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_x86_AtomicIncrement(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_x86_AtomicIncrement
michael@0:     .align 4
michael@0: _PR_x86_AtomicIncrement:
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_x86_AtomicDecrement(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_x86_AtomicDecrement
michael@0:     .align 4
michael@0: _PR_x86_AtomicDecrement:
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_x86_AtomicSet(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_x86_AtomicSet
michael@0: //   .align 4
michael@0: //_PR_x86_AtomicSet:
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_x86_AtomicSet
michael@0:     .align 4
michael@0: _PR_x86_AtomicSet:
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_x86_AtomicAdd(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_x86_AtomicAdd
michael@0:     .align 4
michael@0: _PR_x86_AtomicAdd:
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
michael@0: 
michael@0: // Magic indicating no need for an executable stack
michael@0: .section .note.GNU-stack, "", @progbits ; .previous