Denis Chertykov wrote:
> 2011/6/26 Georg-Johann Lay <a...@gjlay.de>:
>> Denis Chertykov schrieb:
>>> 2011/6/24 Richard Henderson <r...@redhat.com>:
>>>
>>>> On 06/23/2011 01:15 PM, Denis Chertykov wrote:
>>>>
>>>>>> text data bss dec hex filename
>>>>>> 10032 25 0 10057 2749 bld-avr-orig/gcc/z.o
>>>>>> 5816 25 0 5841 16d1 bld-avr-new/gcc/z.o
>>>>> Richard, can you send me this z.c file ?
>>>>> Right now I'm notice that new code is worse.
>>>> That's gcc.c-torture/compile/950612-1.c.
>>> I have founded that postreload optimizations can't handle results of
>>> new L_R_A code.
>>> I think that it's can be handled by CSE (postreload).
>> Did you try to add constraint alternative to *addhi3?
>> Like "*!d,d,n" or even "*!r,r,n"
>>
>> I saw some code improvement with that alternative.
>
> I'm trying:
>
> (define_insn "*addhi3"
> [(set (match_operand:HI 0 "register_operand" "=r,!w,!w,d,r,r,!d")
> (plus:HI
> (match_operand:HI 1 "register_operand" "%0,0,0,0,0,0,!r")
> (match_operand:HI 2 "nonmemory_operand" "r,I,J,i,P,N,!ri")))]
> ""
> "@
> add %A0,%A2\;adc %B0,%B2
> adiw %A0,%2
> sbiw %A0,%n2
> subi %A0,lo8(-(%2))\;sbci %B0,hi8(-(%2))
> sec\;adc %A0,__zero_reg__\;adc %B0,__zero_reg__
> sec\;sbc %A0,__zero_reg__\;sbc %B0,__zero_reg__
> #"
> [(set_attr "length" "2,1,1,2,3,3,4")
> (set_attr "cc" "set_n,set_czn,set_czn,set_czn,set_n,set_n,set_n")])
>
That split will split always:
> ;; Special split three addressing addhi3
> ;; to make postreload optimization possible
> (define_split ; addhi3 !d,!r,!ri
> [(set (match_operand:HI 0 "d_register_operand" "")
> (plus:HI (match_operand:HI 1 "register_operand" "")
> (match_operand:HI 2 "nonmemory_operand" "")))]
> "reload_completed"
&& REGNO(operands[0]) != REGNO(operands[1])"
> [(set (match_dup 0) (match_dup 2))
> (set (match_dup 0) (plus:HI (match_dup 0) (match_dup 1)))]
> "")
Maybe it can also restrict to const_int_operand in #2 and then it's
best to
(set (match_dup 0)
(match_dup 1))
(set (match_dup 0)
(plus:HI (match_dup 0)
(match_dup 2)))
>
> The main problem for me is that the new addressing mode produce a
> worse code in many tests.
You have an example source?
> Although, results for gcc.c-torture/compile/950612-1.c is
> significantly better with new addressing.
That testcase is pathologic for AVR...
>
> Denis.
>
Johann
