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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug debug/47858] New: [4.5/4.6 Regression] IPA-SRA decreases quality of debug info Date: Wed, 23 Feb 2011 14:01:00 -0000 [thread overview] Message-ID: <bug-47858-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47858 Summary: [4.5/4.6 Regression] IPA-SRA decreases quality of debug info Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: debug AssignedTo: unassigned@gcc.gnu.org ReportedBy: jakub@gcc.gnu.org CC: aoliva@gcc.gnu.org struct inode { char i_pad[16]; unsigned int i_flags; }; struct dentry { unsigned int d_pad[16]; struct inode *d_inode; }; extern int inode_permission (struct inode *, int); extern int fsnotify_create (struct inode *, struct dentry *); static inline int may_create (struct inode *dir, struct dentry *child) { if (child->d_inode) return -17; if (((dir)->i_flags & 16)) return -2; return inode_permission (dir, 2 | 1); } int foo (struct inode *dir, struct dentry *child) { if (may_create (dir, child) < 0) return -1; return fsnotify_create (dir, child); } int bar (struct inode *dir, struct dentry *child) { if (may_create (dir, child) < 0) return -1; return fsnotify_create (dir, child); } int baz (struct inode *dir, struct dentry *child) { if (may_create (dir, child) < 0) return -1; return fsnotify_create (dir, child); } at -Os on x86_64-linux (distilled from Linux kernel) pessimizes debug info because child parameter in may_create (which isn't emitted inline) doesn't have location (well, it doesn't have even DW_TAG_formal_parameter in the out of line DIE, just in the abstract inline DIE). This could be solvable with my proposed DW_TAG_GNU_call_site stuff and the (still in drafting DW_OP_GNU_parameter_ref stuff for completely optimized away parameters - here it isn't completely optimized away, just replaced by something based on it). In this testcase it is of course also questionable why IPA-SRC actually performs this "optimization" when it increases code size and doesn't improve anything at all.
next reply other threads:[~2011-02-23 13:36 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-02-23 14:01 jakub at gcc dot gnu.org [this message] 2011-02-23 15:51 ` [Bug debug/47858] " rguenth at gcc dot gnu.org 2011-02-24 13:59 ` aoliva at gcc dot gnu.org 2011-03-02 12:47 ` jakub at gcc dot gnu.org 2011-04-28 15:38 ` [Bug debug/47858] [4.5/4.6/4.7 " rguenth at gcc dot gnu.org 2011-06-02 12:23 ` jakub at gcc dot gnu.org 2011-06-03 10:46 ` jakub at gcc dot gnu.org 2011-06-07 15:44 ` jakub at gcc dot gnu.org 2011-06-22 10:43 ` jakub at gcc dot gnu.org 2011-11-28 15:34 ` jakub at gcc dot gnu.org
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