MCUXpresso IDEのトピックHow to make sure inline functions are really "inlined" in MCUX IDE on RT1170?

How to make sure inline functions are really "inlined" in MCUX IDE on RT1170?

sutter_zhou — Fri, 05 Mar 2021 05:59:15 GMT

When I'm using MCUX IDE for RT1170 develop, I found most inline functions are actually not inlined, but invoked as a normal function. What went wrong? I can't find anywhere to configure such behavior in the compiler settings.

Such as "MC_PWM_UPDATE" function, it should be inlined, but it's treated as a NOT inline function:

static inline void MC_PWM_UPDATE(GMCLIB_3COOR_T_F16 *psDuty)

See attached project.

Re: How to make sure inline functions are really "inlined" in MCUX IDE on RT1170?

ErichStyger — Fri, 05 Mar 2021 07:02:23 GMT

Hi @sutter_zhou ,

'inline' is just a hint for the compiler: if it is getting inline or not is depending on the compiler decision.

If you really want to have things inlined, you need to use a macro for the code.

Checking the map file if a symbol/function is there does not tell you if it is inlined or not: you need to check the actual calls, because if you take the address of an inlined function there will be both inlined and non-inlined versions.

And check your compiler/optimization settings: if you optimize for code size, the compiler likely will not inline as this in general increases the code size. If not already set: optimize for speed.

I hope this helps,

Erich

Re: How to make sure inline functions are really "inlined" in MCUX IDE on RT1170?

sutter_zhou — Fri, 05 Mar 2021 07:54:42 GMT

Hi @ErichStyger ,

This project has no optimization at all. So I think it should stick to C grammar. I can confirm that inline functions are invoked in the runtime. Do you know any macro or keywords that can make sure functions can be inlined in GCC? Thanks.

Re: How to make sure inline functions are really "inlined" in MCUX IDE on RT1170?

converse — Fri, 05 Mar 2021 08:14:54 GMT

See this:

https://stackoverflow.com/questions/8381293/how-do-i-force-gcc-to-inline-a-function

Re: How to make sure inline functions are really "inlined" in MCUX IDE on RT1170?

sutter_zhou — Fri, 05 Mar 2021 08:36:34 GMT

Thanks, it helps.