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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/62630] [5 regression] gcc.dg/graphite/vect-pr43423.c FAILs Date: Wed, 18 Feb 2015 13:03:00 -0000 [thread overview] Message-ID: <bug-62630-4-KW9cV3RiOM@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-62630-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62630 --- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> --- Btw, graphite generates expressions like MIN_EXPR <(long)n, (long)mid> < 0 that fold does not simplify. Adding a match.pd pattern to shorten min/max expressions we end up with <bb 4>: _28 = MIN_EXPR <n_5(D), mid_6(D)>; _29 = _28 > 0; if (_29 != 0) goto <bb 5>; else goto <bb 8>; <bb 5>: _30 = MIN_EXPR <n_5(D), mid_6(D)>; _31 = (signed long) _30; _32 = _31 + -1; but still niter analysis isn't able to constrain the max iterations to sth that SCEV could later use to prove that (int) graphite_IV doesn't wrap. Analyzing # of iterations of loop 2 exit condition [0, + , 1](no_overflow) < (signed long) _30 + -1 bounds on difference of bases: -9223372036854775808 ... 9223372036854775806 result: zero if _30 <= 0 # of iterations (unsigned long) ((signed long) _30 + -1), bounded by 9223372036854775806 /space/rguenther/src/svn/trunk/gcc/testsuite/gcc.dg/graphite/vect-pr43423.c:12:17: note: Symbolic number of iterations is (unsigned long) MAX_EXPR <_30, 1> so niter analysis can be improved here as _30 is of type int and even if _30 were INT_MIN the upper bound would be 2147483647. We can improve that by stripping sign-/zero-extensions from vars in bound_difference. With those two improvements we can vectorize the first loop.
next prev parent reply other threads:[~2015-02-18 13:03 UTC|newest] Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-09-01 13:21 [Bug tree-optimization/62630] New: " ro at gcc dot gnu.org 2014-09-01 13:24 ` [Bug tree-optimization/62630] " ro at gcc dot gnu.org 2014-09-01 13:26 ` ro at gcc dot gnu.org 2014-09-01 13:32 ` ktkachov at gcc dot gnu.org 2014-11-24 13:13 ` rguenth at gcc dot gnu.org 2015-01-19 13:10 ` rguenth at gcc dot gnu.org 2015-02-12 13:17 ` jakub at gcc dot gnu.org 2015-02-17 10:49 ` rguenth at gcc dot gnu.org 2015-02-17 20:12 ` mircea.namolaru at inria dot fr 2015-02-18 11:23 ` rguenth at gcc dot gnu.org 2015-02-18 11:34 ` rguenth at gcc dot gnu.org 2015-02-18 11:57 ` mircea.namolaru at inria dot fr 2015-02-18 13:03 ` rguenth at gcc dot gnu.org [this message] 2015-02-18 15:06 ` rguenth at gcc dot gnu.org 2015-02-18 15:25 ` rguenth at gcc dot gnu.org 2015-02-18 23:34 ` mircea.namolaru at inria dot fr 2015-02-19 10:19 ` rguenth at gcc dot gnu.org 2015-02-20 0:45 ` mircea.namolaru at inria dot fr 2015-02-20 16:46 ` joseph at codesourcery dot com 2015-02-23 18:21 ` mircea.namolaru at inria dot fr 2015-03-09 14:40 ` jakub at gcc dot gnu.org 2015-03-25 13:14 ` [Bug tree-optimization/62630] [5/6 Regression] gcc.dg/graphite/vect-pr43423.c XFAILed rguenth at gcc dot gnu.org 2015-03-25 13:20 ` rguenth at gcc dot gnu.org 2021-05-14 9:47 ` [Bug tree-optimization/62630] [9/10/11/12 " jakub at gcc dot gnu.org 2021-06-01 8:06 ` rguenth at gcc dot gnu.org 2021-09-14 6:24 ` pinskia at gcc dot gnu.org 2022-05-27 9:35 ` [Bug tree-optimization/62630] [10/11/12/13 " rguenth at gcc dot gnu.org 2022-06-28 10:31 ` jakub at gcc dot gnu.org 2023-07-07 10:30 ` [Bug tree-optimization/62630] [11/12/13/14 " rguenth at gcc dot gnu.org
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