; LLVM IR from ahr9n/psolving-paradigms :: 4.dynamic-programming/14.dp-involving-graphs/AtCoder dp_g - Longest Path.ll (Z2dpi)

; 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"

@head = external dso_local global [200005 x i32], align 16
@nxt = external dso_local global [1000005 x i32], align 16
@to = external dso_local global [1000005 x i32], align 16
@memo = external dso_local global [200005 x i32], align 16

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z2dpi(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds [200005 x i32], ptr @memo, i64 0, i64 %9
  store ptr %10, ptr %4, align 8, !tbaa !9
  %11 = load ptr, ptr %4, align 8, !tbaa !9
  %12 = load i32, ptr %11, align 4, !tbaa !5
  %13 = xor i32 %12, -1
  %14 = icmp ne i32 %13, 0
  br i1 %14, label %15, label %18

15:                                               ; preds = %1
  %16 = load ptr, ptr %4, align 8, !tbaa !9
  %17 = load i32, ptr %16, align 4, !tbaa !5
  store i32 %17, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %47

18:                                               ; preds = %1
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  %19 = load i32, ptr %3, align 4, !tbaa !5
  %20 = sext i32 %19 to i64
  %21 = getelementptr inbounds [200005 x i32], ptr @head, i64 0, i64 %20
  %22 = load i32, ptr %21, align 4, !tbaa !5
  store i32 %22, ptr %6, align 4, !tbaa !5
  br label %23

23:                                               ; preds = %39, %18
  %24 = load i32, ptr %6, align 4, !tbaa !5
  %25 = xor i32 %24, -1
  %26 = icmp ne i32 %25, 0
  br i1 %26, label %28, label %27

27:                                               ; preds = %23
  store i32 2, ptr %5, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  br label %44

28:                                               ; preds = %23
  %29 = load ptr, ptr %4, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #3
  %30 = load i32, ptr %6, align 4, !tbaa !5
  %31 = sext i32 %30 to i64
  %32 = getelementptr inbounds [1000005 x i32], ptr @to, i64 0, i64 %31
  %33 = load i32, ptr %32, align 4, !tbaa !5
  %34 = call noundef i32 @_Z2dpi(i32 noundef %33)
  %35 = add nsw i32 1, %34
  store i32 %35, ptr %7, align 4, !tbaa !5
  %36 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3maxIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4) %29, ptr noundef nonnull align 4 dereferenceable(4) %7)
  %37 = load i32, ptr %36, align 4, !tbaa !5
  %38 = load ptr, ptr %4, align 8, !tbaa !9
  store i32 %37, ptr %38, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #3
  br label %39

39:                                               ; preds = %28
  %40 = load i32, ptr %6, align 4, !tbaa !5
  %41 = sext i32 %40 to i64
  %42 = getelementptr inbounds [1000005 x i32], ptr @nxt, i64 0, i64 %41
  %43 = load i32, ptr %42, align 4, !tbaa !5
  store i32 %43, ptr %6, align 4, !tbaa !5
  br label %23, !llvm.loop !11

44:                                               ; preds = %27
  %45 = load ptr, ptr %4, align 8, !tbaa !9
  %46 = load i32, ptr %45, align 4, !tbaa !5
  store i32 %46, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %47

47:                                               ; preds = %44, %15
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  %48 = load i32, ptr %2, align 4
  ret i32 %48
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3maxIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { inlinehint 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 }

!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 = distinct !{!11, !12}
!12 = !{!"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 [200005 x i32], align 16
@nxt = external dso_local local_unnamed_addr global [1000005 x i32], align 16
@to = external dso_local local_unnamed_addr global [1000005 x i32], align 16
@memo = external dso_local global [200005 x i32], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z2dpi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = alloca i32, align 4
  %3 = sext i32 %0 to i64
  %4 = getelementptr inbounds [200005 x i32], ptr @memo, i64 0, i64 %3
  %5 = load i32, ptr %4, align 4, !tbaa !5
  %.not = icmp eq i32 %5, -1
  br i1 %.not, label %6, label %._crit_edge

6:                                                ; preds = %1
  %7 = getelementptr inbounds [200005 x i32], ptr @head, i64 0, i64 %3
  %.012 = load i32, ptr %7, align 4, !tbaa !5
  %.not1113 = icmp eq i32 %.012, -1
  br i1 %.not1113, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %6, %.lr.ph
  %.014 = phi i32 [ %.0, %.lr.ph ], [ %.012, %6 ]
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #3
  %8 = sext i32 %.014 to i64
  %9 = getelementptr inbounds [1000005 x i32], ptr @to, i64 0, i64 %8
  %10 = load i32, ptr %9, align 4, !tbaa !5
  %11 = call noundef i32 @_Z2dpi(i32 noundef %10)
  %12 = add nsw i32 %11, 1
  store i32 %12, ptr %2, align 4, !tbaa !5
  %13 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3maxIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4) %4, ptr noundef nonnull align 4 dereferenceable(4) %2)
  %14 = load i32, ptr %13, align 4, !tbaa !5
  store i32 %14, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #3
  %15 = getelementptr inbounds [1000005 x i32], ptr @nxt, i64 0, i64 %8
  %.0 = load i32, ptr %15, align 4, !tbaa !5
  %.not11 = icmp eq i32 %.0, -1
  br i1 %.not11, label %._crit_edge, label %.lr.ph, !llvm.loop !9

._crit_edge:                                      ; preds = %.lr.ph, %6, %1
  %.010 = phi i32 [ %5, %1 ], [ -1, %6 ], [ %14, %.lr.ph ]
  ret i32 %.010
}

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3maxIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { 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 #1 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { inlinehint 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 }

!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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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