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Date: Sat, 02 May 2015 12:12:00 -0000
From: Andi Kleen <andi@firstfloor.org>
To: Sriraman Tallam <tmsriram@google.com>
Cc: Xinliang David Li <davidxl@google.com>, "H.J. Lu" <hjl.tools@gmail.com>,	Andi Kleen <andi@firstfloor.org>,	GCC Patches <gcc-patches@gcc.gnu.org>
Subject: Re: [RFC][PATCH][X86_64] Eliminate PLT stubs for specified external functions via -fno-plt=
Message-ID: <20150502121230.GJ2366@two.firstfloor.org>
References: <CAAs8HmxC4KQSc5EWiux7syOj8+ghs_LY8zY-D4-Wjp+ZhHiDuw@mail.gmail.com> <87r3r0mjec.fsf@tassilo.jf.intel.com> <CAAkRFZKPM8h5=vqosOtUX7op45jbS_gaFDyn2kXDqW5xMDhGVw@mail.gmail.com> <CAMe9rOr50fDLZg50CznkLVvR=HsG5jEW-QA5aX304MuxE1LSoA@mail.gmail.com> <CAAkRFZ+2Q_RUMFoLDST1VN05PwHB_KotR6h20_ab9NPUaBB+0Q@mail.gmail.com> <CAAs8HmxRx0iG+n0iGrWMdE7T5DT_1BKGU4DPQjWJN4fUk=y5Gw@mail.gmail.com>
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On Fri, May 01, 2015 at 11:05:58AM -0700, Sriraman Tallam wrote:
> On Fri, May 1, 2015 at 9:26 AM, Xinliang David Li <davidxl@google.com> wrote:
> > yes -- it is good to turn this on by default in LTO mode without
> > requiring user to specify the option.
> 
> Yes, with LTO, we would exactly know what the "truly extern" functions
> are

... unless a function is overwritten somewhere else at dynamic link time 
That's why you may need -fno-semantic...

-Andi