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Re: [C++ patch] Set attributes for C++ runtime library calls

On Thu, Aug 22, 2013 at 11:08 AM, Jan Hubicka <> wrote:
>> This should be a C++ front-end bug.  The specific operator new
>> from <new> used in this placement-new should be folded,
>> even if -fno-inline.  Jason, is this something easily fixable?
>> After overload resolution, we know exactly which operator new
>> we are picking, and we know it is the one coming from the
>> implementation with its definition.  So we should be good to go.
> Great!  I think this is quite important starting point to get some
> heap optimizations done in middle-end :)

In the placement-form, no allocation is done, so the fact that we are
not emitting identity opcode is a bug :-)

The ground for this is (quoting C++11, but this has been true forever)

   These functions are reserved, a C++ program may not define functions
   that displace the versions in the Standard C++ library (17.6.4). The
   provisions of (3.7.4) do not apply to these reserved placement forms
   of operator new and operator delete.

 -- Gaby

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