; LLVM IR from Hunterdii/GeeksforGeeks-POTD :: December 2024 GFG SOLUTION (December-07)

; 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: nounwind uwtable
declare dso_local i32 @mergeAndCount(ptr noundef, ptr noundef, i32 noundef, i32 noundef, i32 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 @mergeSortAndCount(ptr noundef %0, ptr noundef %1, i32 noundef %2, i32 noundef %3) #0 {
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  %10 = alloca i32, align 4
  store ptr %0, ptr %5, align 8, !tbaa !5
  store ptr %1, ptr %6, align 8, !tbaa !5
  store i32 %2, ptr %7, align 4, !tbaa !9
  store i32 %3, ptr %8, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #2
  store i32 0, ptr %9, align 4, !tbaa !9
  %11 = load i32, ptr %7, align 4, !tbaa !9
  %12 = load i32, ptr %8, align 4, !tbaa !9
  %13 = icmp slt i32 %11, %12
  br i1 %13, label %14, label %44

14:                                               ; preds = %4
  call void @llvm.lifetime.start.p0(i64 4, ptr %10) #2
  %15 = load i32, ptr %7, align 4, !tbaa !9
  %16 = load i32, ptr %8, align 4, !tbaa !9
  %17 = load i32, ptr %7, align 4, !tbaa !9
  %18 = sub nsw i32 %16, %17
  %19 = sdiv i32 %18, 2
  %20 = add nsw i32 %15, %19
  store i32 %20, ptr %10, align 4, !tbaa !9
  %21 = load ptr, ptr %5, align 8, !tbaa !5
  %22 = load ptr, ptr %6, align 8, !tbaa !5
  %23 = load i32, ptr %7, align 4, !tbaa !9
  %24 = load i32, ptr %10, align 4, !tbaa !9
  %25 = call i32 @mergeSortAndCount(ptr noundef %21, ptr noundef %22, i32 noundef %23, i32 noundef %24)
  %26 = load i32, ptr %9, align 4, !tbaa !9
  %27 = add nsw i32 %26, %25
  store i32 %27, ptr %9, align 4, !tbaa !9
  %28 = load ptr, ptr %5, align 8, !tbaa !5
  %29 = load ptr, ptr %6, align 8, !tbaa !5
  %30 = load i32, ptr %10, align 4, !tbaa !9
  %31 = add nsw i32 %30, 1
  %32 = load i32, ptr %8, align 4, !tbaa !9
  %33 = call i32 @mergeSortAndCount(ptr noundef %28, ptr noundef %29, i32 noundef %31, i32 noundef %32)
  %34 = load i32, ptr %9, align 4, !tbaa !9
  %35 = add nsw i32 %34, %33
  store i32 %35, ptr %9, align 4, !tbaa !9
  %36 = load ptr, ptr %5, align 8, !tbaa !5
  %37 = load ptr, ptr %6, align 8, !tbaa !5
  %38 = load i32, ptr %7, align 4, !tbaa !9
  %39 = load i32, ptr %10, align 4, !tbaa !9
  %40 = load i32, ptr %8, align 4, !tbaa !9
  %41 = call i32 @mergeAndCount(ptr noundef %36, ptr noundef %37, i32 noundef %38, i32 noundef %39, i32 noundef %40)
  %42 = load i32, ptr %9, align 4, !tbaa !9
  %43 = add nsw i32 %42, %41
  store i32 %43, ptr %9, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %10) #2
  br label %44

44:                                               ; preds = %14, %4
  %45 = load i32, ptr %9, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #2
  ret i32 %45
}

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 = { 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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}


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

; Function Attrs: nounwind uwtable
define dso_local i32 @mergeSortAndCount(ptr noundef %0, ptr noundef %1, i32 noundef %2, i32 noundef %3) local_unnamed_addr #0 {
  %5 = icmp slt i32 %2, %3
  br i1 %5, label %6, label %common.ret23

common.ret23:                                     ; preds = %4, %6
  %common.ret23.op = phi i32 [ %15, %6 ], [ 0, %4 ]
  ret i32 %common.ret23.op

6:                                                ; preds = %4
  %7 = sub nsw i32 %3, %2
  %8 = sdiv i32 %7, 2
  %9 = add nsw i32 %8, %2
  %10 = tail call i32 @mergeSortAndCount(ptr noundef %0, ptr noundef %1, i32 noundef %2, i32 noundef %9)
  %11 = add nsw i32 %9, 1
  %12 = tail call i32 @mergeSortAndCount(ptr noundef %0, ptr noundef %1, i32 noundef %11, i32 noundef %3)
  %13 = add nsw i32 %12, %10
  %14 = tail call i32 @mergeAndCount(ptr noundef %0, ptr noundef %1, i32 noundef %2, i32 noundef %9, i32 noundef %3)
  %15 = add nsw i32 %13, %14
  br label %common.ret23
}

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" }

!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)"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass