public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
* [Bug tree-optimization/39132] New: wrong code generated with -ftree-loop-disttribution @ 2009-02-08 19:05 kazu at gcc dot gnu dot org 2009-02-10 13:16 ` [Bug tree-optimization/39132] " rguenth at gcc dot gnu dot org ` (4 more replies) 0 siblings, 5 replies; 6+ messages in thread From: kazu at gcc dot gnu dot org @ 2009-02-08 19:05 UTC (permalink / raw) To: gcc-bugs The following testcase calls abort when it is compiled with -O3 -ftree-loop-distribution. /* Derived from gcc.c-torture/execute/20010910-1.c. */ extern void abort(void); struct epic_private { unsigned int *rx_ring; unsigned int rx_skbuff[5]; }; int main (void) { struct epic_private ep; unsigned int rx_ring[5]; int i; ep.rx_skbuff[0] = 5; ep.rx_ring = rx_ring; for (i = 0; i < 5; i++) { ep.rx_ring[i] = i; ep.rx_skbuff[i] = 0; } if (ep.rx_skbuff[0] != 0) abort (); return 0; } The loop distribution pass produces: <bb 2>: ep.rx_skbuff[0] = 5; <bb 8>: # i_22 = PHI <i_36(9), 0(2)> D.1604_11 = (long unsigned int) i_22; D.1605_30 = D.1604_11 * 4; D.1606_31 = &rx_ring + D.1605_30; i.0_32 = (unsigned int) i_22; *D.1606_31 = i.0_32; i_36 = i_22 + 1; if (i_36 <= 4) goto <bb 9>; else goto <bb 10>; <bb 9>: goto <bb 8>; <bb 10>: Invalid sum of outgoing probabilities 0.0% D.1642_37 = &ep + 8; __builtin_memset (D.1642_37, 0, 20); <bb 5>: Invalid sum of incoming frequencies 0, should be 1667 D.1609_10 = ep.rx_skbuff[0]; if (D.1609_10 != 0) goto <bb 6>; else goto <bb 7>; <bb 6>: abort (); <bb 7>: return 0; dom2 in turn produces: ep.rx_skbuff[0] = 5; rx_ring[0] = 0; D.1606_47 = &rx_ring[1]; rx_ring[1] = 1; D.1606_59 = &rx_ring[2]; rx_ring[2] = 2; D.1606_71 = &rx_ring[3]; rx_ring[3] = 3; D.1606_31 = &rx_ring[4]; rx_ring[4] = 4; D.1642_37 = &ep + 8; __builtin_memset (D.1642_37, 0, 20); D.1609_10 = 5; abort (); Note that the end of the function is replaced with an unconditional abort. GCC puts an unconditional abort at the rtl level when compiling The original gcc.c-torture/execute/20010910-1.c. Once I remove extra source code, I can observe an unconditional abort at the tree level. The compiler probably does not notice that the value of ep.rx_skbuff[0] changes across __builtin_memset. This sounds like an alias problem of some sort. -- Summary: wrong code generated with -ftree-loop-disttribution Product: gcc Version: 4.4.0 Status: UNCONFIRMED Keywords: wrong-code Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: kazu at gcc dot gnu dot org GCC build triplet: x86_64-unknown-linux-gnu GCC host triplet: x86_64-unknown-linux-gnu GCC target triplet: x86_64-unknown-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39132 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/39132] wrong code generated with -ftree-loop-disttribution 2009-02-08 19:05 [Bug tree-optimization/39132] New: wrong code generated with -ftree-loop-disttribution kazu at gcc dot gnu dot org @ 2009-02-10 13:16 ` rguenth at gcc dot gnu dot org 2009-02-10 13:30 ` rguenth at gcc dot gnu dot org ` (3 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu dot org @ 2009-02-10 13:16 UTC (permalink / raw) To: gcc-bugs ------- Comment #1 from rguenth at gcc dot gnu dot org 2009-02-10 13:15 ------- Confirmed. There is wrong alias-information on the memset: <bb 10>: Invalid sum of outgoing probabilities 0.0% D.1641_35 = &ep + 8; # rx_ring_36 = VDEF <rx_ring_31> # SMT.12_37 = VDEF <SMT.12_32> __builtin_memset (D.1641_35, 0, 20); <bb 5>: Invalid sum of incoming frequencies 0, should be 1667 # VUSE <ep_15> D.1609_10 = ep.rx_skbuff[0]; if (D.1609_10 != 0) the memset should clobber ep. Investigating. -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed|0 |1 Last reconfirmed|0000-00-00 00:00:00 |2009-02-10 13:15:51 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39132 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/39132] wrong code generated with -ftree-loop-disttribution 2009-02-08 19:05 [Bug tree-optimization/39132] New: wrong code generated with -ftree-loop-disttribution kazu at gcc dot gnu dot org 2009-02-10 13:16 ` [Bug tree-optimization/39132] " rguenth at gcc dot gnu dot org @ 2009-02-10 13:30 ` rguenth at gcc dot gnu dot org 2009-02-10 14:54 ` rguenth at gcc dot gnu dot org ` (2 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu dot org @ 2009-02-10 13:30 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from rguenth at gcc dot gnu dot org 2009-02-10 13:29 ------- I have a patch. -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- AssignedTo|unassigned at gcc dot gnu |rguenth at gcc dot gnu dot |dot org |org Status|NEW |ASSIGNED Last reconfirmed|2009-02-10 13:15:51 |2009-02-10 13:29:52 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39132 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/39132] wrong code generated with -ftree-loop-disttribution 2009-02-08 19:05 [Bug tree-optimization/39132] New: wrong code generated with -ftree-loop-disttribution kazu at gcc dot gnu dot org 2009-02-10 13:16 ` [Bug tree-optimization/39132] " rguenth at gcc dot gnu dot org 2009-02-10 13:30 ` rguenth at gcc dot gnu dot org @ 2009-02-10 14:54 ` rguenth at gcc dot gnu dot org 2009-02-10 16:12 ` rguenth at gcc dot gnu dot org 2009-02-10 16:20 ` kazu at gcc dot gnu dot org 4 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu dot org @ 2009-02-10 14:54 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from rguenth at gcc dot gnu dot org 2009-02-10 14:54 ------- Subject: Bug 39132 Author: rguenth Date: Tue Feb 10 14:54:13 2009 New Revision: 144060 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=144060 Log: 2009-02-10 Richard Guenther <rguenther@suse.de> PR tree-optimization/39132 * tree-loop-distribution.c (todo): New global var. (generate_memset_zero): Trigger TODO_rebuild_alias. (tree_loop_distribution): Return todo. * gcc.dg/torture/pr39132.c: New testcase. Added: trunk/gcc/testsuite/gcc.dg/torture/pr39132.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-loop-distribution.c -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39132 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/39132] wrong code generated with -ftree-loop-disttribution 2009-02-08 19:05 [Bug tree-optimization/39132] New: wrong code generated with -ftree-loop-disttribution kazu at gcc dot gnu dot org ` (2 preceding siblings ...) 2009-02-10 14:54 ` rguenth at gcc dot gnu dot org @ 2009-02-10 16:12 ` rguenth at gcc dot gnu dot org 2009-02-10 16:20 ` kazu at gcc dot gnu dot org 4 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu dot org @ 2009-02-10 16:12 UTC (permalink / raw) To: gcc-bugs ------- Comment #4 from rguenth at gcc dot gnu dot org 2009-02-10 16:12 ------- Fixed. -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |RESOLVED Resolution| |FIXED Target Milestone|--- |4.4.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39132 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/39132] wrong code generated with -ftree-loop-disttribution 2009-02-08 19:05 [Bug tree-optimization/39132] New: wrong code generated with -ftree-loop-disttribution kazu at gcc dot gnu dot org ` (3 preceding siblings ...) 2009-02-10 16:12 ` rguenth at gcc dot gnu dot org @ 2009-02-10 16:20 ` kazu at gcc dot gnu dot org 4 siblings, 0 replies; 6+ messages in thread From: kazu at gcc dot gnu dot org @ 2009-02-10 16:20 UTC (permalink / raw) To: gcc-bugs ------- Comment #5 from kazu at gcc dot gnu dot org 2009-02-10 16:19 ------- Thanks, Richard! -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39132 ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2009-02-10 16:20 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2009-02-08 19:05 [Bug tree-optimization/39132] New: wrong code generated with -ftree-loop-disttribution kazu at gcc dot gnu dot org 2009-02-10 13:16 ` [Bug tree-optimization/39132] " rguenth at gcc dot gnu dot org 2009-02-10 13:30 ` rguenth at gcc dot gnu dot org 2009-02-10 14:54 ` rguenth at gcc dot gnu dot org 2009-02-10 16:12 ` rguenth at gcc dot gnu dot org 2009-02-10 16:20 ` kazu at gcc dot gnu dot org
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).