; LLVM IR from pranjalwalia/Competitive-programming :: mat/fib.ll (Z15fib_memoizationx)

; 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"

@F = external dso_local global [51 x i64], align 16

; Function Attrs: mustprogress uwtable
define dso_local noundef i64 @_Z15fib_memoizationx(i64 noundef %0) #0 {
  %2 = alloca i64, align 8
  %3 = alloca i64, align 8
  store i64 %0, ptr %3, align 8, !tbaa !5
  %4 = load i64, ptr %3, align 8, !tbaa !5
  %5 = icmp sle i64 %4, 1
  br i1 %5, label %6, label %8

6:                                                ; preds = %1
  %7 = load i64, ptr %3, align 8, !tbaa !5
  store i64 %7, ptr %2, align 8
  br label %30

8:                                                ; preds = %1
  %9 = load i64, ptr %3, align 8, !tbaa !5
  %10 = getelementptr inbounds [51 x i64], ptr @F, i64 0, i64 %9
  %11 = load i64, ptr %10, align 8, !tbaa !5
  %12 = icmp ne i64 %11, -1
  br i1 %12, label %13, label %17

13:                                               ; preds = %8
  %14 = load i64, ptr %3, align 8, !tbaa !5
  %15 = getelementptr inbounds [51 x i64], ptr @F, i64 0, i64 %14
  %16 = load i64, ptr %15, align 8, !tbaa !5
  store i64 %16, ptr %2, align 8
  br label %30

17:                                               ; preds = %8
  %18 = load i64, ptr %3, align 8, !tbaa !5
  %19 = sub nsw i64 %18, 1
  %20 = call noundef i64 @_Z15fib_memoizationx(i64 noundef %19)
  %21 = load i64, ptr %3, align 8, !tbaa !5
  %22 = sub nsw i64 %21, 2
  %23 = call noundef i64 @_Z15fib_memoizationx(i64 noundef %22)
  %24 = add nsw i64 %20, %23
  %25 = load i64, ptr %3, align 8, !tbaa !5
  %26 = getelementptr inbounds [51 x i64], ptr @F, i64 0, i64 %25
  store i64 %24, ptr %26, align 8, !tbaa !5
  %27 = load i64, ptr %3, align 8, !tbaa !5
  %28 = getelementptr inbounds [51 x i64], ptr @F, i64 0, i64 %27
  %29 = load i64, ptr %28, align 8, !tbaa !5
  store i64 %29, ptr %2, align 8
  br label %30

30:                                               ; preds = %17, %13, %6
  %31 = load i64, ptr %2, align 8
  ret i64 %31
}

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 = !{!"long 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"

@F = external dso_local local_unnamed_addr global [51 x i64], align 16

; Function Attrs: mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef i64 @_Z15fib_memoizationx(i64 noundef %0) local_unnamed_addr #0 {
  %2 = icmp slt i64 %0, 2
  br i1 %2, label %common.ret11, label %3

3:                                                ; preds = %1
  %4 = getelementptr inbounds [51 x i64], ptr @F, i64 0, i64 %0
  %5 = load i64, ptr %4, align 8, !tbaa !5
  %.not = icmp eq i64 %5, -1
  br i1 %.not, label %6, label %common.ret11

common.ret11:                                     ; preds = %3, %1, %6
  %common.ret11.op = phi i64 [ %11, %6 ], [ %0, %1 ], [ %5, %3 ]
  ret i64 %common.ret11.op

6:                                                ; preds = %3
  %7 = add nsw i64 %0, -1
  %8 = tail call noundef i64 @_Z15fib_memoizationx(i64 noundef %7)
  %9 = add nsw i64 %0, -2
  %10 = tail call noundef i64 @_Z15fib_memoizationx(i64 noundef %9)
  %11 = add nsw i64 %10, %8
  store i64 %11, ptr %4, align 8, !tbaa !5
  br label %common.ret11
}

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 = !{!"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