; LLVM IR from pacifiquem/awesome-algorithms :: src/Dynamic Programming/examples/fibonnaci.ll (Z9fibonaccii)

; 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::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl" }
%"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl" = type { %"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl_data" }
%"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl_data" = type { ptr, ptr, ptr }

@dp = external dso_local global %"class.std::vector", align 8

; Function Attrs: mustprogress uwtable
define dso_local noundef i64 @_Z9fibonaccii(i32 noundef %0) #0 {
  %2 = alloca i64, align 8
  %3 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  %4 = load i32, ptr %3, align 4, !tbaa !5
  %5 = icmp sle i32 %4, 1
  br i1 %5, label %6, label %9

6:                                                ; preds = %1
  %7 = load i32, ptr %3, align 4, !tbaa !5
  %8 = sext i32 %7 to i64
  store i64 %8, ptr %2, align 8
  br label %35

9:                                                ; preds = %1
  %10 = load i32, ptr %3, align 4, !tbaa !5
  %11 = sext i32 %10 to i64
  %12 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24) @dp, i64 noundef %11) #2
  %13 = load i64, ptr %12, align 8, !tbaa !9
  %14 = icmp ne i64 %13, -1
  br i1 %14, label %15, label %20

15:                                               ; preds = %9
  %16 = load i32, ptr %3, align 4, !tbaa !5
  %17 = sext i32 %16 to i64
  %18 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24) @dp, i64 noundef %17) #2
  %19 = load i64, ptr %18, align 8, !tbaa !9
  store i64 %19, ptr %2, align 8
  br label %35

20:                                               ; preds = %9
  %21 = load i32, ptr %3, align 4, !tbaa !5
  %22 = sub nsw i32 %21, 1
  %23 = call noundef i64 @_Z9fibonaccii(i32 noundef %22)
  %24 = load i32, ptr %3, align 4, !tbaa !5
  %25 = sub nsw i32 %24, 2
  %26 = call noundef i64 @_Z9fibonaccii(i32 noundef %25)
  %27 = add nsw i64 %23, %26
  %28 = load i32, ptr %3, align 4, !tbaa !5
  %29 = sext i32 %28 to i64
  %30 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24) @dp, i64 noundef %29) #2
  store i64 %27, ptr %30, align 8, !tbaa !9
  %31 = load i32, ptr %3, align 4, !tbaa !5
  %32 = sext i32 %31 to i64
  %33 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24) @dp, i64 noundef %32) #2
  %34 = load i64, ptr %33, align 8, !tbaa !9
  store i64 %34, ptr %2, align 8
  br label %35

35:                                               ; preds = %20, %15, %6
  %36 = load i64, ptr %2, align 8
  ret i64 %36
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) #1 align 2

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 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"long long", !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"

%"class.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl" }
%"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl" = type { %"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl_data" }
%"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl_data" = type { ptr, ptr, ptr }

@dp = external dso_local global %"class.std::vector", align 8

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i64 @_Z9fibonaccii(i32 noundef %0) local_unnamed_addr #0 {
  %2 = icmp slt i32 %0, 2
  br i1 %2, label %3, label %5

3:                                                ; preds = %1
  %4 = sext i32 %0 to i64
  br label %common.ret10

5:                                                ; preds = %1
  %6 = zext nneg i32 %0 to i64
  %7 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24) @dp, i64 noundef %6) #1
  %8 = load i64, ptr %7, align 8, !tbaa !5
  %.not = icmp eq i64 %8, -1
  br i1 %.not, label %12, label %9

9:                                                ; preds = %5
  %10 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24) @dp, i64 noundef %6) #1
  %11 = load i64, ptr %10, align 8, !tbaa !5
  br label %common.ret10

common.ret10:                                     ; preds = %9, %3, %12
  %common.ret10.op = phi i64 [ %20, %12 ], [ %4, %3 ], [ %11, %9 ]
  ret i64 %common.ret10.op

12:                                               ; preds = %5
  %13 = add nsw i32 %0, -1
  %14 = tail call noundef i64 @_Z9fibonaccii(i32 noundef %13)
  %15 = add nsw i32 %0, -2
  %16 = tail call noundef i64 @_Z9fibonaccii(i32 noundef %15)
  %17 = add nsw i64 %16, %14
  %18 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24) @dp, i64 noundef %6) #1
  store i64 %17, ptr %18, align 8, !tbaa !5
  %19 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24) @dp, i64 noundef %6) #1
  %20 = load i64, ptr %19, align 8, !tbaa !5
  br label %common.ret10
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) local_unnamed_addr #0 align 2

attributes #0 = { 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 #1 = { 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 = !{!"long long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}


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