Re: [PATCH, i386] RTM support

[Patrick Marlier <patrick dot marlier at gmail dot com>]

On 02/16/2012 11:47 AM, Jakub Jelinek wrote:
> if you want to use different fallback code from the transaction code.
> So the above is right and needed, though perhaps we might want
> a combine pattern or peephole to turn the
> movl $-1, %eax
> xbegin .+6
> cmpl %eax, $-1
> jne 1f
> sequence into
> movl $-1, %eax
> xbegin 1f
> if flags register is dead at that point, and perhaps also remove the
> movl $-1, %eax if %eax is not live when not jumping.

Yes this is what I meant. In fact, I was expecting that to be 
implemented directly with the RTM support otherwise as Andi said, asm 
macros is enough to use RTM. I think the goal of Intel was to avoid this 
cmp/jne but at least this a first step to implement RTM intrinsics in 
GCC. (It was just a note that it could be improved, no more).

On 02/16/2012 12:11 PM, Andi Kleen wrote:
> For macros asm goto maps well to XBEGIN today.
Yes, I tried it when HJ committed it in binutils but thanks for the info.
--
Patrick.