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/=============================================================================
/ tas.s -- test and set lock for solaris_i386
/=============================================================================
.file "tas.s"
.text
.align 16
.L1.text:
.globl tas
tas:
pushl %ebp /save prev base pointer
movl %esp,%ebp /new base pointer
pushl %ebx /save prev bx
movl 8(%ebp),%ebx /load bx with address of lock
movl $255,%eax /put something in ax
xchgb %al,(%ebx) /swap lock value with "0"
cmpb $0,%al /did we get the lock?
jne .Locked
subl %eax,%eax /yes, we got it -- return 0
jmp .Finish
.align 4
.Locked:
movl $1,%eax /no, we didn't get it - return 1
.Finish:
popl %ebx /restore prev bx
movl %ebp,%esp /restore stack state
popl %ebp
ret /return
.align 4
.type tas,@function
.size tas,.-tas
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