; LLVM IR from TheAlgorithms/C-Plus-Plus :: data_structures/doubly_linked_list.ll (ZN18double_linked_list6insertEi)

; 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"

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

@start = external dso_local global ptr, align 8

; Function Attrs: mustprogress uwtable
define dso_local void @_ZN18double_linked_list6insertEi(ptr noundef nonnull align 1 dereferenceable(1) %0, i32 noundef %1) #0 align 2 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  %8 = load ptr, ptr %3, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  %9 = load ptr, ptr @start, align 8, !tbaa !5
  store ptr %9, ptr %5, align 8, !tbaa !5
  %10 = load ptr, ptr @start, align 8, !tbaa !5
  %11 = icmp ne ptr %10, null
  br i1 %11, label %12, label %35

12:                                               ; preds = %2
  br label %13

13:                                               ; preds = %18, %12
  %14 = load ptr, ptr %5, align 8, !tbaa !5
  %15 = getelementptr inbounds %struct.node, ptr %14, i32 0, i32 2
  %16 = load ptr, ptr %15, align 8, !tbaa !11
  %17 = icmp ne ptr %16, null
  br i1 %17, label %18, label %22

18:                                               ; preds = %13
  %19 = load ptr, ptr %5, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct.node, ptr %19, i32 0, i32 2
  %21 = load ptr, ptr %20, align 8, !tbaa !11
  store ptr %21, ptr %5, align 8, !tbaa !5
  br label %13, !llvm.loop !13

22:                                               ; preds = %13
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #3
  %23 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 24) #4
  store ptr %23, ptr %6, align 8, !tbaa !5
  %24 = load ptr, ptr %6, align 8, !tbaa !5
  %25 = load ptr, ptr %5, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.node, ptr %25, i32 0, i32 2
  store ptr %24, ptr %26, align 8, !tbaa !11
  %27 = load ptr, ptr %5, align 8, !tbaa !5
  %28 = load ptr, ptr %6, align 8, !tbaa !5
  %29 = getelementptr inbounds %struct.node, ptr %28, i32 0, i32 1
  store ptr %27, ptr %29, align 8, !tbaa !15
  %30 = load i32, ptr %4, align 4, !tbaa !9
  %31 = load ptr, ptr %6, align 8, !tbaa !5
  %32 = getelementptr inbounds %struct.node, ptr %31, i32 0, i32 0
  store i32 %30, ptr %32, align 8, !tbaa !16
  %33 = load ptr, ptr %6, align 8, !tbaa !5
  %34 = getelementptr inbounds %struct.node, ptr %33, i32 0, i32 2
  store ptr null, ptr %34, align 8, !tbaa !11
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #3
  br label %45

35:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #3
  %36 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 24) #4
  store ptr %36, ptr %7, align 8, !tbaa !5
  %37 = load i32, ptr %4, align 4, !tbaa !9
  %38 = load ptr, ptr %7, align 8, !tbaa !5
  %39 = getelementptr inbounds %struct.node, ptr %38, i32 0, i32 0
  store i32 %37, ptr %39, align 8, !tbaa !16
  %40 = load ptr, ptr %7, align 8, !tbaa !5
  %41 = getelementptr inbounds %struct.node, ptr %40, i32 0, i32 1
  store ptr null, ptr %41, align 8, !tbaa !15
  %42 = load ptr, ptr %7, align 8, !tbaa !5
  %43 = getelementptr inbounds %struct.node, ptr %42, i32 0, i32 2
  store ptr null, ptr %43, align 8, !tbaa !11
  %44 = load ptr, ptr %7, align 8, !tbaa !5
  store ptr %44, ptr @start, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #3
  br label %45

45:                                               ; preds = %35, %22
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  ret void
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 noundef) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #3 = { nounwind }
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, !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 16}
!12 = !{!"_ZTS4node", !10, i64 0, !6, i64 8, !6, i64 16}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = !{!12, !6, i64 8}
!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"

@start = external dso_local local_unnamed_addr global ptr, align 8

; Function Attrs: mustprogress uwtable
define dso_local void @_ZN18double_linked_list6insertEi(ptr nocapture noundef nonnull readnone align 1 dereferenceable(1) %0, i32 noundef %1) local_unnamed_addr #0 align 2 {
  %3 = load ptr, ptr @start, align 8, !tbaa !5
  %.not = icmp eq ptr %3, null
  br i1 %.not, label %11, label %.preheader

.preheader:                                       ; preds = %2, %.preheader
  %.0 = phi ptr [ %5, %.preheader ], [ %3, %2 ]
  %4 = getelementptr inbounds i8, ptr %.0, i64 16
  %5 = load ptr, ptr %4, align 8, !tbaa !9
  %.not16 = icmp eq ptr %5, null
  br i1 %.not16, label %6, label %.preheader, !llvm.loop !12

6:                                                ; preds = %.preheader
  %7 = getelementptr inbounds i8, ptr %.0, i64 16
  %8 = tail call noalias noundef nonnull dereferenceable(24) ptr @_Znwm(i64 noundef 24) #3
  store ptr %8, ptr %7, align 8, !tbaa !9
  %9 = getelementptr inbounds i8, ptr %8, i64 8
  store ptr %.0, ptr %9, align 8, !tbaa !14
  store i32 %1, ptr %8, align 8, !tbaa !15
  %10 = getelementptr inbounds i8, ptr %8, i64 16
  store ptr null, ptr %10, align 8, !tbaa !9
  br label %14

11:                                               ; preds = %2
  %12 = tail call noalias noundef nonnull dereferenceable(24) ptr @_Znwm(i64 noundef 24) #3
  store i32 %1, ptr %12, align 8, !tbaa !15
  %13 = getelementptr inbounds i8, ptr %12, i64 8
  tail call void @llvm.memset.p0.i64(ptr noundef nonnull align 8 dereferenceable(16) %13, i8 0, i64 16, i1 false)
  store ptr %12, ptr @start, align 8, !tbaa !5
  br label %14

14:                                               ; preds = %11, %6
  ret void
}

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

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #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 = { 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 = { nocallback nofree nounwind willreturn memory(argmem: write) }
attributes #3 = { 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, !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, !6, i64 8}
!15 = !{!10, !11, i64 0}


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