; LLVM IR from Hunterdii/GeeksforGeeks-POTD :: December 2024 GFG SOLUTION (December-08)

; 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"

%struct.Interval = type { i32, i32 }

@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [6 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [7 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [2 x i8], align 1
@.str.4 = external hidden unnamed_addr constant [3 x i8], align 1

; Function Attrs: nounwind uwtable
declare dso_local i32 @mergeOverlap(ptr noundef, i32 noundef, ptr noundef) #0

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

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

; Function Attrs: nounwind uwtable
define dso_local i32 @main() #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca i64, align 8
  %6 = alloca i32, align 4
  %7 = alloca i64, align 8
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #4
  %10 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %2)
  br label %11

11:                                               ; preds = %65, %0
  %12 = load i32, ptr %2, align 4, !tbaa !5
  %13 = add nsw i32 %12, -1
  store i32 %13, ptr %2, align 4, !tbaa !5
  %14 = icmp ne i32 %12, 0
  br i1 %14, label %15, label %69

15:                                               ; preds = %11
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #4
  %16 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %3)
  %17 = load i32, ptr %3, align 4, !tbaa !5
  %18 = zext i32 %17 to i64
  %19 = call ptr @llvm.stacksave.p0()
  store ptr %19, ptr %4, align 8
  %20 = alloca %struct.Interval, i64 %18, align 16
  store i64 %18, ptr %5, align 8
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #4
  store i32 0, ptr %6, align 4, !tbaa !5
  br label %21

21:                                               ; preds = %36, %15
  %22 = load i32, ptr %6, align 4, !tbaa !5
  %23 = load i32, ptr %3, align 4, !tbaa !5
  %24 = icmp slt i32 %22, %23
  br i1 %24, label %26, label %25

25:                                               ; preds = %21
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #4
  br label %39

26:                                               ; preds = %21
  %27 = load i32, ptr %6, align 4, !tbaa !5
  %28 = sext i32 %27 to i64
  %29 = getelementptr inbounds %struct.Interval, ptr %20, i64 %28
  %30 = getelementptr inbounds %struct.Interval, ptr %29, i32 0, i32 0
  %31 = load i32, ptr %6, align 4, !tbaa !5
  %32 = sext i32 %31 to i64
  %33 = getelementptr inbounds %struct.Interval, ptr %20, i64 %32
  %34 = getelementptr inbounds %struct.Interval, ptr %33, i32 0, i32 1
  %35 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str.1, ptr noundef %30, ptr noundef %34)
  br label %36

36:                                               ; preds = %26
  %37 = load i32, ptr %6, align 4, !tbaa !5
  %38 = add nsw i32 %37, 1
  store i32 %38, ptr %6, align 4, !tbaa !5
  br label %21, !llvm.loop !9

39:                                               ; preds = %25
  %40 = load i32, ptr %3, align 4, !tbaa !5
  %41 = zext i32 %40 to i64
  %42 = alloca %struct.Interval, i64 %41, align 16
  store i64 %41, ptr %7, align 8
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #4
  %43 = load i32, ptr %3, align 4, !tbaa !5
  %44 = call i32 @mergeOverlap(ptr noundef %20, i32 noundef %43, ptr noundef %42)
  store i32 %44, ptr %8, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #4
  store i32 0, ptr %9, align 4, !tbaa !5
  br label %45

45:                                               ; preds = %62, %39
  %46 = load i32, ptr %9, align 4, !tbaa !5
  %47 = load i32, ptr %8, align 4, !tbaa !5
  %48 = icmp slt i32 %46, %47
  br i1 %48, label %50, label %49

49:                                               ; preds = %45
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #4
  br label %65

50:                                               ; preds = %45
  %51 = load i32, ptr %9, align 4, !tbaa !5
  %52 = sext i32 %51 to i64
  %53 = getelementptr inbounds %struct.Interval, ptr %42, i64 %52
  %54 = getelementptr inbounds %struct.Interval, ptr %53, i32 0, i32 0
  %55 = load i32, ptr %54, align 8, !tbaa !11
  %56 = load i32, ptr %9, align 4, !tbaa !5
  %57 = sext i32 %56 to i64
  %58 = getelementptr inbounds %struct.Interval, ptr %42, i64 %57
  %59 = getelementptr inbounds %struct.Interval, ptr %58, i32 0, i32 1
  %60 = load i32, ptr %59, align 4, !tbaa !13
  %61 = call i32 (ptr, ...) @printf(ptr noundef @.str.2, i32 noundef %55, i32 noundef %60)
  br label %62

62:                                               ; preds = %50
  %63 = load i32, ptr %9, align 4, !tbaa !5
  %64 = add nsw i32 %63, 1
  store i32 %64, ptr %9, align 4, !tbaa !5
  br label %45, !llvm.loop !14

65:                                               ; preds = %49
  %66 = call i32 (ptr, ...) @printf(ptr noundef @.str.3)
  %67 = call i32 (ptr, ...) @printf(ptr noundef @.str.4)
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #4
  %68 = load ptr, ptr %4, align 8
  call void @llvm.stackrestore.p0(ptr %68)
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #4
  br label %11, !llvm.loop !15

