; LLVM IR from codemistic/Data-Structures-and-Algorithms :: CPP/LINKED LIST/SOME LEET CODE QUESTIONS/Odd_Pairs.ll (Z24number_of_required_pairsi)

; 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
define dso_local noundef i64 @_Z24number_of_required_pairsi(i32 noundef %0) #0 {
  %2 = alloca i64, align 8
  %3 = alloca i32, align 4
  %4 = alloca i64, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  store i64 0, ptr %4, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 0, ptr %5, align 4, !tbaa !5
  br label %8

8:                                                ; preds = %56, %1
  %9 = load i32, ptr %5, align 4, !tbaa !5
  %10 = load i32, ptr %3, align 4, !tbaa !5
  %11 = icmp slt i32 %9, %10
  br i1 %11, label %13, label %12

12:                                               ; preds = %8
  store i32 2, ptr %6, align 4
  br label %59

13:                                               ; preds = %8
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  store i32 0, ptr %7, align 4, !tbaa !5
  br label %14

14:                                               ; preds = %50, %13
  %15 = load i32, ptr %7, align 4, !tbaa !5
  %16 = load i32, ptr %3, align 4, !tbaa !5
  %17 = icmp slt i32 %15, %16
  br i1 %17, label %19, label %18

18:                                               ; preds = %14
  store i32 5, ptr %6, align 4
  br label %53

19:                                               ; preds = %14
  %20 = load i32, ptr %5, align 4, !tbaa !5
  %21 = icmp eq i32 %20, 0
  br i1 %21, label %22, label %26

22:                                               ; preds = %19
  %23 = load i32, ptr %7, align 4, !tbaa !5
  %24 = icmp eq i32 %23, 0
  br i1 %24, label %25, label %26

25:                                               ; preds = %22
  store i64 0, ptr %2, align 8
  store i32 1, ptr %6, align 4
  br label %53

26:                                               ; preds = %22, %19
  %27 = load i32, ptr %5, align 4, !tbaa !5
  %28 = icmp sge i32 %27, 1
  br i1 %28, label %29, label %49

29:                                               ; preds = %26
  %30 = load i32, ptr %7, align 4, !tbaa !5
  %31 = icmp sge i32 %30, 1
  br i1 %31, label %32, label %49

32:                                               ; preds = %29
  %33 = load i32, ptr %5, align 4, !tbaa !5
  %34 = load i32, ptr %3, align 4, !tbaa !5
  %35 = icmp sle i32 %33, %34
  br i1 %35, label %36, label %49

36:                                               ; preds = %32
  %37 = load i32, ptr %7, align 4, !tbaa !5
  %38 = load i32, ptr %3, align 4, !tbaa !5
  %39 = icmp sle i32 %37, %38
  br i1 %39, label %40, label %49

40:                                               ; preds = %36
  %41 = load i32, ptr %5, align 4, !tbaa !5
  %42 = load i32, ptr %7, align 4, !tbaa !5
  %43 = add nsw i32 %41, %42
  %44 = srem i32 %43, 2
  %45 = icmp ne i32 %44, 0
  br i1 %45, label %46, label %49

46:                                               ; preds = %40
  %47 = load i64, ptr %4, align 8, !tbaa !9
  %48 = add nsw i64 %47, 1
  store i64 %48, ptr %4, align 8, !tbaa !9
  br label %49

49:                                               ; preds = %46, %40, %36, %32, %29, %26
  br label %50

50:                                               ; preds = %49
  %51 = load i32, ptr %7, align 4, !tbaa !5
  %52 = add nsw i32 %51, 1
  store i32 %52, ptr %7, align 4, !tbaa !5
  br label %14, !llvm.loop !11

53:                                               ; preds = %25, %18
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  %54 = load i32, ptr %6, align 4
  switch i32 %54, label %59 [
    i32 5, label %55
  ]

55:                                               ; preds = %53
  br label %56

56:                                               ; preds = %55
  %57 = load i32, ptr %5, align 4, !tbaa !5
  %58 = add nsw i32 %57, 1
  store i32 %58, ptr %5, align 4, !tbaa !5
  br label %8, !llvm.loop !13

59:                                               ; preds = %53, %12
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  %60 = load i32, ptr %6, align 4
  switch i32 %60, label %63 [
    i32 2, label %61
  ]

61:                                               ; preds = %59
  %62 = load i64, ptr %4, align 8, !tbaa !9
  store i64 %62, ptr %2, align 8
  store i32 1, ptr %6, align 4
  br label %63

63:                                               ; preds = %61, %59
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  %64 = load i64, ptr %2, align 8
  ret i64 %64
}

; 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

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 = { 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 = !{!10, !10, i64 0}
!10 = !{!"long long", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}


; 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 nofree norecurse nosync nounwind willreturn memory(none) uwtable
define dso_local noundef i64 @_Z24number_of_required_pairsi(i32 noundef %0) local_unnamed_addr #0 {
  ret i64 0
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(none) 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