; LLVM IR from ayush-tulsyan/ACM-ICPC-Handbook :: code/BFS.ll (Z7callBFSi)

; 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"

@ComNum = external dso_local global [101000 x i32], align 16
@visited = external dso_local global [101000 x i8], align 16

; 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 uwtable
declare dso_local void @_Z3BFSii(i32 noundef, i32 noundef) #1

; Function Attrs: mustprogress uwtable
define dso_local void @_Z7callBFSi(i32 noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  %5 = load i32, ptr %2, align 4, !tbaa !5
  %6 = sext i32 %5 to i64
  call void @llvm.memset.p0.i64(ptr align 16 @visited, i8 0, i64 %6, i1 false)
  %7 = load i32, ptr %2, align 4, !tbaa !5
  %8 = mul nsw i32 4, %7
  %9 = sext i32 %8 to i64
  call void @llvm.memset.p0.i64(ptr align 16 @ComNum, i8 0, i64 %9, i1 false)
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  store i32 0, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  store i32 0, ptr %4, align 4, !tbaa !5
  br label %10

10:                                               ; preds = %30, %1
  %11 = load i32, ptr %4, align 4, !tbaa !5
  %12 = load i32, ptr %2, align 4, !tbaa !5
  %13 = icmp slt i32 %11, %12
  br i1 %13, label %15, label %14

14:                                               ; preds = %10
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  br label %33

15:                                               ; preds = %10
  %16 = load i32, ptr %4, align 4, !tbaa !5
  %17 = sext i32 %16 to i64
  %18 = getelementptr inbounds [101000 x i8], ptr @visited, i64 0, i64 %17
  %19 = load i8, ptr %18, align 1, !tbaa !9, !range !11, !noundef !12
  %20 = trunc i8 %19 to i1
  br i1 %20, label %29, label %21

21:                                               ; preds = %15
  %22 = load i32, ptr %3, align 4, !tbaa !5
  %23 = add nsw i32 %22, 1
  store i32 %23, ptr %3, align 4, !tbaa !5
  %24 = load i32, ptr %4, align 4, !tbaa !5
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds [101000 x i8], ptr @visited, i64 0, i64 %25
  store i8 1, ptr %26, align 1, !tbaa !9
  %27 = load i32, ptr %4, align 4, !tbaa !5
  %28 = load i32, ptr %3, align 4, !tbaa !5
  call void @_Z3BFSii(i32 noundef %27, i32 noundef %28)
  br label %29

29:                                               ; preds = %21, %15
  br label %30

30:                                               ; preds = %29
  %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 %10, !llvm.loop !13

33:                                               ; preds = %14
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  ret void
}

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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 = { nocallback nofree nounwind willreturn memory(argmem: write) }
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 = !{!10, !10, i64 0}
!10 = !{!"bool", !7, i64 0}
!11 = !{i8 0, i8 2}
!12 = !{}
!13 = distinct !{!13, !14}
!14 = !{!"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"

@ComNum = external dso_local local_unnamed_addr global [101000 x i32], align 16
@visited = external dso_local local_unnamed_addr global [101000 x i8], align 16

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3BFSii(i32 noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
define dso_local void @_Z7callBFSi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = sext i32 %0 to i64
  tail call void @llvm.memset.p0.i64(ptr nonnull align 16 @visited, i8 0, i64 %2, i1 false)
  %3 = shl nsw i32 %0, 2
  %4 = sext i32 %3 to i64
  tail call void @llvm.memset.p0.i64(ptr nonnull align 16 @ComNum, i8 0, i64 %4, i1 false)
  %5 = icmp sgt i32 %0, 0
  br i1 %5, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %1
  %wide.trip.count = zext nneg i32 %0 to i64
  br label %.lr.ph

._crit_edge:                                      ; preds = %12, %1
  ret void

.lr.ph:                                           ; preds = %.lr.ph.preheader, %12
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next, %12 ]
  %.01011 = phi i32 [ 0, %.lr.ph.preheader ], [ %.1, %12 ]
  %6 = getelementptr inbounds [101000 x i8], ptr @visited, i64 0, i64 %indvars.iv
  %7 = load i8, ptr %6, align 1, !tbaa !5, !range !9, !noundef !10
  %8 = trunc nuw i8 %7 to i1
  br i1 %8, label %12, label %9

9:                                                ; preds = %.lr.ph
  %10 = add nsw i32 %.01011, 1
  store i8 1, ptr %6, align 1, !tbaa !5
  %11 = trunc nuw nsw i64 %indvars.iv to i32
  tail call void @_Z3BFSii(i32 noundef %11, i32 noundef %10)
  br label %12

12:                                               ; preds = %.lr.ph, %9
  %.1 = phi i32 [ %.01011, %.lr.ph ], [ %10, %9 ]
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !11
}

; Function Attrs: mustprogress nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #1

attributes #0 = { mustprogress 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 = { mustprogress nocallback nofree nounwind willreturn memory(argmem: write) }

!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 = !{!"bool", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{i8 0, i8 2}
!10 = !{}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass