ARM > Efficient C for ARM > C Data Types

by David Thomas on —

C Data Types

Certain C data types are more efficient to use for local variables than others.

  • ARM has 32-bit wide registers and 32-bit data processing instructions.

Therefore the machine’s natural word type, int, is 32-bit.

C Data Type Implementation
char unsigned 8-bit byte
short signed 16-bit halfword
int signed 32-bit word
long signed 32-bit word
long long signed 64-bit double word