; LLVM IR from sbshah97/DS-Algo-Handbook :: Data-Structures/Linked_List/Doubly_Linked_List (doubly-linkedlist)

; 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 { ptr, ptr, i32 }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str.1 = external hidden unnamed_addr constant [27 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: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 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 noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #2

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z12post_elementP4nodeii(ptr noundef %0, i32 noundef %1, i32 noundef %2) #3 {
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca ptr, align 8
  %9 = alloca ptr, 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
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #5
  call void @llvm.lifetime.start.p0(i64 8, ptr %9) #5
  %11 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 24) #6
  store ptr %11, ptr %8, align 8, !tbaa !5
  %12 = load i32, ptr %6, align 4, !tbaa !9
  %13 = load ptr, ptr %8, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.node, ptr %13, i32 0, i32 2
  store i32 %12, ptr %14, align 8, !tbaa !11
  %15 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %15, ptr %9, align 8, !tbaa !5
  br label %16

16:                                               ; preds = %49, %3
  %17 = load ptr, ptr %9, align 8, !tbaa !5
  %18 = icmp ne ptr %17, null
  br i1 %18, label %19, label %53

19:                                               ; preds = %16
  %20 = load ptr, ptr %9, align 8, !tbaa !5
  %21 = getelementptr inbounds %struct.node, ptr %20, i32 0, i32 2
  %22 = load i32, ptr %21, align 8, !tbaa !11
  %23 = load i32, ptr %7, align 4, !tbaa !9
  %24 = icmp eq i32 %22, %23
  br i1 %24, label %25, label %49

25:                                               ; preds = %19
  %26 = load ptr, ptr %9, align 8, !tbaa !5
  %27 = load ptr, ptr %8, align 8, !tbaa !5
  %28 = getelementptr inbounds %struct.node, ptr %27, i32 0, i32 0
  store ptr %26, ptr %28, align 8, !tbaa !13
  %29 = load ptr, ptr %9, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.node, ptr %29, i32 0, i32 1
  %31 = load ptr, ptr %30, align 8, !tbaa !14
  %32 = load ptr, ptr %8, align 8, !tbaa !5
  %33 = getelementptr inbounds %struct.node, ptr %32, i32 0, i32 1
  store ptr %31, ptr %33, align 8, !tbaa !14
  %34 = load ptr, ptr %9, align 8, !tbaa !5
  %35 = getelementptr inbounds %struct.node, ptr %34, i32 0, i32 1
  %36 = load ptr, ptr %35, align 8, !tbaa !14
  %37 = icmp ne ptr %36, null
  br i1 %37, label %38, label %44

38:                                               ; preds = %25
  %39 = load ptr, ptr %8, align 8, !tbaa !5
  %40 = load ptr, ptr %9, align 8, !tbaa !5
  %41 = getelementptr inbounds %struct.node, ptr %40, i32 0, i32 1
  %42 = load ptr, ptr %41, align 8, !tbaa !14
  %43 = getelementptr inbounds %struct.node, ptr %42, i32 0, i32 0
  store ptr %39, ptr %43, align 8, !tbaa !13
  br label %44

44:                                               ; preds = %38, %25
  %45 = load ptr, ptr %8, align 8, !tbaa !5
  %46 = load ptr, ptr %9, align 8, !tbaa !5
  %47 = getelementptr inbounds %struct.node, ptr %46, i32 0, i32 1
  store ptr %45, ptr %47, align 8, !tbaa !14
  %48 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %48, ptr %4, align 8
  store i32 1, ptr %10, align 4
  br label %58

49:                                               ; preds = %19
  %50 = load ptr, ptr %9, align 8, !tbaa !5
  %51 = getelementptr inbounds %struct.node, ptr %50, i32 0, i32 1
  %52 = load ptr, ptr %51, align 8, !tbaa !14
  store ptr %52, ptr %9, align 8, !tbaa !5
  br label %16, !llvm.loop !15

53:                                               ; preds = %16
  %54 = load i32, ptr %7, align 4, !tbaa !9
  %55 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %54)
  %56 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %55, ptr noundef @.str.1)
  %57 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %57, ptr %4, align 8
  store i32 1, ptr %10, align 4
  br label %58

58:                                               ; preds = %53, %44
  call void @llvm.lifetime.end.p0(i64 8, ptr %9) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #5
  %59 = load ptr, ptr %4, align 8
  ret ptr %59
}

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #4

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { nobuiltin allocsize(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 = { 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 = { "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 #5 = { nounwind }
attributes #6 = { builtin allocsize(0) }

!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, !10, i64 16}
!12 = !{!"_ZTS4node", !6, i64 0, !6, i64 8, !10, i64 16}
!13 = !{!12, !6, i64 0}
!14 = !{!12, !6, i64 8}
!15 = distinct !{!15, !16}
!16 = !{!"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::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.1 = external hidden unnamed_addr constant [27 x i8], align 1

; Function Attrs: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 noundef) local_unnamed_addr #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) local_unnamed_addr #1

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z12post_elementP4nodeii(ptr noundef returned %0, i32 noundef %1, i32 noundef %2) local_unnamed_addr #2 {
  %4 = tail call noalias noundef nonnull dereferenceable(24) ptr @_Znwm(i64 noundef 24) #4
  %5 = getelementptr inbounds i8, ptr %4, i64 16
  store i32 %1, ptr %5, align 8, !tbaa !5
  %.not23 = icmp eq ptr %0, null
  br i1 %.not23, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %3, %15
  %.024 = phi ptr [ %17, %15 ], [ %0, %3 ]
  %6 = getelementptr inbounds i8, ptr %.024, i64 16
  %7 = load i32, ptr %6, align 8, !tbaa !5
  %8 = icmp eq i32 %7, %2
  br i1 %8, label %9, label %15

9:                                                ; preds = %.lr.ph
  store ptr %.024, ptr %4, align 8, !tbaa !11
  %10 = getelementptr inbounds i8, ptr %.024, i64 8
  %11 = load ptr, ptr %10, align 8, !tbaa !12
  %12 = getelementptr inbounds i8, ptr %4, i64 8
  store ptr %11, ptr %12, align 8, !tbaa !12
  %.not21 = icmp eq ptr %11, null
  br i1 %.not21, label %14, label %13

13:                                               ; preds = %9
  store ptr %4, ptr %11, align 8, !tbaa !11
  br label %14

14:                                               ; preds = %13, %9
  store ptr %4, ptr %10, align 8, !tbaa !12
  br label %20

15:                                               ; preds = %.lr.ph
  %16 = getelementptr inbounds i8, ptr %.024, i64 8
  %17 = load ptr, ptr %16, align 8, !tbaa !12
  %.not = icmp eq ptr %17, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %15, %3
  %18 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %2)
  %19 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %18, ptr noundef nonnull @.str.1)
  br label %20

20:                                               ; preds = %._crit_edge, %14
  ret ptr %0
}

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

attributes #0 = { nobuiltin allocsize(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 = { 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 = { builtin allocsize(0) }

!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 16}
!6 = !{!"_ZTS4node", !7, i64 0, !7, i64 8, !10, i64 16}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"int", !8, i64 0}
!11 = !{!6, !7, i64 0}
!12 = !{!6, !7, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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