; LLVM IR from Mohammed-Shoaib/Coding-Problems :: Codeforces/Solutions/520B.ll (Z11two_buttonsii)

; 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 @_Z11two_buttonsii(i32 noundef %0, i32 noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = 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) #3
  store i32 0, ptr %5, align 4, !tbaa !5
  br label %6

6:                                                ; preds = %34, %2
  %7 = load i32, ptr %4, align 4, !tbaa !5
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = icmp ne i32 %7, %8
  br i1 %9, label %10, label %35

10:                                               ; preds = %6
  %11 = load i32, ptr %5, align 4, !tbaa !5
  %12 = add nsw i32 %11, 1
  store i32 %12, ptr %5, align 4, !tbaa !5
  %13 = load i32, ptr %4, align 4, !tbaa !5
  %14 = load i32, ptr %3, align 4, !tbaa !5
  %15 = icmp slt i32 %13, %14
  br i1 %15, label %16, label %23

16:                                               ; preds = %10
  %17 = load i32, ptr %3, align 4, !tbaa !5
  %18 = call noundef i32 @_ZSt8exchangeIiRiET_RS1_OT0_(ptr noundef nonnull align 4 dereferenceable(4) %4, ptr noundef nonnull align 4 dereferenceable(4) %3) #3
  %19 = sub nsw i32 %17, %18
  %20 = sub nsw i32 %19, 1
  %21 = load i32, ptr %5, align 4, !tbaa !5
  %22 = add nsw i32 %21, %20
  store i32 %22, ptr %5, align 4, !tbaa !5
  br label %34

23:                                               ; preds = %10
  %24 = load i32, ptr %4, align 4, !tbaa !5
  %25 = srem i32 %24, 2
  %26 = icmp eq i32 %25, 0
  br i1 %26, label %27, label %30

27:                                               ; preds = %23
  %28 = load i32, ptr %4, align 4, !tbaa !5
  %29 = sdiv i32 %28, 2
  store i32 %29, ptr %4, align 4, !tbaa !5
  br label %33

30:                                               ; preds = %23
  %31 = load i32, ptr %4, align 4, !tbaa !5
  %32 = add nsw i32 %31, 1
  store i32 %32, ptr %4, align 4, !tbaa !5
  br label %33

33:                                               ; preds = %30, %27
  br label %34

34:                                               ; preds = %33, %16
  br label %6, !llvm.loop !9

35:                                               ; preds = %6
  %36 = load i32, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  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: inlinehint mustprogress nounwind uwtable
declare dso_local noundef i32 @_ZSt8exchangeIiRiET_RS1_OT0_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) #2

; 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 = { inlinehint 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 #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"}


; 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 nounwind uwtable
define dso_local noundef i32 @_Z11two_buttonsii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  %.not5 = icmp eq i32 %1, %0
  br i1 %.not5, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %21
  %5 = phi i32 [ %22, %21 ], [ %0, %2 ]
  %6 = phi i32 [ %23, %21 ], [ %1, %2 ]
  %.06 = phi i32 [ %.1, %21 ], [ 0, %2 ]
  %7 = add nsw i32 %.06, 1
  %8 = icmp slt i32 %6, %5
  br i1 %8, label %9, label %14

9:                                                ; preds = %.lr.ph
  %10 = call noundef i32 @_ZSt8exchangeIiRiET_RS1_OT0_(ptr noundef nonnull align 4 dereferenceable(4) %4, ptr noundef nonnull align 4 dereferenceable(4) %3) #2
  %11 = xor i32 %10, -1
  %12 = add i32 %5, %7
  %13 = add i32 %12, %11
  %.pre = load i32, ptr %4, align 4, !tbaa !5
  %.pre7 = load i32, ptr %3, align 4, !tbaa !5
  br label %21

14:                                               ; preds = %.lr.ph
  %15 = and i32 %6, 1
  %16 = icmp eq i32 %15, 0
  br i1 %16, label %17, label %19

17:                                               ; preds = %14
  %18 = ashr exact i32 %6, 1
  store i32 %18, ptr %4, align 4, !tbaa !5
  br label %21

19:                                               ; preds = %14
  %20 = add nsw i32 %6, 1
  store i32 %20, ptr %4, align 4, !tbaa !5
  br label %21

21:                                               ; preds = %17, %19, %9
  %22 = phi i32 [ %.pre7, %9 ], [ %5, %17 ], [ %5, %19 ]
  %23 = phi i32 [ %.pre, %9 ], [ %18, %17 ], [ %20, %19 ]
  %.1 = phi i32 [ %13, %9 ], [ %7, %17 ], [ %7, %19 ]
  %.not = icmp eq i32 %23, %22
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9

._crit_edge:                                      ; preds = %21, %2
  %.0.lcssa = phi i32 [ 0, %2 ], [ %.1, %21 ]
  ret i32 %.0.lcssa
}

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef i32 @_ZSt8exchangeIiRiET_RS1_OT0_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #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 = { inlinehint 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 = !{!"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,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,ReassociatePass,SROAPass,SimplifyCFGPass