michael@0: / -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
michael@0: / 
michael@0: / This Source Code Form is subject to the terms of the Mozilla Public
michael@0: / License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0: / file, You can obtain one at http://mozilla.org/MPL/2.0/.
michael@0: 
michael@0: / PRInt32 __PR_MD_ATOMIC_INCREMENT(PRInt32 *val)
michael@0: /
michael@0: / Atomically increment the integer pointed to by 'val' and return
michael@0: / the result of the increment.
michael@0: /
michael@0:     .text
michael@0:     .globl __PR_MD_ATOMIC_INCREMENT
michael@0:     .align 4
michael@0: __PR_MD_ATOMIC_INCREMENT:
michael@0:     movl 4(%esp), %ecx
michael@0:     movl $1, %eax
michael@0:     lock
michael@0:     xaddl %eax, (%ecx)
michael@0:     incl %eax
michael@0:     ret
michael@0: 
michael@0: / PRInt32 __PR_MD_ATOMIC_DECREMENT(PRInt32 *val)
michael@0: /
michael@0: / Atomically decrement the integer pointed to by 'val' and return
michael@0: / the result of the decrement.
michael@0: /
michael@0:     .text
michael@0:     .globl __PR_MD_ATOMIC_DECREMENT
michael@0:     .align 4
michael@0: __PR_MD_ATOMIC_DECREMENT:
michael@0:     movl 4(%esp), %ecx
michael@0:     movl $-1, %eax
michael@0:     lock
michael@0:     xaddl %eax, (%ecx)
michael@0:     decl %eax
michael@0:     ret
michael@0: 
michael@0: / PRInt32 __PR_MD_ATOMIC_SET(PRInt32 *val, PRInt32 newval)
michael@0: /
michael@0: / Atomically set the integer pointed to by 'val' to the new
michael@0: / value 'newval' and return the old value.
michael@0: /
michael@0: / An alternative implementation:
michael@0: /   .text
michael@0: /   .globl __PR_MD_ATOMIC_SET
michael@0: /   .align 4
michael@0: /__PR_MD_ATOMIC_SET:
michael@0: /   movl 4(%esp), %ecx
michael@0: /   movl 8(%esp), %edx
michael@0: /   movl (%ecx), %eax
michael@0: /retry:
michael@0: /   lock
michael@0: /   cmpxchgl %edx, (%ecx)
michael@0: /   jne retry
michael@0: /   ret
michael@0: /
michael@0:     .text
michael@0:     .globl __PR_MD_ATOMIC_SET
michael@0:     .align 4
michael@0: __PR_MD_ATOMIC_SET:
michael@0:     movl 4(%esp), %ecx
michael@0:     movl 8(%esp), %eax
michael@0:     xchgl %eax, (%ecx)
michael@0:     ret
michael@0: 
michael@0: / PRInt32 __PR_MD_ATOMIC_ADD(PRInt32 *ptr, PRInt32 val)
michael@0: /
michael@0: / Atomically add 'val' to the integer pointed to by 'ptr'
michael@0: / and return the result of the addition.
michael@0: /
michael@0:     .text
michael@0:     .globl __PR_MD_ATOMIC_ADD
michael@0:     .align 4
michael@0: __PR_MD_ATOMIC_ADD:
michael@0:     movl 4(%esp), %ecx
michael@0:     movl 8(%esp), %eax
michael@0:     movl %eax, %edx
michael@0:     lock
michael@0:     xaddl %eax, (%ecx)
michael@0:     addl %edx, %eax
michael@0:     ret