; LLVM IR from brewlin/garbage-collect :: tri-color-marking (stack)

; 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.link_list = type { ptr, ptr }
%struct.stack_header = type { ptr, ptr }

; Function Attrs: nounwind uwtable
define dso_local void @push(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  %6 = call noalias ptr @malloc(i64 noundef 16) #4
  store ptr %6, ptr %5, align 8, !tbaa !5
  %7 = load ptr, ptr %4, align 8, !tbaa !5
  %8 = load ptr, ptr %5, align 8, !tbaa !5
  %9 = getelementptr inbounds %struct.link_list, ptr %8, i32 0, i32 0
  store ptr %7, ptr %9, align 8, !tbaa !9
  %10 = load ptr, ptr %5, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.link_list, ptr %10, i32 0, i32 1
  store ptr null, ptr %11, align 8, !tbaa !11
  %12 = load ptr, ptr %3, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.stack_header, ptr %12, i32 0, i32 0
  %14 = load ptr, ptr %13, align 8, !tbaa !12
  %15 = icmp eq ptr %14, null
  br i1 %15, label %16, label %20

16:                                               ; preds = %2
  %17 = load ptr, ptr %5, align 8, !tbaa !5
  %18 = load ptr, ptr %3, align 8, !tbaa !5
  %19 = getelementptr inbounds %struct.stack_header, ptr %18, i32 0, i32 0
  store ptr %17, ptr %19, align 8, !tbaa !12
  br label %20

20:                                               ; preds = %16, %2
  %21 = load ptr, ptr %3, align 8, !tbaa !5
  %22 = getelementptr inbounds %struct.stack_header, ptr %21, i32 0, i32 1
  %23 = load ptr, ptr %22, align 8, !tbaa !14
  %24 = icmp eq ptr %23, null
  br i1 %24, label %25, label %31

25:                                               ; preds = %20
  %26 = load ptr, ptr %3, align 8, !tbaa !5
  %27 = getelementptr inbounds %struct.stack_header, ptr %26, i32 0, i32 0
  %28 = load ptr, ptr %27, align 8, !tbaa !12
  %29 = load ptr, ptr %3, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.stack_header, ptr %29, i32 0, i32 1
  store ptr %28, ptr %30, align 8, !tbaa !14
  br label %40

31:                                               ; preds = %20
  %32 = load ptr, ptr %5, align 8, !tbaa !5
  %33 = load ptr, ptr %3, align 8, !tbaa !5
  %34 = getelementptr inbounds %struct.stack_header, ptr %33, i32 0, i32 1
  %35 = load ptr, ptr %34, align 8, !tbaa !14
  %36 = getelementptr inbounds %struct.link_list, ptr %35, i32 0, i32 1
  store ptr %32, ptr %36, align 8, !tbaa !11
  %37 = load ptr, ptr %5, align 8, !tbaa !5
  %38 = load ptr, ptr %3, align 8, !tbaa !5
  %39 = getelementptr inbounds %struct.stack_header, ptr %38, i32 0, i32 1
  store ptr %37, ptr %39, align 8, !tbaa !14
  br label %40

40:                                               ; preds = %31, %25
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  ret void
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nounwind allocsize(0)
declare noalias ptr @malloc(i64 noundef) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #3 = { nounwind }
attributes #4 = { 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, !6, i64 0}
!10 = !{!"link_list", !6, i64 0, !6, i64 8}
!11 = !{!10, !6, i64 8}
!12 = !{!13, !6, i64 0}
!13 = !{!"stack_header", !6, i64 0, !6, i64 8}
!14 = !{!13, !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, argmem: readwrite, inaccessiblemem: readwrite) uwtable
define dso_local void @push(ptr nocapture noundef %0, ptr noundef %1) local_unnamed_addr #0 {
  %3 = tail call noalias dereferenceable_or_null(16) ptr @malloc(i64 noundef 16) #2
  store ptr %1, ptr %3, align 8, !tbaa !5
  %4 = getelementptr inbounds i8, ptr %3, i64 8
  store ptr null, ptr %4, align 8, !tbaa !10
  %5 = load ptr, ptr %0, align 8, !tbaa !11
  %6 = icmp eq ptr %5, null
  br i1 %6, label %7, label %8

7:                                                ; preds = %2
  store ptr %3, ptr %0, align 8, !tbaa !11
  br label %8

8:                                                ; preds = %7, %2
  %9 = phi ptr [ %3, %7 ], [ %5, %2 ]
  %10 = getelementptr inbounds i8, ptr %0, i64 8
  %11 = load ptr, ptr %10, align 8, !tbaa !13
  %12 = icmp eq ptr %11, null
  br i1 %12, label %15, label %13

13:                                               ; preds = %8
  %14 = getelementptr inbounds i8, ptr %11, i64 8
  store ptr %3, ptr %14, align 8, !tbaa !10
  br label %15

15:                                               ; preds = %8, %13
  %storemerge = phi ptr [ %3, %13 ], [ %9, %8 ]
  store ptr %storemerge, ptr %10, align 8, !tbaa !13
  ret void
}

; 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

attributes #0 = { mustprogress nofree nounwind willreturn memory(write, argmem: readwrite, 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 = { 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, !7, i64 0}
!6 = !{!"link_list", !7, i64 0, !7, i64 8}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!6, !7, i64 8}
!11 = !{!12, !7, i64 0}
!12 = !{!"stack_header", !7, i64 0, !7, i64 8}
!13 = !{!12, !7, i64 8}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,PostOrderFunctionAttrsPass,SROAPass,TailCallElimPass