Messages in this thread | | | From | gchen gchen <> | Subject | Re: [PATCH] cris: arch-v10: kernel: kgdb: let is_dyn_brkp as extern variable | Date | Thu, 9 Jul 2015 09:26:57 +0800 |
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On 07/07/2015 06:28 AM, Chen Gang wrote: > On 7/6/15 18:31, Valdis.Kletnieks@vt.edu wrote: >> On Mon, 06 Jul 2015 15:49:20 +0800, Chen Gang said: >>> On 07/06/2015 02:25 AM, Valdis.Kletnieks@vt.edu wrote: >>>> On Sun, 05 Jul 2015 06:07:54 +0800, Chen Gang said: >>>>> For upstream cris toolchain (gcc is 6.0 >>>> >>>> typo? >>>> >>> >>> Do you mean "toolchain" -> "tool chain"? >> >> No, I was wondering where a gcc 6.0 managed to escape when 5.1 just got >> released about 2 weeks ago.... >> >
Oh, sorry, gcc 5.1 is the same, and at present, for me:
- The new gcc have additional optimization for the static variables. It should notice about the related c code when optimizing, but gcc has no idea about assembly code (it should passes them to gas, directly).
- If one want gcc skip the related optimization, it can use 'volatile' for it (the static variable which may be used by both c code and assembly code in one file).
- So I guess, we need add 'volatile' to the related static variable, we do not want to disable this optimization only because of this issue.
Welcome any additional ideas, suggestions and completions.
> OK, thanks. At present, gcc 6.0 is the latest in master branch. > > After check fedora released toolchain (gcc 4.9.1, binutils 2.25), it has > no issue (support static variable in our case). So this patch can be > dropped, and I shall try: > > - Use the same configuration parameters of fedora released toolchain to > build the upstream latest cross toolchain again, and try. > > - If it still has issue (not support static variable), I shall try to > fix it. > > > Thanks. >
-- Chen Gang
Open, share, and attitude like air, water, and life which God blessed
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