; LLVM IR from devparthgarg/Data-Structures-and-Algorithms :: 06. Searching/03 Index of Last Occurrence (03b index of last occurrence)

; 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"

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z14lastOccurrenceSt6vectorIiSaIiEEi(ptr noundef %0, i32 noundef %1) #0 {
  %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
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  %10 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  %11 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %0) #2
  %12 = trunc i64 %11 to i32
  store i32 %12, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  store i32 0, ptr %7, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  %13 = load i32, ptr %6, align 4, !tbaa !9
  %14 = sub nsw i32 %13, 1
  store i32 %14, ptr %8, align 4, !tbaa !9
  br label %15

15:                                               ; preds = %69, %2
  %16 = load i32, ptr %7, align 4, !tbaa !9
  %17 = load i32, ptr %8, align 4, !tbaa !9
  %18 = icmp sle i32 %16, %17
  br i1 %18, label %19, label %70

19:                                               ; preds = %15
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #2
  %20 = load i32, ptr %7, align 4, !tbaa !9
  %21 = load i32, ptr %8, align 4, !tbaa !9
  %22 = add nsw i32 %20, %21
  %23 = sdiv i32 %22, 2
  store i32 %23, ptr %9, align 4, !tbaa !9
  %24 = load i32, ptr %9, align 4, !tbaa !9
  %25 = sext i32 %24 to i64
  %26 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %0, i64 noundef %25) #2
  %27 = load i32, ptr %26, align 4, !tbaa !9
  %28 = load i32, ptr %5, align 4, !tbaa !9
  %29 = icmp sgt i32 %27, %28
  br i1 %29, label %30, label %33

30:                                               ; preds = %19
  %31 = load i32, ptr %9, align 4, !tbaa !9
  %32 = sub nsw i32 %31, 1
  store i32 %32, ptr %8, align 4, !tbaa !9
  br label %66

33:                                               ; preds = %19
  %34 = load i32, ptr %9, align 4, !tbaa !9
  %35 = sext i32 %34 to i64
  %36 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %0, i64 noundef %35) #2
  %37 = load i32, ptr %36, align 4, !tbaa !9
  %38 = load i32, ptr %5, align 4, !tbaa !9
  %39 = icmp slt i32 %37, %38
  br i1 %39, label %40, label %43

40:                                               ; preds = %33
  %41 = load i32, ptr %9, align 4, !tbaa !9
  %42 = add nsw i32 %41, 1
  store i32 %42, ptr %7, align 4, !tbaa !9
  br label %65

43:                                               ; preds = %33
  %44 = load i32, ptr %9, align 4, !tbaa !9
  %45 = load i32, ptr %6, align 4, !tbaa !9
  %46 = sub nsw i32 %45, 1
  %47 = icmp eq i32 %44, %46
  br i1 %47, label %59, label %48

48:                                               ; preds = %43
  %49 = load i32, ptr %9, align 4, !tbaa !9
  %50 = add nsw i32 %49, 1
  %51 = sext i32 %50 to i64
  %52 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %0, i64 noundef %51) #2
  %53 = load i32, ptr %52, align 4, !tbaa !9
  %54 = load i32, ptr %9, align 4, !tbaa !9
  %55 = sext i32 %54 to i64
  %56 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %0, i64 noundef %55) #2
  %57 = load i32, ptr %56, align 4, !tbaa !9
  %58 = icmp ne i32 %53, %57
  br i1 %58, label %59, label %61

59:                                               ; preds = %48, %43
  %60 = load i32, ptr %9, align 4, !tbaa !9
  store i32 %60, ptr %3, align 4
  store i32 1, ptr %10, align 4
  br label %67

61:                                               ; preds = %48
  %62 = load i32, ptr %9, align 4, !tbaa !9
  %63 = add nsw i32 %62, 1
  store i32 %63, ptr %7, align 4, !tbaa !9
  br label %64

64:                                               ; preds = %61
  br label %65

65:                                               ; preds = %64, %40
  br label %66

66:                                               ; preds = %65, %30
  store i32 0, ptr %10, align 4
  br label %67

67:                                               ; preds = %66, %59
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #2
  %68 = load i32, ptr %10, align 4
  switch i32 %68, label %71 [
    i32 0, label %69
  ]

69:                                               ; preds = %67
  br label %15, !llvm.loop !11

70:                                               ; preds = %15
  store i32 -1, ptr %3, align 4
  store i32 1, ptr %10, align 4
  br label %71

71:                                               ; preds = %70, %67
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  %72 = load i32, ptr %3, align 4
  ret i32 %72
}

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

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) #0 align 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 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !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"

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z14lastOccurrenceSt6vectorIiSaIiEEi(ptr noundef nonnull %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = tail call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %0) #1
  %4 = trunc i64 %3 to i32
  %5 = add nsw i32 %4, -1
  %.not33 = icmp slt i32 %4, 1
  br i1 %.not33, label %.thread, label %.lr.ph

.lr.ph:                                           ; preds = %2, %29
  %.02035 = phi i32 [ %.222, %29 ], [ %5, %2 ]
  %.02334 = phi i32 [ %.225, %29 ], [ 0, %2 ]
  %6 = add nuw nsw i32 %.02035, %.02334
  %7 = lshr i32 %6, 1
  %8 = zext nneg i32 %7 to i64
  %9 = tail call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %0, i64 noundef %8) #1
  %10 = load i32, ptr %9, align 4, !tbaa !5
  %11 = icmp sgt i32 %10, %1
  br i1 %11, label %12, label %14

12:                                               ; preds = %.lr.ph
  %13 = add nsw i32 %7, -1
  br label %29

14:                                               ; preds = %.lr.ph
  %15 = tail call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %0, i64 noundef %8) #1
  %16 = load i32, ptr %15, align 4, !tbaa !5
  %17 = icmp slt i32 %16, %1
  br i1 %17, label %18, label %20

18:                                               ; preds = %14
  %19 = add nuw nsw i32 %7, 1
  br label %29

20:                                               ; preds = %14
  %21 = icmp eq i32 %7, %5
  br i1 %21, label %.thread, label %22

22:                                               ; preds = %20
  %23 = add nuw nsw i32 %7, 1
  %24 = zext nneg i32 %23 to i64
  %25 = tail call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %0, i64 noundef %24) #1
  %26 = load i32, ptr %25, align 4, !tbaa !5
  %27 = tail call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %0, i64 noundef %8) #1
  %28 = load i32, ptr %27, align 4, !tbaa !5
  %.not28 = icmp eq i32 %26, %28
  br i1 %.not28, label %29, label %.thread

29:                                               ; preds = %22, %12, %18
  %.225 = phi i32 [ %.02334, %12 ], [ %19, %18 ], [ %23, %22 ]
  %.222 = phi i32 [ %13, %12 ], [ %.02035, %18 ], [ %.02035, %22 ]
  %.not = icmp sgt i32 %.225, %.222
  br i1 %.not, label %.thread, label %.lr.ph, !llvm.loop !9

.thread:                                          ; preds = %29, %22, %20, %2
  %.2 = phi i32 [ -1, %2 ], [ %5, %20 ], [ %7, %22 ], [ -1, %29 ]
  ret i32 %.2
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) local_unnamed_addr #0 align 2

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 = { 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: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass