From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17457 invoked by alias); 14 Sep 2010 21:31:50 -0000 Received: (qmail 17410 invoked by uid 48); 14 Sep 2010 21:31:38 -0000 Date: Tue, 14 Sep 2010 21:31:00 -0000 Message-ID: <20100914213138.17409.qmail@sourceware.org> From: "eblake at redhat dot com" To: glibc-bugs@sources.redhat.com In-Reply-To: <20100914154213.12019.eblake@redhat.com> References: <20100914154213.12019.eblake@redhat.com> Reply-To: sourceware-bugzilla@sourceware.org Subject: [Bug libc/12019] memchr overshoots on Alpha X-Bugzilla-Reason: CC Mailing-List: contact glibc-bugs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: glibc-bugs-owner@sourceware.org X-SW-Source: 2010-09/txt/msg00063.txt.bz2 ------- Additional Comments From eblake at redhat dot com 2010-09-14 21:31 ------- Richard, I compiled patch 4980 on Alpha, and ran it through gnulib's testsuite; it still fails for the same reason: 0x000000012000095c in ldq_u (s=2199023419392) at ../../gltests/test-memchr.c:28 28 return *(const word *)(s & -8); (gdb) bt #0 0x000000012000095c in ldq_u (s=2199023419392) at ../../gltests/test-memchr.c:28 #1 0x0000000120000a38 in memchr1 (xs=0x20000027fff, xc=85, n=2) at ../../gltests/test-memchr.c:62 #2 0x0000000120001948 in main () at ../../gltests/test-memchr.c:298 57 if (unlikely (n <= 8)) 58 { 59 /* Tweak the standard unaligned quadword load sequence by issuing 60 the second ldq_u at (s + n - 1) instead of (s + 8 - 1). This 61 avoids crossing a page boundary when S+N doesn't. */ 62 word last = extqh (ldq_u (s + n - 1), s); 63 word first = extql (current, s); In other words, s+n-1 might STILL validly cross a page boundary, in the case where n is an over-estimate. -- http://sourceware.org/bugzilla/show_bug.cgi?id=12019 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is.