69:                                               ; preds = %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #4
  ret i32 0
}

declare i32 @__isoc99_scanf(ptr noundef, ...) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare ptr @llvm.stacksave.p0() #3

declare i32 @printf(ptr noundef, ...) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare void @llvm.stackrestore.p0(ptr) #3

attributes #0 = { 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 = { "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 = { nocallback nofree nosync nounwind willreturn }
attributes #4 = { 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/C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!12, !6, i64 0}
!12 = !{!"", !6, i64 0, !6, i64 4}
!13 = !{!12, !6, i64 4}
!14 = distinct !{!14, !10}
!15 = distinct !{!15, !10}


; 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"

%struct.Interval = type { i32, i32 }

@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [6 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [7 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [2 x i8], align 1
@.str.4 = external hidden unnamed_addr constant [3 x i8], align 1

; Function Attrs: nounwind uwtable
declare dso_local i32 @mergeOverlap(ptr noundef, i32 noundef, ptr noundef) local_unnamed_addr #0

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

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

; Function Attrs: nounwind uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #4
  %3 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, 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
  %.not16 = icmp eq i32 %4, 0
  br i1 %.not16, label %._crit_edge19, label %.lr.ph18

.lr.ph18:                                         ; preds = %0, %._crit_edge15
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #4
  %6 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %2)
  %7 = load i32, ptr %2, align 4, !tbaa !5
  %8 = zext i32 %7 to i64
  %9 = call ptr @llvm.stacksave.p0()
  %10 = alloca %struct.Interval, i64 %8, align 16
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = icmp sgt i32 %11, 0
  br i1 %12, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %.lr.ph18
  %.lcssa = phi i32 [ %11, %.lr.ph18 ], [ %20, %.lr.ph ]
  %13 = zext i32 %.lcssa to i64
  %14 = alloca %struct.Interval, i64 %13, align 16
  %15 = call i32 @mergeOverlap(ptr noundef nonnull %10, i32 noundef %.lcssa, ptr noundef nonnull %14)
  %16 = icmp sgt i32 %15, 0
  br i1 %16, label %.lr.ph14.preheader, label %._crit_edge15

.lr.ph14.preheader:                               ; preds = %._crit_edge
  %wide.trip.count = zext nneg i32 %15 to i64
  br label %.lr.ph14

.lr.ph:                                           ; preds = %.lr.ph18, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %.lr.ph18 ]
  %17 = getelementptr inbounds %struct.Interval, ptr %10, i64 %indvars.iv
  %18 = getelementptr inbounds i8, ptr %17, i64 4
  %19 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.1, ptr noundef nonnull %17, ptr noundef nonnull %18)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %20 = load i32, ptr %2, align 4, !tbaa !5
  %21 = sext i32 %20 to i64
  %22 = icmp slt i64 %indvars.iv.next, %21
  br i1 %22, label %.lr.ph, label %._crit_edge, !llvm.loop !9

._crit_edge15:                                    ; preds = %.lr.ph14, %._crit_edge
  %23 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.3)
  %24 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.4)
  call void @llvm.stackrestore.p0(ptr %9)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #4
  %25 = load i32, ptr %1, align 4, !tbaa !5
  %26 = add nsw i32 %25, -1
  store i32 %26, ptr %1, align 4, !tbaa !5
  %.not = icmp eq i32 %25, 0
  br i1 %.not, label %._crit_edge19, label %.lr.ph18, !llvm.loop !11

.lr.ph14:                                         ; preds = %.lr.ph14.preheader, %.lr.ph14
  %indvars.iv22 = phi i64 [ 0, %.lr.ph14.preheader ], [ %indvars.iv.next23, %.lr.ph14 ]
  %27 = getelementptr inbounds %struct.Interval, ptr %14, i64 %indvars.iv22
  %28 = load i32, ptr %27, align 8, !tbaa !12
  %29 = getelementptr inbounds i8, ptr %27, i64 4
  %30 = load i32, ptr %29, align 4, !tbaa !14
  %31 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.2, i32 noundef %28, i32 noundef %30)
  %indvars.iv.next23 = add nuw nsw i64 %indvars.iv22, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next23, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge15, label %.lr.ph14, !llvm.loop !15

._crit_edge19:                                    ; preds = %._crit_edge15, %0
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #4
  ret i32 0
}

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn
declare ptr @llvm.stacksave.p0() #3

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn
declare void @llvm.stackrestore.p0(ptr) #3

attributes #0 = { 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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #3 = { mustprogress nocallback nofree nosync nounwind willreturn }
attributes #4 = { 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/C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = distinct !{!11, !10}
!12 = !{!13, !6, i64 0}
!13 = !{!"", !6, i64 0, !6, i64 4}
!14 = !{!13, !6, i64 4}
!15 = distinct !{!15, !10}


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