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From: Andrew Haley <>
To: Andrew MacLeod <>,
	       Richard Biener <>,
	       Richard Henderson <>,
	       gcc-patches <>
Cc: Jeff Law <>,
Subject: Re: [patch] Provide a can_compare_and_swap_p target hook.
Date: Thu, 06 Nov 2014 18:23:00 -0000	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On 11/06/2014 05:57 PM, Andrew MacLeod wrote:
> It looks like java is deciding whether or not GCC can inline atomic 
> operations or not, and if it can't, doesn't want the atomic 
> operations...   which presumably means there is no dependency on 
> libatomic at runtime.
> A call to can_compare_and_swap_p(mode) is analogous to a compile time 
> version of folding atomic_always_lock_free(mode) to a constant...   
> Frankly that seems like a reasonable question for some front end to 
> ask...  and elect not to emit atomic calls if so desired. (which is what 
> java is doing I think)
> whether it still needs to do that is a question for some java person.

I did it because some targets did not have library support for some
builtins, so a compile would fail with a (to a Java programmer)
baffling error message.

The Java operations certainly should use the generic builtins.


  reply	other threads:[~2014-11-06 18:23 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <>
     [not found] ` <>
     [not found]   ` <>
     [not found]     ` <>
     [not found]       ` <>
     [not found]         ` <>
     [not found]           ` <>
2014-11-06 17:57             ` Andrew MacLeod
2014-11-06 18:23               ` Andrew Haley [this message]
2014-11-06 19:05                 ` Andrew MacLeod
2014-11-07  9:31                   ` Andrew Haley
2014-11-07 13:31                     ` Andrew MacLeod

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