36 lines
1.2 KiB
ArmAsm
36 lines
1.2 KiB
ArmAsm
/=============================================================================
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/ tas.s -- test and set lock for i386_solaris
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/=============================================================================
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.file "tas.s"
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.text
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.align 16
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.L1.text:
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.globl tas
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tas:
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pushl %ebp /save prev base pointer
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movl %esp,%ebp /new base pointer
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pushl %ebx /save prev bx
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movl 8(%ebp),%ebx /load bx with address of lock
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pushl %ebx /save prev bx
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movl 8(%ebp),%ebx /load bx with address of lock
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movl $255,%eax /put something in ax
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xchgb %al,(%ebx) /swap lock value with "0"
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cmpb $0,%al /did we get the lock?
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jne .Locked
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subl %eax,%eax /yes, we got it -- return 0
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jmp .Finish
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.align 4
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.Locked:
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movl $1,%eax /no, we didn't get it - return 1
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.Finish:
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popl %ebx /restore prev bx
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movl %ebp,%esp /restore stack state
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popl %ebp
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ret /return
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.align 4
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.type tas,@function
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.size tas,.-tas
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