; LLVM IR from sbshah97/DS-Algo-Handbook :: Data-Structures/Trees/Binary_Search_Trees (BinarSearchTree)

; 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.node = type { i32, ptr, ptr }

@t2 = external dso_local global ptr, align 8

; Function Attrs: nounwind uwtable
define dso_local i32 @largst(ptr noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  %4 = load ptr, ptr %3, align 8, !tbaa !5
  %5 = getelementptr inbounds %struct.node, ptr %4, i32 0, i32 2
  %6 = load ptr, ptr %5, align 8, !tbaa !9
  %7 = icmp ne ptr %6, null
  br i1 %7, label %8, label %14

8:                                                ; preds = %1
  %9 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %9, ptr @t2, align 8, !tbaa !5
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.node, ptr %10, i32 0, i32 2
  %12 = load ptr, ptr %11, align 8, !tbaa !9
  %13 = call i32 @largst(ptr noundef %12)
  store i32 %13, ptr %2, align 4
  br label %18

14:                                               ; preds = %1
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  %16 = getelementptr inbounds %struct.node, ptr %15, i32 0, i32 0
  %17 = load i32, ptr %16, align 8, !tbaa !12
  store i32 %17, ptr %2, align 4
  br label %18

18:                                               ; preds = %14, %8
  %19 = load i32, ptr %2, align 4
  ret i32 %19
}

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, !6, i64 16}
!10 = !{!"node", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !11, 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"

@t2 = external dso_local local_unnamed_addr global ptr, align 8

; Function Attrs: nofree norecurse nosync nounwind memory(readwrite, argmem: read, inaccessiblemem: none) uwtable
define dso_local i32 @largst(ptr noundef %0) local_unnamed_addr #0 {
  %2 = getelementptr inbounds i8, ptr %0, i64 16
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %.not4 = icmp eq ptr %3, null
  br i1 %.not4, label %7, label %tailrecurse

tailrecurse:                                      ; preds = %1, %tailrecurse
  %4 = phi ptr [ %6, %tailrecurse ], [ %3, %1 ]
  %.tr5 = phi ptr [ %4, %tailrecurse ], [ %0, %1 ]
  %5 = getelementptr inbounds i8, ptr %4, i64 16
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  %.not = icmp eq ptr %6, null
  br i1 %.not, label %tailrecurse._crit_edge, label %tailrecurse

tailrecurse._crit_edge:                           ; preds = %tailrecurse
  store ptr %.tr5, ptr @t2, align 8, !tbaa !11
  br label %7

7:                                                ; preds = %tailrecurse._crit_edge, %1
  %.tr.lcssa = phi ptr [ %4, %tailrecurse._crit_edge ], [ %0, %1 ]
  %8 = load i32, ptr %.tr.lcssa, align 8, !tbaa !12
  ret i32 %8
}

attributes #0 = { nofree norecurse nosync nounwind memory(readwrite, argmem: 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, !10, i64 16}
!6 = !{!"node", !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 = !{!10, !10, i64 0}
!12 = !{!6, !7, i64 0}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass