; LLVM IR from Hunterdii/GeeksforGeeks-POTD :: February 2025 GFG SOLUTION (February-05)

; 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"

@.str.4 = external hidden unnamed_addr constant [4 x i8], align 1
@stdin = external global ptr, align 8
@.str.5 = external hidden unnamed_addr constant [3 x i8], align 1

; 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: nounwind
declare void @free(ptr noundef) #1

; Function Attrs: nounwind uwtable
declare dso_local ptr @buildTree(ptr noundef) #2

; Function Attrs: nounwind willreturn memory(read)
declare i64 @strlen(ptr noundef) #3

; Function Attrs: nounwind uwtable
declare dso_local ptr @levelOrder(ptr noundef) #2

; Function Attrs: nounwind uwtable
declare dso_local void @mirror(ptr noundef) #2

; Function Attrs: nounwind uwtable
define dso_local i32 @main() #2 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca [2000000 x i8], align 16
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #5
  %6 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str.4, ptr noundef %2)
  br label %7

7:                                                ; preds = %11, %0
  %8 = load i32, ptr %2, align 4, !tbaa !5
  %9 = add nsw i32 %8, -1
  store i32 %9, ptr %2, align 4, !tbaa !5
  %10 = icmp ne i32 %8, 0
  br i1 %10, label %11, label %28

11:                                               ; preds = %7
  call void @llvm.lifetime.start.p0(i64 2000000, ptr %3) #5
  %12 = getelementptr inbounds [2000000 x i8], ptr %3, i64 0, i64 0
  %13 = load ptr, ptr @stdin, align 8, !tbaa !9
  %14 = call ptr @fgets(ptr noundef %12, i32 noundef 2000000, ptr noundef %13)
  %15 = getelementptr inbounds [2000000 x i8], ptr %3, i64 0, i64 0
  %16 = call i64 @strlen(ptr noundef %15) #6
  %17 = sub i64 %16, 1
  %18 = getelementptr inbounds [2000000 x i8], ptr %3, i64 0, i64 %17
  store i8 0, ptr %18, align 1, !tbaa !11
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #5
  %19 = getelementptr inbounds [2000000 x i8], ptr %3, i64 0, i64 0
  %20 = call ptr @buildTree(ptr noundef %19)
  store ptr %20, ptr %4, align 8, !tbaa !9
  %21 = load ptr, ptr %4, align 8, !tbaa !9
  call void @mirror(ptr noundef %21)
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #5
  %22 = load ptr, ptr %4, align 8, !tbaa !9
  %23 = call ptr @levelOrder(ptr noundef %22)
  store ptr %23, ptr %5, align 8, !tbaa !9
  %24 = load ptr, ptr %5, align 8, !tbaa !9
  %25 = call i32 @puts(ptr noundef %24)
  %26 = call i32 (ptr, ...) @printf(ptr noundef @.str.5)
  %27 = load ptr, ptr %5, align 8, !tbaa !9
  call void @free(ptr noundef %27) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #5
  call void @llvm.lifetime.end.p0(i64 2000000, ptr %3) #5
  br label %7, !llvm.loop !12

28:                                               ; preds = %7
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #5
  ret i32 0
}

declare i32 @__isoc99_scanf(ptr noundef, ...) #4

declare ptr @fgets(ptr noundef, i32 noundef, ptr noundef) #4

declare i32 @puts(ptr noundef) #4

declare i32 @printf(ptr noundef, ...) #4

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { nounwind "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 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 willreturn memory(read) "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 #4 = { "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 #5 = { nounwind }
attributes #6 = { nounwind willreturn memory(read) }

!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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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"

@.str.4 = external hidden unnamed_addr constant [4 x i8], align 1
@stdin = external local_unnamed_addr global ptr, align 8
@.str.5 = external hidden unnamed_addr constant [3 x i8], align 1

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #1

; Function Attrs: nounwind uwtable
declare dso_local ptr @buildTree(ptr noundef) local_unnamed_addr #2

; Function Attrs: mustprogress nofree nounwind willreturn memory(argmem: read)
declare i64 @strlen(ptr nocapture noundef) local_unnamed_addr #3

; Function Attrs: nounwind uwtable
declare dso_local ptr @levelOrder(ptr noundef) local_unnamed_addr #2

; Function Attrs: nounwind uwtable
declare dso_local void @mirror(ptr noundef) local_unnamed_addr #2

; Function Attrs: nounwind uwtable
define dso_local noundef i32 @main() local_unnamed_addr #2 {
  %1 = alloca i32, align 4
  %2 = alloca [2000000 x i8], align 16
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #5
  %3 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.4, ptr noundef nonnull %1)
  %4 = load i32, ptr %1, align 4, !tbaa !5
  %5 = add nsw i32 %4, -1
  store i32 %5, ptr %1, align 4, !tbaa !5
  %.not4 = icmp eq i32 %4, 0
  br i1 %.not4, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %0, %.lr.ph
  call void @llvm.lifetime.start.p0(i64 2000000, ptr nonnull %2) #5
  %6 = load ptr, ptr @stdin, align 8, !tbaa !9
  %7 = call ptr @fgets(ptr noundef nonnull %2, i32 noundef 2000000, ptr noundef %6)
  %8 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %2) #6
  %9 = add i64 %8, -1
  %10 = getelementptr inbounds [2000000 x i8], ptr %2, i64 0, i64 %9
  store i8 0, ptr %10, align 1, !tbaa !11
  %11 = call ptr @buildTree(ptr noundef nonnull %2)
  call void @mirror(ptr noundef %11)
  %12 = call ptr @levelOrder(ptr noundef %11)
  %13 = call i32 @puts(ptr noundef nonnull dereferenceable(1) %12)
  %14 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.5)
  call void @free(ptr noundef %12) #5
  call void @llvm.lifetime.end.p0(i64 2000000, ptr nonnull %2) #5
  %15 = load i32, ptr %1, align 4, !tbaa !5
  %16 = add nsw i32 %15, -1
  store i32 %16, ptr %1, align 4, !tbaa !5
  %.not = icmp eq i32 %15, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !12

._crit_edge:                                      ; preds = %.lr.ph, %0
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #5
  ret i32 0
}

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #4

; Function Attrs: nofree nounwind
declare noundef ptr @fgets(ptr noundef, i32 noundef, ptr nocapture noundef) local_unnamed_addr #4

; Function Attrs: nofree nounwind
declare noundef i32 @puts(ptr nocapture noundef readonly) local_unnamed_addr #4

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #4

attributes #0 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite) "alloc-family"="malloc" "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 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 = { mustprogress nofree nounwind willreturn memory(argmem: read) "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 #4 = { nofree nounwind "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 #5 = { nounwind }
attributes #6 = { nounwind willreturn memory(read) }

!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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


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