; LLVM IR from kaynewbie/algorithm :: algorithm/CodingInterviews (question-26)

; 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"

%struct.TreeNode = type { i32, ptr, ptr }

; Function Attrs: nounwind uwtable
define dso_local zeroext i1 @isSubtreeCore(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca i1, align 1
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  %6 = load ptr, ptr %4, align 8, !tbaa !5
  %7 = icmp eq ptr %6, null
  br i1 %7, label %8, label %9

8:                                                ; preds = %2
  store i1 true, ptr %3, align 1
  br label %39

9:                                                ; preds = %2
  %10 = load ptr, ptr %5, align 8, !tbaa !5
  %11 = icmp eq ptr %10, null
  br i1 %11, label %12, label %13

12:                                               ; preds = %9
  store i1 false, ptr %3, align 1
  br label %39

13:                                               ; preds = %9
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  %15 = getelementptr inbounds %struct.TreeNode, ptr %14, i32 0, i32 0
  %16 = load i32, ptr %15, align 8, !tbaa !9
  %17 = load ptr, ptr %5, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.TreeNode, ptr %17, i32 0, i32 0
  %19 = load i32, ptr %18, align 8, !tbaa !9
  %20 = icmp eq i32 %16, %19
  br i1 %20, label %21, label %37

21:                                               ; preds = %13
  %22 = load ptr, ptr %4, align 8, !tbaa !5
  %23 = getelementptr inbounds %struct.TreeNode, ptr %22, i32 0, i32 1
  %24 = load ptr, ptr %23, align 8, !tbaa !12
  %25 = load ptr, ptr %5, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.TreeNode, ptr %25, i32 0, i32 1
  %27 = load ptr, ptr %26, align 8, !tbaa !12
  %28 = call zeroext i1 @isSubtreeCore(ptr noundef %24, ptr noundef %27)
  br i1 %28, label %29, label %37

29:                                               ; preds = %21
  %30 = load ptr, ptr %5, align 8, !tbaa !5
  %31 = getelementptr inbounds %struct.TreeNode, ptr %30, i32 0, i32 2
  %32 = load ptr, ptr %31, align 8, !tbaa !13
  %33 = load ptr, ptr %5, align 8, !tbaa !5
  %34 = getelementptr inbounds %struct.TreeNode, ptr %33, i32 0, i32 2
  %35 = load ptr, ptr %34, align 8, !tbaa !13
  %36 = call zeroext i1 @isSubtreeCore(ptr noundef %32, ptr noundef %35)
  br label %37

37:                                               ; preds = %29, %21, %13
  %38 = phi i1 [ false, %21 ], [ false, %13 ], [ %36, %29 ]
  store i1 %38, ptr %3, align 1
  br label %39

39:                                               ; preds = %37, %12, %8
  %40 = load i1, ptr %3, align 1
  ret i1 %40
}

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)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !11, i64 0}
!10 = !{!"TreeNode", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 8}
!13 = !{!10, !6, i64 16}


; 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: nofree nosync nounwind memory(read, inaccessiblemem: none) uwtable
define dso_local noundef zeroext i1 @isSubtreeCore(ptr noundef readonly %0, ptr noundef readonly %1) local_unnamed_addr #0 {
  %3 = icmp eq ptr %0, null
  br i1 %3, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %tailrecurse
  %.tr1113 = phi ptr [ %16, %tailrecurse ], [ %1, %2 ]
  %.tr12 = phi ptr [ %16, %tailrecurse ], [ %0, %2 ]
  %4 = icmp eq ptr %.tr1113, null
  br i1 %4, label %._crit_edge, label %5

5:                                                ; preds = %.lr.ph
  %6 = load i32, ptr %.tr12, align 8, !tbaa !5
  %7 = load i32, ptr %.tr1113, align 8, !tbaa !5
  %8 = icmp eq i32 %6, %7
  br i1 %8, label %9, label %._crit_edge

9:                                                ; preds = %5
  %10 = getelementptr inbounds i8, ptr %.tr12, i64 8
  %11 = load ptr, ptr %10, align 8, !tbaa !11
  %12 = getelementptr inbounds i8, ptr %.tr1113, i64 8
  %13 = load ptr, ptr %12, align 8, !tbaa !11
  %14 = tail call zeroext i1 @isSubtreeCore(ptr noundef %11, ptr noundef %13)
  br i1 %14, label %tailrecurse, label %._crit_edge

tailrecurse:                                      ; preds = %9
  %15 = getelementptr inbounds i8, ptr %.tr1113, i64 16
  %16 = load ptr, ptr %15, align 8, !tbaa !12
  %17 = icmp eq ptr %16, null
  br i1 %17, label %._crit_edge, label %.lr.ph

._crit_edge:                                      ; preds = %tailrecurse, %.lr.ph, %9, %5, %2
  %.0 = phi i1 [ true, %2 ], [ false, %5 ], [ false, %9 ], [ false, %.lr.ph ], [ true, %tailrecurse ]
  ret i1 %.0
}

attributes #0 = { nofree nosync nounwind memory(read, inaccessiblemem: 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)"}
!5 = !{!6, !7, i64 0}
!6 = !{!"TreeNode", !7, i64 0, !10, i64 8, !10, i64 16}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = !{!6, !10, i64 8}
!12 = !{!6, !10, i64 16}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass