; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 10. Linked List/delete middle of linked list.ll (Z9deleteMidP4Node)

; 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 }

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

; Function Attrs: nobuiltin nounwind
declare void @_ZdlPvm(ptr noundef, 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: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z9deleteMidP4Node(ptr noundef %0) #2 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  %6 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %6, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  %7 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %7, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  store ptr null, ptr %5, align 8, !tbaa !5
  br label %8

8:                                                ; preds = %18, %1
  %9 = load ptr, ptr %3, align 8, !tbaa !5
  %10 = icmp ne ptr %9, null
  br i1 %10, label %11, label %16

11:                                               ; preds = %8
  %12 = load ptr, ptr %3, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.Node, ptr %12, i32 0, i32 1
  %14 = load ptr, ptr %13, align 8, !tbaa !9
  %15 = icmp ne ptr %14, null
  br label %16

16:                                               ; preds = %11, %8
  %17 = phi i1 [ false, %8 ], [ %15, %11 ]
  br i1 %17, label %18, label %28

18:                                               ; preds = %16
  %19 = load ptr, ptr %3, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct.Node, ptr %19, i32 0, i32 1
  %21 = load ptr, ptr %20, align 8, !tbaa !9
  %22 = getelementptr inbounds %struct.Node, ptr %21, i32 0, i32 1
  %23 = load ptr, ptr %22, align 8, !tbaa !9
  store ptr %23, ptr %3, align 8, !tbaa !5
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %24, ptr %5, align 8, !tbaa !5
  %25 = load ptr, ptr %4, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.Node, ptr %25, i32 0, i32 1
  %27 = load ptr, ptr %26, align 8, !tbaa !9
  store ptr %27, ptr %4, align 8, !tbaa !5
  br label %8, !llvm.loop !12

28:                                               ; preds = %16
  %29 = load ptr, ptr %4, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.Node, ptr %29, i32 0, i32 1
  %31 = load ptr, ptr %30, align 8, !tbaa !9
  %32 = load ptr, ptr %5, align 8, !tbaa !5
  %33 = getelementptr inbounds %struct.Node, ptr %32, i32 0, i32 1
  store ptr %31, ptr %33, align 8, !tbaa !9
  %34 = load ptr, ptr %4, align 8, !tbaa !5
  %35 = icmp eq ptr %34, null
  br i1 %35, label %37, label %36

36:                                               ; preds = %28
  call void @_ZdlPvm(ptr noundef %34, i64 noundef 16) #4
  br label %37

37:                                               ; preds = %36, %28
  %38 = load ptr, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  ret ptr %38
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { nobuiltin nounwind "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 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 #3 = { nounwind }
attributes #4 = { builtin 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 8}
!10 = !{!"_ZTS4Node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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"

; Function Attrs: nobuiltin nounwind
declare void @_ZdlPvm(ptr noundef, i64 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z9deleteMidP4Node(ptr noundef returned %0) local_unnamed_addr #1 {
  %.not15 = icmp ne ptr %0, null
  tail call void @llvm.assume(i1 %.not15)
  %2 = getelementptr inbounds i8, ptr %0, i64 8
  %3 = load ptr, ptr %2, align 8, !tbaa !5, !nonnull !11, !noundef !11
  br label %.lr.ph26

.lr.ph:                                           ; preds = %.lr.ph26
  %4 = getelementptr inbounds i8, ptr %8, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %.not14 = icmp eq ptr %5, null
  br i1 %.not14, label %._crit_edge, label %.lr.ph26, !llvm.loop !12

.lr.ph26:                                         ; preds = %1, %.lr.ph
  %6 = phi ptr [ %5, %.lr.ph ], [ %3, %1 ]
  %.0111724 = phi ptr [ %10, %.lr.ph ], [ %0, %1 ]
  %7 = getelementptr inbounds i8, ptr %6, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %9 = getelementptr inbounds i8, ptr %.0111724, i64 8
  %10 = load ptr, ptr %9, align 8, !tbaa !5
  %.not = icmp eq ptr %8, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !12

._crit_edge:                                      ; preds = %.lr.ph26, %.lr.ph
  %11 = getelementptr inbounds i8, ptr %10, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !5
  %13 = getelementptr inbounds i8, ptr %.0111724, i64 8
  store ptr %12, ptr %13, align 8, !tbaa !5
  tail call void @_ZdlPvm(ptr noundef %10, i64 noundef 16) #3
  ret ptr %0
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: write)
declare void @llvm.assume(i1 noundef) #2

attributes #0 = { nobuiltin nounwind "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 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 = { nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: write) }
attributes #3 = { builtin 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, !10, i64 8}
!6 = !{!"_ZTS4Node", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = !{}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


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