Atmel CAVR-4 Manual De Usuario

CAVR-4

Descriptions of pragma directives

Reference Guide

Note: If you use the 

#pragma

 

optimize

 directive to specify an optimization level that 

is higher than the optimization level you specify using a compiler option, the pragma 
directive is ignored.

#pragma optimize=s 9

int small_and_used_often()

{

    ...

}

#pragma optimize=z 9

int big_and_seldom_used()

{

    ...

}

#pragma pack

#pragma pack([[{push|pop},][name,]][n])

The 

#pragma

 

pack

 directive is used for specifying the alignment of structures and 

union members.

Note: In the AVR IAR Compiler, alignment is always 1 and this pragma directive has 
no effect. It is available in order to maintain compatibility with other IAR Systems 
compilers.

pack(n)

 sets the structure alignment to 

. The 

pack(n)

 only affects declarations of 

structures following the pragma directive and to the next 

#pragma

 

pack

 or end of file.

pack()

 resets the structure alignment to default.

pack(push

 

[,name]

 

[,n])

 pushes the current alignment with the label 

 and sets 

alignment to 

. Note that both 

 and 

 are optional.

pack(pop

 

[,name]

 

[,n])

 pops to the label 

 and sets alignment to 

. Note that 

both 

 and 

 are optional.

If 

 is omitted, only top alignment is removed. If 

 is omitted, alignment is set to the 

value popped from the stack.

Packing alignment, one of: 1, 2, 4, 8, or 16

Pushed or popped alignment label