optimisation for default_print_insn().

[matthew green]

hi folks.


i've been looking at the cgen generated disassemblers lately
and i've noticed that it reads target memory twice for the
initial portion of the instruction.  in default_print_insn(),
there is a call to (*info->read_memory_func)() and then it
calls print_insn().  the first thing print_insn() does is
call read_insn() which performs the exact same read_memory_func
call (same arguments, buffers, etc.)  as read_insn() is used 
in other places, i believe the best way to fix this double
read is to remove the copy in default_print_insn().  i have
tested this with a couple of ports and nothing appeas to be
broken.


the patch below simply comments the block in
default_print_insn() rather than removing it entirely.  if
people think it should be removed, i can change my patch.


OK to commit?


.mrg.


2001-04-09  matthew green  <mrg@redhat.com>

	* cgen-dis.in (default_print_insn): Remove redundant call to
	(*info->read_memory_func)().


Index: cgen-dis.in
===================================================================
RCS file: /cvs/src/src/opcodes/cgen-dis.in,v
retrieving revision 1.5
diff -p -r1.5 cgen-dis.in
*** cgen-dis.in	2001/01/09 17:00:21	1.5
--- cgen-dis.in	2001/04/09 10:55:03
*************** default_print_insn (cd, pc, info)
*** 319,324 ****
--- 319,325 ----
    char buf[CGEN_MAX_INSN_SIZE];
    int status;
  
+ #if 0	/* Done in print_insn().  */
    /* Read the base part of the insn.  */
  
    status = (*info->read_memory_func) (pc, buf, cd->base_insn_bitsize / 8, info);
*************** default_print_insn (cd, pc, info)
*** 327,332 ****
--- 328,334 ----
        (*info->memory_error_func) (status, pc, info);
        return -1;
      }
+ #endif
  
    return print_insn (cd, pc, info, buf, cd->base_insn_bitsize / 8);
  }