; LLVM IR from VAR-solutions/Algorithms :: Mathematics/NChooseK/cpp/NChooseK.ll (Z13binomialCoeffii)

; 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: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z13binomialCoeffii(i32 noundef %0, i32 noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = 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 4, ptr %5) #2
  store i32 1, ptr %5, align 4, !tbaa !5
  %7 = load i32, ptr %4, align 4, !tbaa !5
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = load i32, ptr %4, align 4, !tbaa !5
  %10 = sub nsw i32 %8, %9
  %11 = icmp sgt i32 %7, %10
  br i1 %11, label %12, label %16

12:                                               ; preds = %2
  %13 = load i32, ptr %3, align 4, !tbaa !5
  %14 = load i32, ptr %4, align 4, !tbaa !5
  %15 = sub nsw i32 %13, %14
  store i32 %15, ptr %4, align 4, !tbaa !5
  br label %16

16:                                               ; preds = %12, %2
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  store i32 0, ptr %6, align 4, !tbaa !5
  br label %17

17:                                               ; preds = %32, %16
  %18 = load i32, ptr %6, align 4, !tbaa !5
  %19 = load i32, ptr %4, align 4, !tbaa !5
  %20 = icmp slt i32 %18, %19
  br i1 %20, label %22, label %21

21:                                               ; preds = %17
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  br label %35

22:                                               ; preds = %17
  %23 = load i32, ptr %3, align 4, !tbaa !5
  %24 = load i32, ptr %6, align 4, !tbaa !5
  %25 = sub nsw i32 %23, %24
  %26 = load i32, ptr %5, align 4, !tbaa !5
  %27 = mul nsw i32 %26, %25
  store i32 %27, ptr %5, align 4, !tbaa !5
  %28 = load i32, ptr %6, align 4, !tbaa !5
  %29 = add nsw i32 %28, 1
  %30 = load i32, ptr %5, align 4, !tbaa !5
  %31 = sdiv i32 %30, %29
  store i32 %31, ptr %5, align 4, !tbaa !5
  br label %32

32:                                               ; preds = %22
  %33 = load i32, ptr %6, align 4, !tbaa !5
  %34 = add nsw i32 %33, 1
  store i32 %34, ptr %6, align 4, !tbaa !5
  br label %17, !llvm.loop !9

35:                                               ; preds = %21
  %36 = load i32, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  ret i32 %36
}

; 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"

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none) uwtable
define dso_local noundef i32 @_Z13binomialCoeffii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = sub nsw i32 %0, %1
  %spec.select = tail call i32 @llvm.smin.i32(i32 %3, i32 %1)
  %4 = icmp sgt i32 %spec.select, 0
  br i1 %4, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %xtraiter = and i32 %spec.select, 1
  %5 = icmp eq i32 %spec.select, 1
  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 i32 %spec.select, 2147483646
  br label %.lr.ph

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %.lcssa.ph = phi i32 [ poison, %.lr.ph.preheader ], [ %17, %.lr.ph ]
  %.019.unr = phi i32 [ 0, %.lr.ph.preheader ], [ %16, %.lr.ph ]
  %.01418.unr = phi i32 [ 1, %.lr.ph.preheader ], [ %17, %.lr.ph ]
  %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
  %6 = sub nsw i32 %0, %.019.unr
  %7 = mul nsw i32 %6, %.01418.unr
  %8 = add nuw nsw i32 %.019.unr, 1
  %9 = sdiv i32 %7, %8
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph.epil, %._crit_edge.loopexit.unr-lcssa, %2
  %.014.lcssa = phi i32 [ 1, %2 ], [ %.lcssa.ph, %._crit_edge.loopexit.unr-lcssa ], [ %9, %.lr.ph.epil ]
  ret i32 %.014.lcssa

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %.019 = phi i32 [ 0, %.lr.ph.preheader.new ], [ %16, %.lr.ph ]
  %.01418 = phi i32 [ 1, %.lr.ph.preheader.new ], [ %17, %.lr.ph ]
  %niter = phi i32 [ 0, %.lr.ph.preheader.new ], [ %niter.next.1, %.lr.ph ]
  %10 = sub nsw i32 %0, %.019
  %11 = mul nsw i32 %10, %.01418
  %12 = or disjoint i32 %.019, 1
  %13 = sdiv i32 %11, %12
  %14 = sub nsw i32 %0, %12
  %15 = mul nsw i32 %14, %13
  %16 = add nuw nsw i32 %.019, 2
  %17 = sdiv i32 %15, %16
  %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, label %.lr.ph, !llvm.loop !5
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.smin.i32(i32, i32) #1

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn 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" }
attributes #1 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }

!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,TailCallElimPass