From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id A0AD5385840C; Mon, 16 May 2022 03:06:57 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A0AD5385840C From: "crazylht at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/105513] [9/10/11/12/13 Regression] Unnecessary SSE spill since r9-5748-g1d4b4f4979171ef0 Date: Mon, 16 May 2022 03:06:57 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: 12.1.0 X-Bugzilla-Keywords: missed-optimization, ra X-Bugzilla-Severity: normal X-Bugzilla-Who: crazylht at gmail dot com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 9.5 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 May 2022 03:06:57 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105513 --- Comment #5 from Hongtao.liu --- And for constraint like 'vm', it's different from 'v,m' in calculating mem_= cost which will impact RA when op is REG_P. For 'v,m' mem_cost is just 1 * frequency, but for 'vm' mem_cost is much bigger(memory_move_cost - 1) * frequency. It means the impact of writing 'v,m' instead of 'vm' makes RA mo= re likely to choose mem instead of register. 928 if (op_class =3D=3D NO_REGS) 929 /* Although we don't need insn to reload from 930 memory, still accessing memory is usually more 931 expensive than a register. */ 932 pp->mem_cost =3D frequency; 933 else 934 /* If the alternative actually allows memory, make 935 things a bit cheaper since we won't need an 936 extra insn to load it. */ 937 pp->mem_cost 938 =3D ((out_p ? ira_memory_move_cost[mode][op_class= ][0] : 0) 939 + (in_p ? ira_memory_move_cost[mode][op_class]= [1] : 0) 940=3D> - allows_mem[i]) * frequency;=