; LLVM IR from tangjz/acm-icpc :: self_training/2015-09-21/H.ll (Z1Cxx)

; 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 @_Z1Cxx(i64 noundef %0, i64 noundef %1) #1 {
  %3 = alloca i64, align 8
  %4 = alloca i64, align 8
  %5 = alloca i64, align 8
  %6 = alloca i32, align 4
  store i64 %0, ptr %3, align 8, !tbaa !5
  store i64 %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  store i64 1, ptr %5, align 8, !tbaa !5
  %7 = load i64, ptr %3, align 8, !tbaa !5
  %8 = load i64, ptr %4, align 8, !tbaa !5
  %9 = sub nsw i64 %7, %8
  %10 = load i64, ptr %4, align 8, !tbaa !5
  %11 = icmp slt i64 %9, %10
  br i1 %11, label %12, label %16

12:                                               ; preds = %2
  %13 = load i64, ptr %3, align 8, !tbaa !5
  %14 = load i64, ptr %4, align 8, !tbaa !5
  %15 = sub nsw i64 %13, %14
  store i64 %15, ptr %4, align 8, !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 !9
  br label %17

17:                                               ; preds = %35, %16
  %18 = load i32, ptr %6, align 4, !tbaa !9
  %19 = sext i32 %18 to i64
  %20 = load i64, ptr %4, align 8, !tbaa !5
  %21 = icmp slt i64 %19, %20
  br i1 %21, label %23, label %22

22:                                               ; preds = %17
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  br label %38

23:                                               ; preds = %17
  %24 = load i64, ptr %3, align 8, !tbaa !5
  %25 = load i32, ptr %6, align 4, !tbaa !9
  %26 = sext i32 %25 to i64
  %27 = sub nsw i64 %24, %26
  %28 = load i64, ptr %5, align 8, !tbaa !5
  %29 = mul nsw i64 %28, %27
  store i64 %29, ptr %5, align 8, !tbaa !5
  %30 = load i32, ptr %6, align 4, !tbaa !9
  %31 = add nsw i32 %30, 1
  %32 = sext i32 %31 to i64
  %33 = load i64, ptr %5, align 8, !tbaa !5
  %34 = sdiv i64 %33, %32
  store i64 %34, ptr %5, align 8, !tbaa !5
  br label %35

35:                                               ; preds = %23
  %36 = load i32, ptr %6, align 4, !tbaa !9
  %37 = add nsw i32 %36, 1
  store i32 %37, ptr %6, align 4, !tbaa !9
  br label %17, !llvm.loop !11

38:                                               ; preds = %22
  %39 = load i64, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  ret i64 %39
}

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 = !{!"long long", !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"

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none) uwtable
define dso_local noundef i64 @_Z1Cxx(i64 noundef %0, i64 noundef %1) local_unnamed_addr #0 {
  %3 = sub nsw i64 %0, %1
  %spec.select = tail call i64 @llvm.smin.i64(i64 %3, i64 %1)
  %4 = icmp sgt i64 %spec.select, 0
  br i1 %4, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %xtraiter = and i64 %spec.select, 1
  %5 = icmp eq i64 %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 i64 %spec.select, 9223372036854775806
  br label %.lr.ph

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %.lcssa.ph = phi i64 [ poison, %.lr.ph.preheader ], [ %14, %.lr.ph ]
  %indvars.iv.unr = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next.1, %.lr.ph ]
  %.01419.unr = phi i64 [ 1, %.lr.ph.preheader ], [ %14, %.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 = sub nsw i64 %0, %indvars.iv.unr
  %7 = mul nsw i64 %6, %.01419.unr
  %indvars.iv.next.epil = add nuw nsw i64 %indvars.iv.unr, 1
  %8 = sdiv i64 %7, %indvars.iv.next.epil
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph.epil, %._crit_edge.loopexit.unr-lcssa, %2
  %.014.lcssa = phi i64 [ 1, %2 ], [ %.lcssa.ph, %._crit_edge.loopexit.unr-lcssa ], [ %8, %.lr.ph.epil ]
  ret i64 %.014.lcssa

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader.new ], [ %indvars.iv.next.1, %.lr.ph ]
  %.01419 = phi i64 [ 1, %.lr.ph.preheader.new ], [ %14, %.lr.ph ]
  %niter = phi i64 [ 0, %.lr.ph.preheader.new ], [ %niter.next.1, %.lr.ph ]
  %9 = sub nsw i64 %0, %indvars.iv
  %10 = mul nsw i64 %9, %.01419
  %indvars.iv.next = or disjoint i64 %indvars.iv, 1
  %11 = sdiv i64 %10, %indvars.iv.next
  %12 = sub nsw i64 %0, %indvars.iv.next
  %13 = mul nsw i64 %12, %11
  %indvars.iv.next.1 = add nuw nsw i64 %indvars.iv, 2
  %14 = sdiv i64 %13, %indvars.iv.next.1
  %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
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i64 @llvm.smin.i64(i64, i64) #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