; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/ds/Queue_all_operations_using_linkedlist.ll (Z6insertP4Node)

; 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 }

@rear = external dso_local global ptr, align 8
@front = external dso_local global ptr, align 8

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z6insertP4Node(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  %3 = load ptr, ptr @front, align 8, !tbaa !5
  %4 = icmp eq ptr %3, null
  br i1 %4, label %5, label %7

5:                                                ; preds = %1
  %6 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %6, ptr @rear, align 8, !tbaa !5
  store ptr %6, ptr @front, align 8, !tbaa !5
  br label %12

7:                                                ; preds = %1
  %8 = load ptr, ptr %2, align 8, !tbaa !5
  %9 = load ptr, ptr @rear, align 8, !tbaa !5
  %10 = getelementptr inbounds %struct.Node, ptr %9, i32 0, i32 1
  store ptr %8, ptr %10, align 8, !tbaa !9
  %11 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %11, ptr @rear, align 8, !tbaa !5
  br label %12

12:                                               ; preds = %7, %5
  ret void
}

attributes #0 = { mustprogress 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++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"_ZTS4Node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, 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"

@rear = external dso_local local_unnamed_addr global ptr, align 8
@front = external dso_local local_unnamed_addr global ptr, align 8

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(readwrite, argmem: write, inaccessiblemem: none) uwtable
define dso_local void @_Z6insertP4Node(ptr noundef %0) local_unnamed_addr #0 {
  %2 = load ptr, ptr @front, align 8, !tbaa !5
  %3 = icmp eq ptr %2, null
  %4 = load ptr, ptr @rear, align 8
  %5 = getelementptr inbounds i8, ptr %4, i64 8
  %.sink = select i1 %3, ptr @front, ptr %5
  store ptr %0, ptr %.sink, align 8, !tbaa !5
  store ptr %0, ptr @rear, align 8
  ret void
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(readwrite, argmem: write, 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, !6, i64 0}
!6 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}


; Effective O3 passes: GlobalOptPass,InstCombinePass,MergedLoadStoreMotionPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass