; LLVM IR from AlgoGenesis/C :: Linked_list/Singly_linked_list/middleelement (middleelement)

; 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.Node = type { i32, ptr }

@head = external dso_local global ptr, align 8
@.str.3 = external hidden unnamed_addr constant [3 x i8], align 1

; 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

declare i32 @printf(ptr noundef, ...) #1

; Function Attrs: nounwind uwtable
define dso_local void @middleelement() #2 {
  %1 = alloca ptr, align 8
  %2 = alloca ptr, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr %1) #3
  %3 = load ptr, ptr @head, align 8, !tbaa !5
  store ptr %3, ptr %1, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #3
  %4 = load ptr, ptr @head, align 8, !tbaa !5
  store ptr %4, ptr %2, align 8, !tbaa !5
  br label %5

5:                                                ; preds = %15, %0
  %6 = load ptr, ptr %2, align 8, !tbaa !5
  %7 = icmp ne ptr %6, null
  br i1 %7, label %8, label %13

8:                                                ; preds = %5
  %9 = load ptr, ptr %2, align 8, !tbaa !5
  %10 = getelementptr inbounds %struct.Node, ptr %9, i32 0, i32 1
  %11 = load ptr, ptr %10, align 8, !tbaa !9
  %12 = icmp ne ptr %11, null
  br label %13

13:                                               ; preds = %8, %5
  %14 = phi i1 [ false, %5 ], [ %12, %8 ]
  br i1 %14, label %15, label %24

15:                                               ; preds = %13
  %16 = load ptr, ptr %1, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.Node, ptr %16, i32 0, i32 1
  %18 = load ptr, ptr %17, align 8, !tbaa !9
  store ptr %18, ptr %1, align 8, !tbaa !5
  %19 = load ptr, ptr %2, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct.Node, ptr %19, i32 0, i32 1
  %21 = load ptr, ptr %20, align 8, !tbaa !9
  %22 = getelementptr inbounds %struct.Node, ptr %21, i32 0, i32 1
  %23 = load ptr, ptr %22, align 8, !tbaa !9
  store ptr %23, ptr %2, align 8, !tbaa !5
  br label %5, !llvm.loop !12

24:                                               ; preds = %13
  %25 = load ptr, ptr %1, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.Node, ptr %25, i32 0, i32 0
  %27 = load i32, ptr %26, align 8, !tbaa !14
  %28 = call i32 (ptr, ...) @printf(ptr noundef @.str.3, i32 noundef %27)
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %1) #3
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { "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 8}
!10 = !{!"Node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}
!14 = !{!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"

@head = external dso_local local_unnamed_addr global ptr, align 8
@.str.3 = external hidden unnamed_addr constant [3 x i8], align 1

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #0

; Function Attrs: nofree nounwind uwtable
define dso_local void @middleelement() local_unnamed_addr #1 {
  %1 = load ptr, ptr @head, align 8, !tbaa !5, !nonnull !9, !noundef !9
  br label %.lr.ph

.lr.ph:                                           ; preds = %0, %4
  %.010 = phi ptr [ %8, %4 ], [ %1, %0 ]
  %.059 = phi ptr [ %6, %4 ], [ %1, %0 ]
  %2 = getelementptr inbounds i8, ptr %.010, i64 8
  %3 = load ptr, ptr %2, align 8, !tbaa !10
  %.not7 = icmp eq ptr %3, null
  br i1 %.not7, label %.critedge, label %4

4:                                                ; preds = %.lr.ph
  %5 = getelementptr inbounds i8, ptr %.059, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !10
  %7 = getelementptr inbounds i8, ptr %3, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !10
  %.not = icmp eq ptr %8, null
  br i1 %.not, label %.critedge, label %.lr.ph, !llvm.loop !13

.critedge:                                        ; preds = %.lr.ph, %4
  %.05.lcssa = phi ptr [ %6, %4 ], [ %.059, %.lr.ph ]
  %9 = load i32, ptr %.05.lcssa, align 8, !tbaa !15
  %10 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.3, i32 noundef %9)
  ret void
}

attributes #0 = { nofree 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 #1 = { nofree 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 = !{!11, !6, i64 8}
!11 = !{!"Node", !12, i64 0, !6, i64 8}
!12 = !{!"int", !7, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = !{!11, !12, i64 0}


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