This is the mail archive of the crossgcc@sourceware.org mailing list for the crossgcc project.

See crosstool-NG for lots more information.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: gcc CXX_FLAGS


> Dear all,
>
> I am working since many weeks now on a armv7-a toolchain with gcc 4.8. It
> builds with no issue since a while.
> I am now trying to pass some optimization CXX_FLAGS.
>
> When I enable the -03 flag for example, I write this in my .config:
>
> # gcc other options
> #
> CT_CC_ENABLE_CXX_FLAGS="-O3".
>
> It builds fine. Now I am wondering if I have to pass again this flag when
I
> use this toolchain to build, let's say, android ROM.
> Shall I :
> $ make -03
>
> or as this flag has been activated when building the toolchain I do not
need
> to pass it again ?
>
> In short, $ make or $ make -03 ?
>
> Thank you for help

On Sat, May 25, 2013 at 8:43 PM, Anthony Foiani [via Sourceware.org] <
ml-node+s1504n233259h8@n7.nabble.com> wrote:

> Arnaud --
>
> Most makefiles are set up so you can specify flags for that
> compilation on the make command line.  You probably want to do
> something like this:
>
>   make CFLAGS=-O3 CXXFLAGS=-O3
>
> If you are passing multiple flags, you'll need to quote those values:
>
>   make CFLAGS="-O3 -g" ...
>
> (If you try just:
>
>   make -O3
>
> then 'make' will think you're trying to pass some flag "-O" to make
> itself, not to the compilers invoked by make.)
>
> Best regards,
> Anthony Foiani
>
>
Anthony,

thank you for your answer. In fact I was doing wrong.
Now I am still wondering if I need to pass again the flags when I build the
android ROM or Kernel.

here is part of my crosstool .config :

[DEBUG]    CT_CC_ENABLE_CXX_FLAGS="-O3 -fstrict-aliasing -Wdouble-promotion
-Wno-error -Wunsafe-loop-optimizations -funsafe-loop-optimizations
-floop-nest-optimize -floop-parallelize-all -fsanitize=thread
-fsanitize=address"
[DEBUG]    CT_CC_CORE_EXTRA_CONFIG_ARRAY="--with-float=hard
--with-mfpu=neon --enable-tls"
[DEBUG]    CT_CC_EXTRA_CONFIG_ARRAY="--with-float=hard --with-mfpu=neon
--enable-tls"

 Once the toolchain is built and used to build Android, shall I pass again
all these flags, or are they in fact already activated in
the arm-cortexa9_neon-linux-gnueabihf-gcc ?
I guess I can
$ export CFLAGS="..........."  before building Android ?



>
> ------------------------------
>  If you reply to this email, your message will be added to the discussion
> below:
> http://sourceware-org.1504.n7.nabble.com/gcc-CXX-FLAGS-tp233249p233259.html
>  To start a new topic under Sourceware - crossgcc list, email
> ml-node+s1504n151058h77@n7.nabble.com
> To unsubscribe from Sourceware - crossgcc list, click here<http://sourceware-org.1504.n7.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=151058&code=YXJuYXVkLmdhYm91cnlAZ21haWwuY29tfDE1MTA1OHwtMTM0MTY5MTAz>
> .
> NAML<http://sourceware-org.1504.n7.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml>
>




--
View this message in context: http://sourceware-org.1504.n7.nabble.com/gcc-CXX-FLAGS-tp233249p233265.html
Sent from the Sourceware - crossgcc list mailing list archive at Nabble.com.

--
For unsubscribe information see http://sourceware.org/lists.html#faq


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]