; LLVM IR from VastoLorde95/Competitive-Programming :: Codeforces/131 Division 1/Problem B/B.ll (Z6invmodx)

; 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"

@MOD = external dso_local global i64, align 8

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i64 @_Z6invmodx(i64 noundef %0) #0 {
  %2 = alloca i64, align 8
  %3 = alloca i64, align 8
  %4 = alloca i64, align 8
  store i64 %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  %5 = load i64, ptr @MOD, align 8, !tbaa !5
  %6 = sub nsw i64 %5, 2
  store i64 %6, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  store i64 1, ptr %4, align 8, !tbaa !5
  br label %7

7:                                                ; preds = %20, %1
  %8 = load i64, ptr %3, align 8, !tbaa !5
  %9 = icmp ne i64 %8, 0
  br i1 %9, label %10, label %28

10:                                               ; preds = %7
  %11 = load i64, ptr %3, align 8, !tbaa !5
  %12 = srem i64 %11, 2
  %13 = icmp ne i64 %12, 0
  br i1 %13, label %14, label %20

14:                                               ; preds = %10
  %15 = load i64, ptr %4, align 8, !tbaa !5
  %16 = load i64, ptr %2, align 8, !tbaa !5
  %17 = mul nsw i64 %15, %16
  %18 = load i64, ptr @MOD, align 8, !tbaa !5
  %19 = srem i64 %17, %18
  store i64 %19, ptr %4, align 8, !tbaa !5
  br label %20

20:                                               ; preds = %14, %10
  %21 = load i64, ptr %2, align 8, !tbaa !5
  %22 = load i64, ptr %2, align 8, !tbaa !5
  %23 = mul nsw i64 %21, %22
  %24 = load i64, ptr @MOD, align 8, !tbaa !5
  %25 = srem i64 %23, %24
  store i64 %25, ptr %2, align 8, !tbaa !5
  %26 = load i64, ptr %3, align 8, !tbaa !5
  %27 = ashr i64 %26, 1
  store i64 %27, ptr %3, align 8, !tbaa !5
  br label %7, !llvm.loop !9

28:                                               ; preds = %7
  %29 = load i64, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  ret i64 %29
}

; 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 = !{!"long long", !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"

@MOD = external dso_local local_unnamed_addr global i64, align 8

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef i64 @_Z6invmodx(i64 noundef %0) local_unnamed_addr #0 {
  %2 = load i64, ptr @MOD, align 8, !tbaa !5
  %3 = add nsw i64 %2, -2
  %.not11 = icmp eq i64 %3, 0
  br i1 %.not11, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %8
  %.014 = phi i64 [ %.1, %8 ], [ 1, %1 ]
  %.0813 = phi i64 [ %11, %8 ], [ %3, %1 ]
  %.0912 = phi i64 [ %10, %8 ], [ %0, %1 ]
  %4 = and i64 %.0813, 1
  %.not10 = icmp eq i64 %4, 0
  br i1 %.not10, label %8, label %5

5:                                                ; preds = %.lr.ph
  %6 = mul nsw i64 %.014, %.0912
  %7 = srem i64 %6, %2
  br label %8

8:                                                ; preds = %5, %.lr.ph
  %.1 = phi i64 [ %7, %5 ], [ %.014, %.lr.ph ]
  %9 = mul nsw i64 %.0912, %.0912
  %10 = srem i64 %9, %2
  %11 = ashr i64 %.0813, 1
  %.not = icmp ult i64 %.0813, 2
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9

._crit_edge:                                      ; preds = %8, %1
  %.0.lcssa = phi i64 [ 1, %1 ], [ %.1, %8 ]
  ret i64 %.0.lcssa
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: 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 = !{!6, !6, i64 0}
!6 = !{!"long long", !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,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass