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Compiler-specific Features
4.3.2 __attribute__((always_inline))
This function attribute indicates that a function must be inlined.
The compiler attempts to inline the function, regardless of the characteristics of the
function. However, the compiler does not inline a function if doing so causes problems.
For example, a recursive function is inlined into itself only once.
Note
This function attribute is a GNU compiler extension that is supported by the ARM
compiler. It has the keyword equivalent __forceinline.
Example
static int max(int x, int y) __attribute__((always_inline))
{
return x > y x : y; // always inline if possible
}
See also
• --forceinline on page 2-58
• __forceinline on page 4-6.
4.3.3 __attribute__((const))
Many functions examine only the arguments passed to them, and have no effects except
for the return value. This is a much stricter class than __attribute__((pure)), because a
function is not permitted to read global memory. If a function is known to operate only
on its arguments then it can be subject to common sub-expression elimination and loop
optimizations.
Note
This function attribute is a GNU compiler extension that is supported by the ARM
compiler. It has the keyword equivalent __pure.
Example
int Function_Attributes_const_0(int b) __attribute__ ((const));
int Function_Attributes_const_2(int b)
{
int aLocal=0;
aLocal += Function_Attributes_const_0(b);
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