; LLVM IR from gzc/CLRS :: C16-Greedy-Algorithms/huffman/BinaryStdOut.ll (ZN12BinaryStdOut11clearBufferEv)

; 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.BinaryStdOut = type { i8, i32, %"class.std::basic_ofstream" }
%"class.std::basic_ofstream" = type { %"class.std::basic_ostream.base", %"class.std::basic_filebuf", %"class.std::basic_ios" }
%"class.std::basic_ostream.base" = type { ptr }
%"class.std::basic_filebuf" = type { %"class.std::basic_streambuf", %union.pthread_mutex_t, %"class.std::__basic_file", i32, %struct.__mbstate_t, %struct.__mbstate_t, %struct.__mbstate_t, ptr, i64, i8, i8, i8, i8, ptr, ptr, i8, ptr, ptr, i64, ptr, ptr }
%"class.std::basic_streambuf" = type { ptr, ptr, ptr, ptr, ptr, ptr, ptr, %"class.std::locale" }
%"class.std::locale" = type { ptr }
%union.pthread_mutex_t = type { %struct.__pthread_mutex_s }
%struct.__pthread_mutex_s = type { i32, i32, i32, i32, i32, i16, i16, %struct.__pthread_internal_list }
%struct.__pthread_internal_list = type { ptr, ptr }
%"class.std::__basic_file" = type <{ ptr, i8, [7 x i8] }>
%struct.__mbstate_t = type { i32, %union.anon.0 }
%union.anon.0 = type { i32 }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }

; Function Attrs: mustprogress uwtable
define dso_local void @_ZN12BinaryStdOut11clearBufferEv(ptr noundef nonnull align 8 dereferenceable(520) %0) #0 align 2 {
  %2 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  %3 = load ptr, ptr %2, align 8
  %4 = getelementptr inbounds %class.BinaryStdOut, ptr %3, i32 0, i32 1
  %5 = load i32, ptr %4, align 4, !tbaa !9
  %6 = icmp eq i32 %5, 0
  br i1 %6, label %7, label %8

7:                                                ; preds = %1
  br label %28

8:                                                ; preds = %1
  %9 = getelementptr inbounds %class.BinaryStdOut, ptr %3, i32 0, i32 1
  %10 = load i32, ptr %9, align 4, !tbaa !9
  %11 = icmp sgt i32 %10, 0
  br i1 %11, label %12, label %21

12:                                               ; preds = %8
  %13 = getelementptr inbounds %class.BinaryStdOut, ptr %3, i32 0, i32 1
  %14 = load i32, ptr %13, align 4, !tbaa !9
  %15 = sub nsw i32 8, %14
  %16 = getelementptr inbounds %class.BinaryStdOut, ptr %3, i32 0, i32 0
  %17 = load i8, ptr %16, align 8, !tbaa !22
  %18 = sext i8 %17 to i32
  %19 = shl i32 %18, %15
  %20 = trunc i32 %19 to i8
  store i8 %20, ptr %16, align 8, !tbaa !22
  br label %21

21:                                               ; preds = %12, %8
  %22 = getelementptr inbounds %class.BinaryStdOut, ptr %3, i32 0, i32 2
  %23 = getelementptr inbounds %class.BinaryStdOut, ptr %3, i32 0, i32 0
  %24 = load i8, ptr %23, align 8, !tbaa !22
  %25 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) %22, i8 noundef signext %24)
  %26 = getelementptr inbounds %class.BinaryStdOut, ptr %3, i32 0, i32 1
  store i32 0, ptr %26, align 4, !tbaa !9
  %27 = getelementptr inbounds %class.BinaryStdOut, ptr %3, i32 0, i32 0
  store i8 0, ptr %27, align 8, !tbaa !22
  br label %28

28:                                               ; preds = %21, %7
  ret void
}

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8), i8 noundef signext) #1

attributes #0 = { mustprogress 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 = { inlinehint mustprogress 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, !11, i64 4}
!10 = !{!"_ZTS12BinaryStdOut", !7, i64 0, !11, i64 4, !12, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!"_ZTSSt14basic_ofstreamIcSt11char_traitsIcEE", !13, i64 0, !14, i64 8}
!13 = !{!"_ZTSSo"}
!14 = !{!"_ZTSSt13basic_filebufIcSt11char_traitsIcEE", !15, i64 0, !7, i64 64, !17, i64 104, !19, i64 120, !20, i64 124, !20, i64 132, !20, i64 140, !6, i64 152, !21, i64 160, !18, i64 168, !18, i64 169, !18, i64 170, !7, i64 171, !6, i64 176, !6, i64 184, !18, i64 192, !6, i64 200, !6, i64 208, !21, i64 216, !6, i64 224, !6, i64 232}
!15 = !{!"_ZTSSt15basic_streambufIcSt11char_traitsIcEE", !6, i64 8, !6, i64 16, !6, i64 24, !6, i64 32, !6, i64 40, !6, i64 48, !16, i64 56}
!16 = !{!"_ZTSSt6locale", !6, i64 0}
!17 = !{!"_ZTSSt12__basic_fileIcE", !6, i64 0, !18, i64 8}
!18 = !{!"bool", !7, i64 0}
!19 = !{!"_ZTSSt13_Ios_Openmode", !7, i64 0}
!20 = !{!"_ZTS11__mbstate_t", !11, i64 0, !7, i64 4}
!21 = !{!"long", !7, i64 0}
!22 = !{!10, !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: mustprogress uwtable
define dso_local void @_ZN12BinaryStdOut11clearBufferEv(ptr noundef nonnull align 8 dereferenceable(520) %0) local_unnamed_addr #0 align 2 {
  %2 = getelementptr inbounds i8, ptr %0, i64 4
  %3 = load i32, ptr %2, align 4, !tbaa !5
  %4 = icmp eq i32 %3, 0
  br i1 %4, label %16, label %5

5:                                                ; preds = %1
  %6 = icmp sgt i32 %3, 0
  %.pre = load i8, ptr %0, align 8, !tbaa !21
  br i1 %6, label %7, label %12

7:                                                ; preds = %5
  %8 = sub nsw i32 8, %3
  %9 = zext i8 %.pre to i32
  %10 = shl nuw nsw i32 %9, %8
  %11 = trunc i32 %10 to i8
  store i8 %11, ptr %0, align 8, !tbaa !21
  br label %12

12:                                               ; preds = %7, %5
  %13 = phi i8 [ %11, %7 ], [ %.pre, %5 ]
  %14 = getelementptr inbounds i8, ptr %0, i64 8
  %15 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) %14, i8 noundef signext %13)
  store i32 0, ptr %2, align 4, !tbaa !5
  store i8 0, ptr %0, align 8, !tbaa !21
  br label %16

16:                                               ; preds = %1, %12
  ret void
}

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8), i8 noundef signext) local_unnamed_addr #1

attributes #0 = { mustprogress 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 = { inlinehint mustprogress 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, !9, i64 4}
!6 = !{!"_ZTS12BinaryStdOut", !7, i64 0, !9, i64 4, !10, i64 8}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!"int", !7, i64 0}
!10 = !{!"_ZTSSt14basic_ofstreamIcSt11char_traitsIcEE", !11, i64 0, !12, i64 8}
!11 = !{!"_ZTSSo"}
!12 = !{!"_ZTSSt13basic_filebufIcSt11char_traitsIcEE", !13, i64 0, !7, i64 64, !16, i64 104, !18, i64 120, !19, i64 124, !19, i64 132, !19, i64 140, !14, i64 152, !20, i64 160, !17, i64 168, !17, i64 169, !17, i64 170, !7, i64 171, !14, i64 176, !14, i64 184, !17, i64 192, !14, i64 200, !14, i64 208, !20, i64 216, !14, i64 224, !14, i64 232}
!13 = !{!"_ZTSSt15basic_streambufIcSt11char_traitsIcEE", !14, i64 8, !14, i64 16, !14, i64 24, !14, i64 32, !14, i64 40, !14, i64 48, !15, i64 56}
!14 = !{!"any pointer", !7, i64 0}
!15 = !{!"_ZTSSt6locale", !14, i64 0}
!16 = !{!"_ZTSSt12__basic_fileIcE", !14, i64 0, !17, i64 8}
!17 = !{!"bool", !7, i64 0}
!18 = !{!"_ZTSSt13_Ios_Openmode", !7, i64 0}
!19 = !{!"_ZTS11__mbstate_t", !9, i64 0, !7, i64 4}
!20 = !{!"long", !7, i64 0}
!21 = !{!6, !7, i64 0}


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