; LLVM IR from devparthgarg/Data-Structures-and-Algorithms :: 06. Searching/03 Index of Last Occurrence (03a 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
  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
  %9 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %0) #2
  %10 = trunc i64 %9 to i32
  store i32 %10, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  %11 = load i32, ptr %6, align 4, !tbaa !9
  %12 = sub nsw i32 %11, 1
  store i32 %12, ptr %7, align 4, !tbaa !9
  br label %13

13:                                               ; preds = %27, %2
  %14 = load i32, ptr %7, align 4, !tbaa !9
  %15 = icmp sge i32 %14, 0
  br i1 %15, label %17, label %16

16:                                               ; preds = %13
  store i32 2, ptr %8, align 4
  br label %30

17:                                               ; preds = %13
  %18 = load i32, ptr %7, align 4, !tbaa !9
  %19 = sext i32 %18 to i64
  %20 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %0, i64 noundef %19) #2
  %21 = load i32, ptr %20, align 4, !tbaa !9
  %22 = load i32, ptr %5, align 4, !tbaa !9
  %23 = icmp eq i32 %21, %22
  br i1 %23, label %24, label %26

24:                                               ; preds = %17
  %25 = load i32, ptr %7, align 4, !tbaa !9
  store i32 %25, ptr %3, align 4
  store i32 1, ptr %8, align 4
  br label %30

26:                                               ; preds = %17
  br label %27

27:                                               ; preds = %26
  %28 = load i32, ptr %7, align 4, !tbaa !9
  %29 = add nsw i32 %28, -1
  store i32 %29, ptr %7, align 4, !tbaa !9
  br label %13, !llvm.loop !11

30:                                               ; preds = %24, %16
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  %31 = load i32, ptr %8, align 4
  switch i32 %31, label %33 [
    i32 2, label %32
  ]

32:                                               ; preds = %30
  store i32 -1, ptr %3, align 4
  store i32 1, ptr %8, align 4
  br label %33

33:                                               ; preds = %32, %30
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  %34 = load i32, ptr %3, align 4
  ret i32 %34
}

; 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 range(i32 -2147483648, 2147483647) 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 = and i64 %3, 4294967295
  br label %5

5:                                                ; preds = %8, %2
  %indvars.iv = phi i64 [ %indvars.iv.next, %8 ], [ %4, %2 ]
  %6 = trunc nuw i64 %indvars.iv to i32
  %7 = icmp slt i32 %6, 1
  br i1 %7, label %.split.loop.exit11, label %8

8:                                                ; preds = %5
  %indvars.iv.next = add nsw i64 %indvars.iv, -1
  %9 = and i64 %indvars.iv.next, 4294967295
  %10 = tail call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %0, i64 noundef %9) #1
  %11 = load i32, ptr %10, align 4, !tbaa !5
  %12 = icmp eq i32 %11, %1
  br i1 %12, label %.split.loop.exit, label %5, !llvm.loop !9

.split.loop.exit:                                 ; preds = %8
  %indvars.le = trunc i64 %indvars.iv.next to i32
  br label %.split.loop.exit11

.split.loop.exit11:                               ; preds = %5, %.split.loop.exit
  %spec.select = phi i32 [ %indvars.le, %.split.loop.exit ], [ -1, %5 ]
  ret i32 %spec.select
}

; 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: GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LICMPass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass