; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/math/Ackermann_function.ll (Z18Ackermann_Functionii)

; 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 uwtable
define dso_local noundef i32 @_Z18Ackermann_Functionii(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 %4, align 4, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !5
  %6 = load i32, ptr %4, align 4, !tbaa !5
  %7 = icmp eq i32 %6, 0
  br i1 %7, label %8, label %11

8:                                                ; preds = %2
  %9 = load i32, ptr %5, align 4, !tbaa !5
  %10 = add nsw i32 %9, 1
  store i32 %10, ptr %3, align 4
  br label %38

11:                                               ; preds = %2
  %12 = load i32, ptr %4, align 4, !tbaa !5
  %13 = icmp sgt i32 %12, 0
  br i1 %13, label %14, label %21

14:                                               ; preds = %11
  %15 = load i32, ptr %5, align 4, !tbaa !5
  %16 = icmp eq i32 %15, 0
  br i1 %16, label %17, label %21

17:                                               ; preds = %14
  %18 = load i32, ptr %4, align 4, !tbaa !5
  %19 = sub nsw i32 %18, 1
  %20 = call noundef i32 @_Z18Ackermann_Functionii(i32 noundef %19, i32 noundef 1)
  store i32 %20, ptr %3, align 4
  br label %38

21:                                               ; preds = %14, %11
  %22 = load i32, ptr %4, align 4, !tbaa !5
  %23 = icmp sgt i32 %22, 0
  br i1 %23, label %24, label %35

24:                                               ; preds = %21
  %25 = load i32, ptr %5, align 4, !tbaa !5
  %26 = icmp sgt i32 %25, 0
  br i1 %26, label %27, label %35

27:                                               ; preds = %24
  %28 = load i32, ptr %4, align 4, !tbaa !5
  %29 = sub nsw i32 %28, 1
  %30 = load i32, ptr %4, align 4, !tbaa !5
  %31 = load i32, ptr %5, align 4, !tbaa !5
  %32 = sub nsw i32 %31, 1
  %33 = call noundef i32 @_Z18Ackermann_Functionii(i32 noundef %30, i32 noundef %32)
  %34 = call noundef i32 @_Z18Ackermann_Functionii(i32 noundef %29, i32 noundef %33)
  store i32 %34, ptr %3, align 4
  br label %38

35:                                               ; preds = %24, %21
  br label %36

36:                                               ; preds = %35
  br label %37

37:                                               ; preds = %36
  unreachable

38:                                               ; preds = %27, %17, %8
  %39 = load i32, ptr %3, align 4
  ret i32 %39
}

attributes #0 = { 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" }

!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"}


; 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 nosync nounwind memory(inaccessiblemem: write) uwtable
define dso_local noundef range(i32 -2147483647, -2147483648) i32 @_Z18Ackermann_Functionii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp eq i32 %0, 0
  br i1 %3, label %tailrecurse._crit_edge, label %.lr.ph

tailrecurse._crit_edge:                           ; preds = %tailrecurse.backedge, %2
  %.tr15.lcssa = phi i32 [ %1, %2 ], [ %.tr15.be, %tailrecurse.backedge ]
  %4 = add nsw i32 %.tr15.lcssa, 1
  ret i32 %4

.lr.ph:                                           ; preds = %2, %tailrecurse.backedge
  %.tr1517 = phi i32 [ %.tr15.be, %tailrecurse.backedge ], [ %1, %2 ]
  %.tr16 = phi i32 [ %.tr.be, %tailrecurse.backedge ], [ %0, %2 ]
  %5 = icmp sgt i32 %.tr16, 0
  %6 = icmp eq i32 %.tr1517, 0
  %or.cond = and i1 %5, %6
  br i1 %or.cond, label %tailrecurse.backedge, label %8

tailrecurse.backedge:                             ; preds = %.lr.ph, %8
  %.tr15.be = phi i32 [ %11, %8 ], [ 1, %.lr.ph ]
  %.tr.be = add nsw i32 %.tr16, -1
  %7 = icmp eq i32 %.tr.be, 0
  br i1 %7, label %tailrecurse._crit_edge, label %.lr.ph

8:                                                ; preds = %.lr.ph
  %9 = icmp sgt i32 %.tr1517, 0
  tail call void @llvm.assume(i1 %5)
  tail call void @llvm.assume(i1 %9)
  %10 = add nsw i32 %.tr1517, -1
  %11 = tail call noundef i32 @_Z18Ackermann_Functionii(i32 noundef %.tr16, i32 noundef %10)
  br label %tailrecurse.backedge
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: write)
declare void @llvm.assume(i1 noundef) #1

attributes #0 = { mustprogress nofree nosync nounwind memory(inaccessiblemem: write) 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(inaccessiblemem: write) }

!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,GVNPass,GlobalOptPass,IPSCCPPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass