From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12934 invoked by alias); 13 Nov 2012 14:31:34 -0000 Received: (qmail 12852 invoked by uid 48); 13 Nov 2012 14:31:12 -0000 From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug debug/55094] [4.7/4.8 Regression] ICE in maybe_record_trace_start, at dwarf2cfi.c:2224 Date: Tue, 13 Nov 2012 14:31:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: debug X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: jakub at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.7.3 X-Bugzilla-Changed-Fields: Status Last reconfirmed CC Ever Confirmed Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2012-11/txt/msg01157.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55094 Jakub Jelinek changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2012-11-13 CC| |jakub at gcc dot gnu.org, | |rth at gcc dot gnu.org, | |vmakarov at gcc dot gnu.org Ever Confirmed|0 |1 --- Comment #1 from Jakub Jelinek 2012-11-13 14:31:11 UTC --- Doesn't ICE on the trunk anymore since LRA merge, apparently because LRA decides for some reason to use frame pointer anyway, despite -fomit-frame-pointer -Os. CCing Vlad to see why. Apparently it happens in: 665 if (ep->from_rtx == XEXP (x, 0) 666 || (ep->to_rtx == XEXP (x, 0) 667 && ep->to_rtx != hard_frame_pointer_rtx)) 668 setup_can_eliminate (ep, false); where ep->from_rtx is (frame), ep->to_rtx is (sp) and x is (pre_dec:SI (reg/f:SI 7 sp)). Is that intentional? Anyway, testcase that also ICEs on 4.7 branch is e.g. extern int puts (const char *); int x; int main (int argc, char **argv) { if (argc) { puts (argv[0]); x = 1; __builtin_unreachable (); } x = 1; __builtin_unreachable (); } with the same options - similar reason, crossjumping during jump2 crossjumps bbs with different ARGS_SIZE final depth. For noreturn calls we've handled it by adding REG_ARGS_SIZE note on the noreturn call I think, for unconditional TRAP_IF we perhaps could do the same, but not sure what we can do for __builtin_unreachable which expands to nothing..., with no outgoing edge from the bb at all.