RtlClearAllBitsEx

VOID __fastcall RtlClearAllBitsEx(_RTL_BITMAP_EX *BitMapHeader){
  memset(
    BitMapHeader->Buffer,
    0i64,
    4 * ((BitMapHeader->SizeOfBitMap >> 5) + ((BitMapHeader->SizeOfBitMap & 0x1F) != 0)));
}

Referenced by:

IopLiveDumpAllocAndInitResources
IopLiveDumpEstimateMemoryPages
IopLiveDumpWriteDumpFileWithExtraPages
MiCopyToCfgBitMap
MiUpdateCfgSystemWideBitmapWorker