Re: Can't build product that uses DEFAULTTUNE="arm926ejs"

[Adrian Bunk <bunk@stusta.de>]

On Sat, Mar 16, 2019 at 09:21:57AM +0000, Peter Kjellerstedt wrote:
> 
> While I agree that your patch will solve the problem with arm926ejs, I 
> believe there are advantages in applying my patches instead. In addition 
> to fixing the problem with arm926ejs, my patches (patch set 4, not patch 
> set 2 that is currently on master-next) also:
> 
> * make it so that there is no change to TUNE_FEATURES,
> * make it explicit whether -mcpu or -march is used, and
> * make the extra arguments added to -mcpu or -march for armv8 explicit.
> 
> That last point was something that confused me when I read the original 
> tune files. I did not realize that those extra features were added to 
> whatever -mcpu or -march happened to be added to TUNE_CCARGS before the 
> arch-armv8a.inc file was included (especially as it was written to make 
> it look as they were only added to the -march option).

For armv8 a larger redesign is actually required - it doesn't scale
to have variables like TUNE_FEATURES_tune-armv8a-crc-crypto with
160k possible combinations[1] in gcc 8.

> //Peter

cu
Adrian

[1] target architectures 8.0-8.4 and 15 feature modifiers

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