Parameters for AArch64 processor

I'm trying to compile an old code with an AArch64 processor but it's leading to memory leaks. After some troubleshooting, I have been able to locate one potential hot spot that includes the following definitions:

#define	MAXCHAR		255
#define	MAXSHORT	32767
#define MINSHORT	-32768
#define MAXTABLE	32500
#define BITS_PER_WORD	32
#define	BIT(r, n)	((((r)[(n)>>5])>>((n)&31))&1)
#define	SETBIT(r, n)	((r)[(n)>>5]|=((unsigned)1<<((n)&31)))

These values are unlikely to be accurate for an AArch64 CPU and I was wondering if anyone has any suggestions on what values to assign (note: the compiler is GCC-11). Thank you.