; LLVM IR from VAR-solutions/Algorithms :: data structures/linked list/cpp/linked-list(doubly-singly).ll (Z7del_endv)

; 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 }
%struct.node = type { i32, ptr, ptr }

@head = external dso_local global ptr, align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str.6 = external hidden unnamed_addr constant [21 x i8], align 1
@.str.7 = external hidden unnamed_addr constant [32 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: 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) #1

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

; Function Attrs: inlinehint mustprogress uwtable
declare i32 @getchar() #1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z6singlyv() #2

; Function Attrs: mustprogress uwtable
define dso_local void @_Z7del_endv() #2 {
  %1 = alloca ptr, align 8
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr %1) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #3
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  store i32 0, ptr %3, align 4, !tbaa !5
  %5 = load ptr, ptr @head, align 8, !tbaa !9
  store ptr %5, ptr %1, align 8, !tbaa !9
  %6 = load ptr, ptr @head, align 8, !tbaa !9
  store ptr %6, ptr %2, align 8, !tbaa !9
  %7 = load ptr, ptr @head, align 8, !tbaa !9
  %8 = icmp eq ptr %7, null
  br i1 %8, label %9, label %11

9:                                                ; preds = %0
  %10 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str.6)
  br label %37

11:                                               ; preds = %0
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  br label %12

12:                                               ; preds = %17, %11
  %13 = load ptr, ptr %1, align 8, !tbaa !9
  %14 = getelementptr inbounds %struct.node, ptr %13, i32 0, i32 1
  %15 = load ptr, ptr %14, align 8, !tbaa !11
  %16 = icmp ne ptr %15, null
  br i1 %16, label %17, label %23

17:                                               ; preds = %12
  %18 = load ptr, ptr %1, align 8, !tbaa !9
  %19 = getelementptr inbounds %struct.node, ptr %18, i32 0, i32 1
  %20 = load ptr, ptr %19, align 8, !tbaa !11
  store ptr %20, ptr %1, align 8, !tbaa !9
  %21 = load i32, ptr %3, align 4, !tbaa !5
  %22 = add nsw i32 %21, 1
  store i32 %22, ptr %3, align 4, !tbaa !5
  br label %12, !llvm.loop !13

23:                                               ; preds = %12
  br label %24

24:                                               ; preds = %28, %23
  %25 = load i32, ptr %3, align 4, !tbaa !5
  %26 = sub nsw i32 %25, 1
  %27 = icmp sgt i32 %26, 0
  br i1 %27, label %28, label %34

28:                                               ; preds = %24
  %29 = load ptr, ptr %2, align 8, !tbaa !9
  %30 = getelementptr inbounds %struct.node, ptr %29, i32 0, i32 1
  %31 = load ptr, ptr %30, align 8, !tbaa !11
  store ptr %31, ptr %2, align 8, !tbaa !9
  %32 = load i32, ptr %3, align 4, !tbaa !5
  %33 = add nsw i32 %32, -1
  store i32 %33, ptr %3, align 4, !tbaa !5
  br label %24, !llvm.loop !15

34:                                               ; preds = %24
  %35 = load ptr, ptr %2, align 8, !tbaa !9
  %36 = getelementptr inbounds %struct.node, ptr %35, i32 0, i32 1
  store ptr null, ptr %36, align 8, !tbaa !11
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  br label %37

37:                                               ; preds = %34, %9
  %38 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str.7)
  %39 = call i32 @getchar()
  call void @_Z6singlyv()
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %1) #3
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { 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 = { 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !10, i64 8}
!12 = !{!"_ZTS4node", !6, i64 0, !10, i64 8, !10, i64 16}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = distinct !{!15, !14}


; 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 }

@head = external dso_local local_unnamed_addr global ptr, align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str.6 = external hidden unnamed_addr constant [21 x i8], align 1
@.str.7 = external hidden unnamed_addr constant [32 x i8], align 1

; 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 #0

; Function Attrs: inlinehint mustprogress nofree nounwind uwtable
declare noundef i32 @getchar() local_unnamed_addr #1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z6singlyv() local_unnamed_addr #2

; Function Attrs: mustprogress uwtable
define dso_local void @_Z7del_endv() local_unnamed_addr #2 {
  %1 = load ptr, ptr @head, align 8, !tbaa !5
  %2 = icmp eq ptr %1, null
  br i1 %2, label %3, label %.preheader10

3:                                                ; preds = %0
  %4 = 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.6)
  br label %34

.preheader10:                                     ; preds = %0, %.preheader10
  %.06 = phi i32 [ %7, %.preheader10 ], [ 0, %0 ]
  %.0 = phi ptr [ %6, %.preheader10 ], [ %1, %0 ]
  %5 = getelementptr inbounds i8, ptr %.0, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !9
  %.not = icmp eq ptr %6, null
  %7 = add nuw nsw i32 %.06, 1
  br i1 %.not, label %.preheader, label %.preheader10, !llvm.loop !12

.preheader:                                       ; preds = %.preheader10
  %8 = icmp ugt i32 %.06, 1
  br i1 %8, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %.preheader
  %9 = add nuw i32 %.06, 7
  %10 = add nsw i32 %.06, -2
  %xtraiter = and i32 %9, 7
  %lcmp.mod.not = icmp eq i32 %xtraiter, 0
  br i1 %lcmp.mod.not, label %.lr.ph.prol.loopexit, label %.lr.ph.prol

.lr.ph.prol:                                      ; preds = %.lr.ph.preheader, %.lr.ph.prol
  %.112.prol = phi i32 [ %13, %.lr.ph.prol ], [ %.06, %.lr.ph.preheader ]
  %.0711.prol = phi ptr [ %12, %.lr.ph.prol ], [ %1, %.lr.ph.preheader ]
  %prol.iter = phi i32 [ %prol.iter.next, %.lr.ph.prol ], [ 0, %.lr.ph.preheader ]
  %11 = getelementptr inbounds i8, ptr %.0711.prol, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !9
  %13 = add nsw i32 %.112.prol, -1
  %prol.iter.next = add i32 %prol.iter, 1
  %prol.iter.cmp.not = icmp eq i32 %prol.iter.next, %xtraiter
  br i1 %prol.iter.cmp.not, label %.lr.ph.prol.loopexit, label %.lr.ph.prol, !llvm.loop !14

.lr.ph.prol.loopexit:                             ; preds = %.lr.ph.prol, %.lr.ph.preheader
  %.112.unr = phi i32 [ %.06, %.lr.ph.preheader ], [ %13, %.lr.ph.prol ]
  %.0711.unr = phi ptr [ %1, %.lr.ph.preheader ], [ %12, %.lr.ph.prol ]
  %.lcssa.unr = phi ptr [ poison, %.lr.ph.preheader ], [ %12, %.lr.ph.prol ]
  %14 = icmp ult i32 %10, 7
  br i1 %14, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.prol.loopexit, %.lr.ph
  %.112 = phi i32 [ %31, %.lr.ph ], [ %.112.unr, %.lr.ph.prol.loopexit ]
  %.0711 = phi ptr [ %30, %.lr.ph ], [ %.0711.unr, %.lr.ph.prol.loopexit ]
  %15 = getelementptr inbounds i8, ptr %.0711, i64 8
  %16 = load ptr, ptr %15, align 8, !tbaa !9
  %17 = getelementptr inbounds i8, ptr %16, i64 8
  %18 = load ptr, ptr %17, align 8, !tbaa !9
  %19 = getelementptr inbounds i8, ptr %18, i64 8
  %20 = load ptr, ptr %19, align 8, !tbaa !9
  %21 = getelementptr inbounds i8, ptr %20, i64 8
  %22 = load ptr, ptr %21, align 8, !tbaa !9
  %23 = getelementptr inbounds i8, ptr %22, i64 8
  %24 = load ptr, ptr %23, align 8, !tbaa !9
  %25 = getelementptr inbounds i8, ptr %24, i64 8
  %26 = load ptr, ptr %25, align 8, !tbaa !9
  %27 = getelementptr inbounds i8, ptr %26, i64 8
  %28 = load ptr, ptr %27, align 8, !tbaa !9
  %29 = getelementptr inbounds i8, ptr %28, i64 8
  %30 = load ptr, ptr %29, align 8, !tbaa !9
  %31 = add nsw i32 %.112, -8
  %32 = icmp sgt i32 %.112, 9
  br i1 %32, label %.lr.ph, label %._crit_edge, !llvm.loop !16

._crit_edge:                                      ; preds = %.lr.ph.prol.loopexit, %.lr.ph, %.preheader
  %.07.lcssa = phi ptr [ %1, %.preheader ], [ %.lcssa.unr, %.lr.ph.prol.loopexit ], [ %30, %.lr.ph ]
  %33 = getelementptr inbounds i8, ptr %.07.lcssa, i64 8
  store ptr null, ptr %33, align 8, !tbaa !9
  br label %34

34:                                               ; preds = %._crit_edge, %3
  %35 = 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.7)
  %36 = tail call i32 @getchar()
  tail call void @_Z6singlyv()
  ret void
}

attributes #0 = { 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 #1 = { inlinehint mustprogress nofree 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 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 = !{!10, !6, i64 8}
!10 = !{!"_ZTS4node", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}
!14 = distinct !{!14, !15}
!15 = !{!"llvm.loop.unroll.disable"}
!16 = distinct !{!16, !13}


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