cdc2c30e99
semaphore locks have much higher overhead than initially presented in the "Semaphores in Plan9" paper. until the reason for it has been found out i will revert the changes.
34 lines
494 B
ArmAsm
34 lines
494 B
ArmAsm
/*
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* magnum user level lock code
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*/
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#define LL(base, rt) WORD $((060<<26)|((base)<<21)|((rt)<<16))
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#define SC(base, rt) WORD $((070<<26)|((base)<<21)|((rt)<<16))
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#define NOOP WORD $0x27
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#define COP3 WORD $(023<<26)
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TEXT C_3ktas(SB),$0
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MOVW R1, R21
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btas:
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MOVW R21, R1
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MOVB R0, 1(R1)
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NOOP
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COP3
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BLTZ R1, btas
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RET
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TEXT C_4ktas(SB), $0
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MOVW R1, R2 /* address of key */
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tas1:
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MOVW $1, R3
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LL(2, 1)
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NOOP
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SC(2, 3)
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NOOP
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BEQ R3, tas1
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RET
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TEXT C_fcr0(SB), $0
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MOVW FCR0, R1
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RET
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