From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 95491381E92E; Tue, 4 Jun 2024 08:07:55 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 95491381E92E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1717488475; bh=xU1zEjYmOP/LV47mJxqwx4NYveKOVZL52uC8VCjXN5E=; h=From:To:Subject:Date:In-Reply-To:References:From; b=U+Wx8WlVj10DukXooSQlIHESyWlyTD0tLrxVx8NX+1JkACiqglhKfaT5b8lChV/l+ BLITDhfzsCwj9AVX3273ZcnEqGnakF/llaGDM9xUGWgmZnJBEtZBbGtinA+ehc+r8+ xsFPu4CoUPzRMo+FaqxU6X4C+Diu6SL96GYoX+7Y= From: "cvs-commit at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/113910] [12 Regression] Factor 15 slowdown compiling AMDGPUDisassembler.cpp on SPARC Date: Tue, 04 Jun 2024 08:07:53 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Version: 14.0 X-Bugzilla-Keywords: compile-time-hog, needs-bisection X-Bugzilla-Severity: normal X-Bugzilla-Who: cvs-commit at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: rguenth at gcc dot gnu.org X-Bugzilla-Target-Milestone: 12.4 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 List-Id: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D113910 --- Comment #19 from GCC Commits --- The releases/gcc-12 branch has been updated by Richard Biener : https://gcc.gnu.org/g:db0f236aa1c30f703ff564960bd9f3dbd747ea7b commit r12-10490-gdb0f236aa1c30f703ff564960bd9f3dbd747ea7b Author: Richard Biener Date: Wed Feb 14 12:33:13 2024 +0100 tree-optimization/113910 - huge compile time during PTA For the testcase in PR113910 we spend a lot of time in PTA comparing bitmaps for looking up equivalence class members. This points to the very weak bitmap_hash function which effectively hashes set and a subset of not set bits. The major problem with it is that it simply truncates the BITMAP_WORD sized intermediate hash to hashval_t which is unsigned int, effectively not hashing half of the bits. This reduces the compile-time for the testcase from tens of minutes to 42 seconds and PTA time from 99% to 46%. PR tree-optimization/113910 * bitmap.cc (bitmap_hash): Mix the full element "hash" to the hashval_t hash. (cherry picked from commit ad7a365aaccecd23ea287c7faaab9c7bd50b944a)=