Re: [Nasm-devel] adding AVX2 transactional synchronization extensions

[Cyrill G. <gor...@op...>]

On Tue, Feb 14, 2012 at 02:17:22PM -0800, H. Peter Anvin wrote:
> On 02/14/2012 02:03 PM, Cyrill Gorcunov wrote:
> >Hi, while disasm is not yet done, here what I thought about
> >assembler part. It's not yet complete but just to share.
> >
> >At moment the idea is to try to guess if we need to emit
> >additional lock prefix for xacquire/release instructions.
> >
> >(the patch for insns.dat
> >
> >+;
> >+; transactional synchronization extensions
> >+XABORT		imm8				[i:	c6 f8 ib] FUTURE,HLE
> >+XBEGIN		imm16				[i:	c7 f8 iw] FUTURE,HLE
> >+XBEGIN		imm32				[i:	c7 f8 id] FUTURE,HLE
> >+XEND		void				[	0f 01 d5] FUTURE,HLE
> >+XTEST		void				[	0f 01 d6] FUTURE,HLE,RTM
> >+
> >
> >is in my tree already, simply desided to not push it upstream
> >until everything is done).
> >
> 
> I pushed that one (with fixes) already.
> 

Ah, I forgot to update repo ;)

> I would strongly suggest that this should be data-driven; either a
> byte code or a flag.

ok, i'll think about it, thanks!

> 
> IIRC MOV never requires LOCK, nor does it accept it.
> 

quoting spec:
The XRELEASE prefix hint can only be used with the following instructions:

 - The "MOV mem, reg" (Opcode 88H/89H) and "MOV mem, imm" (Opcode C6H/C7H) instructions.
   In these cases, the XRELEASE is recognized without the presence of the LOCK
   prefix.

So I seem to miss something obvious?

	Cyrill