1 files changed, 85 insertions, 0 deletions
diff --git a/nsprpub/pr/src/md/unix/os_Linux_x86.s b/nsprpub/pr/src/md/unix/os_Linux_x86.s
new file mode 100644
index 0000000000..83e10b4552
--- /dev/null
+++ b/nsprpub/pr/src/md/unix/os_Linux_x86.s
@@ -0,0 +1,85 @@
+// -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+// PRInt32 _PR_x86_AtomicIncrement(PRInt32 *val)
+//
+// Atomically increment the integer pointed to by 'val' and return
+// the result of the increment.
+//
+    .text
+    .globl _PR_x86_AtomicIncrement
+    .align 4
+_PR_x86_AtomicIncrement:
+    movl 4(%esp), %ecx
+    movl $1, %eax
+    lock
+    xaddl %eax, (%ecx)
+    incl %eax
+    ret
+
+// PRInt32 _PR_x86_AtomicDecrement(PRInt32 *val)
+//
+// Atomically decrement the integer pointed to by 'val' and return
+// the result of the decrement.
+//
+    .text
+    .globl _PR_x86_AtomicDecrement
+    .align 4
+_PR_x86_AtomicDecrement:
+    movl 4(%esp), %ecx
+    movl $-1, %eax
+    lock
+    xaddl %eax, (%ecx)
+    decl %eax
+    ret
+
+// PRInt32 _PR_x86_AtomicSet(PRInt32 *val, PRInt32 newval)
+//
+// Atomically set the integer pointed to by 'val' to the new
+// value 'newval' and return the old value.
+//
+// An alternative implementation:
+//   .text
+//   .globl _PR_x86_AtomicSet
+//   .align 4
+//_PR_x86_AtomicSet:
+//   movl 4(%esp), %ecx
+//   movl 8(%esp), %edx
+//   movl (%ecx), %eax
+//retry:
+//   lock
+//   cmpxchgl %edx, (%ecx)
+//   jne retry
+//   ret
+//
+    .text
+    .globl _PR_x86_AtomicSet
+    .align 4
+_PR_x86_AtomicSet:
+    movl 4(%esp), %ecx
+    movl 8(%esp), %eax
+    xchgl %eax, (%ecx)
+    ret
+
+// PRInt32 _PR_x86_AtomicAdd(PRInt32 *ptr, PRInt32 val)
+//
+// Atomically add 'val' to the integer pointed to by 'ptr'
+// and return the result of the addition.
+//
+    .text
+    .globl _PR_x86_AtomicAdd
+    .align 4
+_PR_x86_AtomicAdd:
+    movl 4(%esp), %ecx
+    movl 8(%esp), %eax
+    movl %eax, %edx
+    lock
+    xaddl %eax, (%ecx)
+    addl %edx, %eax
+    ret
+
+// Magic indicating no need for an executable stack
+.section .note.GNU-stack, "", @progbits