; LLVM IR from graphitemaster/libintrusive :: list (list_pop_back)

; 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.list_s = type { ptr, ptr }
%struct.link_s = type { 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 ptr @list_pop_back(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  %7 = getelementptr inbounds %struct.list_s, ptr %6, i32 0, i32 1
  %8 = load ptr, ptr %7, align 8, !tbaa !9
  store ptr %8, ptr %4, align 8, !tbaa !5
  %9 = load ptr, ptr %4, align 8, !tbaa !5
  %10 = icmp ne ptr %9, null
  br i1 %10, label %12, label %11

11:                                               ; preds = %1
  store ptr null, ptr %2, align 8
  store i32 1, ptr %5, align 4
  br label %64

12:                                               ; preds = %1
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.link_s, ptr %13, i32 0, i32 1
  %15 = load ptr, ptr %14, align 8, !tbaa !11
  %16 = icmp ne ptr %15, null
  br i1 %16, label %17, label %25

17:                                               ; preds = %12
  %18 = load ptr, ptr %4, align 8, !tbaa !5
  %19 = getelementptr inbounds %struct.link_s, ptr %18, i32 0, i32 0
  %20 = load ptr, ptr %19, align 8, !tbaa !13
  %21 = load ptr, ptr %4, align 8, !tbaa !5
  %22 = getelementptr inbounds %struct.link_s, ptr %21, i32 0, i32 1
  %23 = load ptr, ptr %22, align 8, !tbaa !11
  %24 = getelementptr inbounds %struct.link_s, ptr %23, i32 0, i32 0
  store ptr %20, ptr %24, align 8, !tbaa !13
  br label %25

25:                                               ; preds = %17, %12
  %26 = load ptr, ptr %4, align 8, !tbaa !5
  %27 = getelementptr inbounds %struct.link_s, ptr %26, i32 0, i32 0
  %28 = load ptr, ptr %27, align 8, !tbaa !13
  %29 = icmp ne ptr %28, null
  br i1 %29, label %30, label %38

30:                                               ; preds = %25
  %31 = load ptr, ptr %4, align 8, !tbaa !5
  %32 = getelementptr inbounds %struct.link_s, ptr %31, i32 0, i32 1
  %33 = load ptr, ptr %32, align 8, !tbaa !11
  %34 = load ptr, ptr %4, align 8, !tbaa !5
  %35 = getelementptr inbounds %struct.link_s, ptr %34, i32 0, i32 0
  %36 = load ptr, ptr %35, align 8, !tbaa !13
  %37 = getelementptr inbounds %struct.link_s, ptr %36, i32 0, i32 1
  store ptr %33, ptr %37, align 8, !tbaa !11
  br label %38

38:                                               ; preds = %30, %25
  %39 = load ptr, ptr %3, align 8, !tbaa !5
  %40 = getelementptr inbounds %struct.list_s, ptr %39, i32 0, i32 0
  %41 = load ptr, ptr %40, align 8, !tbaa !14
  %42 = load ptr, ptr %4, align 8, !tbaa !5
  %43 = icmp eq ptr %41, %42
  br i1 %43, label %44, label %50

44:                                               ; preds = %38
  %45 = load ptr, ptr %4, align 8, !tbaa !5
  %46 = getelementptr inbounds %struct.link_s, ptr %45, i32 0, i32 1
  %47 = load ptr, ptr %46, align 8, !tbaa !11
  %48 = load ptr, ptr %3, align 8, !tbaa !5
  %49 = getelementptr inbounds %struct.list_s, ptr %48, i32 0, i32 0
  store ptr %47, ptr %49, align 8, !tbaa !14
  br label %50

50:                                               ; preds = %44, %38
  %51 = load ptr, ptr %3, align 8, !tbaa !5
  %52 = getelementptr inbounds %struct.list_s, ptr %51, i32 0, i32 1
  %53 = load ptr, ptr %52, align 8, !tbaa !9
  %54 = load ptr, ptr %4, align 8, !tbaa !5
  %55 = icmp eq ptr %53, %54
  br i1 %55, label %56, label %62

56:                                               ; preds = %50
  %57 = load ptr, ptr %4, align 8, !tbaa !5
  %58 = getelementptr inbounds %struct.link_s, ptr %57, i32 0, i32 0
  %59 = load ptr, ptr %58, align 8, !tbaa !13
  %60 = load ptr, ptr %3, align 8, !tbaa !5
  %61 = getelementptr inbounds %struct.list_s, ptr %60, i32 0, i32 1
  store ptr %59, ptr %61, align 8, !tbaa !9
  br label %62

62:                                               ; preds = %56, %50
  %63 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %63, ptr %2, align 8
  store i32 1, ptr %5, align 4
  br label %64

64:                                               ; preds = %62, %11
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  %65 = load ptr, ptr %2, align 8
  ret ptr %65
}

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 }

!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 = !{!"list_s", !6, i64 0, !6, i64 8}
!11 = !{!12, !6, i64 8}
!12 = !{!"link_s", !6, i64 0, !6, i64 8}
!13 = !{!12, !6, i64 0}
!14 = !{!10, !6, 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"

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(readwrite, inaccessiblemem: none) uwtable
define dso_local ptr @list_pop_back(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 %17, label %4

4:                                                ; preds = %1
  %5 = getelementptr inbounds i8, ptr %3, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !10
  %.not21 = icmp eq ptr %6, null
  %.pre = load ptr, ptr %3, align 8, !tbaa !12
  br i1 %.not21, label %8, label %7

7:                                                ; preds = %4
  store ptr %.pre, ptr %6, align 8, !tbaa !12
  br label %8

8:                                                ; preds = %7, %4
  %.not22 = icmp eq ptr %.pre, null
  br i1 %.not22, label %11, label %9

9:                                                ; preds = %8
  %10 = getelementptr inbounds i8, ptr %.pre, i64 8
  store ptr %6, ptr %10, align 8, !tbaa !10
  br label %11

11:                                               ; preds = %9, %8
  %12 = load ptr, ptr %0, align 8, !tbaa !13
  %13 = icmp eq ptr %12, %3
  br i1 %13, label %14, label %16

14:                                               ; preds = %11
  %15 = load ptr, ptr %5, align 8, !tbaa !10
  store ptr %15, ptr %0, align 8, !tbaa !13
  br label %16

16:                                               ; preds = %11, %14
  store ptr %.pre, ptr %2, align 8, !tbaa !5
  br label %17

17:                                               ; preds = %16, %1
  ret ptr %3
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(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 = !{!"list_s", !7, i64 0, !7, i64 8}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!11, !7, i64 8}
!11 = !{!"link_s", !7, i64 0, !7, i64 8}
!12 = !{!11, !7, i64 0}
!13 = !{!6, !7, i64 0}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass