Re: [patch 2.6.20-rc1 4/6] PXA GPIO wrappers

Bill Gatliff
2006-12-21T20:51:37Z

Guys:

>>Probably? What I am wondering is this: can the compiler
>>optimize away the range check that is duplicated in GPSR/GPCR
>>and GPIO_bit for __gpio_set/get_value? Or could we optimize
>>this case by expanding the macros in place (which would mean
>>duplicating code from pxa-regs.h)...
>>
>>

Who cares? :)

I don't think there's much point in optimizing here, since these
functions won't be hot paths anyway. Yes, they'll be called in
interrupt handlers and so we don't want them to be _too_ heavy, but
compared to the overhead of an interrupt handler, a few extra
instructions in the GPIO access will get lost in the noise.

Inlines generally seem to be more maintainable, give you a symbol that
you can disassemble and breakpoint, etc. I'll take them over the macro
implementations any day, in this case even if there's a cost of a few
instructions.

All IMHO, of course.

b.g.

--
Bill Gatliff
bgat@billgatliff.com