From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by oss.sgi.com (8.11.2/8.11.3) id g151TCn07877 for linux-mips-outgoing; Mon, 4 Feb 2002 17:29:12 -0800 Received: from ocean.lucon.org (12-234-19-19.client.attbi.com [12.234.19.19]) by oss.sgi.com (8.11.2/8.11.3) with SMTP id g151SwA07872 for ; Mon, 4 Feb 2002 17:28:58 -0800 Received: by ocean.lucon.org (Postfix, from userid 1000) id CEDCC125C8; Mon, 4 Feb 2002 17:28:57 -0800 (PST) Date: Mon, 4 Feb 2002 17:28:57 -0800 From: "H . J . Lu" To: Dominic Sweetman Cc: GNU C Library , linux-mips@oss.sgi.com Subject: Re: PATCH: Fix ll/sc for mips (take 3) Message-ID: <20020204172857.A22337@lucon.org> References: <20020201180126.A23740@nevyn.them.org> <20020201151513.A15913@lucon.org> <20020201222657.A13339@nevyn.them.org> <1012676003.1563.6.camel@xyzzy.stargate.net> <20020202120354.A1522@lucon.org> <15454.22661.855423.532827@gladsmuir.algor.co.uk> <20020204083115.C13384@lucon.org> <15454.47823.837119.847975@gladsmuir.algor.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <15454.47823.837119.847975@gladsmuir.algor.co.uk>; from dom@algor.co.uk on Mon, Feb 04, 2002 at 04:46:07PM +0000 Sender: owner-linux-mips@oss.sgi.com Precedence: bulk On Mon, Feb 04, 2002 at 04:46:07PM +0000, Dominic Sweetman wrote: > > H . J . Lu (hjl@lucon.org) writes: > > > I can change glibc not to use branch-likely without using nop. But it > > may require one or two instructions outside of the loop. Should I do > > it given what we know now? > > I would not recommend using "branch likely" in assembler coding, if > that's what you're asking. > Here is a patch to remove branch likely. But I couldn't find a way not to fill the delay slot with nop. BTW, is that safe to remove ".set noreorder"? H.J. --- 2002-02-04 H.J. Lu * sysdeps/mips/pspinlock.c (__pthread_spin_lock): Not use branch likely. * sysdeps/mips/pt-machine.h (testandset): Liekwise. (__compare_and_swap): Liekwise. 2002-02-04 H.J. Lu * sysdeps/mips/atomicity.h (exchange_and_add): Not use branch likely. (atomic_add): Likewise. (compare_and_swap): Likewise. * sysdeps/unix/sysv/linux/mips/sys/tas.h (_test_and_set): Likewise. --- libc/linuxthreads/sysdeps/mips/pspinlock.c.llsc Mon Feb 4 13:45:01 2002 +++ libc/linuxthreads/sysdeps/mips/pspinlock.c Mon Feb 4 17:09:02 2002 @@ -40,7 +40,7 @@ __pthread_spin_lock (pthread_spinlock_t "bnez %1,1b\n\t" " li %2,1\n\t" "sc %2,%0\n\t" - "beqzl %2,1b\n\t" + "beqz %2,1b\n\t" " ll %1,%3\n\t" ".set pop" : "=m" (*lock), "=&r" (tmp1), "=&r" (tmp2) --- libc/linuxthreads/sysdeps/mips/pt-machine.h.llsc Mon Feb 4 13:45:01 2002 +++ libc/linuxthreads/sysdeps/mips/pt-machine.h Mon Feb 4 17:09:36 2002 @@ -66,7 +66,7 @@ __compare_and_swap (long int *p, long in " move %0,$0\n\t" "move %0,%4\n\t" "sc %0,%2\n\t" - "beqzl %0,1b\n\t" + "beqz %0,1b\n\t" " ll %1,%5\n\t" ".set pop\n" "2:\n\t" --- libc/sysdeps/mips/atomicity.h.llsc Mon Feb 4 13:45:18 2002 +++ libc/sysdeps/mips/atomicity.h Mon Feb 4 17:14:48 2002 @@ -32,15 +32,15 @@ exchange_and_add (volatile uint32_t *mem int result, tmp; __asm__ __volatile__ - ("/* Inline exchange & add */\n\t" + ("/* Inline exchange & add */\n" + "1:\n" "ll %0,%3\n" - "1:\n\t" "addu %1,%4,%0\n\t" "sc %1,%2\n\t" ".set push\n\t" ".set noreorder\n\t" - "beqzl %1,1b\n\t" - " ll %0,%3\n\t" + "beqz %1,1b\n\t" + " nop\n\t" ".set pop\n\t" "/* End exchange & add */" : "=&r"(result), "=&r"(tmp), "=m"(*mem) @@ -57,15 +57,15 @@ atomic_add (volatile uint32_t *mem, int int result; __asm__ __volatile__ - ("/* Inline atomic add */\n\t" - "ll %0,%2\n" + ("/* Inline atomic add */\n" "1:\n\t" + "ll %0,%2\n" "addu %0,%3,%0\n\t" "sc %0,%1\n\t" ".set push\n\t" ".set noreorder\n\t" - "beqzl %0,1b\n\t" - " ll %0,%2\n\t" + "beqz %0,1b\n\t" + " nop\n\t" ".set pop\n\t" "/* End atomic add */" : "=&r"(result), "=m"(*mem) @@ -89,7 +89,7 @@ compare_and_swap (volatile long int *p, " move %0,$0\n\t" "move %0,%4\n\t" "sc %0,%2\n\t" - "beqzl %0,1b\n\t" + "beqz %0,1b\n\t" " ll %1,%5\n\t" ".set pop\n" "2:\n\t" --- libc/sysdeps/unix/sysv/linux/mips/sys/tas.h.llsc Mon Feb 4 13:45:28 2002 +++ libc/sysdeps/unix/sysv/linux/mips/sys/tas.h Mon Feb 4 17:19:06 2002 @@ -42,16 +42,16 @@ _test_and_set (int *p, int v) __THROW int r, t; __asm__ __volatile__ - ("/* Inline test and set */\n\t" - "ll %0,%3\n" + ("/* Inline test and set */\n" "1:\n\t" + "ll %0,%3\n" ".set push\n\t" ".set noreorder\n\t" "beq %0,%4,2f\n\t" " move %1,%4\n\t" "sc %1,%2\n\t" - "beqzl %1,1b\n\t" - " ll %0,%3\n\t" + "beqz %1,1b\n\t" + " nop\n\t" ".set pop\n" "2:\n\t" "/* End test and set */"