libera/#sbcl - IRC Chatlog

6:34:15 hayley I think we're missing sb-simd-avx2:u8.32-string-ref for loading from base-strings.

6:36:58 hayley (Asked heisig for u32.8-string-ref and movemask, but forgot about 8-bit strings, oops)

10:01:50 kami_ moon-child, hayley: thank you for your hints.

10:02:05 kami_ hayley: how did you contact him?

10:04:42 hayley He used to be active on IRC, but I think he's now busy with PhD work. But if I get the time (I'm also busy with university) I can see about adding in a u8.32-string-ref, though that of course would only be usable from the SBCL release after I do that.

10:07:03 kami_ Is there any commit in the source tree which adds something like this?

10:08:21 hayley There is not.

10:08:29 kami_ Yes, just checked, sb-simd was committed in one chunk

10:09:07 hayley I have https://github.com/telekons/one-more-re-nightmare/blob/master/Code/SIMD/new-sbcl-x86-64.lisp#L236-L250 (see lines 70-80 for DEFINE-BORING-VOP) which you could use.

10:09:28 hayley (Also note that it's in the SB-VM package)

10:11:27 kami_ Heh, was looking at one-more-re-nightmare two days ago. Thank you!

10:13:11 kami_ And I don't see any mention of vptest

10:13:26 kami_ ... in sb-simd

12:09:32 kami_ hayley: thank you. The load works like a charm.

12:19:23 kami_ But I seem to miss something. When trying to create a vop for vptest, I get an error 'invalid number of arguments: 4'

12:20:32 kami_ https://pastebin.com/Xbsw6sYj

12:21:48 hayley What function signals the error? I can't tell immediately from that code.

12:22:06 hayley (Alas, my phone lacks AVX2)

12:22:16 kami_ :D

12:22:26 kami_ the defun in mypackage

12:24:04 kami_ when the first compilation occurs. Wait, I'll paste the stack

12:25:06 hayley My understanding is VPTEST sets flags and not a register; DEFINE-BORING-VOP won't work there. I can't remember how to specify which flag the VOP "returns", but you'd need to specify the Carry flag.

12:25:38 hayley And so the instruction is (inst vptest a b)

12:28:53 kami_ Ah, right. Thanks!

12:30:39 hayley The DEFINE-VOP form should have (:conditional :c) I think, and similarly the DEFKNOWN should return a BOOLEAN. A guess though, I don't have any conditional VOPs I wrote on me.

12:32:17 kami_ I'll check the vop sources. Thanks again