UINT8 __fastcall MiDecrementSystemCacheViewCount(UINT64 a1){
UINT64 v1;
char *v2;
UINT8 result;
UINT64 v4;
v4 = MI_READ_PTE_LOCK_FREE((INT64)MmGetPdeBase() + ((a1 >> 18) & 0x3FFFFFF8));
v1 = v4;
MiPteInShadowRange((UINT64)&v4);
v2 = (char *)MmGetPfnDb() + 48 * ((v1 >> 12) & 0xFFFFFFFFFi64);
result = v2[39] - 1;
v2[39] = result;
return result;
}