[PATCH] Vector mode addresses

Jakub Jelinek jakub@redhat.com
Thu Jan 30 21:06:00 GMT 2014

On Thu, Jan 30, 2014 at 08:27:47PM +0000, Paulo Matos wrote:
> Yes, it looks strange but it was the way we came up with to
> implement an instruction that loads from a pair of addresses.
> From what I wrote previously to Richard.
> "We have an instruction that loads two 32 bit values into a lower
> and upper parts of a 64bit register using a base register and a 64
> bit register used as a double index.
> So,
> r1 <- [r0, r2]
> means:
> low(r1) = [r0 + low(r2)]
> high(r1) = [r0 + high(r2)]"

That sounds like gather instruction e.g. i?86 AVX2/AVX512F has.
I don't like using vector mode for the address though, i?86 uses UNSPECs and
IMNSHO you should too.  Or express it as vec_concat of two MEM loads
where address of each one will be the base + vec_select of the vector


More information about the Gcc-patches mailing list