; LLVM IR from ahampriyanshu/algo-ds-101 :: Algorithms/Sorting/Merge_Sort/Application of Merge Sort (Count_Inversions)

; 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 = external hidden unnamed_addr constant [5 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [6 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
declare ptr @llvm.stacksave.p0() #1

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

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare void @llvm.stackrestore.p0(ptr) #1

; Function Attrs: nounwind uwtable
declare dso_local i64 @merge_sort(ptr noundef, i64 noundef, i64 noundef) #2

; Function Attrs: nounwind uwtable
define dso_local i32 @main() #2 {
  %1 = alloca i32, align 4
  %2 = alloca i64, align 8
  %3 = alloca ptr, align 8
  %4 = alloca i64, align 8
  %5 = alloca i32, align 4
  %6 = alloca i64, align 8
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #4
  %7 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %2)
  %8 = load i64, ptr %2, align 8, !tbaa !5
  %9 = call ptr @llvm.stacksave.p0()
  store ptr %9, ptr %3, align 8
  %10 = alloca i64, i64 %8, align 16
  store i64 %8, ptr %4, align 8
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #4
  store i32 0, ptr %5, align 4, !tbaa !9
  br label %11

11:                                               ; preds = %22, %0
  %12 = load i32, ptr %5, align 4, !tbaa !9
  %13 = sext i32 %12 to i64
  %14 = load i64, ptr %2, align 8, !tbaa !5
  %15 = icmp slt i64 %13, %14
  br i1 %15, label %17, label %16

16:                                               ; preds = %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #4
  br label %25

17:                                               ; preds = %11
  %18 = load i32, ptr %5, align 4, !tbaa !9
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds i64, ptr %10, i64 %19
  %21 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %20)
  br label %22

22:                                               ; preds = %17
  %23 = load i32, ptr %5, align 4, !tbaa !9
  %24 = add nsw i32 %23, 1
  store i32 %24, ptr %5, align 4, !tbaa !9
  br label %11, !llvm.loop !11

25:                                               ; preds = %16
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #4
  %26 = load i64, ptr %2, align 8, !tbaa !5
  %27 = sub nsw i64 %26, 1
  %28 = call i64 @merge_sort(ptr noundef %10, i64 noundef 0, i64 noundef %27)
  store i64 %28, ptr %6, align 8, !tbaa !5
  %29 = load i64, ptr %6, align 8, !tbaa !5
  %30 = call i32 (ptr, ...) @printf(ptr noundef @.str.1, i64 noundef %29)
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #4
  %31 = load ptr, ptr %3, align 8
  call void @llvm.stackrestore.p0(ptr %31)
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #4
  %32 = load i32, ptr %1, align 4
  ret i32 %32
}

declare i32 @__isoc99_scanf(ptr noundef, ...) #3

declare i32 @printf(ptr noundef, ...) #3

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { nocallback nofree nosync nounwind willreturn }
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 = { "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 = { 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 = !{!"long long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/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"

@.str = external hidden unnamed_addr constant [5 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [6 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
declare ptr @llvm.stacksave.p0() #1

; 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 nocallback nofree nosync nounwind willreturn
declare void @llvm.stackrestore.p0(ptr) #1

; Function Attrs: nounwind uwtable
declare dso_local i64 @merge_sort(ptr noundef, i64 noundef, i64 noundef) local_unnamed_addr #2

; Function Attrs: nounwind uwtable
define dso_local noundef i32 @main() local_unnamed_addr #2 {
  %1 = alloca i64, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %1) #4
  %2 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %1)
  %3 = load i64, ptr %1, align 8, !tbaa !5
  %4 = call ptr @llvm.stacksave.p0()
  %5 = alloca i64, i64 %3, align 16
  %6 = load i64, ptr %1, align 8, !tbaa !5
  %7 = icmp sgt i64 %6, 0
  br i1 %7, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %0
  %.lcssa = phi i64 [ %6, %0 ], [ %13, %.lr.ph ]
  %8 = add nsw i64 %.lcssa, -1
  %9 = call i64 @merge_sort(ptr noundef nonnull %5, i64 noundef 0, i64 noundef %8)
  %10 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, i64 noundef %9)
  call void @llvm.stackrestore.p0(ptr %4)
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %1) #4
  ret i32 0

.lr.ph:                                           ; preds = %0, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %0 ]
  %11 = getelementptr inbounds i64, ptr %5, i64 %indvars.iv
  %12 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %11)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %13 = load i64, ptr %1, align 8, !tbaa !5
  %14 = icmp sgt i64 %13, %indvars.iv.next
  br i1 %14, label %.lr.ph, label %._crit_edge, !llvm.loop !9
}

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #3

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #3

attributes #0 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress nocallback nofree nosync nounwind willreturn }
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 = { 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 #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 = !{!"long long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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