• Marco Leise (7/7) Jun 05 2013 I was just experimenting with core.atomic and noticed only a
• David Nadlinger (6/11) Jun 05 2013 atomicLoad/atomicStore are implemented for LDC.
• carryonjutta (4/4) Dec 31 2014 Is this because it isn't implemented or because it can be
• John Colvin (4/16) Jan 02 2015 Those who are interested in this topic should watch Herb Sutter's

Marco Leise <Marco.Leise gmx.de> writes:

I was just experimenting with core.atomic and noticed only a
marginal speed difference when accessing variables using
atomicLoad.
Is this because it isn't implemented or because it can be
reduced to a no-op on x86 hardware?

-- 
Marco

"David Nadlinger" <code klickverbot.at> writes:

On 5 Jun 2013, at 19:19, Marco Leise wrote:
 I was just experimenting with core.atomic and noticed only a
 marginal speed difference when accessing variables using
 atomicLoad.
 Is this because it isn't implemented or because it can be
 reduced to a no-op on x86 hardware?

atomicLoad/atomicStore are implemented for LDC.

As for what causes the speed difference, the only sensible answer is to 
have a look at the produced assembly. atomicLoad can't be transformed 
into a normal load in the general case even on x86.

David

"carryonjutta" <carryonjutta144 gmail.com> writes:

Is this because it isn't implemented or because it can be
reduced to a no-op on x86 hardware?


________________
dhoom

"John Colvin" <john.loughran.colvin gmail.com> writes:

On Wednesday, 5 June 2013 at 17:25:32 UTC, David Nadlinger wrote:
 On 5 Jun 2013, at 19:19, Marco Leise wrote:
 I was just experimenting with core.atomic and noticed only a
 marginal speed difference when accessing variables using
 atomicLoad.
 Is this because it isn't implemented or because it can be
 reduced to a no-op on x86 hardware?

 atomicLoad/atomicStore are implemented for LDC.

 As for what causes the speed difference, the only sensible 
 answer is to have a look at the produced assembly. atomicLoad 
 can't be transformed into a normal load in the general case 
 even on x86.

 David

Those who are interested in this topic should watch Herb Sutter's 
2012 talk on std::atomic
http://channel9.msdn.com/Shows/Going+Deep/Cpp-and-Beyond-2012-Herb-Sutter-atomic-Weapons-1-of-2