; LLVM IR from HarshCasper/NeoAlgo :: C/ds (doubly_linked_list)

; 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
@.str.13 = external hidden unnamed_addr constant [3 x i8], align 1
@.str.20 = external hidden unnamed_addr constant [57 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

declare i32 @printf(ptr noundef, ...) #1

declare i32 @__isoc99_scanf(ptr 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: nounwind uwtable
define dso_local ptr @find() #2 {
  %1 = alloca ptr, align 8
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  %5 = load ptr, ptr @start, align 8, !tbaa !5
  %6 = icmp eq ptr %5, null
  br i1 %6, label %7, label %8

7:                                                ; preds = %0
  store ptr null, ptr %1, align 8
  store i32 1, ptr %4, align 4
  br label %29

8:                                                ; preds = %0
  %9 = call i32 (ptr, ...) @printf(ptr noundef @.str.20)
  %10 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str.13, ptr noundef %2)
  %11 = load ptr, ptr @start, align 8, !tbaa !5
  store ptr %11, ptr %3, align 8, !tbaa !5
  br label %12

12:                                               ; preds = %27, %8
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  %14 = icmp ne ptr %13, null
  br i1 %14, label %15, label %28

15:                                               ; preds = %12
  %16 = load ptr, ptr %3, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.node, ptr %16, i32 0, i32 0
  %18 = load i32, ptr %17, align 8, !tbaa !9
  %19 = load i32, ptr %2, align 4, !tbaa !12
  %20 = icmp eq i32 %18, %19
  br i1 %20, label %21, label %23

21:                                               ; preds = %15
  %22 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %22, ptr %1, align 8
  store i32 1, ptr %4, align 4
  br label %29

23:                                               ; preds = %15
  %24 = load ptr, ptr %3, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.node, ptr %24, i32 0, i32 2
  %26 = load ptr, ptr %25, align 8, !tbaa !13
  store ptr %26, ptr %3, align 8, !tbaa !5
  br label %27

27:                                               ; preds = %23
  br label %12, !llvm.loop !14

28:                                               ; preds = %12
  store ptr null, ptr %1, align 8
  store i32 1, ptr %4, align 4
  br label %29

29:                                               ; preds = %28, %21, %7
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #3
  %30 = load ptr, ptr %1, align 8
  ret ptr %30
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { 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 }

!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/C++ TBAA"}
!9 = !{!10, !11, i64 0}
!10 = !{!"node", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!11, !11, i64 0}
!13 = !{!10, !6, i64 16}
!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"

@start = external dso_local local_unnamed_addr global ptr, align 8
@.str.13 = external hidden unnamed_addr constant [3 x i8], align 1
@.str.20 = external hidden unnamed_addr constant [57 x i8], align 1

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

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

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

; Function Attrs: nofree nounwind uwtable
define dso_local noundef ptr @find() local_unnamed_addr #2 {
  %1 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #3
  %2 = load ptr, ptr @start, align 8, !tbaa !5
  %3 = icmp eq ptr %2, null
  br i1 %3, label %.loopexit, label %4

4:                                                ; preds = %0
  %5 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.20)
  %6 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.13, ptr noundef nonnull %1)
  %.06 = load ptr, ptr @start, align 8, !tbaa !5
  %.not7 = icmp eq ptr %.06, null
  br i1 %.not7, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %4
  %7 = load i32, ptr %1, align 4, !tbaa !9
  br label %8

8:                                                ; preds = %.lr.ph, %11
  %.08 = phi ptr [ %.06, %.lr.ph ], [ %.0, %11 ]
  %9 = load i32, ptr %.08, align 8, !tbaa !11
  %10 = icmp eq i32 %9, %7
  br i1 %10, label %.loopexit, label %11

11:                                               ; preds = %8
  %12 = getelementptr inbounds i8, ptr %.08, i64 16
  %.0 = load ptr, ptr %12, align 8, !tbaa !5
  %.not = icmp eq ptr %.0, null
  br i1 %.not, label %.loopexit, label %8, !llvm.loop !13

.loopexit:                                        ; preds = %8, %11, %4, %0
  %.05 = phi ptr [ null, %0 ], [ null, %4 ], [ %.08, %8 ], [ null, %11 ]
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #3
  ret ptr %.05
}

attributes #0 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { nofree 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 = { nofree 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 }

!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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !10, i64 0}
!12 = !{!"node", !10, i64 0, !6, i64 8, !6, i64 16}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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