[Bug tree-optimization/54570] [4.8 Regression] FAIL: gcc.dg/builtin-object-size-8.c execution test

rguenth at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Tue Dec 11 12:55:00 GMT 2012


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54570

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> 2012-12-11 12:54:43 UTC ---
An alternative suggestion was to allow arbitrary complex addresses (well,
"arbitrary" == gimplified ADDR_EXPRs) in call arguments (either in general
or just for specially marked builtins).  That way they escape SSA based CSE.

Yet another variant would be to have an optional 2nd operand for ADDR_EXPRs
for the Frontend to fill in, specifying the "size" of the object at that
address.  Preserving that across propagation/substitution would be required
of course (details on what the 'size' of &a[2] with int a[4]; would be is
still to be determined).

I'm leaning towards trying to have explicit information tracked from their
origin rather than trying to re-discover them after optimizations obfuscated
them.



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