-passes):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%"class.std::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char>::_Alloc_hider", i64, %union.anon }
%"struct.std::__cxx11::basic_string<char>::_Alloc_hider" = type { ptr }
%union.anon = type { i64, [8 x i8] }

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z10RecurTwinsNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEi(ptr noundef %0, i32 noundef %1) #0 personality ptr @__gxx_personality_v0 {
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca %"class.std::__cxx11::basic_string", align 8
  %7 = alloca ptr, align 8
  %8 = alloca i32, align 4
  %9 = alloca %"class.std::__cxx11::basic_string", align 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  %10 = load i32, ptr %5, align 4, !tbaa !9
  %11 = sext i32 %10 to i64
  %12 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %11)
  %13 = load i8, ptr %12, align 1, !tbaa !11
  %14 = sext i8 %13 to i32
  %15 = icmp eq i32 %14, 0
  br i1 %15, label %24, label %16

16:                                               ; preds = %2
  %17 = load i32, ptr %5, align 4, !tbaa !9
  %18 = add nsw i32 %17, 1
  %19 = sext i32 %18 to i64
  %20 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %19)
  %21 = load i8, ptr %20, align 1, !tbaa !11
  %22 = sext i8 %21 to i32
  %23 = icmp eq i32 %22, 0
  br i1 %23, label %24, label %25

24:                                               ; preds = %16, %2
  store i32 0, ptr %3, align 4
  br label %57

25:                                               ; preds = %16
  %26 = load i32, ptr %5, align 4, !tbaa !9
  %27 = sext i32 %26 to i64
  %28 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %27)
  %29 = load i8, ptr %28, align 1, !tbaa !11
  %30 = sext i8 %29 to i32
  %31 = load i32, ptr %5, align 4, !tbaa !9
  %32 = add nsw i32 %31, 2
  %33 = sext i32 %32 to i64
  %34 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %33)
  %35 = load i8, ptr %34, align 1, !tbaa !11
  %36 = sext i8 %35 to i32
  %37 = icmp eq i32 %30, %36
  br i1 %37, label %38, label %48

38:                                               ; preds = %25
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32) %6, ptr noundef nonnull align 8 dereferenceable(32) %0)
  %39 = load i32, ptr %5, align 4, !tbaa !9
  %40 = add nsw i32 %39, 1
  %41 = invoke noundef i32 @_Z10RecurTwinsNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEi(ptr noundef %6, i32 noundef %40)
          to label %42 unwind label %44

42:                                               ; preds = %38
  %43 = add nsw i32 1, %41
  store i32 %43, ptr %3, align 4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %6) #2
  br label %57

44:                                               ; preds = %38
  %45 = landingpad { ptr, i32 }
          cleanup
  %46 = extractvalue { ptr, i32 } %45, 0
  store ptr %46, ptr %7, align 8
  %47 = extractvalue { ptr, i32 } %45, 1
  store i32 %47, ptr %8, align 4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %6) #2
  br label %59

48:                                               ; preds = %25
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32) %9, ptr noundef nonnull align 8 dereferenceable(32) %0)
  %49 = load i32, ptr %5, align 4, !tbaa !9
  %50 = add nsw i32 %49, 1
  %51 = invoke noundef i32 @_Z10RecurTwinsNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEi(ptr noundef %9, i32 noundef %50)
          to label %52 unwind label %53

52:                                               ; preds = %48
  store i32 %51, ptr %3, align 4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %9) #2
  br label %57

53:                                               ; preds = %48
  %54 = landingpad { ptr, i32 }
          cleanup
  %55 = extractvalue { ptr, i32 } %54, 0
  store ptr %55, ptr %7, align 8
  %56 = extractvalue { ptr, i32 } %54, 1
  store i32 %56, ptr %8, align 4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %9) #2
  br label %59

57:                                               ; preds = %52, %42, %24
  %58 = load i32, ptr %3, align 4
  ret i32 %58

59:                                               ; preds = %53, %44
  %60 = load ptr, ptr %7, align 8
  %61 = load i32, ptr %8, align 4
  %62 = insertvalue { ptr, i32 } poison, ptr %60, 0
  %63 = insertvalue { ptr, i32 } %62, i32 %61, 1
  resume { ptr, i32 } %63
}

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) #1 align 2

; Function Attrs: mustprogress uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32), ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #0 align 2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #1 align 2

attributes #0 = { mustprogress uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #1 = { mustprogress nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #2 = { nounwind }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!7, !7, i64 0}


; Optimized IR (opt -passes='default<O3>'):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%"class.std::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char>::_Alloc_hider", i64, %union.anon }
%"struct.std::__cxx11::basic_string<char>::_Alloc_hider" = type { ptr }
%union.anon = type { i64, [8 x i8] }

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z10RecurTwinsNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEi(ptr noundef nonnull %0, i32 noundef %1) local_unnamed_addr #0 personality ptr @__gxx_personality_v0 {
  %3 = alloca %"class.std::__cxx11::basic_string", align 8
  %4 = alloca %"class.std::__cxx11::basic_string", align 8
  %5 = sext i32 %1 to i64
  %6 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %5)
  %7 = load i8, ptr %6, align 1, !tbaa !5
  %8 = icmp eq i8 %7, 0
  br i1 %8, label %33, label %9

9:                                                ; preds = %2
  %10 = add nsw i32 %1, 1
  %11 = sext i32 %10 to i64
  %12 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %11)
  %13 = load i8, ptr %12, align 1, !tbaa !5
  %14 = icmp eq i8 %13, 0
  br i1 %14, label %33, label %15

15:                                               ; preds = %9
  %16 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %5)
  %17 = load i8, ptr %16, align 1, !tbaa !5
  %18 = add nsw i32 %1, 2
  %19 = sext i32 %18 to i64
  %20 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %19)
  %21 = load i8, ptr %20, align 1, !tbaa !5
  %22 = icmp eq i8 %17, %21
  br i1 %22, label %23, label %29

23:                                               ; preds = %15
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32) %3, ptr noundef nonnull align 8 dereferenceable(32) %0)
  %24 = invoke noundef i32 @_Z10RecurTwinsNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEi(ptr noundef nonnull %3, i32 noundef %10)
          to label %25 unwind label %27

25:                                               ; preds = %23
  %26 = add nsw i32 %24, 1
  br label %.sink.split

27:                                               ; preds = %23
  %28 = landingpad { ptr, i32 }
          cleanup
  br label %34

29:                                               ; preds = %15
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32) %4, ptr noundef nonnull align 8 dereferenceable(32) %0)
  %30 = invoke noundef i32 @_Z10RecurTwinsNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEi(ptr noundef nonnull %4, i32 noundef %10)
          to label %.sink.split unwind label %31

31:                                               ; preds = %29
  %32 = landingpad { ptr, i32 }
          cleanup
  br label %34

.sink.split:                                      ; preds = %29, %25
  %.sink = phi ptr [ %3, %25 ], [ %4, %29 ]
  %.09.ph = phi i32 [ %26, %25 ], [ %30, %29 ]
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %.sink) #2
  br label %33

33:                                               ; preds = %.sink.split, %2, %9
  %.09 = phi i32 [ 0, %9 ], [ 0, %2 ], [ %.09.ph, %.sink.split ]
  ret i32 %.09

34:                                               ; preds = %31, %27
  %.sink11 = phi ptr [ %4, %31 ], [ %3, %27 ]
  %.pn = phi { ptr, i32 } [ %32, %31 ], [ %28, %27 ]
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %.sink11) #2
  resume { ptr, i32 } %.pn
}

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32), ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #0 align 2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #1 align 2

attributes #0 = { mustprogress uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #1 = { mustprogress nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #2 = { nounwind }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InstCombinePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass