Re: [PATCH v4 1/3] lib: add bitrev8x4()

From: Anatolij Gustschin
Date: Fri Dec 02 2016 - 02:52:29 EST


Hi Joshua,

On Thu, 1 Dec 2016 16:04:09 -0800
Joshua Clayton stillcompiling@xxxxxxxxx wrote:
...
>>> +static __always_inline __attribute_const__ u32 __arch_bitrev8x4(u32 x)
>>> +{
>>> + __asm__ ("rbit %0, %1; rev %0, %0" : "=r" (x) : "r" (x));
>> return x;
>Oops thats a little embarrassing;
>I'll add a return.
>>> +}
>> otherwise you get
>>
>> In function '__arch_bitrev8x4':
>> warning: no return statement in function returning non-void [-Wreturn-type]
>>
>
>I wonder why I do not see this warning when compiling. The inlining, maybe?

do you have CONFIG_HAVE_ARCH_BITREVERSE=y in your .config?
Probably not optimized code is used, otherwise you will send wrong
data to FPGA (due to wrong return values from __arch_bitrev8x4).

Anatolij