; LLVM IR from Leet-Us-Code/DSA-A-Z-Practice :: Sid's Levels/Level - 1/Backtracking (Permutations)

; 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 void @_Z12permutationsNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEiiRSt6vectorIS4_SaIS4_EE(ptr noundef %0, i32 noundef %1, i32 noundef %2, ptr noundef nonnull align 8 dereferenceable(24) %3) #0 personality ptr @__gxx_personality_v0 {
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca ptr, align 8
  %9 = alloca i32, align 4
  %10 = alloca %"class.std::__cxx11::basic_string", align 8
  %11 = alloca ptr, align 8
  %12 = alloca i32, align 4
  store ptr %0, ptr %5, align 8, !tbaa !5
  store i32 %1, ptr %6, align 4, !tbaa !9
  store i32 %2, ptr %7, align 4, !tbaa !9
  store ptr %3, ptr %8, align 8, !tbaa !5
  %13 = load i32, ptr %6, align 4, !tbaa !9
  %14 = load i32, ptr %7, align 4, !tbaa !9
  %15 = icmp eq i32 %13, %14
  br i1 %15, label %16, label %18

16:                                               ; preds = %4
  %17 = load ptr, ptr %8, align 8, !tbaa !5
  call void @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EE9push_backERKS5_(ptr noundef nonnull align 8 dereferenceable(24) %17, ptr noundef nonnull align 8 dereferenceable(32) %0)
  br label %51

18:                                               ; preds = %4
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #4
  %19 = load i32, ptr %6, align 4, !tbaa !9
  store i32 %19, ptr %9, align 4, !tbaa !9
  br label %20

20:                                               ; preds = %43, %18
  %21 = load i32, ptr %9, align 4, !tbaa !9
  %22 = load i32, ptr %7, align 4, !tbaa !9
  %23 = icmp sle i32 %21, %22
  br i1 %23, label %25, label %24

24:                                               ; preds = %20
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #4
  br label %50

25:                                               ; preds = %20
  %26 = load i32, ptr %6, 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 i32, ptr %9, align 4, !tbaa !9
  %30 = sext i32 %29 to i64
  %31 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %30)
  call void @_ZSt4swapIcENSt9enable_ifIXsr6__and_ISt6__not_ISt15__is_tuple_likeIT_EESt21is_move_constructibleIS3_ESt18is_move_assignableIS3_EEE5valueEvE4typeERS3_SC_(ptr noundef nonnull align 1 dereferenceable(1) %28, ptr noundef nonnull align 1 dereferenceable(1) %31) #4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32) %10, ptr noundef nonnull align 8 dereferenceable(32) %0)
  %32 = load i32, ptr %6, align 4, !tbaa !9
  %33 = add nsw i32 %32, 1
  %34 = load i32, ptr %7, align 4, !tbaa !9
  %35 = load ptr, ptr %8, align 8, !tbaa !5
  invoke void @_Z12permutationsNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEiiRSt6vectorIS4_SaIS4_EE(ptr noundef %10, i32 noundef %33, i32 noundef %34, ptr noundef nonnull align 8 dereferenceable(24) %35)
          to label %36 unwind label %46

36:                                               ; preds = %25
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %10) #4
  %37 = load i32, ptr %6, align 4, !tbaa !9
  %38 = sext i32 %37 to i64
  %39 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %38)
  %40 = load i32, ptr %9, align 4, !tbaa !9
  %41 = sext i32 %40 to i64
  %42 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %41)
  call void @_ZSt4swapIcENSt9enable_ifIXsr6__and_ISt6__not_ISt15__is_tuple_likeIT_EESt21is_move_constructibleIS3_ESt18is_move_assignableIS3_EEE5valueEvE4typeERS3_SC_(ptr noundef nonnull align 1 dereferenceable(1) %39, ptr noundef nonnull align 1 dereferenceable(1) %42) #4
  br label %43

43:                                               ; preds = %36
  %44 = load i32, ptr %9, align 4, !tbaa !9
  %45 = add nsw i32 %44, 1
  store i32 %45, ptr %9, align 4, !tbaa !9
  br label %20, !llvm.loop !11

46:                                               ; preds = %25
  %47 = landingpad { ptr, i32 }
          cleanup
  %48 = extractvalue { ptr, i32 } %47, 0
  store ptr %48, ptr %11, align 8
  %49 = extractvalue { ptr, i32 } %47, 1
  store i32 %49, ptr %12, align 4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %10) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #4
  br label %52

50:                                               ; preds = %24
  br label %51

51:                                               ; preds = %50, %16
  ret void

52:                                               ; preds = %46
  %53 = load ptr, ptr %11, align 8
  %54 = load i32, ptr %12, align 4
  %55 = insertvalue { ptr, i32 } poison, ptr %53, 0
  %56 = insertvalue { ptr, i32 } %55, i32 %54, 1
  resume { ptr, i32 } %56
}

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EE9push_backERKS5_(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 8 dereferenceable(32)) #0 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local void @_ZSt4swapIcENSt9enable_ifIXsr6__and_ISt6__not_ISt15__is_tuple_likeIT_EESt21is_move_constructibleIS3_ESt18is_move_assignableIS3_EEE5valueEvE4typeERS3_SC_(ptr noundef nonnull align 1 dereferenceable(1), ptr noundef nonnull align 1 dereferenceable(1)) #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) #3 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 #3 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #3 = { 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 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"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] }

; Function Attrs: mustprogress uwtable
define dso_local void @_Z12permutationsNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEiiRSt6vectorIS4_SaIS4_EE(ptr noundef %0, i32 noundef %1, i32 noundef %2, ptr noundef nonnull align 8 dereferenceable(24) %3) local_unnamed_addr #0 personality ptr @__gxx_personality_v0 {
  %5 = alloca %"class.std::__cxx11::basic_string", align 8
  %6 = icmp eq i32 %1, %2
  br i1 %6, label %10, label %.preheader

.preheader:                                       ; preds = %4
  %.not17 = icmp sgt i32 %1, %2
  br i1 %.not17, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %.preheader
  %7 = sext i32 %1 to i64
  %8 = add nsw i32 %1, 1
  %9 = add i32 %2, 1
  br label %11

10:                                               ; preds = %4
  tail call void @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EE9push_backERKS5_(ptr noundef nonnull align 8 dereferenceable(24) %3, ptr noundef nonnull align 8 dereferenceable(32) %0)
  br label %.loopexit

11:                                               ; preds = %.lr.ph, %14
  %indvars.iv = phi i64 [ %7, %.lr.ph ], [ %indvars.iv.next, %14 ]
  %12 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %7)
  %13 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %indvars.iv)
  call void @_ZSt4swapIcENSt9enable_ifIXsr6__and_ISt6__not_ISt15__is_tuple_likeIT_EESt21is_move_constructibleIS3_ESt18is_move_assignableIS3_EEE5valueEvE4typeERS3_SC_(ptr noundef nonnull align 1 dereferenceable(1) %12, ptr noundef nonnull align 1 dereferenceable(1) %13) #3
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32) %5, ptr noundef nonnull align 8 dereferenceable(32) %0)
  invoke void @_Z12permutationsNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEiiRSt6vectorIS4_SaIS4_EE(ptr noundef nonnull %5, i32 noundef %8, i32 noundef %2, ptr noundef nonnull align 8 dereferenceable(24) %3)
          to label %14 unwind label %17

14:                                               ; preds = %11
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %5) #3
  %15 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %7)
  %16 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %indvars.iv)
  call void @_ZSt4swapIcENSt9enable_ifIXsr6__and_ISt6__not_ISt15__is_tuple_likeIT_EESt21is_move_constructibleIS3_ESt18is_move_assignableIS3_EEE5valueEvE4typeERS3_SC_(ptr noundef nonnull align 1 dereferenceable(1) %15, ptr noundef nonnull align 1 dereferenceable(1) %16) #3
  %indvars.iv.next = add nsw i64 %indvars.iv, 1
  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
  %exitcond.not = icmp eq i32 %9, %lftr.wideiv
  br i1 %exitcond.not, label %.loopexit, label %11, !llvm.loop !5

17:                                               ; preds = %11
  %18 = landingpad { ptr, i32 }
          cleanup
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %5) #3
  resume { ptr, i32 } %18

.loopexit:                                        ; preds = %14, %.preheader, %10
  ret void
}

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EE9push_backERKS5_(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #0 align 2

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local void @_ZSt4swapIcENSt9enable_ifIXsr6__and_ISt6__not_ISt15__is_tuple_likeIT_EESt21is_move_constructibleIS3_ESt18is_move_assignableIS3_EEE5valueEvE4typeERS3_SC_(ptr noundef nonnull align 1 dereferenceable(1), ptr noundef nonnull align 1 dereferenceable(1)) local_unnamed_addr #1

; 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 #2 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 #2 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 = { 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 #2 = { 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 #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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass