; LLVM IR from chirag-singhal/Coding-Interview-101 :: Miscellaneous/Codechef/seplong (2)

; 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: nounwind uwtable
define dso_local i64 @nCr(i32 noundef %0, i32 noundef %1) #1 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i64, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  store i64 1, ptr %5, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  %9 = load i32, ptr %4, align 4, !tbaa !5
  %10 = sitofp i32 %9 to float
  %11 = load i32, ptr %3, align 4, !tbaa !5
  %12 = sitofp i32 %11 to float
  %13 = fdiv float %12, 2.000000e+00
  %14 = fcmp oge float %10, %13
  br i1 %14, label %15, label %19

15:                                               ; preds = %2
  %16 = load i32, ptr %3, align 4, !tbaa !5
  %17 = load i32, ptr %4, align 4, !tbaa !5
  %18 = sub nsw i32 %16, %17
  br label %21

19:                                               ; preds = %2
  %20 = load i32, ptr %4, align 4, !tbaa !5
  br label %21

21:                                               ; preds = %19, %15
  %22 = phi i32 [ %18, %15 ], [ %20, %19 ]
  store i32 %22, ptr %6, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  %23 = load i32, ptr %3, align 4, !tbaa !5
  store i32 %23, ptr %7, align 4, !tbaa !5
  store i32 1, ptr %8, align 4, !tbaa !5
  br label %24

24:                                               ; preds = %42, %21
  %25 = load i32, ptr %7, align 4, !tbaa !5
  %26 = load i32, ptr %3, align 4, !tbaa !5
  %27 = load i32, ptr %6, align 4, !tbaa !5
  %28 = sub nsw i32 %26, %27
  %29 = icmp sgt i32 %25, %28
  %30 = zext i1 %29 to i32
  %31 = load i32, ptr %8, align 4, !tbaa !5
  %32 = load i32, ptr %6, align 4, !tbaa !5
  %33 = icmp sle i32 %31, %32
  br i1 %33, label %34, label %47

34:                                               ; preds = %24
  %35 = load i64, ptr %5, align 8, !tbaa !9
  %36 = load i32, ptr %7, align 4, !tbaa !5
  %37 = sext i32 %36 to i64
  %38 = mul i64 %35, %37
  %39 = load i32, ptr %8, align 4, !tbaa !5
  %40 = sext i32 %39 to i64
  %41 = udiv i64 %38, %40
  store i64 %41, ptr %5, align 8, !tbaa !9
  br label %42

42:                                               ; preds = %34
  %43 = load i32, ptr %7, align 4, !tbaa !5
  %44 = add nsw i32 %43, -1
  store i32 %44, ptr %7, align 4, !tbaa !5
  %45 = load i32, ptr %8, align 4, !tbaa !5
  %46 = add nsw i32 %45, 1
  store i32 %46, ptr %8, align 4, !tbaa !5
  br label %24, !llvm.loop !11

47:                                               ; preds = %24
  %48 = load i64, ptr %5, align 8, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  ret i64 %48
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/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: nofree norecurse nosync nounwind memory(none) uwtable
define dso_local i64 @nCr(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = sitofp i32 %1 to float
  %4 = sitofp i32 %0 to float
  %5 = fmul float %4, 5.000000e-01
  %6 = fcmp ole float %5, %3
  %7 = sub nsw i32 %0, %1
  %8 = select i1 %6, i32 %7, i32 %1
  %.not19 = icmp slt i32 %8, 1
  br i1 %.not19, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %2
  %9 = sext i32 %0 to i64
  %10 = zext nneg i32 %8 to i64
  %xtraiter = and i64 %10, 1
  %11 = icmp eq i32 %8, 1
  br i1 %11, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph.preheader.new

.lr.ph.preheader.new:                             ; preds = %.lr.ph.preheader
  %unroll_iter = and i64 %10, 2147483646
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %indvars.iv23 = phi i64 [ %9, %.lr.ph.preheader.new ], [ %indvars.iv.next24.1, %.lr.ph ]
  %indvars.iv = phi i64 [ 1, %.lr.ph.preheader.new ], [ %indvars.iv.next.1, %.lr.ph ]
  %.01820 = phi i64 [ 1, %.lr.ph.preheader.new ], [ %15, %.lr.ph ]
  %niter = phi i64 [ 0, %.lr.ph.preheader.new ], [ %niter.next.1, %.lr.ph ]
  %12 = mul i64 %.01820, %indvars.iv23
  %13 = udiv i64 %12, %indvars.iv
  %indvars.iv.next24 = add nsw i64 %indvars.iv23, -1
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %14 = mul i64 %13, %indvars.iv.next24
  %15 = udiv i64 %14, %indvars.iv.next
  %indvars.iv.next24.1 = add nsw i64 %indvars.iv23, -2
  %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, label %.lr.ph, !llvm.loop !5

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %.lcssa.ph = phi i64 [ poison, %.lr.ph.preheader ], [ %15, %.lr.ph ]
  %indvars.iv23.unr = phi i64 [ %9, %.lr.ph.preheader ], [ %indvars.iv.next24.1, %.lr.ph ]
  %indvars.iv.unr = phi i64 [ 1, %.lr.ph.preheader ], [ %indvars.iv.next.1, %.lr.ph ]
  %.01820.unr = phi i64 [ 1, %.lr.ph.preheader ], [ %15, %.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
  %16 = mul i64 %.01820.unr, %indvars.iv23.unr
  %17 = udiv i64 %16, %indvars.iv.unr
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph.epil, %._crit_edge.loopexit.unr-lcssa, %2
  %.018.lcssa = phi i64 [ 1, %2 ], [ %.lcssa.ph, %._crit_edge.loopexit.unr-lcssa ], [ %17, %.lr.ph.epil ]
  ret i64 %.018.lcssa
}

attributes #0 = { nofree norecurse nosync nounwind memory(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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}


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