; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/ds (Find_first_and_last_positions_of_an_element_in_a_sorted_array)

; 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: 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: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z14Last_positionsPiii(ptr noundef %0, i32 noundef %1, i32 noundef %2) #1 {
  %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
  store i32 %2, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  store i32 -1, ptr %8, align 4, !tbaa !9
  %9 = load i32, ptr %5, align 4, !tbaa !9
  %10 = sub nsw i32 %9, 1
  store i32 %10, ptr %7, align 4, !tbaa !9
  br label %11

11:                                               ; preds = %25, %3
  %12 = load i32, ptr %7, align 4, !tbaa !9
  %13 = icmp sge i32 %12, 0
  br i1 %13, label %14, label %28

14:                                               ; preds = %11
  %15 = load ptr, ptr %4, align 8, !tbaa !5
  %16 = load i32, ptr %7, align 4, !tbaa !9
  %17 = sext i32 %16 to i64
  %18 = getelementptr inbounds i32, ptr %15, i64 %17
  %19 = load i32, ptr %18, align 4, !tbaa !9
  %20 = load i32, ptr %6, align 4, !tbaa !9
  %21 = icmp eq i32 %19, %20
  br i1 %21, label %22, label %24

22:                                               ; preds = %14
  %23 = load i32, ptr %7, align 4, !tbaa !9
  store i32 %23, ptr %8, align 4, !tbaa !9
  br label %28

24:                                               ; preds = %14
  br label %25

25:                                               ; preds = %24
  %26 = load i32, ptr %7, align 4, !tbaa !9
  %27 = add nsw i32 %26, -1
  store i32 %27, ptr %7, align 4, !tbaa !9
  br label %11, !llvm.loop !11

28:                                               ; preds = %22, %11
  %29 = load i32, ptr %8, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  ret i32 %29
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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 nofree norecurse nosync nounwind willreturn memory(argmem: read) uwtable
define dso_local noundef range(i32 -1, 2147483647) i32 @_Z14Last_positionsPiii(ptr nocapture noundef readonly %0, i32 noundef %1, i32 noundef %2) local_unnamed_addr #0 {
  %4 = zext i32 %1 to i64
  br label %5

5:                                                ; preds = %8, %3
  %indvars.iv = phi i64 [ %indvars.iv.next, %8 ], [ %4, %3 ]
  %6 = trunc nuw i64 %indvars.iv to i32
  %7 = icmp sgt i32 %6, 0
  br i1 %7, label %8, label %.split.loop.exit9

8:                                                ; preds = %5
  %indvars.iv.next = add nsw i64 %indvars.iv, -1
  %9 = and i64 %indvars.iv.next, 4294967295
  %10 = getelementptr inbounds i32, ptr %0, i64 %9
  %11 = load i32, ptr %10, align 4, !tbaa !5
  %12 = icmp eq i32 %11, %2
  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.exit9

.split.loop.exit9:                                ; preds = %5, %.split.loop.exit
  %.0 = phi i32 [ %indvars.le, %.split.loop.exit ], [ -1, %5 ]
  ret i32 %.0
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: read) 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, !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