; LLVM IR from ayush-tulsyan/ACM-ICPC-Handbook :: code/BIT.ll (Z6getindi)

; 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"

@tree = external dso_local global [131073 x i32], align 16
@N = external dso_local global i32, align 4

; 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 @_Z6getindi(i32 noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  store i32 0, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  %6 = load i32, ptr @N, align 4, !tbaa !5
  store i32 %6, ptr %4, align 4, !tbaa !5
  br label %7

7:                                                ; preds = %34, %1
  %8 = load i32, ptr %4, align 4, !tbaa !5
  %9 = icmp ne i32 %8, 0
  br i1 %9, label %10, label %14

10:                                               ; preds = %7
  %11 = load i32, ptr %3, align 4, !tbaa !5
  %12 = load i32, ptr @N, align 4, !tbaa !5
  %13 = icmp slt i32 %11, %12
  br label %14

14:                                               ; preds = %10, %7
  %15 = phi i1 [ false, %7 ], [ %13, %10 ]
  br i1 %15, label %16, label %37

16:                                               ; preds = %14
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  %17 = load i32, ptr %3, align 4, !tbaa !5
  %18 = load i32, ptr %4, align 4, !tbaa !5
  %19 = add nsw i32 %17, %18
  store i32 %19, ptr %5, align 4, !tbaa !5
  %20 = load i32, ptr %2, align 4, !tbaa !5
  %21 = load i32, ptr %5, align 4, !tbaa !5
  %22 = sext i32 %21 to i64
  %23 = getelementptr inbounds [131073 x i32], ptr @tree, i64 0, i64 %22
  %24 = load i32, ptr %23, align 4, !tbaa !5
  %25 = icmp sge i32 %20, %24
  br i1 %25, label %26, label %34

26:                                               ; preds = %16
  %27 = load i32, ptr %5, align 4, !tbaa !5
  store i32 %27, ptr %3, align 4, !tbaa !5
  %28 = load i32, ptr %5, align 4, !tbaa !5
  %29 = sext i32 %28 to i64
  %30 = getelementptr inbounds [131073 x i32], ptr @tree, i64 0, i64 %29
  %31 = load i32, ptr %30, align 4, !tbaa !5
  %32 = load i32, ptr %2, align 4, !tbaa !5
  %33 = sub nsw i32 %32, %31
  store i32 %33, ptr %2, align 4, !tbaa !5
  br label %34

34:                                               ; preds = %26, %16
  %35 = load i32, ptr %4, align 4, !tbaa !5
  %36 = ashr i32 %35, 1
  store i32 %36, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  br label %7, !llvm.loop !9

37:                                               ; preds = %14
  %38 = load i32, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret i32 %38
}

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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"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"

@tree = external dso_local local_unnamed_addr global [131073 x i32], align 16
@N = external dso_local local_unnamed_addr global i32, align 4

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef i32 @_Z6getindi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = load i32, ptr @N, align 4
  %3 = icmp sgt i32 %2, 0
  br i1 %3, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.018 = phi i32 [ %spec.select15, %.lr.ph ], [ %0, %1 ]
  %.01117 = phi i32 [ %9, %.lr.ph ], [ %2, %1 ]
  %.01216 = phi i32 [ %spec.select, %.lr.ph ], [ 0, %1 ]
  %4 = add nsw i32 %.01117, %.01216
  %5 = sext i32 %4 to i64
  %6 = getelementptr inbounds [131073 x i32], ptr @tree, i64 0, i64 %5
  %7 = load i32, ptr %6, align 4, !tbaa !5
  %.not = icmp slt i32 %.018, %7
  %spec.select = select i1 %.not, i32 %.01216, i32 %4
  %8 = select i1 %.not, i32 0, i32 %7
  %spec.select15 = sub nsw i32 %.018, %8
  %9 = lshr i32 %.01117, 1
  %10 = icmp ugt i32 %.01117, 1
  %11 = icmp slt i32 %spec.select, %2
  %12 = select i1 %10, i1 %11, i1 false
  br i1 %12, label %.lr.ph, label %._crit_edge, !llvm.loop !9

._crit_edge:                                      ; preds = %.lr.ph, %1
  %.012.lcssa = phi i32 [ 0, %1 ], [ %spec.select, %.lr.ph ]
  ret i32 %.012.lcssa
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: none) 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: EarlyCSEPass,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass