; LLVM IR from eyangch/competitive-programming :: GoogleKickstart/2020A/workout.ll (Z2oki)

; 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"

@N = external dso_local global i32, align 4
@K = external dso_local global i32, align 4
@gaps = external dso_local global [100000 x i32], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef zeroext i1 @_Z2oki(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  store i32 0, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 0, ptr %4, align 4, !tbaa !5
  br label %5

5:                                                ; preds = %24, %1
  %6 = load i32, ptr %4, align 4, !tbaa !5
  %7 = load i32, ptr @N, align 4, !tbaa !5
  %8 = sub nsw i32 %7, 1
  %9 = icmp slt i32 %6, %8
  br i1 %9, label %11, label %10

10:                                               ; preds = %5
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  br label %27

11:                                               ; preds = %5
  %12 = load i32, ptr %4, align 4, !tbaa !5
  %13 = sext i32 %12 to i64
  %14 = getelementptr inbounds [100000 x i32], ptr @gaps, i64 0, i64 %13
  %15 = load i32, ptr %14, align 4, !tbaa !5
  %16 = load i32, ptr %2, align 4, !tbaa !5
  %17 = add nsw i32 %15, %16
  %18 = sub nsw i32 %17, 1
  %19 = load i32, ptr %2, align 4, !tbaa !5
  %20 = sdiv i32 %18, %19
  %21 = sub nsw i32 %20, 1
  %22 = load i32, ptr %3, align 4, !tbaa !5
  %23 = add nsw i32 %22, %21
  store i32 %23, ptr %3, align 4, !tbaa !5
  br label %24

24:                                               ; preds = %11
  %25 = load i32, ptr %4, align 4, !tbaa !5
  %26 = add nsw i32 %25, 1
  store i32 %26, ptr %4, align 4, !tbaa !5
  br label %5, !llvm.loop !9

27:                                               ; preds = %10
  %28 = load i32, ptr %3, align 4, !tbaa !5
  %29 = load i32, ptr @K, align 4, !tbaa !5
  %30 = icmp sle i32 %28, %29
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret i1 %30
}

; 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 = !{!"int", !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"

@N = external dso_local local_unnamed_addr global i32, align 4
@K = external dso_local local_unnamed_addr global i32, align 4
@gaps = external dso_local local_unnamed_addr global [100000 x i32], align 16

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef zeroext i1 @_Z2oki(i32 noundef %0) local_unnamed_addr #0 {
  %2 = load i32, ptr @N, align 4, !tbaa !5
  %3 = icmp sgt i32 %2, 1
  br i1 %3, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %1
  %4 = add nsw i32 %2, -1
  %5 = add i32 %0, -1
  %wide.trip.count = zext nneg i32 %4 to i64
  %xtraiter = and i64 %wide.trip.count, 1
  %6 = icmp eq i32 %4, 1
  br i1 %6, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph.new

.lr.ph.new:                                       ; preds = %.lr.ph
  %unroll_iter = and i64 %wide.trip.count, 2147483646
  br label %15

._crit_edge.loopexit.unr-lcssa.loopexit:          ; preds = %15
  %7 = add i32 %27, -1
  br label %._crit_edge.loopexit.unr-lcssa

._crit_edge.loopexit.unr-lcssa:                   ; preds = %._crit_edge.loopexit.unr-lcssa.loopexit, %.lr.ph
  %.lcssa.ph = phi i32 [ poison, %.lr.ph ], [ %27, %._crit_edge.loopexit.unr-lcssa.loopexit ]
  %indvars.iv.unr = phi i64 [ 0, %.lr.ph ], [ %indvars.iv.next.1, %._crit_edge.loopexit.unr-lcssa.loopexit ]
  %.078.unr = phi i32 [ -1, %.lr.ph ], [ %7, %._crit_edge.loopexit.unr-lcssa.loopexit ]
  %lcmp.mod.not = icmp eq i64 %xtraiter, 0
  br i1 %lcmp.mod.not, label %._crit_edge, label %._crit_edge.loopexit.epilog-lcssa

._crit_edge.loopexit.epilog-lcssa:                ; preds = %._crit_edge.loopexit.unr-lcssa
  %8 = getelementptr inbounds [100000 x i32], ptr @gaps, i64 0, i64 %indvars.iv.unr
  %9 = load i32, ptr %8, align 4, !tbaa !5
  %10 = add i32 %5, %9
  %11 = sdiv i32 %10, %0
  %12 = add i32 %.078.unr, %11
  br label %._crit_edge

._crit_edge:                                      ; preds = %._crit_edge.loopexit.epilog-lcssa, %._crit_edge.loopexit.unr-lcssa, %1
  %.07.lcssa = phi i32 [ 0, %1 ], [ %.lcssa.ph, %._crit_edge.loopexit.unr-lcssa ], [ %12, %._crit_edge.loopexit.epilog-lcssa ]
  %13 = load i32, ptr @K, align 4, !tbaa !5
  %14 = icmp sle i32 %.07.lcssa, %13
  ret i1 %14

15:                                               ; preds = %15, %.lr.ph.new
  %indvars.iv = phi i64 [ 0, %.lr.ph.new ], [ %indvars.iv.next.1, %15 ]
  %.078 = phi i32 [ 0, %.lr.ph.new ], [ %27, %15 ]
  %niter = phi i64 [ 0, %.lr.ph.new ], [ %niter.next.1, %15 ]
  %16 = getelementptr inbounds [100000 x i32], ptr @gaps, i64 0, i64 %indvars.iv
  %17 = load i32, ptr %16, align 8, !tbaa !5
  %18 = add i32 %5, %17
  %19 = sdiv i32 %18, %0
  %20 = add i32 %.078, -1
  %21 = add i32 %20, %19
  %indvars.iv.next = or disjoint i64 %indvars.iv, 1
  %22 = getelementptr inbounds [100000 x i32], ptr @gaps, i64 0, i64 %indvars.iv.next
  %23 = load i32, ptr %22, align 4, !tbaa !5
  %24 = add i32 %5, %23
  %25 = sdiv i32 %24, %0
  %26 = add i32 %21, -1
  %27 = add i32 %26, %25
  %indvars.iv.next.1 = add nuw nsw i64 %indvars.iv, 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.loopexit, label %15, !llvm.loop !9
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(read, 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"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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