; LLVM IR from bartobri/data-structures-c :: graph/depth-first-recursive-list-traversal (graph)

; 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 }

@adj = external hidden global ptr, align 8
@visited = external hidden 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: 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 void @traverse(i32 noundef %0, ptr noundef %1) #1 {
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  store i32 %0, ptr %3, align 4, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  %6 = load ptr, ptr %4, align 8, !tbaa !9
  %7 = load i32, ptr %3, align 4, !tbaa !5
  call void %6(i32 noundef %7)
  %8 = load ptr, ptr @visited, align 8, !tbaa !9
  %9 = load i32, ptr %3, align 4, !tbaa !5
  %10 = sext i32 %9 to i64
  %11 = getelementptr inbounds i32, ptr %8, i64 %10
  store i32 1, ptr %11, align 4, !tbaa !5
  %12 = load ptr, ptr @adj, align 8, !tbaa !9
  %13 = load i32, ptr %3, align 4, !tbaa !5
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds ptr, ptr %12, i64 %14
  %16 = load ptr, ptr %15, align 8, !tbaa !9
  store ptr %16, ptr %5, align 8, !tbaa !9
  br label %17

17:                                               ; preds = %35, %2
  %18 = load ptr, ptr %5, align 8, !tbaa !9
  %19 = icmp ne ptr %18, null
  br i1 %19, label %20, label %39

20:                                               ; preds = %17
  %21 = load ptr, ptr @visited, align 8, !tbaa !9
  %22 = load ptr, ptr %5, align 8, !tbaa !9
  %23 = getelementptr inbounds %struct.node, ptr %22, i32 0, i32 0
  %24 = load i32, ptr %23, align 8, !tbaa !11
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds i32, ptr %21, i64 %25
  %27 = load i32, ptr %26, align 4, !tbaa !5
  %28 = icmp eq i32 %27, 0
  br i1 %28, label %29, label %34

29:                                               ; preds = %20
  %30 = load ptr, ptr %5, align 8, !tbaa !9
  %31 = getelementptr inbounds %struct.node, ptr %30, i32 0, i32 0
  %32 = load i32, ptr %31, align 8, !tbaa !11
  %33 = load ptr, ptr %4, align 8, !tbaa !9
  call void @traverse(i32 noundef %32, ptr noundef %33)
  br label %34

34:                                               ; preds = %29, %20
  br label %35

35:                                               ; preds = %34
  %36 = load ptr, ptr %5, align 8, !tbaa !9
  %37 = getelementptr inbounds %struct.node, ptr %36, i32 0, i32 1
  %38 = load ptr, ptr %37, align 8, !tbaa !13
  store ptr %38, ptr %5, align 8, !tbaa !9
  br label %17, !llvm.loop !14

39:                                               ; preds = %17
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  ret void
}

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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !6, i64 0}
!12 = !{!"node", !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"

@adj = external hidden local_unnamed_addr global ptr, align 8
@visited = external hidden local_unnamed_addr global ptr, align 8

; Function Attrs: nounwind uwtable
define dso_local void @traverse(i32 noundef %0, ptr nocapture noundef readonly %1) local_unnamed_addr #0 {
  tail call void %1(i32 noundef %0) #1
  %3 = load ptr, ptr @visited, align 8, !tbaa !5
  %4 = sext i32 %0 to i64
  %5 = getelementptr inbounds i32, ptr %3, i64 %4
  store i32 1, ptr %5, align 4, !tbaa !9
  %6 = load ptr, ptr @adj, align 8, !tbaa !5
  %7 = getelementptr inbounds ptr, ptr %6, i64 %4
  %.08 = load ptr, ptr %7, align 8, !tbaa !5
  %.not9 = icmp eq ptr %.08, null
  br i1 %.not9, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %15
  %8 = phi ptr [ %16, %15 ], [ %3, %2 ]
  %.010 = phi ptr [ %.0, %15 ], [ %.08, %2 ]
  %9 = load i32, ptr %.010, align 8, !tbaa !11
  %10 = sext i32 %9 to i64
  %11 = getelementptr inbounds i32, ptr %8, i64 %10
  %12 = load i32, ptr %11, align 4, !tbaa !9
  %13 = icmp eq i32 %12, 0
  br i1 %13, label %14, label %15

14:                                               ; preds = %.lr.ph
  tail call void @traverse(i32 noundef %9, ptr noundef %1)
  %.pre = load ptr, ptr @visited, align 8, !tbaa !5
  br label %15

15:                                               ; preds = %.lr.ph, %14
  %16 = phi ptr [ %8, %.lr.ph ], [ %.pre, %14 ]
  %17 = getelementptr inbounds i8, ptr %.010, i64 8
  %.0 = load ptr, ptr %17, align 8, !tbaa !5
  %.not = icmp eq ptr %.0, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %15, %2
  ret void
}

attributes #0 = { 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 #1 = { 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}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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