public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "hubicka at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/56049] [4.8 Regression] Simplification to constants not done Date: Mon, 11 Feb 2013 22:56:00 -0000 [thread overview] Message-ID: <bug-56049-4-rkw5yqydXC@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-56049-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56049 --- Comment #5 from Jan Hubicka <hubicka at gcc dot gnu.org> 2013-02-11 22:55:44 UTC --- Well, I think we should try to toamn fantasy of our optimizers here. What unroller sees at -O3 -fno-tree-vectorize is quite ugly: <bb 2>: a = {}; <bb 3>: # i_1 = PHI <1(2), i_7(7)> # prephitmp_99 = PHI <0(2), pretmp_98(7)> # prephitmp_102 = PHI <0(2), pretmp_101(7)> # prephitmp_105 = PHI <0(2), pretmp_104(7)> # prephitmp_108 = PHI <0(2), pretmp_107(7)> # prephitmp_111 = PHI <0(2), pretmp_110(7)> # prephitmp_114 = PHI <0(2), pretmp_113(7)> # prephitmp_117 = PHI <0(2), pretmp_116(7)> # prephitmp_120 = PHI <0(2), pretmp_119(7)> # ivtmp_57 = PHI <10000000(2), ivtmp_64(7)> <bb 4>: # S.0_90 = PHI <S.0_36(5), 1(3)> # prephitmp_126 = PHI <pretmp_125(5), prephitmp_99(3)> # prephitmp_129 = PHI <pretmp_128(5), prephitmp_102(3)> # prephitmp_132 = PHI <pretmp_131(5), prephitmp_105(3)> # prephitmp_135 = PHI <pretmp_134(5), prephitmp_108(3)> # prephitmp_138 = PHI <pretmp_137(5), prephitmp_111(3)> # prephitmp_141 = PHI <pretmp_140(5), prephitmp_114(3)> # prephitmp_144 = PHI <pretmp_143(5), prephitmp_117(3)> # prephitmp_147 = PHI <pretmp_146(5), prephitmp_120(3)> # ivtmp_43 = PHI <ivtmp_50(5), 8(3)> _29 = S.0_90 * 8; _42 = _29 + -8; _44 = prephitmp_126 + 1; b[_42] = _44; _49 = _29 + -7; _51 = prephitmp_129 + 1; b[_49] = _51; _56 = _29 + -6; _58 = prephitmp_132 + 1; b[_56] = _58; _63 = _29 + -5; _65 = prephitmp_135 + 1; b[_63] = _65; _70 = _29 + -4; b[_63] = _65; _70 = _29 + -4; _72 = prephitmp_138 + 1; b[_70] = _72; _77 = _29 + -3; _79 = prephitmp_141 + 1; b[_77] = _79; _84 = _29 + -2; _86 = prephitmp_144 + 1; b[_84] = _86; _91 = _29 + -1; _93 = prephitmp_147 + 1; b[_91] = _93; S.0_36 = S.0_90 + 1; ivtmp_50 = ivtmp_43 - 1; if (ivtmp_50 == 0) goto <bb 6>; else goto <bb 5>; <bb 5>: pretmp_122 = S.0_36 * 8; pretmp_124 = pretmp_122 + -8; pretmp_125 = a[pretmp_124]; pretmp_127 = pretmp_122 + -7; pretmp_128 = a[pretmp_127]; pretmp_130 = pretmp_122 + -6; pretmp_131 = a[pretmp_130]; pretmp_133 = pretmp_122 + -5; pretmp_134 = a[pretmp_133]; pretmp_136 = pretmp_122 + -4; pretmp_137 = a[pretmp_136]; pretmp_139 = pretmp_122 + -3; pretmp_140 = a[pretmp_139]; pretmp_142 = pretmp_122 + -2; pretmp_143 = a[pretmp_142]; pretmp_145 = pretmp_122 + -1; pretmp_146 = a[pretmp_145]; goto <bb 4>; With vectorization we actually unroll the inner loop but the outer one gets so ugly that we don't do much about it... So what about keeping it as enhancement request? I will try to poke about it, but htere is but about PR overactivity of this type already, right?
next prev parent reply other threads:[~2013-02-11 22:56 UTC|newest] Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-01-20 10:23 [Bug tree-optimization/56049] New: " tkoenig at gcc dot gnu.org 2013-01-20 10:28 ` [Bug tree-optimization/56049] " tkoenig at gcc dot gnu.org 2013-01-20 10:32 ` dominiq at lps dot ens.fr 2013-01-20 17:42 ` jakub at gcc dot gnu.org 2013-01-21 13:30 ` rguenth at gcc dot gnu.org 2013-02-08 15:11 ` rguenth at gcc dot gnu.org 2013-02-11 22:02 ` aldyh at gcc dot gnu.org 2013-02-11 22:56 ` hubicka at gcc dot gnu.org [this message] 2013-02-12 11:07 ` rguenther at suse dot de 2013-02-12 14:22 ` aldyh at gcc dot gnu.org 2013-02-12 14:28 ` jakub at gcc dot gnu.org 2013-03-22 14:43 ` [Bug tree-optimization/56049] [4.8/4.9 " jakub at gcc dot gnu.org 2013-05-31 10:58 ` jakub at gcc dot gnu.org 2013-10-16 9:48 ` jakub at gcc dot gnu.org 2014-05-22 9:01 ` [Bug tree-optimization/56049] [4.8/4.9/4.10 " rguenth at gcc dot gnu.org 2014-12-19 13:25 ` [Bug tree-optimization/56049] [4.8/4.9/5 " jakub at gcc dot gnu.org 2015-06-23 8:14 ` [Bug tree-optimization/56049] [4.8/4.9/5/6 " rguenth at gcc dot gnu.org 2015-06-26 19:53 ` [Bug tree-optimization/56049] [4.9/5/6 " jakub at gcc dot gnu.org 2015-06-26 20:26 ` jakub at gcc dot gnu.org
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=bug-56049-4-rkw5yqydXC@http.gcc.gnu.org/bugzilla/ \ --to=gcc-bugzilla@gcc.gnu.org \ --cc=gcc-bugs@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
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).