; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 10. Linked List/LinkedListBasic-Operations.ll (Z10deleteHeadRP4node)

; 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"

%class.node = type { i32, ptr }

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nobuiltin nounwind
declare void @_ZdlPvm(ptr noundef, i64 noundef) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z10deleteHeadRP4node(ptr noundef nonnull align 8 dereferenceable(8) %0) #2 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  %4 = load ptr, ptr %2, align 8, !tbaa !5
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %6 = icmp eq ptr %5, null
  br i1 %6, label %7, label %8

7:                                                ; preds = %1
  br label %20

8:                                                ; preds = %1
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  %9 = load ptr, ptr %2, align 8, !tbaa !5
  %10 = load ptr, ptr %9, align 8, !tbaa !5
  store ptr %10, ptr %3, align 8, !tbaa !5
  %11 = load ptr, ptr %2, align 8, !tbaa !5
  %12 = load ptr, ptr %11, align 8, !tbaa !5
  %13 = getelementptr inbounds %class.node, ptr %12, i32 0, i32 1
  %14 = load ptr, ptr %13, align 8, !tbaa !9
  %15 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %14, ptr %15, align 8, !tbaa !5
  %16 = load ptr, ptr %3, align 8, !tbaa !5
  %17 = icmp eq ptr %16, null
  br i1 %17, label %19, label %18

18:                                               ; preds = %8
  call void @_ZdlPvm(ptr noundef %16, i64 noundef 16) #4
  br label %19

19:                                               ; preds = %18, %8
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  br label %20

20:                                               ; preds = %19, %7
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { nobuiltin 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 = { 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" }
attributes #3 = { nounwind }
attributes #4 = { builtin 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++ 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"

; Function Attrs: nobuiltin nounwind
declare void @_ZdlPvm(ptr noundef, i64 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z10deleteHeadRP4node(ptr nocapture noundef nonnull align 8 dereferenceable(8) %0) local_unnamed_addr #1 {
  %2 = load ptr, ptr %0, align 8, !tbaa !5
  %3 = icmp eq ptr %2, null
  br i1 %3, label %7, label %4

4:                                                ; preds = %1
  %5 = getelementptr inbounds i8, ptr %2, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !9
  store ptr %6, ptr %0, align 8, !tbaa !5
  tail call void @_ZdlPvm(ptr noundef nonnull %2, i64 noundef 16) #2
  br label %7

7:                                                ; preds = %1, %4
  ret void
}

attributes #0 = { nobuiltin 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 = { 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" }
attributes #2 = { builtin 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++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"_ZTS4node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}


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