; LLVM IR from overnote/over-algorithm :: code/code-c/01-list (03-DLinkList)

; 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.DNode = type { i32, ptr, ptr }

@.str = external hidden unnamed_addr constant [15 x i8], align 1

; Function Attrs: nounwind uwtable
define dso_local i32 @InitDLinkList(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  %3 = call noalias ptr @malloc(i64 noundef 24) #4
  %4 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %3, ptr %4, align 8, !tbaa !5
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  %6 = icmp eq ptr %5, null
  br i1 %6, label %7, label %9

7:                                                ; preds = %1
  %8 = call i32 (ptr, ...) @printf(ptr noundef @.str)
  call void @exit(i32 noundef 1) #5
  unreachable

9:                                                ; preds = %1
  %10 = load ptr, ptr %2, align 8, !tbaa !5
  %11 = load ptr, ptr %10, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.DNode, ptr %11, i32 0, i32 0
  store i32 0, ptr %12, align 8, !tbaa !9
  %13 = load ptr, ptr %2, align 8, !tbaa !5
  %14 = load ptr, ptr %13, align 8, !tbaa !5
  %15 = getelementptr inbounds %struct.DNode, ptr %14, i32 0, i32 2
  store ptr null, ptr %15, align 8, !tbaa !12
  %16 = load ptr, ptr %2, align 8, !tbaa !5
  %17 = load ptr, ptr %16, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.DNode, ptr %17, i32 0, i32 1
  store ptr null, ptr %18, align 8, !tbaa !13
  %19 = load ptr, ptr %2, align 8, !tbaa !5
  %20 = load ptr, ptr %19, align 8, !tbaa !5
  %21 = getelementptr inbounds %struct.DNode, ptr %20, i32 0, i32 2
  store ptr null, ptr %21, align 8, !tbaa !12
  ret i32 1
}

; Function Attrs: nounwind allocsize(0)
declare noalias ptr @malloc(i64 noundef) #1

declare i32 @printf(ptr noundef, ...) #2

; Function Attrs: noreturn nounwind
declare void @exit(i32 noundef) #3

attributes #0 = { 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 #1 = { nounwind allocsize(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 = { "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 = { noreturn 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 #4 = { nounwind allocsize(0) }
attributes #5 = { noreturn 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, !11, i64 0}
!10 = !{!"DNode", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 16}
!13 = !{!10, !6, i64 8}


; 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: mustprogress nofree nounwind willreturn memory(write, inaccessiblemem: readwrite) uwtable
define dso_local noundef i32 @InitDLinkList(ptr nocapture noundef writeonly %0) local_unnamed_addr #0 {
  %2 = tail call noalias dereferenceable_or_null(24) ptr @malloc(i64 noundef 24) #3
  store ptr %2, ptr %0, align 8, !tbaa !5
  store i32 0, ptr %2, align 8, !tbaa !9
  %3 = getelementptr inbounds i8, ptr %2, i64 8
  tail call void @llvm.memset.p0.i64(ptr noundef nonnull align 8 dereferenceable(16) %3, i8 0, i64 16, i1 false)
  ret i32 1
}

; Function Attrs: mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite)
declare noalias noundef ptr @malloc(i64 noundef) local_unnamed_addr #1

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #2

attributes #0 = { mustprogress nofree nounwind willreturn memory(write, inaccessiblemem: readwrite) 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 #1 = { mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite) "alloc-family"="malloc" "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 = { nocallback nofree nounwind willreturn memory(argmem: write) }
attributes #3 = { nounwind allocsize(0) }

!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 = !{!"DNode", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}


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