; LLVM IR from bhrigukansra/algorithms-in-C-Cplusplus-Java-Python-JavaScript :: Algorithms/Dynamic Programming/C++/fibonacci.ll (Z3fibi)

; 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"

@LUP = external dso_local global [10000 x i32], align 16

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z3fibi(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %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 eq i32 %4, 0
  br i1 %5, label %6, label %7

6:                                                ; preds = %1
  store i32 0, ptr %2, align 4
  br label %50

7:                                                ; preds = %1
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = icmp eq i32 %8, 1
  br i1 %9, label %10, label %11

10:                                               ; preds = %7
  store i32 1, ptr getelementptr inbounds ([10000 x i32], ptr @LUP, i64 0, i64 1), align 4, !tbaa !5
  store i32 1, ptr %2, align 4
  br label %50

11:                                               ; preds = %7
  %12 = load i32, ptr %3, align 4, !tbaa !5
  %13 = sext i32 %12 to i64
  %14 = getelementptr inbounds [10000 x i32], ptr @LUP, i64 0, i64 %13
  %15 = load i32, ptr %14, align 4, !tbaa !5
  %16 = icmp ne i32 %15, 0
  br i1 %16, label %17, label %22

17:                                               ; preds = %11
  %18 = load i32, ptr %3, align 4, !tbaa !5
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds [10000 x i32], ptr @LUP, i64 0, i64 %19
  %21 = load i32, ptr %20, align 4, !tbaa !5
  store i32 %21, ptr %2, align 4
  br label %50

22:                                               ; preds = %11
  %23 = load i32, ptr %3, align 4, !tbaa !5
  %24 = icmp eq i32 %23, 2
  br i1 %24, label %25, label %34

25:                                               ; preds = %22
  %26 = load i32, ptr %3, align 4, !tbaa !5
  %27 = sub nsw i32 %26, 1
  %28 = load i32, ptr %3, align 4, !tbaa !5
  %29 = sub nsw i32 %28, 1
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds [10000 x i32], ptr @LUP, i64 0, i64 %30
  store i32 %27, ptr %31, align 4, !tbaa !5
  %32 = load i32, ptr %3, align 4, !tbaa !5
  %33 = sub nsw i32 %32, 1
  store i32 %33, ptr %2, align 4
  br label %50

34:                                               ; preds = %22
  br label %35

35:                                               ; preds = %34
  %36 = load i32, ptr %3, align 4, !tbaa !5
  %37 = sub nsw i32 %36, 1
  %38 = call noundef i32 @_Z3fibi(i32 noundef %37)
  %39 = load i32, ptr %3, align 4, !tbaa !5
  %40 = sub nsw i32 %39, 2
  %41 = call noundef i32 @_Z3fibi(i32 noundef %40)
  %42 = add nsw i32 %38, %41
  %43 = load i32, ptr %3, align 4, !tbaa !5
  %44 = sext i32 %43 to i64
  %45 = getelementptr inbounds [10000 x i32], ptr @LUP, i64 0, i64 %44
  store i32 %42, ptr %45, align 4, !tbaa !5
  %46 = load i32, ptr %3, align 4, !tbaa !5
  %47 = sext i32 %46 to i64
  %48 = getelementptr inbounds [10000 x i32], ptr @LUP, i64 0, i64 %47
  %49 = load i32, ptr %48, align 4, !tbaa !5
  store i32 %49, ptr %2, align 4
  br label %50

50:                                               ; preds = %35, %25, %17, %10, %6
  %51 = load i32, ptr %2, align 4
  ret i32 %51
}

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" }

!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"}


; 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"

@LUP = external dso_local local_unnamed_addr global [10000 x i32], align 16

; Function Attrs: mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef i32 @_Z3fibi(i32 noundef %0) local_unnamed_addr #0 {
  switch i32 %0, label %3 [
    i32 0, label %common.ret15
    i32 1, label %2
  ]

2:                                                ; preds = %1
  store i32 1, ptr getelementptr inbounds (i8, ptr @LUP, i64 4), align 4, !tbaa !5
  br label %common.ret15

3:                                                ; preds = %1
  %4 = sext i32 %0 to i64
  %5 = getelementptr inbounds [10000 x i32], ptr @LUP, i64 0, i64 %4
  %6 = load i32, ptr %5, align 4, !tbaa !5
  %.not = icmp eq i32 %6, 0
  br i1 %.not, label %7, label %common.ret15

7:                                                ; preds = %3
  %8 = icmp eq i32 %0, 2
  br i1 %8, label %9, label %10

9:                                                ; preds = %7
  store i32 1, ptr getelementptr inbounds (i8, ptr @LUP, i64 4), align 4, !tbaa !5
  br label %common.ret15

common.ret15:                                     ; preds = %3, %1, %9, %2, %10
  %common.ret15.op = phi i32 [ %15, %10 ], [ 1, %2 ], [ 1, %9 ], [ %0, %1 ], [ %6, %3 ]
  ret i32 %common.ret15.op

10:                                               ; preds = %7
  %11 = add nsw i32 %0, -1
  %12 = tail call noundef i32 @_Z3fibi(i32 noundef %11)
  %13 = add nsw i32 %0, -2
  %14 = tail call noundef i32 @_Z3fibi(i32 noundef %13)
  %15 = add nsw i32 %14, %12
  store i32 %15, ptr %5, align 4, !tbaa !5
  br label %common.ret15
}

attributes #0 = { mustprogress nofree nosync nounwind memory(readwrite, argmem: none, 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" }

!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"}


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