public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "vries at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/52081] New: Missed tail merging with pure calls Date: Wed, 01 Feb 2012 10:24:00 -0000 [thread overview] Message-ID: <bug-52081-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52081 Bug #: 52081 Summary: Missed tail merging with pure calls Classification: Unclassified Product: gcc Version: 4.7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassigned@gcc.gnu.org ReportedBy: vries@gcc.gnu.org pr51879-12.c: ... __attribute__((pure)) int bar (int); __attribute__((pure)) int bar2 (int); void baz (int); int x, z; void foo (int y) { int a = 0; if (y == 6) { a += bar (7); a += bar2 (6); } else { a += bar2 (6); a += bar (7); } baz (a); } ... When compiling at -O2, pr51879-12.c.094t.pre looks like this: ... # BLOCK 3 freq:1991 # PRED: 2 [19.9%] (true,exec) # VUSE <.MEMD.1722_12(D)> # USE = nonlocal escaped D.1717_4 = barD.1703 (7); # VUSE <.MEMD.1722_12(D)> # USE = nonlocal escaped D.1718_6 = bar2D.1705 (6); aD.1713_7 = D.1717_4 + D.1718_6; goto <bb 5>; # SUCC: 5 [100.0%] (fallthru,exec) # BLOCK 4 freq:8009 # PRED: 2 [80.1%] (false,exec) # VUSE <.MEMD.1722_12(D)> # USE = nonlocal escaped D.1720_8 = bar2D.1705 (6); # VUSE <.MEMD.1722_12(D)> # USE = nonlocal escaped D.1721_10 = barD.1703 (7); aD.1713_11 = D.1720_8 + D.1721_10; # SUCC: 5 [100.0%] (fallthru,exec) # BLOCK 5 freq:10000 # PRED: 3 [100.0%] (fallthru,exec) 4 [100.0%] (fallthru,exec) # aD.1713_1 = PHI <aD.1713_7(3), aD.1713_11(4)> # .MEMD.1722_13 = VDEF <.MEMD.1722_12(D)> # USE = nonlocal # CLB = nonlocal bazD.1707 (aD.1713_1); # VUSE <.MEMD.1722_13> return; ... Value numbering numbers the two phi arguments a_7 and a_11 the same so the problem is not in value numbering: ... Setting value number of a_11 to a_7 (changed) ...
next reply other threads:[~2012-02-01 10:24 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-02-01 10:24 vries at gcc dot gnu.org [this message] 2012-02-01 10:27 ` [Bug tree-optimization/52081] " vries at gcc dot gnu.org 2012-02-02 10:47 ` vries at gcc dot gnu.org 2012-04-14 6:04 ` vries 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-52081-4@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).