; LLVM IR from TheAlgorithms/C-Plus-Plus :: data_structures/doubly_linked_list.ll (ZN18double_linked_list11reverseShowEv)

; 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 }

@start = external dso_local global ptr, align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str.2 = external hidden unnamed_addr constant [2 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: 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

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #2

; Function Attrs: mustprogress uwtable
define dso_local void @_ZN18double_linked_list11reverseShowEv(ptr noundef nonnull align 1 dereferenceable(1) %0) #3 align 2 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  %4 = load ptr, ptr %2, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #4
  %5 = load ptr, ptr @start, align 8, !tbaa !5
  store ptr %5, ptr %3, align 8, !tbaa !5
  br label %6

6:                                                ; preds = %16, %1
  %7 = load ptr, ptr %3, align 8, !tbaa !5
  %8 = icmp ne ptr %7, null
  br i1 %8, label %9, label %14

9:                                                ; preds = %6
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.node, ptr %10, i32 0, i32 2
  %12 = load ptr, ptr %11, align 8, !tbaa !9
  %13 = icmp ne ptr %12, null
  br label %14

14:                                               ; preds = %9, %6
  %15 = phi i1 [ false, %6 ], [ %13, %9 ]
  br i1 %15, label %16, label %20

16:                                               ; preds = %14
  %17 = load ptr, ptr %3, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.node, ptr %17, i32 0, i32 2
  %19 = load ptr, ptr %18, align 8, !tbaa !9
  store ptr %19, ptr %3, align 8, !tbaa !5
  br label %6, !llvm.loop !12

20:                                               ; preds = %14
  br label %21

21:                                               ; preds = %24, %20
  %22 = load ptr, ptr %3, align 8, !tbaa !5
  %23 = icmp ne ptr %22, null
  br i1 %23, label %24, label %33

24:                                               ; preds = %21
  %25 = load ptr, ptr %3, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.node, ptr %25, i32 0, i32 0
  %27 = load i32, ptr %26, align 8, !tbaa !14
  %28 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %27)
  %29 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %28, ptr noundef @.str.2)
  %30 = load ptr, ptr %3, align 8, !tbaa !5
  %31 = getelementptr inbounds %struct.node, ptr %30, i32 0, i32 1
  %32 = load ptr, ptr %31, align 8, !tbaa !15
  store ptr %32, ptr %3, align 8, !tbaa !5
  br label %21, !llvm.loop !16

33:                                               ; preds = %21
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #4
  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 = { "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 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, !6, i64 16}
!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 = !{!10, !11, i64 0}
!15 = !{!10, !6, i64 8}
!16 = distinct !{!16, !13}


; 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 }

@start = external dso_local local_unnamed_addr global ptr, align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str.2 = external hidden unnamed_addr constant [2 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

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #1

; Function Attrs: mustprogress uwtable
define dso_local void @_ZN18double_linked_list11reverseShowEv(ptr nocapture noundef nonnull readnone align 1 dereferenceable(1) %0) local_unnamed_addr #2 align 2 {
  %2 = load ptr, ptr @start, align 8, !tbaa !5
  br label %3

3:                                                ; preds = %4, %1
  %.0 = phi ptr [ %2, %1 ], [ %6, %4 ]
  %.not = icmp eq ptr %.0, null
  br i1 %.not, label %._crit_edge, label %4

4:                                                ; preds = %3
  %5 = getelementptr inbounds i8, ptr %.0, i64 16
  %6 = load ptr, ptr %5, align 8, !tbaa !9
  %.not8 = icmp eq ptr %6, null
  br i1 %.not8, label %.lr.ph, label %3, !llvm.loop !12

.lr.ph:                                           ; preds = %4, %.lr.ph
  %.111 = phi ptr [ %11, %.lr.ph ], [ %.0, %4 ]
  %7 = load i32, ptr %.111, align 8, !tbaa !14
  %8 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %7)
  %9 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %8, ptr noundef nonnull @.str.2)
  %10 = getelementptr inbounds i8, ptr %.111, i64 8
  %11 = load ptr, ptr %10, align 8, !tbaa !15
  %.not9 = icmp eq ptr %11, null
  br i1 %.not9, label %._crit_edge, label %.lr.ph, !llvm.loop !16

._crit_edge:                                      ; preds = %3, %.lr.ph
  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 = { "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 16}
!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 = !{!10, !11, i64 0}
!15 = !{!10, !6, i64 8}
!16 = distinct !{!16, !13}


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