John Baldwin <[EMAIL PROTECTED]> wrote:
>Uh, there is no xaddl instruction in the x86 instruction set.
It was introduced in the '486. I've been using it for some years now, so I
am confident of its existence.
A quick test using my example:
$ objdump -d jan.o
jan.o: file format elf32-i386
Disassembly of section .text:
00000000 <atomic_decrement>:
0: 55 push %ebp
1: 89 e5 mov %esp,%ebp
3: 8b 4d 08 mov 0x8(%ebp),%ecx
6: b8 ff ff ff ff mov $0xffffffff,%eax
b: f0 0f c1 01 lock xadd %eax,(%ecx)
f: 48 dec %eax
10: c9 leave
11: c3 ret
There shouldn't be a need for a loop like the one you describe for a simple
atomic increment.
I'm pretty new to FreeBSD: what is changing in -current which alters the
behaviour of your code?
Jan Mikkelsen
To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-hackers" in the body of the message
