From f79466a8e909930237d882da8916bbbb1401edf6 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Thu, 20 Mar 2003 10:18:24 +0000 Subject: Update. 2003-03-20 Ulrich Drepper * include/atomic.h: Define atomic_exchange and atomic_decrement_if_positive if not already defined. Add some __builtin_expect. * sysdeps/i386/i486/bits/atomic.h: Define atomic_exchange. * sysdeps/x86_64/bits/atomic.h: Likewise. * sysdeps/ia64/bits/atomic.h: Pretty printing. Define atomic_exchange. * sysdeps/powerpc/bits/atomic.h: Pretty printing. Define atomic_exchange, atomic_exchange_and_add, and atomic_decrement_if_positive --- sysdeps/x86_64/bits/atomic.h | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) (limited to 'sysdeps/x86_64') diff --git a/sysdeps/x86_64/bits/atomic.h b/sysdeps/x86_64/bits/atomic.h index f72f16c501..22d3ab0267 100644 --- a/sysdeps/x86_64/bits/atomic.h +++ b/sysdeps/x86_64/bits/atomic.h @@ -1,4 +1,4 @@ -/* Copyright (C) 2002 Free Software Foundation, Inc. +/* Copyright (C) 2002, 2003 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 2002. @@ -84,6 +84,28 @@ typedef uintmax_t uatomic_max_t; ret; }) +/* Note that we need no lock prefix. */ +#define atomic_exchange(mem, newvalue) \ + ({ __typeof (*mem) result; \ + if (sizeof (*mem) == 1) \ + __asm __volatile ("xchgb %b0, %1" \ + : "=r" (result), "=m" (*mem) \ + : "0" (newvalue), "1" (*mem)); \ + else if (sizeof (*mem) == 2) \ + __asm __volatile ("xchgw %w0, %1" \ + : "=r" (result), "=m" (*mem) \ + : "0" (newvalue), "1" (*mem)); \ + else if (sizeof (*mem) == 4) \ + __asm __volatile ("xchgl %0, %1" \ + : "=r" (result), "=m" (*mem) \ + : "0" (newvalue), "1" (*mem)); \ + else \ + __asm __volatile ("xchgq %q0, %1" \ + : "=r" (result), "=m" (*mem) \ + : "0" (newvalue), "1" (*mem)); \ + result; }) + + #define atomic_exchange_and_add(mem, value) \ ({ __typeof (*mem) result; \ if (sizeof (*mem) == 1) \ -- cgit v1.2.3