; LLVM IR from HarshCasper/NeoAlgo :: C/ds (singly_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.node = type { i32, ptr }

@first = external dso_local global ptr, align 8
@ptr = external dso_local global ptr, align 8
@.str.31 = external hidden unnamed_addr constant [13 x i8], align 1
@.str.42 = external hidden unnamed_addr constant [34 x i8], align 1
@.str.43 = external hidden unnamed_addr constant [4 x i8], align 1

declare i32 @printf(ptr noundef, ...) #0

; Function Attrs: nounwind uwtable
define dso_local void @display() #1 {
  %1 = load ptr, ptr @first, align 8, !tbaa !5
  %2 = icmp eq ptr %1, null
  br i1 %2, label %3, label %6

3:                                                ; preds = %0
  %4 = call i32 (ptr, ...) @printf(ptr noundef @.str.31)
  %5 = call i32 (ptr, ...) @printf(ptr noundef @.str.42)
  br label %21

6:                                                ; preds = %0
  %7 = load ptr, ptr @first, align 8, !tbaa !5
  store ptr %7, ptr @ptr, align 8, !tbaa !5
  br label %8

8:                                                ; preds = %16, %6
  %9 = load ptr, ptr @ptr, align 8, !tbaa !5
  %10 = icmp ne ptr %9, null
  br i1 %10, label %11, label %20

11:                                               ; preds = %8
  %12 = load ptr, ptr @ptr, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.node, ptr %12, i32 0, i32 0
  %14 = load i32, ptr %13, align 8, !tbaa !9
  %15 = call i32 (ptr, ...) @printf(ptr noundef @.str.43, i32 noundef %14)
  br label %16

16:                                               ; preds = %11
  %17 = load ptr, ptr @ptr, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.node, ptr %17, i32 0, i32 1
  %19 = load ptr, ptr %18, align 8, !tbaa !12
  store ptr %19, ptr @ptr, align 8, !tbaa !5
  br label %8, !llvm.loop !13

20:                                               ; preds = %8
  br label %21

21:                                               ; preds = %20, %3
  ret void
}

attributes #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 = { 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, i64 0}
!10 = !{!"node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"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"

@first = external dso_local local_unnamed_addr global ptr, align 8
@ptr = external dso_local local_unnamed_addr global ptr, align 8
@.str.31 = external hidden unnamed_addr constant [13 x i8], align 1
@.str.42 = external hidden unnamed_addr constant [34 x i8], align 1
@.str.43 = external hidden unnamed_addr constant [4 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 @display() local_unnamed_addr #1 {
  %1 = load ptr, ptr @first, align 8, !tbaa !5
  %2 = icmp eq ptr %1, null
  br i1 %2, label %3, label %.preheader

.preheader:                                       ; preds = %0
  store ptr %1, ptr @ptr, align 8, !tbaa !5
  br label %6

3:                                                ; preds = %0
  %4 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.31)
  %5 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.42)
  br label %.loopexit

6:                                                ; preds = %.preheader, %6
  %storemerge2 = phi ptr [ %1, %.preheader ], [ %11, %6 ]
  %7 = load i32, ptr %storemerge2, align 8, !tbaa !9
  %8 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.43, i32 noundef %7)
  %9 = load ptr, ptr @ptr, align 8, !tbaa !5
  %10 = getelementptr inbounds i8, ptr %9, i64 8
  %11 = load ptr, ptr %10, align 8, !tbaa !12
  store ptr %11, ptr @ptr, align 8, !tbaa !5
  %.not = icmp eq ptr %11, null
  br i1 %.not, label %.loopexit, label %6, !llvm.loop !13

.loopexit:                                        ; preds = %6, %3
  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, i64 0}
!10 = !{!"node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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