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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/67121] [6 Regression] wrong code at -O3 on x86_64-linux-gnu Date: Wed, 05 Aug 2015 10:43:00 -0000 [thread overview] Message-ID: <bug-67121-4-LK31m8rZ5H@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-67121-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67121 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |wrong-code Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org --- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> --- Hmm. Visiting statement: h_38 = (char) pretmp_48; Found new range for h_38: VARYING ... Visiting statement: _42 = (int) h_38; Intersecting [-128, 127] and [0, 127] to [0, 127] Found new range for _42: [0, 127] so it seems that the old value-range for _42 is bad: # RANGE [0, 127] NONZERO 127 _42 = (int) h_38; Before if-conversion we have <bb 2>: a[0] = 1; f = 0; pretmp_48 = c; <bb 3>: # f.4_36 = PHI <0(2), _19(6)> # ivtmp_59 = PHI <9(2), ivtmp_28(6)> h_9 = (char) pretmp_48; if (h_9 >= 0) goto <bb 4>; else goto <bb 10>; <bb 4>: # RANGE [0, 127] NONZERO 127 _10 = (int) h_9; while after: <bb 2>: a[0] = 1; f = 0; pretmp_48 = c; <bb 3>: # f.4_36 = PHI <0(2), _19(4)> # ivtmp_59 = PHI <9(2), ivtmp_28(4)> h_9 = (char) pretmp_48; # RANGE [0, 127] NONZERO 127 _10 = (int) h_9; ... prephitmp_3 = h_9 >= 0 ? _14 : _38; so if-conversion has to reset value-range info on stmts previously conditionally executed.
next prev parent reply other threads:[~2015-08-05 10:43 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-08-05 7:49 [Bug tree-optimization/67121] New: " su at cs dot ucdavis.edu 2015-08-05 9:12 ` [Bug tree-optimization/67121] [6 Regression] " mpolacek at gcc dot gnu.org 2015-08-05 10:43 ` rguenth at gcc dot gnu.org [this message] 2015-08-05 13:06 ` mpolacek at gcc dot gnu.org 2015-08-05 14:17 ` rguenth at gcc dot gnu.org 2015-08-05 14:18 ` [Bug tree-optimization/67121] [5 " rguenth at gcc dot gnu.org 2015-08-05 14:18 ` [Bug tree-optimization/67121] [6 " rguenth at gcc dot gnu.org 2015-09-21 9:56 ` [Bug tree-optimization/67121] [5 " rguenth at gcc dot gnu.org 2015-09-21 9:58 ` rguenth at gcc dot gnu.org
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