; LLVM IR from TheAlgorithms/C-Plus-Plus :: math/fibonacci_fast.ll (Z3fibm)

; 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.std::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char>::_Alloc_hider", i64, %union.anon.0 }
%"struct.std::__cxx11::basic_string<char>::_Alloc_hider" = type { ptr }
%union.anon.0 = type { i64, [8 x i8] }

@_ZZ3fibmE2f1 = external hidden global i64, align 8
@_ZZ3fibmE2f2 = external hidden global i64, align 8
@.str = external hidden unnamed_addr constant [23 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [33 x i8], align 1
@_ZTISt16invalid_argument = external constant ptr

; Function Attrs: mustprogress uwtable
define dso_local noundef i64 @_Z3fibm(i64 noundef %0) #0 personality ptr @__gxx_personality_v0 {
  %2 = alloca i64, align 8
  %3 = alloca i64, align 8
  %4 = alloca %"class.std::__cxx11::basic_string", align 8
  %5 = alloca %"class.std::__cxx11::basic_string", align 8
  %6 = alloca %"class.std::__cxx11::basic_string", align 8
  %7 = alloca ptr, align 8
  %8 = alloca i32, align 4
  %9 = alloca i1, align 1
  %10 = alloca i64, align 8
  store i64 %0, ptr %3, align 8, !tbaa !5
  %11 = load i64, ptr %3, align 8, !tbaa !5
  %12 = icmp ule i64 %11, 2
  br i1 %12, label %13, label %15

13:                                               ; preds = %1
  %14 = load i64, ptr @_ZZ3fibmE2f2, align 8, !tbaa !5
  store i64 %14, ptr %2, align 8
  br label %53

15:                                               ; preds = %1
  %16 = load i64, ptr %3, align 8, !tbaa !5
  %17 = icmp uge i64 %16, 93
  br i1 %17, label %18, label %46

18:                                               ; preds = %15
  store i1 true, ptr %9, align 1
  %19 = call ptr @__cxa_allocate_exception(i64 16) #6
  call void @llvm.lifetime.start.p0(i64 32, ptr %4) #6
  call void @llvm.lifetime.start.p0(i64 32, ptr %5) #6
  call void @llvm.lifetime.start.p0(i64 32, ptr %6) #6
  invoke void @_ZNSt7__cxx119to_stringEm(ptr dead_on_unwind writable sret(%"class.std::__cxx11::basic_string") align 8 %6, i64 noundef 93)
          to label %20 unwind label %24

20:                                               ; preds = %18
  invoke void @_ZStplIcSt11char_traitsIcESaIcEENSt7__cxx1112basic_stringIT_T0_T1_EEPKS5_OS8_(ptr dead_on_unwind writable sret(%"class.std::__cxx11::basic_string") align 8 %5, ptr noundef @.str, ptr noundef nonnull align 8 dereferenceable(32) %6)
          to label %21 unwind label %28

21:                                               ; preds = %20
  invoke void @_ZStplIcSt11char_traitsIcESaIcEENSt7__cxx1112basic_stringIT_T0_T1_EEOS8_PKS5_(ptr dead_on_unwind writable sret(%"class.std::__cxx11::basic_string") align 8 %4, ptr noundef nonnull align 8 dereferenceable(32) %5, ptr noundef @.str.1)
          to label %22 unwind label %32

22:                                               ; preds = %21
  invoke void @_ZNSt16invalid_argumentC1ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull align 8 dereferenceable(16) %19, ptr noundef nonnull align 8 dereferenceable(32) %4)
          to label %23 unwind label %36

23:                                               ; preds = %22
  store i1 false, ptr %9, align 1
  invoke void @__cxa_throw(ptr %19, ptr @_ZTISt16invalid_argument, ptr @_ZNSt16invalid_argumentD1Ev) #7
          to label %60 unwind label %36

24:                                               ; preds = %18
  %25 = landingpad { ptr, i32 }
          cleanup
  %26 = extractvalue { ptr, i32 } %25, 0
  store ptr %26, ptr %7, align 8
  %27 = extractvalue { ptr, i32 } %25, 1
  store i32 %27, ptr %8, align 4
  br label %42

28:                                               ; preds = %20
  %29 = landingpad { ptr, i32 }
          cleanup
  %30 = extractvalue { ptr, i32 } %29, 0
  store ptr %30, ptr %7, align 8
  %31 = extractvalue { ptr, i32 } %29, 1
  store i32 %31, ptr %8, align 4
  br label %41

32:                                               ; preds = %21
  %33 = landingpad { ptr, i32 }
          cleanup
  %34 = extractvalue { ptr, i32 } %33, 0
  store ptr %34, ptr %7, align 8
  %35 = extractvalue { ptr, i32 } %33, 1
  store i32 %35, ptr %8, align 4
  br label %40

36:                                               ; preds = %23, %22
  %37 = landingpad { ptr, i32 }
          cleanup
  %38 = extractvalue { ptr, i32 } %37, 0
  store ptr %38, ptr %7, align 8
  %39 = extractvalue { ptr, i32 } %37, 1
  store i32 %39, ptr %8, align 4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %4) #6
  br label %40

40:                                               ; preds = %36, %32
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %5) #6
  br label %41

41:                                               ; preds = %40, %28
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %6) #6
  br label %42

42:                                               ; preds = %41, %24
  call void @llvm.lifetime.end.p0(i64 32, ptr %6) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr %5) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr %4) #6
  %43 = load i1, ptr %9, align 1
  br i1 %43, label %44, label %45

44:                                               ; preds = %42
  call void @__cxa_free_exception(ptr %19) #6
  br label %45

45:                                               ; preds = %44, %42
  br label %55

46:                                               ; preds = %15
  call void @llvm.lifetime.start.p0(i64 8, ptr %10) #6
  %47 = load i64, ptr @_ZZ3fibmE2f2, align 8, !tbaa !5
  store i64 %47, ptr %10, align 8, !tbaa !5
  %48 = load i64, ptr @_ZZ3fibmE2f1, align 8, !tbaa !5
  %49 = load i64, ptr @_ZZ3fibmE2f2, align 8, !tbaa !5
  %50 = add i64 %49, %48
  store i64 %50, ptr @_ZZ3fibmE2f2, align 8, !tbaa !5
  %51 = load i64, ptr %10, align 8, !tbaa !5
  store i64 %51, ptr @_ZZ3fibmE2f1, align 8, !tbaa !5
  %52 = load i64, ptr @_ZZ3fibmE2f2, align 8, !tbaa !5
  store i64 %52, ptr %2, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %10) #6
  br label %53

53:                                               ; preds = %46, %13
  %54 = load i64, ptr %2, align 8
  ret i64 %54

55:                                               ; preds = %45
  %56 = load ptr, ptr %7, align 8
  %57 = load i32, ptr %8, align 4
  %58 = insertvalue { ptr, i32 } poison, ptr %56, 0
  %59 = insertvalue { ptr, i32 } %58, i32 %57, 1
  resume { ptr, i32 } %59

60:                                               ; preds = %23
  unreachable
}

declare ptr @__cxa_allocate_exception(i64)

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

; Function Attrs: inlinehint mustprogress uwtable
declare dso_local void @_ZStplIcSt11char_traitsIcESaIcEENSt7__cxx1112basic_stringIT_T0_T1_EEOS8_PKS5_(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, ptr noundef nonnull align 8 dereferenceable(32), ptr noundef) #2

; Function Attrs: inlinehint mustprogress uwtable
declare dso_local void @_ZStplIcSt11char_traitsIcESaIcEENSt7__cxx1112basic_stringIT_T0_T1_EEPKS5_OS8_(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, ptr noundef, ptr noundef nonnull align 8 dereferenceable(32)) #2

; Function Attrs: inlinehint mustprogress uwtable
declare dso_local void @_ZNSt7__cxx119to_stringEm(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, i64 noundef) #2

declare i32 @__gxx_personality_v0(...)

declare void @_ZNSt16invalid_argumentC1ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #3

; Function Attrs: nounwind
declare void @_ZNSt16invalid_argumentD1Ev(ptr noundef nonnull align 8 dereferenceable(16)) unnamed_addr #4

declare void @__cxa_throw(ptr, ptr, ptr)

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #5 align 2

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

declare void @__cxa_free_exception(ptr)

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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" }
attributes #3 = { "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 "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 #5 = { 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 #6 = { nounwind }
attributes #7 = { noreturn }

!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 = !{!"long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}


; 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"

%"class.std::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char>::_Alloc_hider", i64, %union.anon.0 }
%"struct.std::__cxx11::basic_string<char>::_Alloc_hider" = type { ptr }
%union.anon.0 = type { i64, [8 x i8] }

@_ZZ3fibmE2f1 = external hidden local_unnamed_addr global i64, align 8
@_ZZ3fibmE2f2 = external hidden local_unnamed_addr global i64, align 8
@.str = external hidden unnamed_addr constant [23 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [33 x i8], align 1
@_ZTISt16invalid_argument = external constant ptr

; Function Attrs: mustprogress uwtable
define dso_local noundef i64 @_Z3fibm(i64 noundef %0) local_unnamed_addr #0 personality ptr @__gxx_personality_v0 {
  %2 = alloca %"class.std::__cxx11::basic_string", align 8
  %3 = alloca %"class.std::__cxx11::basic_string", align 8
  %4 = alloca %"class.std::__cxx11::basic_string", align 8
  %5 = icmp ult i64 %0, 3
  br i1 %5, label %6, label %8

6:                                                ; preds = %1
  %7 = load i64, ptr @_ZZ3fibmE2f2, align 8, !tbaa !5
  br label %28

8:                                                ; preds = %1
  %9 = icmp ugt i64 %0, 92
  br i1 %9, label %10, label %24

10:                                               ; preds = %8
  %11 = tail call ptr @__cxa_allocate_exception(i64 16) #6
  call void @llvm.lifetime.start.p0(i64 32, ptr nonnull %2) #6
  call void @llvm.lifetime.start.p0(i64 32, ptr nonnull %3) #6
  call void @llvm.lifetime.start.p0(i64 32, ptr nonnull %4) #6
  invoke void @_ZNSt7__cxx119to_stringEm(ptr dead_on_unwind nonnull writable sret(%"class.std::__cxx11::basic_string") align 8 %4, i64 noundef 93)
          to label %12 unwind label %.thread

12:                                               ; preds = %10
  invoke void @_ZStplIcSt11char_traitsIcESaIcEENSt7__cxx1112basic_stringIT_T0_T1_EEPKS5_OS8_(ptr dead_on_unwind nonnull writable sret(%"class.std::__cxx11::basic_string") align 8 %3, ptr noundef nonnull @.str, ptr noundef nonnull align 8 dereferenceable(32) %4)
          to label %13 unwind label %.thread21

13:                                               ; preds = %12
  invoke void @_ZStplIcSt11char_traitsIcESaIcEENSt7__cxx1112basic_stringIT_T0_T1_EEOS8_PKS5_(ptr dead_on_unwind nonnull writable sret(%"class.std::__cxx11::basic_string") align 8 %2, ptr noundef nonnull align 8 dereferenceable(32) %3, ptr noundef nonnull @.str.1)
          to label %14 unwind label %18

14:                                               ; preds = %13
  invoke void @_ZNSt16invalid_argumentC1ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull align 8 dereferenceable(16) %11, ptr noundef nonnull align 8 dereferenceable(32) %2)
          to label %15 unwind label %20

15:                                               ; preds = %14
  invoke void @__cxa_throw(ptr nonnull %11, ptr nonnull @_ZTISt16invalid_argument, ptr nonnull @_ZNSt16invalid_argumentD1Ev) #7
          to label %30 unwind label %20

.thread:                                          ; preds = %10
  %16 = landingpad { ptr, i32 }
          cleanup
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %4) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %3) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %2) #6
  br label %23

.thread21:                                        ; preds = %12
  %17 = landingpad { ptr, i32 }
          cleanup
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %4) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %4) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %3) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %2) #6
  br label %23

18:                                               ; preds = %13
  %19 = landingpad { ptr, i32 }
          cleanup
  br label %22

20:                                               ; preds = %15, %14
  %.06 = phi i1 [ false, %15 ], [ true, %14 ]
  %21 = landingpad { ptr, i32 }
          cleanup
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %2) #6
  br label %22

22:                                               ; preds = %18, %20
  %.pn = phi { ptr, i32 } [ %21, %20 ], [ %19, %18 ]
  %.1 = phi i1 [ %.06, %20 ], [ true, %18 ]
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %3) #6
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %4) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %4) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %3) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %2) #6
  br i1 %.1, label %23, label %29

23:                                               ; preds = %.thread21, %.thread, %22
  %.pn.pn.pn20 = phi { ptr, i32 } [ %16, %.thread ], [ %.pn, %22 ], [ %17, %.thread21 ]
  call void @__cxa_free_exception(ptr %11) #6
  br label %29

24:                                               ; preds = %8
  %25 = load i64, ptr @_ZZ3fibmE2f2, align 8, !tbaa !5
  %26 = load i64, ptr @_ZZ3fibmE2f1, align 8, !tbaa !5
  %27 = add i64 %26, %25
  store i64 %27, ptr @_ZZ3fibmE2f2, align 8, !tbaa !5
  store i64 %25, ptr @_ZZ3fibmE2f1, align 8, !tbaa !5
  br label %28

28:                                               ; preds = %24, %6
  %.0 = phi i64 [ %7, %6 ], [ %27, %24 ]
  ret i64 %.0

29:                                               ; preds = %22, %23
  %.pn.pn.pn19 = phi { ptr, i32 } [ %.pn, %22 ], [ %.pn.pn.pn20, %23 ]
  resume { ptr, i32 } %.pn.pn.pn19

30:                                               ; preds = %15
  unreachable
}

declare ptr @__cxa_allocate_exception(i64) local_unnamed_addr

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

; Function Attrs: inlinehint mustprogress uwtable
declare dso_local void @_ZStplIcSt11char_traitsIcESaIcEENSt7__cxx1112basic_stringIT_T0_T1_EEOS8_PKS5_(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, ptr noundef nonnull align 8 dereferenceable(32), ptr noundef) local_unnamed_addr #2

; Function Attrs: inlinehint mustprogress uwtable
declare dso_local void @_ZStplIcSt11char_traitsIcESaIcEENSt7__cxx1112basic_stringIT_T0_T1_EEPKS5_OS8_(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, ptr noundef, ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #2

; Function Attrs: inlinehint mustprogress uwtable
declare dso_local void @_ZNSt7__cxx119to_stringEm(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, i64 noundef) local_unnamed_addr #2

declare i32 @__gxx_personality_v0(...)

declare void @_ZNSt16invalid_argumentC1ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #3

; Function Attrs: nounwind
declare void @_ZNSt16invalid_argumentD1Ev(ptr noundef nonnull align 8 dereferenceable(16)) unnamed_addr #4

declare void @__cxa_throw(ptr, ptr, ptr) local_unnamed_addr

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #5 align 2

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

declare void @__cxa_free_exception(ptr) local_unnamed_addr

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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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" }
attributes #3 = { "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 "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 #5 = { 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 #6 = { nounwind }
attributes #7 = { noreturn }

!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 = !{!"long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass