2017-01-17 1:55 GMT+03:00 Jakub Jelinek <ja...@redhat.com>:
> On Tue, Jan 17, 2017 at 01:30:11AM +0300, Andrew Senkevich wrote:
>> here is one more part of intrinsics for k-mask registers shifts:
>
> The software developer manuals describe KSHIFT{L,R}* like:
> KSHIFTLW
> COUNT <- imm8[7:0]
> DEST[MAX_KL-1:0] <- 0
> IF COUNT <=15
> THEN DEST[15:0] <- SRC1[15:0] << COUNT;
> FI;
>
> What is the behavior when src1 == dest, like:
> kshiftld $3, %k3, %k3
> ? Is it just a bug in the SDM and will it actually do the expected thing
> (set %k3 to %k3 << 3 and clear just the upper bits), or do we need
> an early-clobber on the destination to make sure GCC never emits these
> insns with the same register as both input and output?
Indeed, it should be different registers, how to do it?
--
WBR,
Andrew
