Enable crc32 for armv7?

[Jonathan Wakely]

On 28 July 2016 at 00:42, Jeffrey Walton wrote:
> This is kind of weird, but I think there's a disconnect in my
> understanding of things. CRC can be enabled with the following:
>
> $ gcc -g3 -O0 -march=armv8-a+crc -mfpu=neon test.cc -o test.exe
> $
>
> However, the Crypto stuff fails to compile:
>
> $ gcc -g3 -O0 -march=armv8-a+crc+crypto -mfpu=neon test.cc -o test.exe
> gcc: error: unrecognized argument in option ‘-march=armv8-a+crc+crypto’
>
> So the question becomes, how do I enable the Crypto extensions?

Have you tried -mfpu=crypto-neon-fp-armv8 ?

That's the only occurrence of "crypto" in the manual page you linked
to, so it seems like a good bet.