Le 19 avr. 2016 à 13:46, Yvan Roux <yvan.roux@linaro.org> a écrit :

Hi Laurent,

On 19 April 2016 at 11:00, Laurent Thévenoux
<laurent.thevenoux@ens-lyon.fr> wrote:

Dear Devs,

I get the following error when I use gcc 4.9.4 with the -mcpu flag set with
a certain configuration of ‘feature/nofeature’, i.e.:
-mcpu=cortex-a57+fp+simd+nocrypto+nocrc will fail, but
-mcpu=cortex-a57+fp+nocrypto+simd+nocrc won’t, for example.

Here the error I get with the former -mcpu flag:

Assembler messages:
Error: unknown architectural extension `n'
Error: unrecognized option -mcpu=cortex-a57+fp+simd+n


Minimal test case: $gcc -march=armv8-a+fp+simd+nocrc+nocrypto
-mcpu=cortex-a57+fp+simd+nocrypto+nocrc -mtune=cortex-a57 helloworld.c.

According to the gcc documentation
<https://gcc.gnu.org/onlinedocs/gcc-4.9.3/gcc/AArch64-Options.html#AArch64-Options>
the order seems to be irrelevant. I obtained the error with the linaro-gcc
4.9.4 binary release, as well as a personal built from linaro sources
package. It also fails with gcc 4.9.2 on the 3.18.0-linaro-hikey debian
distribution.

I also tried with (linaro) gcc 4.8.5, 5.1.1, 5.2.1, and 5.3.1 versions, and
it works well.

On which version of GCC 4.9.4 do you see that issue ? I can't
reproduce with our latest 4.9.4 release (4.9-2016.02) which is
available here:

https://releases.linaro.org/components/toolchain/binaries/4.9-2016.02/aarch64-linux-gnu/