On Mon, Aug 1, 2016 at 9:27 PM, Martin Liška [off-list ref] wrote:

On 08/01/2016 01:09 PM, Michal Hocko wrote:

quoted

[CC our gcc guy - I guess he has some theory for this]

On Sun 31-07-16 14:11:25, Michal Hocko wrote:

quoted

It seems that this has been already reported and Jason has noticed [1] that
the problem is in the disabled optimizations:

$ grep CRYPTO_DEV_UX500_DEBUG .config
CONFIG_CRYPTO_DEV_UX500_DEBUG=y

if I disable this particular option the code compiles just fine. I have
no idea what is wrong about the code but it seems to depend on
optimizations enabled which sounds a bit scrary...

[1] http://www.spinics.net/lists/linux-mm/msg109590.html

Hi.

The difference is that w/o any optimization level, GCC doesn't make %c0 an
intermediate integer operand [1] (see description of "i" constraint).

We recently hit a similar problem on ppc where the compiler couldn't
satisfy an "i" when it was wrapped in an function and optimisations
were disabled. The fix[1] was to change the function signature so that
it's arguments were explicitly const. I don't know enough about gcc to
tell if that behaviour is arch specific or not, but it's worth trying.

Oliver

[1] https://lists.ozlabs.org/pipermail/skiboot/2016-July/004061.html

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