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Re: Compiling for single-threaded use (implicit threading support difference in 4.9.1 vs. 4.8.1)

From: Marc Glisse <marc dot glisse at inria dot fr>
To: Jonathan Wakely <jwakely dot gcc at gmail dot com>
Cc: Johan Alfredsson <sduvan dot gcc at gmail dot com>, gcc-help <gcc-help at gcc dot gnu dot org>
Date: Wed, 15 Oct 2014 13:40:00 +0200 (CEST)
Subject: Re: Compiling for single-threaded use (implicit threading support difference in 4.9.1 vs. 4.8.1)
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On Wed, 15 Oct 2014, Jonathan Wakely wrote:

On 14 October 2014 18:29, Johan Alfredsson wrote:

As my application is single-threaded, I don't want to pay the
performance penalty of mutexes etc. Hence, my question is if it is
possible to explicitly request gcc to compile my application in
single-threaded mode.


It should happen automatically, there's no way to request it because
there should be no need.

Well, I would quite like a compilation flag-fI-promise-not-to-use-threads, that would automatically turn atomics intoplain variables with regular operations, turn TLS into regular memory,remove locks, etc, and perform all the optimizations this enables. Itisn't quite the same as a runtime test that only skips a few mutexes inthe library.


--
Marc Glisse

Follow-Ups:
- Re: Compiling for single-threaded use (implicit threading support difference in 4.9.1 vs. 4.8.1)
  - From: leon zadorin

References:
- Fwd: Compiling for single-threaded use (implicit threading support difference in 4.9.1 vs. 4.8.1)
  - From: Johan Alfredsson
- Re: Compiling for single-threaded use (implicit threading support difference in 4.9.1 vs. 4.8.1)
  - From: Jonathan Wakely

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