; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/other/Fast_fibonacci_last_digit.ll (Z3fibPxx)

; 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"

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i64 @_Z3fibPxx(ptr noundef %0, i64 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca i64, align 8
  %5 = alloca i64, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i64 %1, ptr %4, align 8, !tbaa !9
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  %7 = getelementptr inbounds i64, ptr %6, i64 0
  store i64 0, ptr %7, align 8, !tbaa !9
  %8 = load ptr, ptr %3, align 8, !tbaa !5
  %9 = getelementptr inbounds i64, ptr %8, i64 1
  store i64 1, ptr %9, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  store i64 2, ptr %5, align 8, !tbaa !9
  br label %10

10:                                               ; preds = %31, %2
  %11 = load i64, ptr %5, align 8, !tbaa !9
  %12 = load i64, ptr %4, align 8, !tbaa !9
  %13 = icmp sle i64 %11, %12
  br i1 %13, label %15, label %14

14:                                               ; preds = %10
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  br label %34

15:                                               ; preds = %10
  %16 = load ptr, ptr %3, align 8, !tbaa !5
  %17 = load i64, ptr %5, align 8, !tbaa !9
  %18 = sub nsw i64 %17, 1
  %19 = getelementptr inbounds i64, ptr %16, i64 %18
  %20 = load i64, ptr %19, align 8, !tbaa !9
  %21 = load ptr, ptr %3, align 8, !tbaa !5
  %22 = load i64, ptr %5, align 8, !tbaa !9
  %23 = sub nsw i64 %22, 2
  %24 = getelementptr inbounds i64, ptr %21, i64 %23
  %25 = load i64, ptr %24, align 8, !tbaa !9
  %26 = add nsw i64 %20, %25
  %27 = srem i64 %26, 10
  %28 = load ptr, ptr %3, align 8, !tbaa !5
  %29 = load i64, ptr %5, align 8, !tbaa !9
  %30 = getelementptr inbounds i64, ptr %28, i64 %29
  store i64 %27, ptr %30, align 8, !tbaa !9
  br label %31

31:                                               ; preds = %15
  %32 = load i64, ptr %5, align 8, !tbaa !9
  %33 = add nsw i64 %32, 1
  store i64 %33, ptr %5, align 8, !tbaa !9
  br label %10, !llvm.loop !11

34:                                               ; preds = %14
  %35 = load ptr, ptr %3, align 8, !tbaa !5
  %36 = load i64, ptr %4, align 8, !tbaa !9
  %37 = getelementptr inbounds i64, ptr %35, i64 %36
  %38 = load i64, ptr %37, align 8, !tbaa !9
  ret i64 %38
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"long long", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"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"

; Function Attrs: mustprogress nofree norecurse nosync nounwind memory(argmem: readwrite) uwtable
define dso_local noundef i64 @_Z3fibPxx(ptr nocapture noundef %0, i64 noundef %1) local_unnamed_addr #0 {
  store i64 0, ptr %0, align 8, !tbaa !5
  %3 = getelementptr inbounds i8, ptr %0, i64 8
  store i64 1, ptr %3, align 8, !tbaa !5
  %.not13 = icmp slt i64 %1, 2
  br i1 %.not13, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %2
  %scevgep = getelementptr i8, ptr %0, i64 8
  %load_initial = load i64, ptr %scevgep, align 8
  %4 = add nsw i64 %1, -1
  %xtraiter = and i64 %4, 1
  %5 = icmp eq i64 %1, 2
  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 %4, -2
  br label %.lr.ph

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %store_forwarded.unr = phi i64 [ %load_initial, %.lr.ph.preheader ], [ %23, %.lr.ph ]
  %.014.unr = phi i64 [ 2, %.lr.ph.preheader ], [ %24, %.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
  %6 = getelementptr i64, ptr %0, i64 %.014.unr
  %7 = getelementptr i8, ptr %6, i64 -16
  %8 = load i64, ptr %7, align 8, !tbaa !5
  %9 = add nsw i64 %8, %store_forwarded.unr
  %10 = srem i64 %9, 10
  store i64 %10, ptr %6, align 8, !tbaa !5
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph.epil, %._crit_edge.loopexit.unr-lcssa, %2
  %11 = getelementptr inbounds i64, ptr %0, i64 %1
  %12 = load i64, ptr %11, align 8, !tbaa !5
  ret i64 %12

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %store_forwarded = phi i64 [ %load_initial, %.lr.ph.preheader.new ], [ %23, %.lr.ph ]
  %.014 = phi i64 [ 2, %.lr.ph.preheader.new ], [ %24, %.lr.ph ]
  %niter = phi i64 [ 0, %.lr.ph.preheader.new ], [ %niter.next.1, %.lr.ph ]
  %13 = getelementptr i64, ptr %0, i64 %.014
  %14 = getelementptr i8, ptr %13, i64 -16
  %15 = load i64, ptr %14, align 8, !tbaa !5
  %16 = add nsw i64 %15, %store_forwarded
  %17 = srem i64 %16, 10
  store i64 %17, ptr %13, align 8, !tbaa !5
  %18 = or disjoint i64 %.014, 1
  %19 = getelementptr i64, ptr %0, i64 %18
  %20 = getelementptr i8, ptr %19, i64 -16
  %21 = load i64, ptr %20, align 8, !tbaa !5
  %22 = add nsw i64 %21, %17
  %23 = srem i64 %22, 10
  store i64 %23, ptr %19, align 8, !tbaa !5
  %24 = add nuw i64 %.014, 2
  %niter.next.1 = add i64 %niter, 2
  %niter.ncmp.1 = icmp eq i64 %niter.next.1, %unroll_iter
  br i1 %niter.ncmp.1, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph, !llvm.loop !9
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(argmem: readwrite) 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.mustprogress"}


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