; LLVM IR from Ayon-SSP/The-SDE-Prep :: 1]_Data Structures/2]_Linked List (17_loopcheck)

; 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: 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 i32 @checkloop(ptr noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %6, ptr %4, align 8, !tbaa !5
  br label %7

7:                                                ; preds = %34, %1
  %8 = load ptr, ptr %3, align 8, !tbaa !5
  %9 = getelementptr inbounds %struct.Node, ptr %8, i32 0, i32 1
  %10 = load ptr, ptr %9, align 8, !tbaa !9
  store ptr %10, ptr %3, align 8, !tbaa !5
  %11 = load ptr, ptr %4, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.Node, ptr %11, i32 0, i32 1
  %13 = load ptr, ptr %12, align 8, !tbaa !9
  store ptr %13, ptr %4, align 8, !tbaa !5
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  %15 = icmp ne ptr %14, null
  br i1 %15, label %16, label %20

16:                                               ; preds = %7
  %17 = load ptr, ptr %4, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.Node, ptr %17, i32 0, i32 1
  %19 = load ptr, ptr %18, align 8, !tbaa !9
  store ptr %19, ptr %4, align 8, !tbaa !5
  br label %21

20:                                               ; preds = %7
  br label %21

21:                                               ; preds = %20, %16
  %22 = phi ptr [ %19, %16 ], [ null, %20 ]
  %23 = load ptr, ptr %3, align 8, !tbaa !5
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = icmp eq ptr %23, %24
  br i1 %25, label %26, label %27

26:                                               ; preds = %21
  store i32 1, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %37

27:                                               ; preds = %21
  br label %28

28:                                               ; preds = %27
  %29 = load ptr, ptr %3, align 8, !tbaa !5
  %30 = icmp ne ptr %29, null
  br i1 %30, label %31, label %34

31:                                               ; preds = %28
  %32 = load ptr, ptr %4, align 8, !tbaa !5
  %33 = icmp ne ptr %32, null
  br label %34

34:                                               ; preds = %31, %28
  %35 = phi i1 [ false, %28 ], [ %33, %31 ]
  br i1 %35, label %7, label %36, !llvm.loop !12

36:                                               ; preds = %34
  store i32 0, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %37

37:                                               ; preds = %36, %26
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  %38 = load i32, ptr %2, align 4
  ret i32 %38
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 = { 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, !6, i64 8}
!10 = !{!"Node", !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: nofree norecurse nosync nounwind memory(read, inaccessiblemem: none) uwtable
define dso_local range(i32 0, 2) i32 @checkloop(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  br label %2

2:                                                ; preds = %12, %1
  %.09 = phi ptr [ %0, %1 ], [ %4, %12 ]
  %.0 = phi ptr [ %0, %1 ], [ %.1, %12 ]
  %3 = getelementptr inbounds i8, ptr %.09, i64 8
  %4 = load ptr, ptr %3, align 8, !tbaa !5
  %5 = getelementptr inbounds i8, ptr %.0, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  %.not = icmp eq ptr %6, null
  br i1 %.not, label %10, label %7

7:                                                ; preds = %2
  %8 = getelementptr inbounds i8, ptr %6, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !5
  br label %10

10:                                               ; preds = %2, %7
  %.1 = phi ptr [ %9, %7 ], [ null, %2 ]
  %11 = icmp eq ptr %4, %.1
  br i1 %11, label %16, label %12

12:                                               ; preds = %10
  %13 = icmp ne ptr %4, null
  %14 = icmp ne ptr %.1, null
  %15 = and i1 %13, %14
  br i1 %15, label %2, label %16, !llvm.loop !11

16:                                               ; preds = %12, %10
  %.010 = phi i32 [ 1, %10 ], [ 0, %12 ]
  ret i32 %.010
}

attributes #0 = { nofree norecurse nosync nounwind memory(read, inaccessiblemem: none) 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" }

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


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass