; LLVM IR from tangjz/acm-icpc :: 51nod (1639)

; 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"

@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [4 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca double, align 8
  %4 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  store double 1.000000e+00, ptr %3, align 8, !tbaa !5
  %5 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %2)
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  store i32 1, ptr %4, align 4, !tbaa !9
  br label %6

6:                                                ; preds = %22, %0
  %7 = load i32, ptr %4, align 4, !tbaa !9
  %8 = load i32, ptr %2, align 4, !tbaa !9
  %9 = icmp slt i32 %7, %8
  br i1 %9, label %11, label %10

10:                                               ; preds = %6
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  br label %25

11:                                               ; preds = %6
  %12 = load double, ptr %3, align 8, !tbaa !5
  %13 = load i32, ptr %4, align 4, !tbaa !9
  %14 = shl i32 %13, 1
  %15 = sitofp i32 %14 to double
  %16 = fmul double %12, %15
  %17 = load i32, ptr %4, align 4, !tbaa !9
  %18 = shl i32 %17, 1
  %19 = or i32 %18, 1
  %20 = sitofp i32 %19 to double
  %21 = fdiv double %16, %20
  store double %21, ptr %3, align 8, !tbaa !5
  br label %22

22:                                               ; preds = %11
  %23 = load i32, ptr %4, align 4, !tbaa !9
  %24 = add nsw i32 %23, 1
  store i32 %24, ptr %4, align 4, !tbaa !9
  br label %6, !llvm.loop !11

25:                                               ; preds = %10
  %26 = load double, ptr %3, align 8, !tbaa !5
  %27 = call i32 (ptr, ...) @printf(ptr noundef @.str.1, double noundef %26)
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #3
  ret i32 0
}

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

declare i32 @__isoc99_scanf(ptr noundef, ...) #2

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

declare i32 @printf(ptr noundef, ...) #2

attributes #0 = { mustprogress norecurse 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 = { "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 #3 = { 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 = !{!"double", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !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"

@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [4 x i8], align 1

; Function Attrs: mustprogress nofree norecurse nounwind uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #3
  %2 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %1)
  %3 = load i32, ptr %1, align 4, !tbaa !5
  %4 = icmp sgt i32 %3, 1
  br i1 %4, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %0
  %5 = add nsw i32 %3, -1
  %xtraiter = and i32 %5, 1
  %6 = icmp eq i32 %3, 2
  br i1 %6, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph.preheader.new

.lr.ph.preheader.new:                             ; preds = %.lr.ph.preheader
  %unroll_iter = and i32 %5, -2
  br label %.lr.ph

._crit_edge.loopexit.unr-lcssa.loopexit:          ; preds = %.lr.ph
  %7 = shl nuw i32 %27, 1
  br label %._crit_edge.loopexit.unr-lcssa

._crit_edge.loopexit.unr-lcssa:                   ; preds = %._crit_edge.loopexit.unr-lcssa.loopexit, %.lr.ph.preheader
  %.lcssa.ph = phi double [ poison, %.lr.ph.preheader ], [ %26, %._crit_edge.loopexit.unr-lcssa.loopexit ]
  %.07.unr = phi i32 [ 2, %.lr.ph.preheader ], [ %7, %._crit_edge.loopexit.unr-lcssa.loopexit ]
  %.056.unr = phi double [ 1.000000e+00, %.lr.ph.preheader ], [ %26, %._crit_edge.loopexit.unr-lcssa.loopexit ]
  %lcmp.mod.not = icmp eq i32 %xtraiter, 0
  br i1 %lcmp.mod.not, label %._crit_edge, label %.lr.ph.epil

.lr.ph.epil:                                      ; preds = %._crit_edge.loopexit.unr-lcssa
  %8 = sitofp i32 %.07.unr to double
  %9 = fmul double %.056.unr, %8
  %10 = or disjoint i32 %.07.unr, 1
  %11 = sitofp i32 %10 to double
  %12 = fdiv double %9, %11
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph.epil, %._crit_edge.loopexit.unr-lcssa, %0
  %.05.lcssa = phi double [ 1.000000e+00, %0 ], [ %.lcssa.ph, %._crit_edge.loopexit.unr-lcssa ], [ %12, %.lr.ph.epil ]
  %13 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, double noundef %.05.lcssa)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #3
  ret i32 0

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %.07 = phi i32 [ 1, %.lr.ph.preheader.new ], [ %27, %.lr.ph ]
  %.056 = phi double [ 1.000000e+00, %.lr.ph.preheader.new ], [ %26, %.lr.ph ]
  %niter = phi i32 [ 0, %.lr.ph.preheader.new ], [ %niter.next.1, %.lr.ph ]
  %14 = shl nuw i32 %.07, 1
  %15 = sitofp i32 %14 to double
  %16 = fmul double %.056, %15
  %17 = or disjoint i32 %14, 1
  %18 = sitofp i32 %17 to double
  %19 = fdiv double %16, %18
  %20 = shl nuw i32 %.07, 1
  %21 = add i32 %20, 2
  %22 = sitofp i32 %21 to double
  %23 = fmul double %19, %22
  %24 = or disjoint i32 %21, 1
  %25 = sitofp i32 %24 to double
  %26 = fdiv double %23, %25
  %27 = add nuw nsw i32 %.07, 2
  %niter.next.1 = add i32 %niter, 2
  %niter.ncmp.1 = icmp eq i32 %niter.next.1, %unroll_iter
  br i1 %niter.ncmp.1, label %._crit_edge.loopexit.unr-lcssa.loopexit, label %.lr.ph, !llvm.loop !9
}

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

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

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

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

attributes #0 = { mustprogress nofree norecurse 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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nofree nounwind "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 #3 = { 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"}


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