; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 09. String (Break_Palindrome)

; 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] }
%"class.std::allocator" = type { i8 }

@.str = external hidden unnamed_addr constant [1 x i8], align 1

; Function Attrs: mustprogress uwtable
define dso_local void @_Z15breakPalindromeNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef %1) #0 personality ptr @__gxx_personality_v0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca %"class.std::allocator", align 1
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  store ptr %0, ptr %3, align 8
  store ptr %1, ptr %4, align 8, !tbaa !5
  %10 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %11 = icmp eq i64 %10, 1
  br i1 %11, label %12, label %18

12:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 1, ptr %5) #3
  call void @_ZNSaIcEC2Ev(ptr noundef nonnull align 1 dereferenceable(1) %5) #3
  invoke void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2IS3_EEPKcRKS3_(ptr noundef nonnull align 8 dereferenceable(32) %0, ptr noundef @.str, ptr noundef nonnull align 1 dereferenceable(1) %5)
          to label %13 unwind label %14

13:                                               ; preds = %12
  call void @_ZNSt15__new_allocatorIcED2Ev(ptr noundef nonnull align 1 dereferenceable(1) %5) #3
  call void @llvm.lifetime.end.p0(i64 1, ptr %5) #3
  br label %57

14:                                               ; preds = %12
  %15 = landingpad { ptr, i32 }
          cleanup
  %16 = extractvalue { ptr, i32 } %15, 0
  store ptr %16, ptr %6, align 8
  %17 = extractvalue { ptr, i32 } %15, 1
  store i32 %17, ptr %7, align 4
  call void @_ZNSt15__new_allocatorIcED2Ev(ptr noundef nonnull align 1 dereferenceable(1) %5) #3
  call void @llvm.lifetime.end.p0(i64 1, ptr %5) #3
  br label %58

18:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #3
  store i32 0, ptr %8, align 4, !tbaa !9
  br label %19

19:                                               ; preds = %48, %18
  %20 = load i32, ptr %8, align 4, !tbaa !9
  %21 = sext i32 %20 to i64
  %22 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %23 = icmp ult i64 %21, %22
  br i1 %23, label %25, label %24

24:                                               ; preds = %19
  store i32 2, ptr %9, align 4
  br label %51

25:                                               ; preds = %19
  %26 = load i32, ptr %8, 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) %1, i64 noundef %27)
  %29 = load i8, ptr %28, align 1, !tbaa !11
  %30 = sext i8 %29 to i32
  %31 = icmp ne i32 %30, 97
  br i1 %31, label %32, label %47

32:                                               ; preds = %25
  %33 = load i32, ptr %8, align 4, !tbaa !9
  %34 = sext i32 %33 to i64
  %35 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %36 = udiv i64 %35, 2
  %37 = icmp eq i64 %34, %36
  br i1 %37, label %38, label %43

38:                                               ; preds = %32
  %39 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %40 = urem i64 %39, 2
  %41 = icmp eq i64 %40, 1
  br i1 %41, label %42, label %43

42:                                               ; preds = %38
  br label %48

43:                                               ; preds = %38, %32
  %44 = load i32, ptr %8, align 4, !tbaa !9
  %45 = sext i32 %44 to i64
  %46 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %45)
  store i8 97, ptr %46, align 1, !tbaa !11
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2EOS4_(ptr noundef nonnull align 8 dereferenceable(32) %0, ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  store i32 1, ptr %9, align 4
  br label %51

47:                                               ; preds = %25
  br label %48

48:                                               ; preds = %47, %42
  %49 = load i32, ptr %8, align 4, !tbaa !9
  %50 = add nsw i32 %49, 1
  store i32 %50, ptr %8, align 4, !tbaa !9
  br label %19, !llvm.loop !12

51:                                               ; preds = %43, %24
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #3
  %52 = load i32, ptr %9, align 4
  switch i32 %52, label %63 [
    i32 2, label %53
    i32 1, label %57
  ]

53:                                               ; preds = %51
  %54 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %55 = sub i64 %54, 1
  %56 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %55)
  store i8 98, ptr %56, align 1, !tbaa !11
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2EOS4_(ptr noundef nonnull align 8 dereferenceable(32) %0, ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  br label %57

57:                                               ; preds = %53, %51, %13
  ret void

58:                                               ; preds = %14
  %59 = load ptr, ptr %6, align 8
  %60 = load i32, ptr %7, align 4
  %61 = insertvalue { ptr, i32 } poison, ptr %59, 0
  %62 = insertvalue { ptr, i32 } %61, i32 %60, 1
  resume { ptr, i32 } %62

