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Re: lto gimple types and debug info
- From: Mark Mitchell <mark at codesourcery dot com>
- To: Kenneth Zadeck <zadeck at naturalbridge dot com>
- Cc: Paolo Bonzini <bonzini at gnu dot org>, David Edelsohn <dje at watson dot ibm dot com>, GCC Development <gcc at gcc dot gnu dot org>, Diego Novillo <dnovillo at google dot com>, "Hubicha, Jan" <jh at suse dot cz>, Richard Guenther <richard dot guenther at gmail dot com>, "Taylor, Ian Lance" <iant at google dot com>, Ollie Wild <aaw at google dot com>, "Maddox, Bill" <maddox at google dot com>, jason at redhat dot com, Rafael Espindola <espindola at google dot com>, olga at il dot ibm dot com
- Date: Tue, 29 Jul 2008 07:45:11 -0700
- Subject: Re: lto gimple types and debug info
- References: <488A6E70.2060708@codesourcery.com> <200807261748.m6QHmh0O027966@makai.watson.ibm.com> <488CADFB.4020007@codesourcery.com> <488EB8C5.3090308@gnu.org> <488F006A.5040008@naturalbridge.com>
Kenneth Zadeck wrote:
Paolo Bonzini wrote:
Mark Mitchell wrote:
For that matter, "print sizeof(X)" should print the same value when
debugging optimized code as when debugging unoptimized code, even if
the compiler has optimized X away to an empty structure!
I disagree. sizeof(X) in the code will return a value as small as
possible in that case (so that malloc-ing an array of structures) does
not waste memory, and the debugger should do the same.
Paolo
I think I agree with paolo here.
I don't think that's a viable option. The value of sizeof(X) is a
compile-time constant, specified by a combination of ISO C and platform
ABI rules. In C++, sizeof(X) can even be used as a (constant) template
parameter, way before we get to any optimization.
--
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713