RE: [PATCH 00/18] Support -mevex512 for AVX512

["Hu, Lin1" <lin1.hu@intel.com>]

Hi, 

Thanks for you reply.

I'd like to verify that our understanding of your requirements is correct, and that __EVEX256__ can be considered a default macro to determine whether the compiler supports the __EVEX***__ series of switches. 

For example:

I have a segment of code like:
#if defined(__EVEX512__):
__mm512.*__;
#else
__mm256.*__;
#endif

But __EVEX512__ is undefined that doesn't mean I only need 256bit, maybe I use gcc-13, so I can still use 512bit.

So the code should be:
#if defined(__EVEX512__):
__mm512.*__;
#elif defined(__EVEX256__):
__mm256.*__;
#else
__mm512.*__;
#endif

If we understand correctly, we'll consider the request. But since we're about to have a vacation, follow-up replies may be a bit slower.

BRs,
Lin

-----Original Message-----
From: ZiNgA BuRgA <zingaburga@hotmail.com> 
Sent: Thursday, September 28, 2023 8:32 AM
To: Hu, Lin1 <lin1.hu@intel.com>; gcc-patches@gcc.gnu.org
Subject: Re: [PATCH 00/18] Support -mevex512 for AVX512

Thanks for the new patch!

I see that there's a new __EVEX512__ define.  Will there be some __EVEX256__ (or maybe some max EVEX width) define, so that code can detect whether the compiler supports AVX10.1/256 without resorting to version checks?