; LLVM IR from sbshah97/DS-Algo-Handbook :: labs/lab2/Merge_Sort (merge_sort)

; 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"

%"class.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" = type { ptr, ptr, ptr }

@a = external dso_local global %"class.std::vector", align 8
@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [4 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: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) #1 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt6vectorIiSaIiEE9push_backERKi(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 4 dereferenceable(4)) #2 align 2

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

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z9mergeSortii(i32 noundef, i32 noundef) #2

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

7:                                                ; preds = %14, %0
  %8 = load i32, ptr %4, align 4, !tbaa !5
  %9 = load i32, ptr %2, align 4, !tbaa !5
  %10 = icmp slt i32 %8, %9
  br i1 %10, label %12, label %11

11:                                               ; preds = %7
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #5
  br label %17

12:                                               ; preds = %7
  %13 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %3)
  call void @_ZNSt6vectorIiSaIiEE9push_backERKi(ptr noundef nonnull align 8 dereferenceable(24) @a, ptr noundef nonnull align 4 dereferenceable(4) %3)
  br label %14

14:                                               ; preds = %12
  %15 = load i32, ptr %4, align 4, !tbaa !5
  %16 = add nsw i32 %15, 1
  store i32 %16, ptr %4, align 4, !tbaa !5
  br label %7, !llvm.loop !9

17:                                               ; preds = %11
  %18 = load i32, ptr %2, align 4, !tbaa !5
  %19 = sub nsw i32 %18, 1
  call void @_Z9mergeSortii(i32 noundef 0, i32 noundef %19)
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #5
  store i32 0, ptr %5, align 4, !tbaa !5
  br label %20

20:                                               ; preds = %31, %17
  %21 = load i32, ptr %5, align 4, !tbaa !5
  %22 = load i32, ptr %2, align 4, !tbaa !5
  %23 = icmp slt i32 %21, %22
  br i1 %23, label %25, label %24

24:                                               ; preds = %20
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #5
  br label %34

25:                                               ; preds = %20
  %26 = load i32, ptr %5, align 4, !tbaa !5
  %27 = sext i32 %26 to i64
  %28 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) @a, i64 noundef %27) #5
  %29 = load i32, ptr %28, align 4, !tbaa !5
  %30 = call i32 (ptr, ...) @printf(ptr noundef @.str.3, i32 noundef %29)
  br label %31

31:                                               ; preds = %25
  %32 = load i32, ptr %5, align 4, !tbaa !5
  %33 = add nsw i32 %32, 1
  store i32 %33, ptr %5, align 4, !tbaa !5
  br label %20, !llvm.loop !11

34:                                               ; preds = %24
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #5
  ret i32 0
}

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

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

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 = { mustprogress 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 norecurse 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 #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 }

!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"}
!11 = distinct !{!11, !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"

%"class.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" = type { ptr, ptr, ptr }

@a = external dso_local global %"class.std::vector", align 8
@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [4 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 nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt6vectorIiSaIiEE9push_backERKi(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #2 align 2

; 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 uwtable
declare dso_local void @_Z9mergeSortii(i32 noundef, i32 noundef) local_unnamed_addr #2

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

._crit_edge:                                      ; preds = %.lr.ph, %0
  %.lcssa = phi i32 [ %4, %0 ], [ %11, %.lr.ph ]
  %6 = add nsw i32 %.lcssa, -1
  call void @_Z9mergeSortii(i32 noundef 0, i32 noundef %6)
  %7 = load i32, ptr %1, align 4, !tbaa !5
  %8 = icmp sgt i32 %7, 0
  br i1 %8, label %.lr.ph10, label %._crit_edge11

.lr.ph:                                           ; preds = %0, %.lr.ph
  %.057 = phi i32 [ %10, %.lr.ph ], [ 0, %0 ]
  %9 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %2)
  call void @_ZNSt6vectorIiSaIiEE9push_backERKi(ptr noundef nonnull align 8 dereferenceable(24) @a, ptr noundef nonnull align 4 dereferenceable(4) %2)
  %10 = add nuw nsw i32 %.057, 1
  %11 = load i32, ptr %1, align 4, !tbaa !5
  %12 = icmp slt i32 %10, %11
  br i1 %12, label %.lr.ph, label %._crit_edge, !llvm.loop !9

._crit_edge11:                                    ; preds = %.lr.ph10, %._crit_edge
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #5
  ret i32 0

.lr.ph10:                                         ; preds = %._crit_edge, %.lr.ph10
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph10 ], [ 0, %._crit_edge ]
  %13 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) @a, i64 noundef %indvars.iv) #5
  %14 = load i32, ptr %13, align 4, !tbaa !5
  %15 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.3, i32 noundef %14)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %16 = load i32, ptr %1, align 4, !tbaa !5
  %17 = sext i32 %16 to i64
  %18 = icmp slt i64 %indvars.iv.next, %17
  br i1 %18, label %.lr.ph10, label %._crit_edge11, !llvm.loop !11
}

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(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 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 = { mustprogress 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 norecurse 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 #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 }

!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"}
!11 = distinct !{!11, !10}


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