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From: "aoliva at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug debug/48866] gcc hangs when -g is set Date: Fri, 06 May 2011 14:45:00 -0000 [thread overview] Message-ID: <bug-48866-4-w3nJD5OK5x@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-48866-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48866 --- Comment #8 from Alexandre Oliva <aoliva at gcc dot gnu.org> 2011-05-06 14:43:45 UTC --- I don't see how it would. Except for some very particular cases (that do not include the expansion of addresses AFAICT) we just expand each of the replaceable stmts at the time their SSA names are first referenced. It's combine that takes care of creating double-indirect address modes. Anyway, the current situation is highly sub-optimal: we'd be better off, at least in terms of debug info generation, if we emitted the code corresponding to a replaceable def at the point of the def, if it's not effectively replaced/combined. Here's how I'm thinking of implementing this: - in expand_gimple_basic_block, upon encountering a replaceable gimple stmt, instead of skipping it altogether: -- if it is mapped to an expansion in a pointer map, emit the expansion, unmark it as replaceable, and remove the mapping -- otherwise, emit a placeholder note and insert (stmt,placeholder) in the pointer map - in expand_expr_real_1 case SSA_NAME, instead of expanding the replaceable stmt onto the current insn seq, expand it into a separate seq and: -- if the stmt is already in the pointer map, emit the seq before the placeholder, remove the placeholder, and unmark the stmt as replaceable -- if it isn't, insert the pair (stmt, expansion) in the pointer map - at the end of expansion, remove all placeholders before adjusting deferred debug insns Makes sense? Any pitfalls I should watch out for?
next prev parent reply other threads:[~2011-05-06 14:45 UTC|newest] Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-05-04 8:56 [Bug debug/48866] New: " siebert at aicas dot com 2011-05-04 10:37 ` [Bug debug/48866] " paolo.carlini at oracle dot com 2011-05-04 11:43 ` rguenth at gcc dot gnu.org 2011-05-04 12:08 ` jakub at gcc dot gnu.org 2011-05-04 14:28 ` jakub at gcc dot gnu.org 2011-05-05 11:56 ` aoliva at gcc dot gnu.org 2011-05-05 13:06 ` aoliva at gcc dot gnu.org 2011-05-05 13:55 ` jakub at gcc dot gnu.org 2011-05-06 14:45 ` aoliva at gcc dot gnu.org [this message] 2011-05-06 22:30 ` aoliva at gcc dot gnu.org 2011-05-07 6:16 ` jakub at gcc dot gnu.org 2011-05-07 6:37 ` jakub at gcc dot gnu.org 2012-04-13 15:57 ` aoliva at gcc dot gnu.org 2012-06-13 20:42 ` aoliva at gcc dot gnu.org 2012-06-28 7:40 ` aoliva at gcc dot gnu.org
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