; LLVM IR from div-bargali/Data-Structures-and-Algorithms :: C++/Data-Structures/LinkedList (OrderedLinkedListStrings)

; 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.sortedList = type { ptr, i32, ptr }
%class.node = type { %"class.std::__cxx11::basic_string", ptr }

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; 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 #1 align 2

; Function Attrs: mustprogress uwtable
define dso_local void @_ZN10sortedList6getNthB5cxx11Ei(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef nonnull align 8 dereferenceable(24) %1, i32 noundef %2) #1 align 2 {
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca ptr, align 8
  %8 = alloca i32, align 4
  store ptr %0, ptr %4, align 8
  store ptr %1, ptr %5, align 8, !tbaa !5
  store i32 %2, ptr %6, align 4, !tbaa !9
  %9 = load ptr, ptr %5, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #2
  %10 = getelementptr inbounds %class.sortedList, ptr %9, i32 0, i32 0
  %11 = load ptr, ptr %10, align 8, !tbaa !11
  store ptr %11, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  store i32 0, ptr %8, align 4, !tbaa !9
  br label %12

12:                                               ; preds = %27, %3
  %13 = load i32, ptr %8, align 4, !tbaa !9
  %14 = load i32, ptr %6, align 4, !tbaa !9
  %15 = sub nsw i32 %14, 1
  %16 = icmp slt i32 %13, %15
  br i1 %16, label %17, label %20

17:                                               ; preds = %12
  %18 = load ptr, ptr %7, align 8, !tbaa !5
  %19 = icmp ne ptr %18, null
  br label %20

20:                                               ; preds = %17, %12
  %21 = phi i1 [ false, %12 ], [ %19, %17 ]
  br i1 %21, label %23, label %22

22:                                               ; preds = %20
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  br label %30

23:                                               ; preds = %20
  %24 = load ptr, ptr %7, align 8, !tbaa !5
  %25 = getelementptr inbounds %class.node, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !13
  store ptr %26, ptr %7, align 8, !tbaa !5
  br label %27

27:                                               ; preds = %23
  %28 = load i32, ptr %8, align 4, !tbaa !9
  %29 = add nsw i32 %28, 1
  store i32 %29, ptr %8, align 4, !tbaa !9
  br label %12, !llvm.loop !18

30:                                               ; preds = %22
  %31 = load ptr, ptr %7, align 8, !tbaa !5
  %32 = getelementptr inbounds %class.node, ptr %31, i32 0, i32 0
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32) %0, ptr noundef nonnull align 8 dereferenceable(32) %32)
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #2
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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 = !{!12, !6, i64 0}
!12 = !{!"_ZTS10sortedList", !6, i64 0, !10, i64 8, !6, i64 16}
!13 = !{!14, !6, i64 32}
!14 = !{!"_ZTS4node", !15, i64 0, !6, i64 32}
!15 = !{!"_ZTSNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE", !16, i64 0, !17, i64 8, !7, i64 16}
!16 = !{!"_ZTSNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE12_Alloc_hiderE", !6, i64 0}
!17 = !{!"long", !7, i64 0}
!18 = distinct !{!18, !19}
!19 = !{!"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
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

; Function Attrs: mustprogress uwtable
define dso_local void @_ZN10sortedList6getNthB5cxx11Ei(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr nocapture noundef nonnull readonly align 8 dereferenceable(24) %1, i32 noundef %2) local_unnamed_addr #0 align 2 {
  %4 = add nsw i32 %2, -1
  %.067 = load ptr, ptr %1, align 8, !tbaa !5
  %5 = icmp sgt i32 %2, 1
  %6 = icmp ne ptr %.067, null
  %7 = select i1 %5, i1 %6, i1 false
  br i1 %7, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %3
  %.06.lcssa = phi ptr [ %.067, %3 ], [ %.06, %.lr.ph ]
  tail call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32) %0, ptr noundef nonnull align 8 dereferenceable(32) %.06.lcssa)
  ret void

.lr.ph:                                           ; preds = %3, %.lr.ph
  %.069 = phi ptr [ %.06, %.lr.ph ], [ %.067, %3 ]
  %.08 = phi i32 [ %9, %.lr.ph ], [ 0, %3 ]
  %8 = getelementptr inbounds i8, ptr %.069, i64 32
  %9 = add nuw nsw i32 %.08, 1
  %.06 = load ptr, ptr %8, align 8, !tbaa !5
  %10 = icmp slt i32 %9, %4
  %11 = icmp ne ptr %.06, null
  %12 = select i1 %10, i1 %11, i1 false
  br i1 %12, label %.lr.ph, label %._crit_edge, !llvm.loop !9
}

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" }

!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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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