Re: patch for cgen generated decoders

[Dave Brolley <brolley at redhat dot com>]

Yes -- this makes sense due to my change a while back which
caused the extraction functions to extract any fields in the
first sizeof (CGEN_INSN_INT) * 8 bits as if CGEN_INT_INSN_P was
set (see extract_normal).

Dave

matthew green wrote:
> 
> hi folks.
> 
> i need this patch for an architecture where the standard instruction
> bitsize is 16 bits, yet there exists a 48-bit instruction (which
> causes CGEN_INT_INSN_P to be false).  the problem i was seeing is
> that for the 32-bit instruction my ifields were not being extracted
> correctly, because only 16 bits were present in the "insn_value".
> the patch below enables the code previously only available for the
> CGEN_INT_INSN_P==1 case, but ensures that 32-bit instructions are
> passed in their entirity in all cases.
> 
> (actually, this code uses "unsigned long" to hold this value, where
> it should probably use a "CGEN_INSN_INT".  i'm not sure exactly if
> it will work correctly on a LP64 host...)
> 
> i've tested this change with the fr30 & m32r ports and it does not
> affect their operation (fr30 is the only other port that sets
> CGEN_INT_INSN_P to be false).
> 
> 2000-11-05  matthew green  <mrg@redhat.com>
> 
>         * cgen-dis.in (print_insn): Load a full CGEN_INSN_INT in the
>         !CGEN_INT_INSN_P case as well.
> 
> Index: cgen-dis.in
> ===================================================================
> RCS file: /cvs/src/src/opcodes/cgen-dis.in,v
> retrieving revision 1.2
> diff -p -r1.2 cgen-dis.in
> *** cgen-dis.in 2000/08/28 18:36:53     1.2
> --- cgen-dis.in 2000/11/05 02:28:01
> *************** print_insn (cd, pc, info, buf, buflen)
> *** 281,289 ****
>              machine insn and extracts the fields.  The second pass prints
>              them.  */
> 
> ! #if CGEN_INT_INSN_P
> !         /* Make sure the entire insn is loaded into insn_value.  */
> !         if (CGEN_INSN_BITSIZE (insn) > cd->base_insn_bitsize)
>             {
>               unsigned long full_insn_value;
>               int rc = read_insn (cd, pc, info, buf,
> --- 281,290 ----
>              machine insn and extracts the fields.  The second pass prints
>              them.  */
> 
> !         /* Make sure the entire insn is loaded into insn_value, if it
> !            can fit.  */
> !         if (CGEN_INSN_BITSIZE (insn) > cd->base_insn_bitsize &&
> !             (CGEN_INSN_BITSIZE (insn) / 8) <= sizeof (unsigned long))
>             {
>               unsigned long full_insn_value;
>               int rc = read_insn (cd, pc, info, buf,
> *************** print_insn (cd, pc, info, buf, buflen)
> *** 295,304 ****
>                 (cd, insn, &ex_info, full_insn_value, &fields, pc);
>             }
>           else
> ! #endif
> 
> -         length = CGEN_EXTRACT_FN (cd, insn)
> -           (cd, insn, &ex_info, insn_value, &fields, pc);
>           /* length < 0 -> error */
>           if (length < 0)
>             return length;
> --- 296,304 ----
>                 (cd, insn, &ex_info, full_insn_value, &fields, pc);
>             }
>           else
> !           length = CGEN_EXTRACT_FN (cd, insn)
> !             (cd, insn, &ex_info, insn_value, &fields, pc);
> 
>           /* length < 0 -> error */
>           if (length < 0)
>             return length;