; LLVM IR from manishbisht/Competitive-Programming :: Algorithms/Dynamic Programming/Fabonacci Number - Tabulation.ll (Z9fabonaccix)

; 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"

@fab = external dso_local global [100 x i64], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z9fabonaccix(i64 noundef %0) #0 {
  %2 = alloca i64, align 8
  %3 = alloca i64, align 8
  store i64 %0, ptr %2, align 8, !tbaa !5
  store i64 0, ptr @fab, align 16, !tbaa !5
  store i64 1, ptr getelementptr inbounds ([100 x i64], ptr @fab, i64 0, i64 1), align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  store i64 2, ptr %3, align 8, !tbaa !5
  br label %4

4:                                                ; preds = %21, %1
  %5 = load i64, ptr %3, align 8, !tbaa !5
  %6 = load i64, ptr %2, align 8, !tbaa !5
  %7 = icmp slt i64 %5, %6
  br i1 %7, label %9, label %8

8:                                                ; preds = %4
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  br label %24

9:                                                ; preds = %4
  %10 = load i64, ptr %3, align 8, !tbaa !5
  %11 = sub nsw i64 %10, 1
  %12 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %11
  %13 = load i64, ptr %12, align 8, !tbaa !5
  %14 = load i64, ptr %3, align 8, !tbaa !5
  %15 = sub nsw i64 %14, 2
  %16 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %15
  %17 = load i64, ptr %16, align 8, !tbaa !5
  %18 = add nsw i64 %13, %17
  %19 = load i64, ptr %3, align 8, !tbaa !5
  %20 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %19
  store i64 %18, ptr %20, align 8, !tbaa !5
  br label %21

21:                                               ; preds = %9
  %22 = load i64, ptr %3, align 8, !tbaa !5
  %23 = add nsw i64 %22, 1
  store i64 %23, ptr %3, align 8, !tbaa !5
  br label %4, !llvm.loop !9

24:                                               ; preds = %8
  ret void
}

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

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

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = !{!"long long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; 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"

@fab = external dso_local local_unnamed_addr global [100 x i64], align 16

; Function Attrs: mustprogress nofree norecurse nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local void @_Z9fabonaccix(i64 noundef %0) local_unnamed_addr #0 {
  store i64 0, ptr @fab, align 16, !tbaa !5
  store i64 1, ptr getelementptr inbounds (i8, ptr @fab, i64 8), align 8, !tbaa !5
  %2 = icmp sgt i64 %0, 2
  br i1 %2, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %1
  %3 = add nsw i64 %0, -2
  %4 = add nsw i64 %0, -3
  %xtraiter = and i64 %3, 3
  %5 = icmp ult i64 %4, 3
  br i1 %5, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph.preheader.new

.lr.ph.preheader.new:                             ; preds = %.lr.ph.preheader
  %unroll_iter = and i64 %3, -4
  br label %.lr.ph

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %.unr = phi i64 [ 1, %.lr.ph.preheader ], [ %34, %.lr.ph ]
  %.06.unr = phi i64 [ 2, %.lr.ph.preheader ], [ %36, %.lr.ph ]
  %lcmp.mod.not = icmp eq i64 %xtraiter, 0
  br i1 %lcmp.mod.not, label %._crit_edge, label %.lr.ph.epil

.lr.ph.epil:                                      ; preds = %._crit_edge.loopexit.unr-lcssa, %.lr.ph.epil
  %6 = phi i64 [ %10, %.lr.ph.epil ], [ %.unr, %._crit_edge.loopexit.unr-lcssa ]
  %.06.epil = phi i64 [ %12, %.lr.ph.epil ], [ %.06.unr, %._crit_edge.loopexit.unr-lcssa ]
  %epil.iter = phi i64 [ %epil.iter.next, %.lr.ph.epil ], [ 0, %._crit_edge.loopexit.unr-lcssa ]
  %7 = add nsw i64 %.06.epil, -2
  %8 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %7
  %9 = load i64, ptr %8, align 8, !tbaa !5
  %10 = add nsw i64 %9, %6
  %11 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %.06.epil
  store i64 %10, ptr %11, align 8, !tbaa !5
  %12 = add nuw nsw i64 %.06.epil, 1
  %epil.iter.next = add i64 %epil.iter, 1
  %epil.iter.cmp.not = icmp eq i64 %epil.iter.next, %xtraiter
  br i1 %epil.iter.cmp.not, label %._crit_edge, label %.lr.ph.epil, !llvm.loop !9

._crit_edge:                                      ; preds = %._crit_edge.loopexit.unr-lcssa, %.lr.ph.epil, %1
  ret void

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %13 = phi i64 [ 1, %.lr.ph.preheader.new ], [ %34, %.lr.ph ]
  %.06 = phi i64 [ 2, %.lr.ph.preheader.new ], [ %36, %.lr.ph ]
  %niter = phi i64 [ 0, %.lr.ph.preheader.new ], [ %niter.next.3, %.lr.ph ]
  %14 = add nsw i64 %.06, -2
  %15 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %14
  %16 = load i64, ptr %15, align 16, !tbaa !5
  %17 = add nsw i64 %16, %13
  %18 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %.06
  store i64 %17, ptr %18, align 16, !tbaa !5
  %19 = or disjoint i64 %.06, 1
  %20 = add nsw i64 %.06, -1
  %21 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %20
  %22 = load i64, ptr %21, align 8, !tbaa !5
  %23 = add nsw i64 %22, %17
  %24 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %19
  store i64 %23, ptr %24, align 8, !tbaa !5
  %25 = add nuw nsw i64 %.06, 2
  %26 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %.06
  %27 = load i64, ptr %26, align 16, !tbaa !5
  %28 = add nsw i64 %27, %23
  %29 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %25
  store i64 %28, ptr %29, align 16, !tbaa !5
  %30 = add nuw nsw i64 %.06, 3
  %31 = or disjoint i64 %.06, 1
  %32 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %31
  %33 = load i64, ptr %32, align 8, !tbaa !5
  %34 = add nsw i64 %33, %28
  %35 = getelementptr inbounds [100 x i64], ptr @fab, i64 0, i64 %30
  store i64 %34, ptr %35, align 8, !tbaa !5
  %36 = add nuw nsw i64 %.06, 4
  %niter.next.3 = add nuw i64 %niter, 4
  %niter.ncmp.3 = icmp eq i64 %niter.next.3, %unroll_iter
  br i1 %niter.ncmp.3, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph, !llvm.loop !11
}

attributes #0 = { mustprogress nofree norecurse 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"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.unroll.disable"}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: BDCEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferAlignmentPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass