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/i386/i486/bits/atomic.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'sysdeps/i386/i486') diff --git a/sysdeps/i386/i486/bits/atomic.h b/sysdeps/i386/i486/bits/atomic.h index 87739c6cc6..e22e560a38 100644 --- a/sysdeps/i386/i486/bits/atomic.h +++ b/sysdeps/i386/i486/bits/atomic.h @@ -119,6 +119,29 @@ typedef uintmax_t uatomic_max_t; #endif +/* 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 \ + { \ + result = 0; \ + abort (); \ + } \ + result; }) + + #define atomic_exchange_and_add(mem, value) \ ({ __typeof (*mem) result; \ __typeof (value) addval = (value); \ -- cgit 1.4.1