; LLVM IR from sbshah97/DS-Algo-Handbook :: Algorithms/Sort_Algorithms/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"

; Function Attrs: nounwind uwtable
declare dso_local void @merge(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 void @mergeSort(i32 noundef %0, i32 noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  %6 = load i32, ptr %3, align 4, !tbaa !5
  %7 = load i32, ptr %4, align 4, !tbaa !5
  %8 = add nsw i32 %6, %7
  %9 = sdiv i32 %8, 2
  store i32 %9, ptr %5, align 4, !tbaa !5
  %10 = load i32, ptr %3, align 4, !tbaa !5
  %11 = load i32, ptr %4, align 4, !tbaa !5
  %12 = icmp slt i32 %10, %11
  br i1 %12, label %13, label %22

13:                                               ; preds = %2
  %14 = load i32, ptr %3, align 4, !tbaa !5
  %15 = load i32, ptr %5, align 4, !tbaa !5
  call void @mergeSort(i32 noundef %14, i32 noundef %15)
  %16 = load i32, ptr %5, align 4, !tbaa !5
  %17 = add nsw i32 %16, 1
  %18 = load i32, ptr %4, align 4, !tbaa !5
  call void @mergeSort(i32 noundef %17, i32 noundef %18)
  %19 = load i32, ptr %3, align 4, !tbaa !5
  %20 = load i32, ptr %5, align 4, !tbaa !5
  %21 = load i32, ptr %4, align 4, !tbaa !5
  call void @merge(i32 noundef %19, i32 noundef %20, i32 noundef %21)
  br label %22

22:                                               ; preds = %13, %2
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  ret void
}

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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}


; 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 void @merge(i32 noundef, i32 noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local void @mergeSort(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp slt i32 %0, %1
  br i1 %3, label %4, label %common.ret12

common.ret12:                                     ; preds = %2, %4
  ret void

4:                                                ; preds = %2
  %5 = add nsw i32 %1, %0
  %6 = sdiv i32 %5, 2
  tail call void @mergeSort(i32 noundef %0, i32 noundef %6)
  %7 = add nsw i32 %6, 1
  tail call void @mergeSort(i32 noundef %7, i32 noundef %1)
  tail call void @merge(i32 noundef %0, i32 noundef %6, i32 noundef %1)
  br label %common.ret12
}

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: GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass