; LLVM IR from next-step-for-interview-prep/Coding-Ninjas-DSA-course_code_and_notes_cpp :: Milestone-2=Intro_to_C++/questions and solutions/Lec-11=Strings/04-Remove_consecuti_ee81f690/Z27removeConsecutiveDuplicatesNSt7 (traitsIcESaIcEEE)

; 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.__gnu_cxx::__normal_iterator" = type { ptr }

; Function Attrs: mustprogress uwtable
define dso_local void @_Z27removeConsecutiveDuplicatesNSt7__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 i1, align 1
  %6 = alloca i8, align 1
  %7 = alloca ptr, align 8
  %8 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %9 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %10 = alloca i8, align 1
  %11 = alloca ptr, align 8
  %12 = alloca i32, align 4
  store ptr %0, ptr %3, align 8
  store ptr %1, ptr %4, align 8, !tbaa !5
  store i1 false, ptr %5, align 1
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #4
  call void @llvm.lifetime.start.p0(i64 1, ptr %6) #4
  store i8 0, ptr %6, align 1, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #4
  store ptr %1, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #4
  %13 = load ptr, ptr %7, align 8, !tbaa !5
  %14 = call ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE5beginEv(ptr noundef nonnull align 8 dereferenceable(32) %13) #4
  %15 = getelementptr inbounds %"class.__gnu_cxx::__normal_iterator", ptr %8, i32 0, i32 0
  store ptr %14, ptr %15, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr %9) #4
  %16 = load ptr, ptr %7, align 8, !tbaa !5
  %17 = call ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE3endEv(ptr noundef nonnull align 8 dereferenceable(32) %16) #4
  %18 = getelementptr inbounds %"class.__gnu_cxx::__normal_iterator", ptr %9, i32 0, i32 0
  store ptr %17, ptr %18, align 8
  br label %19

19:                                               ; preds = %40, %2
  %20 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEEbRKNS_17__normal_iteratorIT_T0_EESD_(ptr noundef nonnull align 8 dereferenceable(8) %8, ptr noundef nonnull align 8 dereferenceable(8) %9) #4
  br i1 %20, label %22, label %21

21:                                               ; preds = %19
  call void @llvm.lifetime.end.p0(i64 8, ptr %9) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #4
  br label %42

22:                                               ; preds = %19
  call void @llvm.lifetime.start.p0(i64 1, ptr %10) #4
  %23 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %8) #4
  %24 = load i8, ptr %23, align 1, !tbaa !9
  store i8 %24, ptr %10, align 1, !tbaa !9
  %25 = load i8, ptr %10, align 1, !tbaa !9
  %26 = sext i8 %25 to i32
  %27 = load i8, ptr %6, align 1, !tbaa !9
  %28 = sext i8 %27 to i32
  %29 = icmp ne i32 %26, %28
  br i1 %29, label %30, label %39

30:                                               ; preds = %22
  %31 = load i8, ptr %10, align 1, !tbaa !9
  %32 = invoke noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEpLEc(ptr noundef nonnull align 8 dereferenceable(32) %0, i8 noundef signext %31)
          to label %33 unwind label %35

33:                                               ; preds = %30
  %34 = load i8, ptr %10, align 1, !tbaa !9
  store i8 %34, ptr %6, align 1, !tbaa !9
  br label %39

35:                                               ; preds = %30
  %36 = landingpad { ptr, i32 }
          cleanup
  %37 = extractvalue { ptr, i32 } %36, 0
  store ptr %37, ptr %11, align 8
  %38 = extractvalue { ptr, i32 } %36, 1
  store i32 %38, ptr %12, align 4
  call void @llvm.lifetime.end.p0(i64 1, ptr %10) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %9) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #4
  call void @llvm.lifetime.end.p0(i64 1, ptr %6) #4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #4
  br label %46

39:                                               ; preds = %33, %22
  call void @llvm.lifetime.end.p0(i64 1, ptr %10) #4
  br label %40

40:                                               ; preds = %39
  %41 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEppEv(ptr noundef nonnull align 8 dereferenceable(8) %8) #4
  br label %19

42:                                               ; preds = %21
  store i1 true, ptr %5, align 1
  call void @llvm.lifetime.end.p0(i64 1, ptr %6) #4
  %43 = load i1, ptr %5, align 1
  br i1 %43, label %45, label %44

44:                                               ; preds = %42
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #4
  br label %45

45:                                               ; preds = %44, %42
  ret void

46:                                               ; preds = %35
  %47 = load ptr, ptr %11, align 8
  %48 = load i32, ptr %12, align 4
  %49 = insertvalue { ptr, i32 } poison, ptr %47, 0
  %50 = insertvalue { ptr, i32 } %49, i32 %48, 1
  resume { ptr, i32 } %50
}

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #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 ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE5beginEv(ptr noundef nonnull align 8 dereferenceable(32)) #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE3endEv(ptr noundef nonnull align 8 dereferenceable(32)) #1 align 2

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef zeroext i1 @_ZN9__gnu_cxxneIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEEbRKNS_17__normal_iteratorIT_T0_EESD_(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef nonnull align 8 dereferenceable(8)) #3

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 1 dereferenceable(1) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8)) #1 align 2

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEpLEc(ptr noundef nonnull align 8 dereferenceable(32), i8 noundef signext) #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 dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEppEv(ptr noundef nonnull align 8 dereferenceable(8)) #1 align 2

; 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { inlinehint 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 #4 = { 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 = !{!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] }
%"class.__gnu_cxx::__normal_iterator" = type { ptr }

; Function Attrs: mustprogress uwtable
define dso_local void @_Z27removeConsecutiveDuplicatesNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr dead_on_unwind noalias nonnull writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef %1) local_unnamed_addr #0 personality ptr @__gxx_personality_v0 {
  %3 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %4 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  tail call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #4
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %3) #4
  %5 = tail call ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE5beginEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #4
  store ptr %5, ptr %3, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %4) #4
  %6 = tail call ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE3endEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #4
  store ptr %6, ptr %4, align 8
  %7 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEEbRKNS_17__normal_iteratorIT_T0_EESD_(ptr noundef nonnull align 8 dereferenceable(8) %3, ptr noundef nonnull align 8 dereferenceable(8) %4) #4
  br i1 %7, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %14, %2
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %4) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %3) #4
  ret void

.lr.ph:                                           ; preds = %2, %14
  %.08 = phi i8 [ %.1, %14 ], [ 0, %2 ]
  %8 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %3) #4
  %9 = load i8, ptr %8, align 1, !tbaa !5
  %.not = icmp eq i8 %9, %.08
  br i1 %.not, label %14, label %10

10:                                               ; preds = %.lr.ph
  %11 = invoke noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEpLEc(ptr noundef nonnull align 8 dereferenceable(32) %0, i8 noundef signext %9)
          to label %14 unwind label %12

12:                                               ; preds = %10
  %13 = landingpad { ptr, i32 }
          cleanup
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %4) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %3) #4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #4
  resume { ptr, i32 } %13

14:                                               ; preds = %10, %.lr.ph
  %.1 = phi i8 [ %.08, %.lr.ph ], [ %9, %10 ]
  %15 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEppEv(ptr noundef nonnull align 8 dereferenceable(8) %3) #4
  %16 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEEbRKNS_17__normal_iteratorIT_T0_EESD_(ptr noundef nonnull align 8 dereferenceable(8) %3, ptr noundef nonnull align 8 dereferenceable(8) %4) #4
  br i1 %16, label %.lr.ph, label %._crit_edge
}

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32)) 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 ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE5beginEv(ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE3endEv(ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #1 align 2

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef zeroext i1 @_ZN9__gnu_cxxneIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEEbRKNS_17__normal_iteratorIT_T0_EESD_(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #3

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 1 dereferenceable(1) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEpLEc(ptr noundef nonnull align 8 dereferenceable(32), i8 noundef signext) local_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 dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEppEv(ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #1 align 2

; 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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { inlinehint 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 #4 = { 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,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass