33 lines
904 B
ArmAsm
33 lines
904 B
ArmAsm
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/*
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This little bit of code is executed in-place by one CPU, but copied to a different memory region
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by the other CPU. Make sure it stays position-independent.
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*/
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.text
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.align 4
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.global test_fastbus_cp
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.type test_fastbus_cp,@function
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//Args:
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//a2 - fifo addr
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//a3 - buf addr
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//a4 - len
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//a5 - ptr to int to use
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test_fastbus_cp:
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entry a1,64
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back:
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beqi a4, 0, out //check if loop done
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s32i a4, a5, 0 //store value, for shits and/or giggles
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memw //make sure write happens
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l32i a4, a5, 0 //load value again, to thwart any prediction in the pipeline
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bbsi a4, 0, pred //Random jump to check predictive reads. Both branches should do the same.
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l32i a6, a2, 0 //read from fifo 1
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j predout
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pred:
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l32i a6, a2, 0 //read from fifo 2
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predout:
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s8i a6, a3, 0 //store result
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addi a3, a3, 1 //inc ptr
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addi a4, a4, -1 //next
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j back //loop again
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out:
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retw //and we are done
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