rm: Introduce SK_ARM_NEON_WRAP handy wrapper macro.

rm: Introduce SK_ARM_NEON_WRAP handy wrapper macro.
    
It is used to simplify arm/neon dispatch logic code.
Committed: https://code.google.com/p/skia/source/detail?r=4958

[digit1, 2012-08-02 09:44:33]

ping?

[DerekS, 2012-08-02 15:00:49]

http://codereview.appspot.com/6458060/diff/1/src/core/SkUtilsArm.h
File src/core/SkUtilsArm.h (right):

http://codereview.appspot.com/6458060/diff/1/src/core/SkUtilsArm.h#newcode54
src/core/SkUtilsArm.h:54: #    define SK_PURE  __attribute__((pure))
So on arm compilers it seems like pure is equivalent to the const attribute, but
that isn't the case everywhere.  Is there any reason we shouldn't be calling
this attribute const?

If we can use const we can make this macro available to all of Skia not just
this function.  It could live in include/core/SkPreConfig.h going by the
something like SK_FUNC_CONST.

[digit1, 2012-08-06 14:06:11]

Ping. Patch set 3 defines SK_FUNC_CONST in SkPreConfig.h

[caryclark1, 2012-08-06 14:13:07]

lgtm

[DerekS, 2012-08-06 14:19:13]

Sorry for the delay, but we didn't get notified until you sent us the ping. 
Unfortunately, this review tool does not notify reviewers of new patch sets
automatically. It requires the contributor to publish+mail comments each time to
send us an email about it.

http://codereview.appspot.com/6458060/diff/5001/include/core/SkPreConfig.h
File include/core/SkPreConfig.h (right):

http://codereview.appspot.com/6458060/diff/5001/include/core/SkPreConfig.h#ne...
include/core/SkPreConfig.h:187: #  define  SK_PURE_FUNC  __attribute__((pure))
is this supposed to be SK_CONST_FUNC?

[digit, 2012-08-06 14:23:34]

http://codereview.appspot.com/6458060/diff/1/src/core/SkUtilsArm.h
File src/core/SkUtilsArm.h (right):

http://codereview.appspot.com/6458060/diff/1/src/core/SkUtilsArm.h#newcode54
src/core/SkUtilsArm.h:54: #    define SK_PURE  __attribute__((pure))
Will do, thanks.

http://codereview.appspot.com/6458060/diff/5001/include/core/SkPreConfig.h
File include/core/SkPreConfig.h (right):

http://codereview.appspot.com/6458060/diff/5001/include/core/SkPreConfig.h#ne...
include/core/SkPreConfig.h:187: #  define  SK_PURE_FUNC  __attribute__((pure))
((const)) is slightly stricter than ((pure)). Which one is better to use here?

My understanding is that a call to a ((const)) func can be completely removed
from the optimized code because the compiler assumes it has absolutely no
side-effects.

In our specific use, the function does print stuff to the log in debug mode, so
technically not completely true.

[digit1, 2012-08-06 14:35:29]

ok, I'm going to submit the patch as is. If you prefer to define SK_CONST_FUNC
later, we will be able to do that in a later one.

[DerekS, 2012-08-06 14:38:44]

On 2012/08/06 14:35:29, digit1 wrote:
> ok, I'm going to submit the patch as is. If you prefer to define SK_CONST_FUNC
> later, we will be able to do that in a later one.

sounds good to me