API modification request

Till Straumann strauman at SLAC.Stanford.EDU
Tue Feb 4 02:05:09 UTC 2003

-- snip --
> I was referring to low-level ISRs when talking about "callee". On the
> SH1, they don't receive any arguments.
> On the caller/interrupt-handler-installation side, we use an array of
> pointers to functions and use the IRQ-number as an index into this
> array.

AFAIK, on the SH you currently do

   if( _ISR_Vector_table[ vector])
     (*_ISR_Vector_table[ vector ])( vector );

I can't imagine that being so much cheaper than

   if( _ISR_Vector_table[vector].hdl )

Again: weigh this change to what your __ISR_Handler() already does.
&_ISR_Vector_table[vector] has to be computed anyways.
Plus, I can't see any impact on the callee (the routine registered with 
the _ISR_Vector_table).

BTW: isn't that a bug a few lines down???

  if(( _Context_Switch_necessary) || (!_ISR_Signals_to_thread_executing))
       _ISR_Signals_to_thread_executing = FALSE;

I.e. shouldn't you test for _ISR_Signals_to_thread_executing to be
TRUE (libcpu/sh/sh7032/score/cpu_asm.c) ?

-- Till

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