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From: "ofv at wanadoo dot es" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/56746] [4.8 regression] increased memory usage when compiling C++
Date: Sat, 05 Oct 2013 09:29:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56746

ofv at wanadoo dot es changed:

           What    |Removed                     |Added
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                 CC|                            |ofv at wanadoo dot es

--- Comment #13 from ofv at wanadoo dot es ---
My case is similar to the one described by Mathias Gaunard, but with a
difference of 3x memory usage when -ftrack-macro-expansion=0 is not added to
the command line.

I use Boost Preprocessor plus a number of macros to define and instantiate lots
of templates. That's the case that requires 3x more memory (low estimate) with
some TUs requiring way more than 1GB to compile (on a 32 bit machine, which
means that parallel builds usually ends with massive swapping and the compile
jobs killed due to memory starvation.)

I have a version of the same code base that uses variadic templates instead of
Boost Preprocessor, although the macros for instantiating the templates are
still there. That requires about 1.5x more memory.