; LLVM IR from BurntSushi/clibs :: libds (linkedlist)

; 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.DSLinkedList = type { i32, ptr, ptr }
%struct.DSListNode = type { ptr, ptr, ptr }

; 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: nounwind uwtable
define dso_local void @ds_list_free(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  %6 = getelementptr inbounds %struct.DSLinkedList, ptr %5, i32 0, i32 1
  %7 = load ptr, ptr %6, align 8, !tbaa !9
  store ptr %7, ptr %3, align 8, !tbaa !5
  br label %8

8:                                                ; preds = %11, %1
  %9 = load ptr, ptr %3, align 8, !tbaa !5
  %10 = icmp ne ptr %9, null
  br i1 %10, label %11, label %20

11:                                               ; preds = %8
  %12 = load ptr, ptr %3, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.DSListNode, ptr %12, i32 0, i32 2
  %14 = load ptr, ptr %13, align 8, !tbaa !12
  store ptr %14, ptr %4, align 8, !tbaa !5
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  %16 = getelementptr inbounds %struct.DSListNode, ptr %15, i32 0, i32 0
  %17 = load ptr, ptr %16, align 8, !tbaa !14
  call void @free(ptr noundef %17) #3
  %18 = load ptr, ptr %3, align 8, !tbaa !5
  call void @free(ptr noundef %18) #3
  %19 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %19, ptr %3, align 8, !tbaa !5
  br label %8, !llvm.loop !15

20:                                               ; preds = %8
  %21 = load ptr, ptr %2, align 8, !tbaa !5
  call void @free(ptr noundef %21) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  ret void
}

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

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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/C++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"DSLinkedList", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!13, !6, i64 16}
!13 = !{!"DSListNode", !6, i64 0, !6, i64 8, !6, i64 16}
!14 = !{!13, !6, i64 0}
!15 = distinct !{!15, !16}
!16 = !{!"llvm.loop.mustprogress"}


; 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: nounwind uwtable
define dso_local void @ds_list_free(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
  %.not7 = icmp eq ptr %3, null
  br i1 %.not7, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.08 = phi ptr [ %5, %.lr.ph ], [ %3, %1 ]
  %4 = getelementptr inbounds i8, ptr %.08, i64 16
  %5 = load ptr, ptr %4, align 8, !tbaa !11
  %6 = load ptr, ptr %.08, align 8, !tbaa !13
  tail call void @free(ptr noundef %6) #2
  tail call void @free(ptr noundef nonnull %.08) #2
  %.not = icmp eq ptr %5, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !14

._crit_edge:                                      ; preds = %.lr.ph, %1
  tail call void @free(ptr noundef %0) #2
  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 = { 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, !10, i64 8}
!6 = !{!"DSLinkedList", !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 = !{!12, !10, i64 16}
!12 = !{!"DSListNode", !10, i64 0, !10, i64 8, !10, i64 16}
!13 = !{!12, !10, i64 0}
!14 = distinct !{!14, !15}
!15 = !{!"llvm.loop.mustprogress"}


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