; LLVM IR from Bousk/Net :: NetworkLib/src/Utils.ll (ZN5Bousk5Utils15CountNeededBitsEm)

; 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"

@.str = external hidden unnamed_addr constant [7 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [68 x i8], align 1
@__PRETTY_FUNCTION__._ZN5Bousk5Utils15CountNeededBitsEm = external hidden unnamed_addr constant [44 x i8], align 1

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef zeroext i8 @_ZN5Bousk5Utils15CountNeededBitsEm(i64 noundef %0) #0 {
  %2 = alloca i64, align 8
  %3 = alloca i8, align 1
  store i64 %0, ptr %2, align 8, !tbaa !5
  %4 = load i64, ptr %2, align 8, !tbaa !5
  %5 = icmp ne i64 %4, 0
  br i1 %5, label %6, label %7

6:                                                ; preds = %1
  br label %9

7:                                                ; preds = %1
  call void @__assert_fail(ptr noundef @.str, ptr noundef @.str.1, i32 noundef 10, ptr noundef @__PRETTY_FUNCTION__._ZN5Bousk5Utils15CountNeededBitsEm) #3
  unreachable

8:                                                ; No predecessors!
  br label %9

9:                                                ; preds = %8, %6
  call void @llvm.lifetime.start.p0(i64 1, ptr %3) #4
  store i8 0, ptr %3, align 1, !tbaa !9
  br label %10

10:                                               ; preds = %13, %9
  %11 = load i64, ptr %2, align 8, !tbaa !5
  %12 = icmp ne i64 %11, 0
  br i1 %12, label %13, label %18

13:                                               ; preds = %10
  %14 = load i8, ptr %3, align 1, !tbaa !9
  %15 = add i8 %14, 1
  store i8 %15, ptr %3, align 1, !tbaa !9
  %16 = load i64, ptr %2, align 8, !tbaa !5
  %17 = udiv i64 %16, 2
  store i64 %17, ptr %2, align 8, !tbaa !5
  br label %10, !llvm.loop !10

18:                                               ; preds = %10
  %19 = load i8, ptr %3, align 1, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 1, ptr %3) #4
  ret i8 %19
}

; Function Attrs: noreturn nounwind
declare void @__assert_fail(ptr noundef, ptr noundef, i32 noundef, ptr noundef) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

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 = { noreturn nounwind "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 nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { noreturn nounwind }
attributes #4 = { 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", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"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"

@.str = external hidden unnamed_addr constant [7 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [68 x i8], align 1
@__PRETTY_FUNCTION__._ZN5Bousk5Utils15CountNeededBitsEm = external hidden unnamed_addr constant [44 x i8], align 1

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef zeroext i8 @_ZN5Bousk5Utils15CountNeededBitsEm(i64 noundef %0) local_unnamed_addr #0 {
  %.not = icmp eq i64 %0, 0
  br i1 %.not, label %5, label %.preheader.preheader

.preheader.preheader:                             ; preds = %1
  %2 = tail call range(i64 0, 65) i64 @llvm.ctlz.i64(i64 %0, i1 true)
  %3 = trunc nuw nsw i64 %2 to i8
  %4 = sub nuw nsw i8 64, %3
  ret i8 %4

5:                                                ; preds = %1
  tail call void @__assert_fail(ptr noundef nonnull @.str, ptr noundef nonnull @.str.1, i32 noundef 10, ptr noundef nonnull @__PRETTY_FUNCTION__._ZN5Bousk5Utils15CountNeededBitsEm) #3
  unreachable
}

; Function Attrs: noreturn nounwind
declare void @__assert_fail(ptr noundef, ptr noundef, i32 noundef, ptr noundef) local_unnamed_addr #1

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i64 @llvm.ctlz.i64(i64, i1 immarg) #2

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 = { noreturn nounwind "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 nosync nounwind speculatable willreturn memory(none) }
attributes #3 = { noreturn 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)"}


; Effective O3 passes: GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,LCSSAPass,LoopIdiomRecognizePass,LoopRotatePass,LoopSimplifyPass,SCCPPass,SROAPass,SimplifyCFGPass,TailCallElimPass