; LLVM IR from Leet-Us-Code/DSA-A-Z-Practice :: Sid's Levels/Level - 3/Recursion (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"

%"struct.std::pair" = type <{ %"struct.std::_Rb_tree_const_iterator", i8, [7 x i8] }>
%"struct.std::_Rb_tree_const_iterator" = type { ptr }

; Function Attrs: mustprogress uwtable
define dso_local void @_Z6helperRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEiiRSt3setIS4_St4lessIS4_ESaIS4_EE(ptr noundef nonnull align 8 dereferenceable(32) %0, i32 noundef %1, i32 noundef %2, ptr noundef nonnull align 8 dereferenceable(48) %3) #0 {
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca ptr, align 8
  %9 = alloca %"struct.std::pair", align 8
  %10 = 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
  %11 = load i32, ptr %6, align 4, !tbaa !9
  %12 = load i32, ptr %7, align 4, !tbaa !9
  %13 = icmp eq i32 %11, %12
  br i1 %13, label %14, label %22

14:                                               ; preds = %4
  %15 = load ptr, ptr %8, align 8, !tbaa !5
  %16 = load ptr, ptr %5, align 8, !tbaa !5
  %17 = call { ptr, i8 } @_ZNSt3setINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESt4lessIS5_ESaIS5_EE6insertERKS5_(ptr noundef nonnull align 8 dereferenceable(48) %15, ptr noundef nonnull align 8 dereferenceable(32) %16)
  %18 = getelementptr inbounds { ptr, i8 }, ptr %9, i32 0, i32 0
  %19 = extractvalue { ptr, i8 } %17, 0
  store ptr %19, ptr %18, align 8
  %20 = getelementptr inbounds { ptr, i8 }, ptr %9, i32 0, i32 1
  %21 = extractvalue { ptr, i8 } %17, 1
  store i8 %21, ptr %20, align 8
  br label %54

22:                                               ; preds = %4
  call void @llvm.lifetime.start.p0(i64 4, ptr %10) #4
  %23 = load i32, ptr %6, align 4, !tbaa !9
  store i32 %23, ptr %10, align 4, !tbaa !9
  br label %24

24:                                               ; preds = %51, %22
  %25 = load i32, ptr %10, align 4, !tbaa !9
  %26 = load i32, ptr %7, align 4, !tbaa !9
  %27 = icmp sle i32 %25, %26
  br i1 %27, label %29, label %28

28:                                               ; preds = %24
  call void @llvm.lifetime.end.p0(i64 4, ptr %10) #4
  br label %54

29:                                               ; preds = %24
  %30 = load ptr, ptr %5, align 8, !tbaa !5
  %31 = load i32, ptr %10, align 4, !tbaa !9
  %32 = sext i32 %31 to i64
  %33 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %30, i64 noundef %32)
  %34 = load ptr, ptr %5, align 8, !tbaa !5
  %35 = load i32, ptr %6, align 4, !tbaa !9
  %36 = sext i32 %35 to i64
  %37 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %34, i64 noundef %36)
  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) %33, ptr noundef nonnull align 1 dereferenceable(1) %37) #4
  %38 = load ptr, ptr %5, align 8, !tbaa !5
  %39 = load i32, ptr %6, align 4, !tbaa !9
  %40 = add nsw i32 %39, 1
  %41 = load i32, ptr %7, align 4, !tbaa !9
  %42 = load ptr, ptr %8, align 8, !tbaa !5
  call void @_Z6helperRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEiiRSt3setIS4_St4lessIS4_ESaIS4_EE(ptr noundef nonnull align 8 dereferenceable(32) %38, i32 noundef %40, i32 noundef %41, ptr noundef nonnull align 8 dereferenceable(48) %42)
  %43 = load ptr, ptr %5, align 8, !tbaa !5
  %44 = load i32, ptr %10, 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) %43, i64 noundef %45)
  %47 = load ptr, ptr %5, align 8, !tbaa !5
  %48 = load i32, ptr %6, align 4, !tbaa !9
  %49 = sext i32 %48 to i64
  %50 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %47, i64 noundef %49)
  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) %46, ptr noundef nonnull align 1 dereferenceable(1) %50) #4
  br label %51

51:                                               ; preds = %29
  %52 = load i32, ptr %10, align 4, !tbaa !9
  %53 = add nsw i32 %52, 1
  store i32 %53, ptr %10, align 4, !tbaa !9
  br label %24, !llvm.loop !11

54:                                               ; preds = %28, %14
  ret void
}

; Function Attrs: mustprogress uwtable
declare dso_local { ptr, i8 } @_ZNSt3setINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESt4lessIS5_ESaIS5_EE6insertERKS5_(ptr noundef nonnull align 8 dereferenceable(48), 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: 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"

; Function Attrs: mustprogress uwtable
define dso_local void @_Z6helperRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEiiRSt3setIS4_St4lessIS4_ESaIS4_EE(ptr noundef nonnull align 8 dereferenceable(32) %0, i32 noundef %1, i32 noundef %2, ptr noundef nonnull align 8 dereferenceable(48) %3) local_unnamed_addr #0 {
  %5 = icmp eq i32 %1, %2
  br i1 %5, label %9, label %.preheader

.preheader:                                       ; preds = %4
  %.not21 = icmp sgt i32 %1, %2
  br i1 %.not21, label %.loopexit, label %.lr.ph

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

9:                                                ; preds = %4
  %10 = tail call { ptr, i8 } @_ZNSt3setINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESt4lessIS5_ESaIS5_EE6insertERKS5_(ptr noundef nonnull align 8 dereferenceable(48) %3, ptr noundef nonnull align 8 dereferenceable(32) %0)
  br label %.loopexit

11:                                               ; preds = %.lr.ph, %11
  %indvars.iv = phi i64 [ %6, %.lr.ph ], [ %indvars.iv.next, %11 ]
  %12 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %indvars.iv)
  %13 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %6)
  tail 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
  tail call void @_Z6helperRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEiiRSt3setIS4_St4lessIS4_ESaIS4_EE(ptr noundef nonnull align 8 dereferenceable(32) %0, i32 noundef %7, i32 noundef %2, ptr noundef nonnull align 8 dereferenceable(48) %3)
  %14 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %indvars.iv)
  %15 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %6)
  tail 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) %14, ptr noundef nonnull align 1 dereferenceable(1) %15) #3
  %indvars.iv.next = add nsw i64 %indvars.iv, 1
  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
  %exitcond.not = icmp eq i32 %8, %lftr.wideiv
  br i1 %exitcond.not, label %.loopexit, label %11, !llvm.loop !5

.loopexit:                                        ; preds = %11, %.preheader, %9
  ret void
}

; Function Attrs: mustprogress uwtable
declare dso_local { ptr, i8 } @_ZNSt3setINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESt4lessIS5_ESaIS5_EE6insertERKS5_(ptr noundef nonnull align 8 dereferenceable(48), 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

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