; LLVM IR from fmela/libdict :: src (skiplist)

; 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.skiplist_itor = type { ptr, ptr }
%struct.skip_node = type { ptr, ptr, ptr, i32, [0 x ptr] }

; Function Attrs: nounwind uwtable
define dso_local zeroext i1 @skiplist_itor_prev(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %4 = getelementptr inbounds %struct.skiplist_itor, ptr %3, i32 0, i32 1
  %5 = load ptr, ptr %4, align 8, !tbaa !9
  %6 = icmp ne ptr %5, null
  br i1 %6, label %7, label %15

7:                                                ; preds = %1
  %8 = load ptr, ptr %2, align 8, !tbaa !5
  %9 = getelementptr inbounds %struct.skiplist_itor, ptr %8, i32 0, i32 1
  %10 = load ptr, ptr %9, align 8, !tbaa !9
  %11 = getelementptr inbounds %struct.skip_node, ptr %10, i32 0, i32 2
  %12 = load ptr, ptr %11, align 8, !tbaa !5
  %13 = load ptr, ptr %2, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.skiplist_itor, ptr %13, i32 0, i32 1
  store ptr %12, ptr %14, align 8, !tbaa !9
  br label %15

15:                                               ; preds = %7, %1
  %16 = load ptr, ptr %2, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.skiplist_itor, ptr %16, i32 0, i32 1
  %18 = load ptr, ptr %17, align 8, !tbaa !9
  %19 = icmp ne ptr %18, null
  ret i1 %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 8}
!10 = !{!"skiplist_itor", !6, i64 0, !6, i64 8}


; 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(read, argmem: readwrite, inaccessiblemem: none) uwtable
define dso_local zeroext i1 @skiplist_itor_prev(ptr nocapture noundef %0) local_unnamed_addr #0 {
  %2 = getelementptr inbounds i8, ptr %0, i64 8
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %.not = icmp eq ptr %3, null
  br i1 %.not, label %8, label %4

4:                                                ; preds = %1
  %5 = getelementptr inbounds i8, ptr %3, i64 16
  %6 = load ptr, ptr %5, align 8, !tbaa !10
  store ptr %6, ptr %2, align 8, !tbaa !5
  %7 = icmp ne ptr %6, null
  br label %8

8:                                                ; preds = %4, %1
  %9 = phi i1 [ %7, %4 ], [ false, %1 ]
  ret i1 %9
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: readwrite, 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 8}
!6 = !{!"skiplist_itor", !7, i64 0, !7, i64 8}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!7, !7, i64 0}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,InstCombinePass,PostOrderFunctionAttrsPass,SROAPass