From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 104748 invoked by alias); 7 Apr 2018 19:28:23 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 104732 invoked by uid 89); 7 Apr 2018 19:28:22 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.9 required=5.0 tests=AWL,BAYES_00,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy= X-HELO: mx1.redhat.com Received: from mx3-rdu2.redhat.com (HELO mx1.redhat.com) (66.187.233.73) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Sat, 07 Apr 2018 19:28:21 +0000 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E99C9722F2; Sat, 7 Apr 2018 19:28:19 +0000 (UTC) Received: from [127.0.0.1] (ovpn04.gateway.prod.ext.ams2.redhat.com [10.39.146.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id 750152166BB2; Sat, 7 Apr 2018 19:28:19 +0000 (UTC) Subject: Re: [PATCH] Use an std::vector for inline_states To: Simon Marchi , gdb-patches@sourceware.org References: <20180407144205.20909-1-simon.marchi@polymtl.ca> From: Pedro Alves Message-ID: <6bcda047-7dbd-79ed-8eec-2bd5d59f6749@redhat.com> Date: Sat, 07 Apr 2018 19:28:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180407144205.20909-1-simon.marchi@polymtl.ca> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-SW-Source: 2018-04/txt/msg00130.txt.bz2 On 04/07/2018 03:42 PM, Simon Marchi wrote: > /* Locate saved inlined frame state for PTID, if it exists > and is valid. */ > @@ -66,43 +70,29 @@ static VEC(inline_state_s) *inline_states; > static struct inline_state * > find_inline_frame_state (ptid_t ptid) > { > - if (current_pc != state->saved_pc) > - { > - /* PC has changed - this context is invalid. Use the > - default behavior. */ > - VEC_unordered_remove (inline_state_s, inline_states, ix); > - return NULL; ... > - state = VEC_safe_push (inline_state_s, inline_states, NULL); > - memset (state, 0, sizeof (*state)); > - state->ptid = ptid; > + inline_states.erase (state_it); The patch looks good, though it made me realize that when we're replacing VEC_unordered_remove with std::vector::erase, we're introducing a pessimization, which makes me ponder about having an utility/replacement for VEC_unordered_remove that works with std::vector and alikes. I.e., a function that removes an element from a vector simply by moving the last element to the now-vacant position. That's more efficient than erase, because it avoids having to copy/move the remaining elements, making it O(1). Something like: template void unordered_erase (Vector &v, typename Vector::const_iterator pos) { *pos = std::move (v.back ()); v.pop_back (); } Thanks, Pedro Alves