; LLVM IR from MakeContributions/DSA :: algorithms/C/linked-lists (doubly-linked-list)

; 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.dll = type { i32, ptr, ptr }
%struct.node_ = type { i32, 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
declare void @free(ptr noundef) #1

; Function Attrs: nounwind uwtable
define dso_local i32 @pop_back(ptr noundef %0) #2 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  %7 = getelementptr inbounds %struct.dll, ptr %6, i32 0, i32 2
  %8 = load ptr, ptr %7, align 8, !tbaa !9
  %9 = icmp eq ptr %8, null
  br i1 %9, label %10, label %11

10:                                               ; preds = %1
  store i32 -1, ptr %2, align 4
  br label %35

11:                                               ; preds = %1
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  %12 = load ptr, ptr %3, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.dll, ptr %12, i32 0, i32 2
  %14 = load ptr, ptr %13, align 8, !tbaa !9
  store ptr %14, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  %15 = load ptr, ptr %4, 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 %5, align 4, !tbaa !14
  %18 = load ptr, ptr %3, align 8, !tbaa !5
  %19 = getelementptr inbounds %struct.dll, ptr %18, i32 0, i32 2
  %20 = load ptr, ptr %19, align 8, !tbaa !9
  %21 = getelementptr inbounds %struct.node_, ptr %20, i32 0, i32 2
  %22 = load ptr, ptr %21, align 8, !tbaa !15
  %23 = load ptr, ptr %3, align 8, !tbaa !5
  %24 = getelementptr inbounds %struct.dll, ptr %23, i32 0, i32 2
  store ptr %22, ptr %24, align 8, !tbaa !9
  %25 = load ptr, ptr %4, align 8, !tbaa !5
  call void @free(ptr noundef %25) #3
  store ptr null, ptr %4, align 8, !tbaa !5
  %26 = load ptr, ptr %3, align 8, !tbaa !5
  %27 = getelementptr inbounds %struct.dll, ptr %26, i32 0, i32 2
  %28 = load ptr, ptr %27, align 8, !tbaa !9
  %29 = getelementptr inbounds %struct.node_, ptr %28, i32 0, i32 1
  store ptr null, ptr %29, align 8, !tbaa !16
  %30 = load ptr, ptr %3, align 8, !tbaa !5
  %31 = getelementptr inbounds %struct.dll, ptr %30, i32 0, i32 0
  %32 = load i32, ptr %31, align 8, !tbaa !17
  %33 = add i32 %32, -1
  store i32 %33, ptr %31, align 8, !tbaa !17
  %34 = load i32, ptr %5, align 4, !tbaa !14
  store i32 %34, ptr %2, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  br label %35

35:                                               ; preds = %11, %10
  %36 = load i32, ptr %2, align 4
  ret i32 %36
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #2 = { 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 #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 16}
!10 = !{!"", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!13, !11, i64 0}
!13 = !{!"node_", !11, i64 0, !6, i64 8, !6, i64 16}
!14 = !{!11, !11, i64 0}
!15 = !{!13, !6, i64 16}
!16 = !{!13, !6, i64 8}
!17 = !{!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"

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind willreturn uwtable
define dso_local i32 @pop_back(ptr nocapture noundef %0) local_unnamed_addr #1 {
  %2 = getelementptr inbounds i8, ptr %0, i64 16
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %4 = icmp eq ptr %3, null
  br i1 %4, label %13, label %5

5:                                                ; preds = %1
  %6 = load i32, ptr %3, align 8, !tbaa !11
  %7 = getelementptr inbounds i8, ptr %3, i64 16
  %8 = load ptr, ptr %7, align 8, !tbaa !13
  store ptr %8, ptr %2, align 8, !tbaa !5
  tail call void @free(ptr noundef nonnull %3) #2
  %9 = load ptr, ptr %2, align 8, !tbaa !5
  %10 = getelementptr inbounds i8, ptr %9, i64 8
  store ptr null, ptr %10, align 8, !tbaa !14
  %11 = load i32, ptr %0, align 8, !tbaa !15
  %12 = add i32 %11, -1
  store i32 %12, ptr %0, align 8, !tbaa !15
  br label %13

13:                                               ; preds = %1, %5
  %.0 = phi i32 [ %6, %5 ], [ -1, %1 ]
  ret i32 %.0
}

attributes #0 = { 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 #1 = { mustprogress nounwind willreturn 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, !10, i64 16}
!6 = !{!"", !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, !7, i64 0}
!12 = !{!"node_", !7, i64 0, !10, i64 8, !10, i64 16}
!13 = !{!12, !10, i64 16}
!14 = !{!12, !10, i64 8}
!15 = !{!6, !7, i64 0}


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