6.17.3 Fastest Minimum-Width Integer Types

Typedef names that designate signed and unsigned integer types with at least the specified width and that are usually the fastest to work with.

Attention: The types for 24-bit objects are only supported when using PIC devices and MPLAB XC8. The types for 64-bit objects are not supported when using 8-bit AVR, Baseline, or non-enhanced Mid-range PIC devices with MPLAB XC8.

Include

<stdint.h>

TypeDescription
int_fast8_tThe fastest signed integer of at least 8 bits width.
int_fast16_tThe fastest signed integer of at least 16 bits width.
int_fast24_tThe fastest signed integer of at least 24 bits width.
int_fast32_tThe fastest signed integer of at least 32 bits width.
int_fast64_tThe fastest signed integer of at least 64 bits width (see Attention note).
uint_fast8_tThe fastest unsigned integer of at least 8 bits width.
uint_fast16_tThe fastest unsigned integer of at least 16 bits width.
uint_fast24_tThe fastest unsigned integer of at least 24 bits width.
uint_fast32_tThe fastest unsigned integer of at least 32 bits width.
uint_fast64_tThe fastest unsigned integer of at least 64 bits width (see Attention note).