; LLVM IR from MrSupW/C-Source-Code-of-Sorting-Algorithm :: 排序6 归并排序_递归.ll (Z9MergeSortPii)

; 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: mustprogress nounwind uwtable
declare dso_local void @_Z7MergingPiiS_i(ptr noundef, i32 noundef, ptr 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: mustprogress uwtable
define dso_local void @_Z9MergeSortPii(ptr noundef %0, i32 noundef %1) #2 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca ptr, align 8
  %8 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  %9 = load i32, ptr %4, align 4, !tbaa !9
  %10 = icmp sle i32 %9, 1
  br i1 %10, label %11, label %12

11:                                               ; preds = %2
  br label %32

12:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %13, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  %14 = load i32, ptr %4, align 4, !tbaa !9
  %15 = sdiv i32 %14, 2
  store i32 %15, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #3
  %16 = load ptr, ptr %3, align 8, !tbaa !5
  %17 = load i32, ptr %4, align 4, !tbaa !9
  %18 = sdiv i32 %17, 2
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds i32, ptr %16, i64 %19
  store ptr %20, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #3
  %21 = load i32, ptr %4, align 4, !tbaa !9
  %22 = load i32, ptr %6, align 4, !tbaa !9
  %23 = sub nsw i32 %21, %22
  store i32 %23, ptr %8, align 4, !tbaa !9
  %24 = load ptr, ptr %5, align 8, !tbaa !5
  %25 = load i32, ptr %6, align 4, !tbaa !9
  call void @_Z9MergeSortPii(ptr noundef %24, i32 noundef %25)
  %26 = load ptr, ptr %7, align 8, !tbaa !5
  %27 = load i32, ptr %8, align 4, !tbaa !9
  call void @_Z9MergeSortPii(ptr noundef %26, i32 noundef %27)
  %28 = load ptr, ptr %5, align 8, !tbaa !5
  %29 = load i32, ptr %6, align 4, !tbaa !9
  %30 = load ptr, ptr %7, align 8, !tbaa !5
  %31 = load i32, ptr %8, align 4, !tbaa !9
  call void @_Z7MergingPiiS_i(ptr noundef %28, i32 noundef %29, ptr noundef %30, i32 noundef %31)
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  br label %32

32:                                               ; preds = %12, %11
  ret void
}

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { 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++ 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: mustprogress nounwind uwtable
declare dso_local void @_Z7MergingPiiS_i(ptr noundef, i32 noundef, ptr noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z9MergeSortPii(ptr noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp slt i32 %1, 2
  br i1 %3, label %common.ret14, label %4

common.ret14:                                     ; preds = %2, %4
  ret void

4:                                                ; preds = %2
  %5 = lshr i32 %1, 1
  %6 = zext nneg i32 %5 to i64
  %7 = getelementptr inbounds i32, ptr %0, i64 %6
  %8 = sub nsw i32 %1, %5
  tail call void @_Z9MergeSortPii(ptr noundef %0, i32 noundef %5)
  tail call void @_Z9MergeSortPii(ptr noundef %7, i32 noundef %8)
  tail call void @_Z7MergingPiiS_i(ptr noundef %0, i32 noundef %5, ptr noundef %7, i32 noundef %8)
  br label %common.ret14
}

attributes #0 = { 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" }

!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,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass