; LLVM IR from ahampriyanshu/algo-ds-101 :: Data-Structures/LinkedList/Singly_Linked_List (LinkedListAndOperations)

; 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.list = type { i32, ptr }

@head = external dso_local global ptr, align 8

; 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 nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #2

; 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 @_Z13insert_at_midii(i32 noundef %0, i32 noundef %1) #3 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #4
  %8 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 16) #5
  call void @llvm.memset.p0.i64(ptr align 16 %8, i8 0, i64 16, i1 false)
  store ptr %8, ptr %5, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #4
  %9 = load ptr, ptr @head, align 8, !tbaa !9
  store ptr %9, ptr %6, align 8, !tbaa !9
  %10 = load i32, ptr %4, align 4, !tbaa !5
  %11 = load ptr, ptr %5, align 8, !tbaa !9
  %12 = getelementptr inbounds %struct.list, ptr %11, i32 0, i32 0
  store i32 %10, ptr %12, align 8, !tbaa !11
  br label %13

13:                                               ; preds = %31, %2
  %14 = load ptr, ptr %6, align 8, !tbaa !9
  %15 = icmp ne ptr %14, null
  br i1 %15, label %16, label %35

16:                                               ; preds = %13
  %17 = load ptr, ptr %6, align 8, !tbaa !9
  %18 = getelementptr inbounds %struct.list, ptr %17, i32 0, i32 0
  %19 = load i32, ptr %18, align 8, !tbaa !11
  %20 = load i32, ptr %3, align 4, !tbaa !5
  %21 = icmp eq i32 %19, %20
  br i1 %21, label %22, label %31

22:                                               ; preds = %16
  %23 = load ptr, ptr %6, align 8, !tbaa !9
  %24 = getelementptr inbounds %struct.list, ptr %23, i32 0, i32 1
  %25 = load ptr, ptr %24, align 8, !tbaa !13
  %26 = load ptr, ptr %5, align 8, !tbaa !9
  %27 = getelementptr inbounds %struct.list, ptr %26, i32 0, i32 1
  store ptr %25, ptr %27, align 8, !tbaa !13
  %28 = load ptr, ptr %5, align 8, !tbaa !9
  %29 = load ptr, ptr %6, align 8, !tbaa !9
  %30 = getelementptr inbounds %struct.list, ptr %29, i32 0, i32 1
  store ptr %28, ptr %30, align 8, !tbaa !13
  store i32 1, ptr %7, align 4
  br label %36

31:                                               ; preds = %16
  %32 = load ptr, ptr %6, align 8, !tbaa !9
  %33 = getelementptr inbounds %struct.list, ptr %32, i32 0, i32 1
  %34 = load ptr, ptr %33, align 8, !tbaa !13
  store ptr %34, ptr %6, align 8, !tbaa !9
  br label %13, !llvm.loop !14

35:                                               ; preds = %13
  store i32 0, ptr %7, align 4
  br label %36

36:                                               ; preds = %35, %22
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #4
  %37 = load i32, ptr %7, align 4
  switch i32 %37, label %39 [
    i32 0, label %38
    i32 1, label %38
  ]

38:                                               ; preds = %36, %36
  ret void

39:                                               ; preds = %36
  unreachable
}

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 = { nocallback nofree nounwind willreturn memory(argmem: write) }
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 }
attributes #5 = { 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 = !{!"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, !6, i64 0}
!12 = !{!"_ZTS4list", !6, i64 0, !10, i64 8}
!13 = !{!12, !10, i64 8}
!14 = distinct !{!14, !15}
!15 = !{!"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"

@head = external dso_local local_unnamed_addr global ptr, align 8

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

; Function Attrs: mustprogress nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #1

; Function Attrs: mustprogress uwtable
define dso_local void @_Z13insert_at_midii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #2 {
  %3 = tail call noalias noundef nonnull dereferenceable(16) ptr @_Znwm(i64 noundef 16) #3
  tail call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 dereferenceable(16) %3, i8 0, i64 16, i1 false)
  %4 = load ptr, ptr @head, align 8, !tbaa !5
  store i32 %1, ptr %3, align 8, !tbaa !9
  %.not10 = icmp eq ptr %4, null
  br i1 %.not10, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %2, %12
  %.011 = phi ptr [ %8, %12 ], [ %4, %2 ]
  %5 = load i32, ptr %.011, align 8, !tbaa !9
  %6 = icmp eq i32 %5, %0
  %7 = getelementptr inbounds i8, ptr %.011, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !12
  br i1 %6, label %9, label %12

9:                                                ; preds = %.lr.ph
  %10 = getelementptr inbounds i8, ptr %.011, i64 8
  %11 = getelementptr inbounds i8, ptr %3, i64 8
  store ptr %8, ptr %11, align 8, !tbaa !12
  store ptr %3, ptr %10, align 8, !tbaa !12
  br label %.loopexit

12:                                               ; preds = %.lr.ph
  %.not = icmp eq ptr %8, null
  br i1 %.not, label %.loopexit, label %.lr.ph, !llvm.loop !13

.loopexit:                                        ; preds = %12, %2, %9
  ret void
}

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 = { mustprogress nocallback nofree nounwind willreturn memory(argmem: write) }
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 = { 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, !11, i64 0}
!10 = !{!"_ZTS4list", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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