; LLVM IR from sbshah97/DS-Algo-Handbook :: Data-Structures/Linked_List/Circular_Linked_List (circ)

; 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 }

@front = external dso_local global ptr, align 8
@ptr = external dso_local global ptr, align 8
@.str.6 = external hidden unnamed_addr constant [45 x i8], align 1
@.str.7 = external hidden unnamed_addr constant [8 x i8], align 1
@.str.8 = external hidden unnamed_addr constant [5 x i8], align 1
@.str.9 = 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 @front, align 8, !tbaa !5
  store ptr %1, ptr @ptr, align 8, !tbaa !5
  %2 = call i32 (ptr, ...) @printf(ptr noundef @.str.6)
  %3 = load ptr, ptr @ptr, align 8, !tbaa !5
  %4 = getelementptr inbounds %struct.node, ptr %3, i32 0, i32 0
  %5 = load i32, ptr %4, align 8, !tbaa !9
  %6 = call i32 (ptr, ...) @printf(ptr noundef @.str.7, i32 noundef %5)
  %7 = load ptr, ptr @ptr, align 8, !tbaa !5
  %8 = getelementptr inbounds %struct.node, ptr %7, i32 0, i32 1
  %9 = load ptr, ptr %8, align 8, !tbaa !12
  store ptr %9, ptr @ptr, align 8, !tbaa !5
  br label %10

10:                                               ; preds = %19, %0
  %11 = load ptr, ptr @ptr, align 8, !tbaa !5
  %12 = load ptr, ptr @front, align 8, !tbaa !5
  %13 = icmp ne ptr %11, %12
  br i1 %13, label %14, label %23

14:                                               ; preds = %10
  %15 = load ptr, ptr @ptr, align 8, !tbaa !5
  %16 = getelementptr inbounds %struct.node, ptr %15, i32 0, i32 0
  %17 = load i32, ptr %16, align 8, !tbaa !9
  %18 = call i32 (ptr, ...) @printf(ptr noundef @.str.8, i32 noundef %17)
  br label %19

19:                                               ; preds = %14
  %20 = load ptr, ptr @ptr, align 8, !tbaa !5
  %21 = getelementptr inbounds %struct.node, ptr %20, i32 0, i32 1
  %22 = load ptr, ptr %21, align 8, !tbaa !12
  store ptr %22, ptr @ptr, align 8, !tbaa !5
  br label %10, !llvm.loop !13

23:                                               ; preds = %10
  %24 = call i32 (ptr, ...) @printf(ptr noundef @.str.9)
  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"

@front = external dso_local local_unnamed_addr global ptr, align 8
@ptr = external dso_local local_unnamed_addr global ptr, align 8
@.str.6 = external hidden unnamed_addr constant [45 x i8], align 1
@.str.7 = external hidden unnamed_addr constant [8 x i8], align 1
@.str.8 = external hidden unnamed_addr constant [5 x i8], align 1
@.str.9 = 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 @front, align 8, !tbaa !5
  store ptr %1, ptr @ptr, align 8, !tbaa !5
  %2 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.6)
  %3 = load ptr, ptr @ptr, align 8, !tbaa !5
  %4 = load i32, ptr %3, align 8, !tbaa !9
  %5 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.7, i32 noundef %4)
  %.pn1 = load ptr, ptr @ptr, align 8, !tbaa !5
  %storemerge.in2 = getelementptr inbounds i8, ptr %.pn1, i64 8
  %storemerge3 = load ptr, ptr %storemerge.in2, align 8, !tbaa !12
  store ptr %storemerge3, ptr @ptr, align 8, !tbaa !5
  %6 = load ptr, ptr @front, align 8, !tbaa !5
  %.not4 = icmp eq ptr %storemerge3, %6
  br i1 %.not4, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %0, %.lr.ph
  %storemerge5 = phi ptr [ %storemerge, %.lr.ph ], [ %storemerge3, %0 ]
  %7 = load i32, ptr %storemerge5, align 8, !tbaa !9
  %8 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.8, i32 noundef %7)
  %.pn = load ptr, ptr @ptr, align 8, !tbaa !5
  %storemerge.in = getelementptr inbounds i8, ptr %.pn, i64 8
  %storemerge = load ptr, ptr %storemerge.in, align 8, !tbaa !12
  store ptr %storemerge, ptr @ptr, align 8, !tbaa !5
  %9 = load ptr, ptr @front, align 8, !tbaa !5
  %.not = icmp eq ptr %storemerge, %9
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %.lr.ph, %0
  %10 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.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, 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