; LLVM IR from facebook/hermes :: external/llvh/lib/Demangle/MicrosoftDemangle.ll (Z18countEmbeddedNullsPKhj)

; 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 i32 @_Z18countEmbeddedNullsPKhj(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 0, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  store i32 0, ptr %6, align 4, !tbaa !9
  br label %7

7:                                                ; preds = %22, %2
  %8 = load i32, ptr %6, align 4, !tbaa !9
  %9 = load i32, ptr %4, align 4, !tbaa !9
  %10 = icmp ult i32 %8, %9
  br i1 %10, label %12, label %11

11:                                               ; preds = %7
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  br label %25

12:                                               ; preds = %7
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  %14 = getelementptr inbounds i8, ptr %13, i32 1
  store ptr %14, ptr %3, align 8, !tbaa !5
  %15 = load i8, ptr %13, align 1, !tbaa !11
  %16 = zext i8 %15 to i32
  %17 = icmp eq i32 %16, 0
  br i1 %17, label %18, label %21

18:                                               ; preds = %12
  %19 = load i32, ptr %5, align 4, !tbaa !9
  %20 = add i32 %19, 1
  store i32 %20, ptr %5, align 4, !tbaa !9
  br label %21

21:                                               ; preds = %18, %12
  br label %22

22:                                               ; preds = %21
  %23 = load i32, ptr %6, align 4, !tbaa !9
  %24 = add i32 %23, 1
  store i32 %24, ptr %6, align 4, !tbaa !9
  br label %7, !llvm.loop !12

25:                                               ; preds = %11
  %26 = load i32, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  ret i32 %26
}

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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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(read, inaccessiblemem: none) uwtable
define dso_local noundef i32 @_Z18countEmbeddedNullsPKhj(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %.not = icmp eq i32 %1, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %2
  %3 = zext i32 %1 to i64
  %min.iters.check = icmp ult i32 %1, 8
  br i1 %min.iters.check, label %.lr.ph.preheader15, label %vector.ph

.lr.ph.preheader15:                               ; preds = %middle.block, %.lr.ph.preheader
  %.09.ph = phi i32 [ 0, %.lr.ph.preheader ], [ %ind.end, %middle.block ]
  %.058.ph = phi i32 [ 0, %.lr.ph.preheader ], [ %12, %middle.block ]
  %.067.ph = phi ptr [ %0, %.lr.ph.preheader ], [ %ind.end10, %middle.block ]
  br label %.lr.ph

vector.ph:                                        ; preds = %.lr.ph.preheader
  %n.vec = and i64 %3, 4294967288
  %ind.end = trunc nuw i64 %n.vec to i32
  %ind.end10 = getelementptr i8, ptr %0, i64 %n.vec
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
  %vec.phi = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %9, %vector.body ]
  %vec.phi12 = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %10, %vector.body ]
  %next.gep = getelementptr i8, ptr %0, i64 %index
  %4 = getelementptr i8, ptr %next.gep, i64 4
  %wide.load = load <4 x i8>, ptr %next.gep, align 1, !tbaa !5
  %wide.load14 = load <4 x i8>, ptr %4, align 1, !tbaa !5
  %5 = icmp eq <4 x i8> %wide.load, zeroinitializer
  %6 = icmp eq <4 x i8> %wide.load14, zeroinitializer
  %7 = zext <4 x i1> %5 to <4 x i32>
  %8 = zext <4 x i1> %6 to <4 x i32>
  %9 = add <4 x i32> %vec.phi, %7
  %10 = add <4 x i32> %vec.phi12, %8
  %index.next = add nuw i64 %index, 8
  %11 = icmp eq i64 %index.next, %n.vec
  br i1 %11, label %middle.block, label %vector.body, !llvm.loop !8

middle.block:                                     ; preds = %vector.body
  %bin.rdx = add <4 x i32> %10, %9
  %12 = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %bin.rdx)
  %cmp.n = icmp eq i64 %n.vec, %3
  br i1 %cmp.n, label %._crit_edge, label %.lr.ph.preheader15

._crit_edge:                                      ; preds = %.lr.ph, %middle.block, %2
  %.05.lcssa = phi i32 [ 0, %2 ], [ %12, %middle.block ], [ %spec.select, %.lr.ph ]
  ret i32 %.05.lcssa

.lr.ph:                                           ; preds = %.lr.ph.preheader15, %.lr.ph
  %.09 = phi i32 [ %17, %.lr.ph ], [ %.09.ph, %.lr.ph.preheader15 ]
  %.058 = phi i32 [ %spec.select, %.lr.ph ], [ %.058.ph, %.lr.ph.preheader15 ]
  %.067 = phi ptr [ %13, %.lr.ph ], [ %.067.ph, %.lr.ph.preheader15 ]
  %13 = getelementptr inbounds i8, ptr %.067, i64 1
  %14 = load i8, ptr %.067, align 1, !tbaa !5
  %15 = icmp eq i8 %14, 0
  %16 = zext i1 %15 to i32
  %spec.select = add i32 %.058, %16
  %17 = add nuw i32 %.09, 1
  %exitcond.not = icmp eq i32 %17, %1
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !12
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.vector.reduce.add.v4i32(<4 x i32>) #1

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(read, 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" }
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 = !{!6, !6, i64 0}
!6 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = distinct !{!8, !9, !10, !11}
!9 = !{!"llvm.loop.mustprogress"}
!10 = !{!"llvm.loop.isvectorized", i32 1}
!11 = !{!"llvm.loop.unroll.runtime.disable"}
!12 = distinct !{!12, !9, !11, !10}


; Effective O3 passes: CorrelatedValuePropagationPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopLoadEliminationPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,LoopVectorizePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass