2009/11/6 Ian Lance Taylor <i...@google.com>:
> Mohamed Shafi <shafi...@gmail.com> writes:
>
>> It is generating with data registers. Here is the pattern that i have
>> written:
>>
>>
>> (define_insn "*saddl"
>> [(set (match_operand:SI 0 "register_operand" "=r,d")
>> (plus:SI (mult:SI (match_operand:SI 1 "register_operand" "r,d")
>> (match_operand:SI 2 "const24_operand" "J,J"))
>> (match_operand:SI 3 "register_operand" "0,0")))]
>>
>> How can i do this. Will the constraint modifiers '?' or '!' help?
>> How can make GCC generate shift and add sequence when the shift count is 1?
>
> Does 'd' represent a data register? I assume that 'r' is a general
> register, as it always is. What is the constraint character for an
> address register? You don't seem to have an alternative here for
> address registers, so I'm not surprised that the compiler isn't
> picking it. No doubt I misunderstand something.
>
Ok the constrain for address register is 'a'. Thats typo in the
pattern that i given here. The proper pattern is
(define_insn "*saddl"
[(set (match_operand:SI 0 "register_operand" "=a,d")
(plus:SI (mult:SI (match_operand:SI 1 "register_operand" "a,d")
(match_operand:SI 2 "const24_operand" "J,J"))
(match_operand:SI 3 "register_operand" "0,0")))]
So how can i choose the address registers over data registers if that
is more profitable?
Regards,
Shafi