63:                                               ; preds = %51
  unreachable
}

; Function Attrs: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32)) #1 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSaIcEC2Ev(ptr noundef nonnull align 1 dereferenceable(1)) unnamed_addr #1 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2IS3_EEPKcRKS3_(ptr noundef nonnull align 8 dereferenceable(32), ptr noundef, ptr noundef nonnull align 1 dereferenceable(1)) unnamed_addr #0 align 2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

; 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 nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2EOS4_(ptr noundef nonnull align 8 dereferenceable(32), ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZNSt15__new_allocatorIcED2Ev(ptr noundef nonnull align 1 dereferenceable(1)) 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { 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}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


; 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] }
%"class.std::allocator" = type { i8 }

@.str = external hidden unnamed_addr constant [1 x i8], align 1

; Function Attrs: mustprogress uwtable
define dso_local void @_Z15breakPalindromeNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef nonnull %1) local_unnamed_addr #0 personality ptr @__gxx_personality_v0 {
  %3 = alloca %"class.std::allocator", align 1
  %4 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %5 = icmp eq i64 %4, 1
  br i1 %5, label %7, label %.preheader

.preheader:                                       ; preds = %2
  %6 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %.not15 = icmp eq i64 %6, 0
  br i1 %.not15, label %._crit_edge, label %.lr.ph

7:                                                ; preds = %2
  call void @llvm.lifetime.start.p0(i64 1, ptr nonnull %3) #3
  call void @_ZNSaIcEC2Ev(ptr noundef nonnull align 1 dereferenceable(1) %3) #3
  invoke void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2IS3_EEPKcRKS3_(ptr noundef nonnull align 8 dereferenceable(32) %0, ptr noundef nonnull @.str, ptr noundef nonnull align 1 dereferenceable(1) %3)
          to label %8 unwind label %9

8:                                                ; preds = %7
  call void @_ZNSt15__new_allocatorIcED2Ev(ptr noundef nonnull align 1 dereferenceable(1) %3) #3
  call void @llvm.lifetime.end.p0(i64 1, ptr nonnull %3) #3
  br label %28

9:                                                ; preds = %7
  %10 = landingpad { ptr, i32 }
          cleanup
  call void @_ZNSt15__new_allocatorIcED2Ev(ptr noundef nonnull align 1 dereferenceable(1) %3) #3
  call void @llvm.lifetime.end.p0(i64 1, ptr nonnull %3) #3
  resume { ptr, i32 } %10

.lr.ph:                                           ; preds = %.preheader, %20
  %indvars.iv = phi i64 [ %indvars.iv.next, %20 ], [ 0, %.preheader ]
  %11 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %indvars.iv)
  %12 = load i8, ptr %11, align 1, !tbaa !5
  %.not = icmp eq i8 %12, 97
  br i1 %.not, label %20, label %13

13:                                               ; preds = %.lr.ph
  %14 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %15 = lshr i64 %14, 1
  %16 = icmp eq i64 %15, %indvars.iv
  br i1 %16, label %17, label %23

17:                                               ; preds = %13
  %18 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %19 = and i64 %18, 1
  %.not9 = icmp eq i64 %19, 0
  br i1 %.not9, label %23, label %20

20:                                               ; preds = %.lr.ph, %17
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %21 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %22 = icmp ugt i64 %21, %indvars.iv.next
  br i1 %22, label %.lr.ph, label %._crit_edge, !llvm.loop !8

23:                                               ; preds = %13, %17
  %24 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %indvars.iv)
  store i8 97, ptr %24, align 1, !tbaa !5
  tail call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2EOS4_(ptr noundef nonnull align 8 dereferenceable(32) %0, ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  br label %28

._crit_edge:                                      ; preds = %20, %.preheader
  %25 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %26 = add i64 %25, -1
  %27 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %26)
  store i8 98, ptr %27, align 1, !tbaa !5
  tail call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2EOS4_(ptr noundef nonnull align 8 dereferenceable(32) %0, ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  br label %28

28:                                               ; preds = %23, %._crit_edge, %8
  ret void
}

; Function Attrs: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSaIcEC2Ev(ptr noundef nonnull align 1 dereferenceable(1)) unnamed_addr #1 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2IS3_EEPKcRKS3_(ptr noundef nonnull align 8 dereferenceable(32), ptr noundef, ptr noundef nonnull align 1 dereferenceable(1)) unnamed_addr #0 align 2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

; 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 nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2EOS4_(ptr noundef nonnull align 8 dereferenceable(32), ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZNSt15__new_allocatorIcED2Ev(ptr noundef nonnull align 1 dereferenceable(1)) 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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { 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"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass