ARC build -O3 (was Re: subtle side effect of commit a1c48bb160f836)

[Vineet Gupta]

On Wednesday 01 July 2015 08:49 PM, Michal Marek wrote:
> On Wed, Jun 24, 2015 at 05:50:16PM +0530, Vineet Gupta wrote:
>> On Thursday 18 June 2015 04:02 PM, Vineet Gupta wrote:
>>> On Thursday 18 June 2015 03:44 PM, Michal Marek wrote:
>>>> Uh, this is not what I meant. KCFLAGS is a *user* setting. It's meant to
>>>> be set in the environment or command line.
>>>
>>> Well I don't want to rely on external settings whatsoever to enforce this. If this
>>> is not the right way, what do u suggest I do to help fix this.
>>
>>
>> Can I keep this seeming abuse of KCFLAGS or do u suggest alternate approach I can
>> code up !
> 
> Hi Vineet, sorry for the late reply.

NP !

> I had something like the below
> patch in mind, simply allow arc to specify -O3 in ARCH_CFLAGS (that part
> I'm leaving up to you).

See below !

> From e458fdf4ae37e1adce81b58d96b1075b4f0656e6 Mon Sep 17 00:00:00 2001
> From: Michal Marek <mmarek@xxxxxxxx>
> Date: Wed, 1 Jul 2015 17:13:16 +0200
> Subject: [PATCH] kbuild: Allow arch Makefiles to override {cpp,ld,c}flags
> 
> Since commit a1c48bb1 (Makefile: Fix unrecognized cross-compiler command
> line options), the arch Makefile is included earlier by the main
> Makefile, preventing the arc architecture to set its -O3 compiler
> option. Since there might be more use cases for an arch Makefile to
> fine-tune the options, add support for ARCH_CPPFLAGS, ARCH_AFLAGS and
> ARCH_CFLAGS variables that are appended to the respective kbuild
> variables. The user still has the final say via the KCPPFLAGS, KAFLAGS
> and KCFLAGS variables.
> 
> Reported-by: Vineet Gupta <Vineet.Gupta1@xxxxxxxxxxxx>
> Signed-off-by: Michal Marek <mmarek@xxxxxxxx>

Sweet, that works for me with the following patch below.

Some logistics things:
- It would be nice to keep both of these patches together - do u want to do
  that or want me to pick this one up
- For ARC this fixes a regression starting 3.16 - so I'll need a stable backport
  which but obviously requires above to go to stable. Do u have any issues with
  that. Shall we do the stable request after these hit the mainline...

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