NASM - The Netwide Assembler

Please login or register.

Login with username, password and session length
Advanced search  

News:

Author Topic: Functions with XMM works fine while functions with YMM fails x64  (Read 73 times)

coldflame

  • Jr. Member
  • *
  • Offline Offline
  • Posts: 15

Hello,

I have a codes for basic matrix/vector multiplication (overall 12 codes). They are made to use SSE, AVX and FMA. With AVX/FMA, I use YMM registers.

The whole code is linked into .dll and I use Matlab to call these functions.

While functions that uses XMM registers work fine, the ones that uses YMM registers crash SOMETIMES (not always, but mostly Matlab crashes and reports a bug in DLL).

This is kinda strange because I'm not sure what might be the problem here.

So I made a function with AVX instruction BUT with XMM registers and the funciton works well, no crashes.

It seems to be some kind of a problem with using YMM registers.

Have you ever seen something like that? Any help appreciated.

PS: ALL codes are OK - they work as expected (tested in Matlab and DBG).
« Last Edit: April 19, 2017, 09:42:13 PM by coldflame »
Logged

coldflame

  • Jr. Member
  • *
  • Offline Offline
  • Posts: 15
Re: Functions with XMM works fine while functions with YMM fails x64
« Reply #1 on: April 20, 2017, 12:13:39 PM »

I guess it has something to do with alignment. Probably I need to align on 32-byte boundary instead of 16-byte one.
Logged

coldflame

  • Jr. Member
  • *
  • Offline Offline
  • Posts: 15
Re: Functions with XMM works fine while functions with YMM fails x64
« Reply #2 on: April 22, 2017, 01:58:27 PM »

For anyone curious about what was wrong:

- something was wrong with alignment - I've changed all aligned MOV unstructions to unaligned ones and it works fine now.
Logged