; LLVM IR from ybubnov/libhuffman :: src (io)

; 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.__huf_read_writer = type { ptr, ptr, ptr }
%struct.__huf_memstream = type { ptr, i64, i64, i64 }

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

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

; Function Attrs: nounwind uwtable
define dso_local i32 @huf_memrewind(ptr noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 0, ptr %4, align 4, !tbaa !9
  br label %7

7:                                                ; preds = %1
  %8 = load ptr, ptr %3, align 8, !tbaa !5
  %9 = icmp eq ptr %8, null
  br i1 %9, label %10, label %11

10:                                               ; preds = %7
  store i32 2, ptr %4, align 4, !tbaa !9
  br label %22

11:                                               ; preds = %7
  br label %12

12:                                               ; preds = %11
  br label %13

13:                                               ; preds = %12
  %14 = load ptr, ptr %3, align 8, !tbaa !5
  %15 = getelementptr inbounds %struct.__huf_read_writer, ptr %14, i32 0, i32 0
  %16 = load ptr, ptr %15, align 8, !tbaa !11
  store ptr %16, ptr %5, align 8, !tbaa !5
  %17 = load ptr, ptr %5, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.__huf_memstream, ptr %17, i32 0, i32 2
  store i64 0, ptr %18, align 8, !tbaa !13
  %19 = load ptr, ptr %5, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct.__huf_memstream, ptr %19, i32 0, i32 1
  store i64 0, ptr %20, align 8, !tbaa !16
  br label %21

21:                                               ; preds = %13
  br label %22

22:                                               ; preds = %21, %10
  %23 = load i32, ptr %4, align 4, !tbaa !9
  store i32 %23, ptr %2, align 4
  store i32 1, ptr %6, align 4
  br label %26

24:                                               ; No predecessors!
  br label %25

25:                                               ; preds = %24
  store i32 0, ptr %6, align 4
  br label %26

26:                                               ; preds = %25, %22
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  %27 = load i32, ptr %6, align 4
  switch i32 %27, label %30 [
    i32 0, label %28
    i32 1, label %28
  ]

28:                                               ; preds = %26, %26
  %29 = load i32, ptr %2, align 4
  ret i32 %29

30:                                               ; preds = %26
  unreachable
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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" }
attributes #2 = { 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, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !6, i64 0}
!12 = !{!"__huf_read_writer", !6, i64 0, !6, i64 8, !6, i64 16}
!13 = !{!14, !15, i64 16}
!14 = !{!"__huf_memstream", !6, i64 0, !15, i64 8, !15, i64 16, !15, i64 24}
!15 = !{!"long", !7, i64 0}
!16 = !{!14, !15, 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 norecurse nosync nounwind willreturn memory(write, argmem: readwrite, inaccessiblemem: none) uwtable
define dso_local range(i32 0, 3) i32 @huf_memrewind(ptr noundef readonly %0) local_unnamed_addr #0 {
  %2 = icmp eq ptr %0, null
  br i1 %2, label %6, label %3

3:                                                ; preds = %1
  %4 = load ptr, ptr %0, align 8, !tbaa !5
  %5 = getelementptr inbounds i8, ptr %4, i64 8
  tail call void @llvm.memset.p0.i64(ptr noundef nonnull align 8 dereferenceable(16) %5, i8 0, i64 16, i1 false)
  br label %6

6:                                                ; preds = %1, %3
  %.0 = phi i32 [ 0, %3 ], [ 2, %1 ]
  ret i32 %.0
}

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #1

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(write, argmem: readwrite, 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" }
attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: write) }

!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 = !{!"__huf_read_writer", !7, i64 0, !7, i64 8, !7, i64 16}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}


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