Datasheet

ManualsBrandsARM ManualsComputer HardwareVERSION 1.2

ARM Compiler Reference

__inline int f(int x) {return x*5+1;}

int g(int x, int y) {return f(x) + f(y);}

The compiler compiles functions inline when

__inline

is used and the

functions are not too large. Large functions are not compiled inline

because they can adversely affect code density and performance. See

Defining optimization criteria on page 2-24 for information on

command-line options that affect inlining.

__weak

This specifies an

extern

function or object declaration that, if not present,

does not cause the linker to fault an unresolved reference. The linker does

not load the function or object from a library unless another compilation

uses the function or object non-weakly. If the reference remains

unresolved, its value is assumed to be

NULL

. See the ADS Linker and

Utilities Guide for details on library searching.

If the reference is made from code that compiles to a Branch or Branch

Link instruction, the reference is resolved as branching to the next

instruction. This effectively makes the branch a no-op:

__weak void f(void);

...

f(); // call f weakly

A function or object cannot be used both weakly and non-weakly in the

same compilation. For example the following code uses

f()

weakly from

g()

and

h()

void f(void);

void g() {f();}

__weak void f(void);

void h() {f();}

It is not possible to use a function or object weakly from the same

compilation that defines the function or object. The code below uses

f()

non-weakly from

h()

__weak void f(void);

void h() {f();}

void f() {}

3.1.3 Variable declaration keywords

This section describes the implementation of various standard and ARM-specific

variable declaration keywords. Standard C or C++ keywords that do not have

ARM-specific behavior or restrictions are not documented. See also Type qualifiers on

page 3-12 for information on qualifiers such as

volatile

and

__packed