Re: [avr-gcc-list] Compiler bug ?

[Denis Chertykov]

Marek Michalkiewicz <address@hidden> writes:

> On Fri, Apr 18, 2003 at 11:10:54AM -0600, E. Weddington wrote:
> > Well it looks like the bug is still there in the 20030414 snapshot of 
> > GCC 3.3. I get the same output as before.
> > 
> > I'm willing to wait for next week's snapshot to see if this can be 
> > resolved.
> 
> Commenting out the whole "*cmpqi_sign_extend" insn in avr.md fixes
> the bug, but makes inefficient code (the 8-bit value is sign-extended
> to 16 bits and compared with -20 as a 16-bit value, when an 8-bit
> compare would be much cheaper).  The following works better:
> 
> --- avr.md      28 Sep 2002 14:14:12 -0000      1.38
> +++ avr.md      18 Apr 2003 22:17:02 -0000
> @@ -1636,10 +1636,10 @@
>  (define_insn "*cmpqi_sign_extend"
>    [(set (cc0)
>          (compare (sign_extend:HI
>                   (match_operand:QI 0 "register_operand"  "d"))
> -                (match_operand:HI 1 "immediate_operand" "M")))]
> -  ""
> +                (match_operand:HI 1 "const_int_operand" "n")))]

------------------------------------------------------------^
Why not "M" ?

> +  "INTVAL (operands[1]) >= -128 && INTVAL (operands[1]) <= 127"
>    "cpi %0,lo8(%1)"
>    [(set_attr "cc" "compare")
>     (set_attr "length" "1")])
> 
> 
> I'm not committing this just yet, as Denis may suggest a better
> fix...

Why not "M" ?

Denis.