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.
Do I have to open a bug report for this, or maybe, I just misunderstood something, somewhere?
Regards, Laurent Thévenoux