Disable clang's SLP vectorizer.

Disable clang's SLP vectorizer.

It currently generates invalid code, see
http://llvm.org/bugs/show_bug.cgi?id=20354

BUG=none

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=284029

[darin (slow to review), 2014-07-18 05:10:23]

LGTM

[darin (slow to review), 2014-07-18 05:12:09]

https://codereview.chromium.org/393193003/diff/1/build/common.gypi
File build/common.gypi (right):

https://codereview.chromium.org/393193003/diff/1/build/common.gypi#newcode4754
build/common.gypi:4754: ]
missing comma here?

[Nico, 2014-07-18 05:18:23]

On 2014/07/18 05:12:09, darin wrote:
> https://codereview.chromium.org/393193003/diff/1/build/common.gypi
> File build/common.gypi (right):
> 
> https://codereview.chromium.org/393193003/diff/1/build/common.gypi#newcode4754
> build/common.gypi:4754: ]
> missing comma here?

Yes, see patch set 2 (uploaded 10s before your comment) ;-)

[Nico, 2014-07-18 05:19:49]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2014-07-18 05:21:35]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/thakis@chromium.org/393193003/20001

[commit-bot: I haz the power, 2014-07-18 07:32:46]

Change committed as 284029

[skobes, 2014-07-18 18:12:47]

FYI, I think this change doesn't quite work.  In linux release builds the
-fno-slp-vectorize is on the command, but it comes *before* -O2, so it does
nothing.  It has to go after -O2 to have any effect.

[Nico, 2014-07-18 18:40:44]

https://codereview.chromium.org/393193003/diff/20001/build/common.gypi
File build/common.gypi (right):

https://codereview.chromium.org/393193003/diff/20001/build/common.gypi#newcod...
build/common.gypi:3545: ],
Does it work if you add

  'cflags': [ '-fno-slp-vectorize' ],

here?

[Nico, 2014-07-18 19:00:07]

On 2014/07/18 18:40:44, Nico (away) wrote:
> https://codereview.chromium.org/393193003/diff/20001/build/common.gypi
> File build/common.gypi (right):
> 
>
https://codereview.chromium.org/393193003/diff/20001/build/common.gypi#newcod...
> build/common.gypi:3545: ],
> Does it work if you add
> 
>   'cflags': [ '-fno-slp-vectorize' ],
> 
> here?

Follow-up with that change: https://codereview.chromium.org/408523002/