; LLVM IR from ayush-tulsyan/ACM-ICPC-Handbook :: code/SuffixTree.ll (Z25freeSuffixTreeByPostOrderP14SuffixTreeNode)

; 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.SuffixTreeNode = type { [256 x ptr], ptr, i32, ptr, i32 }

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress uwtable
define dso_local void @_Z25freeSuffixTreeByPostOrderP14SuffixTreeNode(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  store ptr %0, ptr %2, align 8, !tbaa !5
  %4 = load ptr, ptr %2, align 8, !tbaa !5
  %5 = icmp eq ptr %4, null
  br i1 %5, label %6, label %7

6:                                                ; preds = %1
  br label %41

7:                                                ; preds = %1
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  store i32 0, ptr %3, align 4, !tbaa !9
  br label %8

8:                                                ; preds = %27, %7
  %9 = load i32, ptr %3, align 4, !tbaa !9
  %10 = icmp slt i32 %9, 256
  br i1 %10, label %11, label %30

11:                                               ; preds = %8
  %12 = load ptr, ptr %2, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.SuffixTreeNode, ptr %12, i32 0, i32 0
  %14 = load i32, ptr %3, align 4, !tbaa !9
  %15 = sext i32 %14 to i64
  %16 = getelementptr inbounds [256 x ptr], ptr %13, i64 0, i64 %15
  %17 = load ptr, ptr %16, align 8, !tbaa !5
  %18 = icmp ne ptr %17, null
  br i1 %18, label %19, label %26

19:                                               ; preds = %11
  %20 = load ptr, ptr %2, align 8, !tbaa !5
  %21 = getelementptr inbounds %struct.SuffixTreeNode, ptr %20, i32 0, i32 0
  %22 = load i32, ptr %3, align 4, !tbaa !9
  %23 = sext i32 %22 to i64
  %24 = getelementptr inbounds [256 x ptr], ptr %21, i64 0, i64 %23
  %25 = load ptr, ptr %24, align 8, !tbaa !5
  call void @_Z25freeSuffixTreeByPostOrderP14SuffixTreeNode(ptr noundef %25)
  br label %26

26:                                               ; preds = %19, %11
  br label %27

27:                                               ; preds = %26
  %28 = load i32, ptr %3, align 4, !tbaa !9
  %29 = add nsw i32 %28, 1
  store i32 %29, ptr %3, align 4, !tbaa !9
  br label %8, !llvm.loop !11

30:                                               ; preds = %8
  %31 = load ptr, ptr %2, align 8, !tbaa !5
  %32 = getelementptr inbounds %struct.SuffixTreeNode, ptr %31, i32 0, i32 4
  %33 = load i32, ptr %32, align 8, !tbaa !13
  %34 = icmp eq i32 %33, -1
  br i1 %34, label %35, label %39

35:                                               ; preds = %30
  %36 = load ptr, ptr %2, align 8, !tbaa !5
  %37 = getelementptr inbounds %struct.SuffixTreeNode, ptr %36, i32 0, i32 3
  %38 = load ptr, ptr %37, align 8, !tbaa !15
  call void @free(ptr noundef %38) #3
  br label %39

39:                                               ; preds = %35, %30
  %40 = load ptr, ptr %2, align 8, !tbaa !5
  call void @free(ptr noundef %40) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  br label %41

41:                                               ; preds = %39, %6
  ret void
}

; Function Attrs: nounwind
declare void @free(ptr noundef) #2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #2 = { nounwind "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}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = !{!14, !10, i64 2072}
!14 = !{!"_ZTS14SuffixTreeNode", !7, i64 0, !6, i64 2048, !10, i64 2056, !6, i64 2064, !10, i64 2072}
!15 = !{!14, !6, i64 2064}


; 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
define dso_local void @_Z25freeSuffixTreeByPostOrderP14SuffixTreeNode(ptr noundef %0) local_unnamed_addr #0 {
  %2 = icmp eq ptr %0, null
  br i1 %2, label %15, label %.preheader

.preheader:                                       ; preds = %1, %6
  %indvars.iv = phi i64 [ %indvars.iv.next, %6 ], [ 0, %1 ]
  %3 = getelementptr inbounds [256 x ptr], ptr %0, i64 0, i64 %indvars.iv
  %4 = load ptr, ptr %3, align 8, !tbaa !5
  %.not = icmp eq ptr %4, null
  br i1 %.not, label %6, label %5

5:                                                ; preds = %.preheader
  tail call void @_Z25freeSuffixTreeByPostOrderP14SuffixTreeNode(ptr noundef nonnull %4)
  br label %6

6:                                                ; preds = %.preheader, %5
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, 256
  br i1 %exitcond.not, label %7, label %.preheader, !llvm.loop !9

7:                                                ; preds = %6
  %8 = getelementptr inbounds i8, ptr %0, i64 2072
  %9 = load i32, ptr %8, align 8, !tbaa !11
  %10 = icmp eq i32 %9, -1
  br i1 %10, label %11, label %14

11:                                               ; preds = %7
  %12 = getelementptr inbounds i8, ptr %0, i64 2064
  %13 = load ptr, ptr %12, align 8, !tbaa !14
  tail call void @free(ptr noundef %13) #2
  br label %14

14:                                               ; preds = %11, %7
  tail call void @free(ptr noundef nonnull %0) #2
  br label %15

15:                                               ; preds = %1, %14
  ret void
}

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #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 = { mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite) "alloc-family"="malloc" "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 #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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!12, !13, i64 2072}
!12 = !{!"_ZTS14SuffixTreeNode", !7, i64 0, !6, i64 2048, !13, i64 2056, !6, i64 2064, !13, i64 2072}
!13 = !{!"int", !7, i64 0}
!14 = !{!12, !6, i64 2064}


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