; LLVM IR from amritansh22/Data-Structures-and-Algorithms-in-cpp :: Print Nth node from end in singly linked list.ll (Z15printNthFromEndP4Nodei)

; 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::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }
%class.Node = type { i32, ptr }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [39 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [22 x i8], align 1

; 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
define dso_local void @_Z15printNthFromEndP4Nodei(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #4
  %9 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %9, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #4
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %10, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #4
  store i32 0, ptr %7, align 4, !tbaa !9
  %11 = load ptr, ptr %3, align 8, !tbaa !5
  %12 = icmp ne ptr %11, null
  br i1 %12, label %13, label %46

13:                                               ; preds = %2
  br label %14

14:                                               ; preds = %23, %13
  %15 = load i32, ptr %7, align 4, !tbaa !9
  %16 = load i32, ptr %4, align 4, !tbaa !9
  %17 = icmp slt i32 %15, %16
  br i1 %17, label %18, label %29

18:                                               ; preds = %14
  %19 = load ptr, ptr %6, align 8, !tbaa !5
  %20 = icmp eq ptr %19, null
  br i1 %20, label %21, label %23

21:                                               ; preds = %18
  %22 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str)
  store i32 1, ptr %8, align 4
  br label %47

23:                                               ; preds = %18
  %24 = load ptr, ptr %6, align 8, !tbaa !5
  %25 = getelementptr inbounds %class.Node, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !11
  store ptr %26, ptr %6, align 8, !tbaa !5
  %27 = load i32, ptr %7, align 4, !tbaa !9
  %28 = add nsw i32 %27, 1
  store i32 %28, ptr %7, align 4, !tbaa !9
  br label %14, !llvm.loop !13

29:                                               ; preds = %14
  br label %30

30:                                               ; preds = %33, %29
  %31 = load ptr, ptr %6, align 8, !tbaa !5
  %32 = icmp ne ptr %31, null
  br i1 %32, label %33, label %40

33:                                               ; preds = %30
  %34 = load ptr, ptr %5, align 8, !tbaa !5
  %35 = getelementptr inbounds %class.Node, ptr %34, i32 0, i32 1
  %36 = load ptr, ptr %35, align 8, !tbaa !11
  store ptr %36, ptr %5, align 8, !tbaa !5
  %37 = load ptr, ptr %6, align 8, !tbaa !5
  %38 = getelementptr inbounds %class.Node, ptr %37, i32 0, i32 1
  %39 = load ptr, ptr %38, align 8, !tbaa !11
  store ptr %39, ptr %6, align 8, !tbaa !5
  br label %30, !llvm.loop !15

40:                                               ; preds = %30
  %41 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str.1)
  %42 = load ptr, ptr %5, align 8, !tbaa !5
  %43 = getelementptr inbounds %class.Node, ptr %42, i32 0, i32 0
  %44 = load i32, ptr %43, align 8, !tbaa !16
  %45 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %41, i32 noundef %44)
  br label %46

46:                                               ; preds = %40, %2
  store i32 0, ptr %8, align 4
  br label %47

47:                                               ; preds = %46, %21
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #4
  %48 = load i32, ptr %8, align 4
  switch i32 %48, label %50 [
    i32 0, label %49
    i32 1, label %49
  ]

49:                                               ; preds = %47, %47
  ret void

50:                                               ; preds = %47
  unreachable
}

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #2

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #3

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 = { inlinehint 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 #3 = { "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 = !{!12, !6, i64 8}
!12 = !{!"_ZTS4Node", !10, i64 0, !6, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = distinct !{!15, !14}
!16 = !{!12, !10, 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::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [39 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [22 x i8], align 1

; Function Attrs: mustprogress uwtable
define dso_local void @_Z15printNthFromEndP4Nodei(ptr noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %.not = icmp eq ptr %0, null
  br i1 %.not, label %18, label %.preheader15

.preheader15:                                     ; preds = %2
  %3 = icmp sgt i32 %1, 0
  br i1 %3, label %.lr.ph, label %.lr.ph22.preheader

.preheader:                                       ; preds = %7
  %.not1419 = icmp eq ptr %9, null
  br i1 %.not1419, label %._crit_edge, label %.lr.ph22.preheader

.lr.ph22.preheader:                               ; preds = %.preheader15, %.preheader
  %.121.ph = phi ptr [ %0, %.preheader15 ], [ %9, %.preheader ]
  br label %.lr.ph22

.lr.ph:                                           ; preds = %.preheader15, %7
  %.018 = phi i32 [ %10, %7 ], [ 0, %.preheader15 ]
  %.01117 = phi ptr [ %9, %7 ], [ %0, %.preheader15 ]
  %4 = icmp eq ptr %.01117, null
  br i1 %4, label %5, label %7

5:                                                ; preds = %.lr.ph
  %6 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @.str)
  br label %18

7:                                                ; preds = %.lr.ph
  %8 = getelementptr inbounds i8, ptr %.01117, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !5
  %10 = add nuw nsw i32 %.018, 1
  %exitcond.not = icmp eq i32 %10, %1
  br i1 %exitcond.not, label %.preheader, label %.lr.ph, !llvm.loop !11

.lr.ph22:                                         ; preds = %.lr.ph22.preheader, %.lr.ph22
  %.121 = phi ptr [ %14, %.lr.ph22 ], [ %.121.ph, %.lr.ph22.preheader ]
  %.01220 = phi ptr [ %12, %.lr.ph22 ], [ %0, %.lr.ph22.preheader ]
  %11 = getelementptr inbounds i8, ptr %.01220, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !5
  %13 = getelementptr inbounds i8, ptr %.121, i64 8
  %14 = load ptr, ptr %13, align 8, !tbaa !5
  %.not14 = icmp eq ptr %14, null
  br i1 %.not14, label %._crit_edge, label %.lr.ph22, !llvm.loop !13

._crit_edge:                                      ; preds = %.lr.ph22, %.preheader
  %.012.lcssa = phi ptr [ %0, %.preheader ], [ %12, %.lr.ph22 ]
  %15 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @.str.1)
  %16 = load i32, ptr %.012.lcssa, align 8, !tbaa !14
  %17 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %15, i32 noundef %16)
  br label %18

18:                                               ; preds = %2, %._crit_edge, %5
  ret void
}

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #1

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #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 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 = { "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, !10, i64 8}
!6 = !{!"_ZTS4Node", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}
!14 = !{!6, !7, i64 0}


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