[9] RFR (XS): loadUB2L_immI8 & loadUS2L_immI16 rules don't match some 8-bit/16-bit masks

[Vladimir Ivanov]

Vladimir, Dean, thanks for the feedback.

I like right_n_bits trick.
Here's an updated webrev:
   http://cr.openjdk.java.net/~vlivanov/8001622/webrev.02

Got rid of immU16 since set can encode 32-bit constants.

Best regards,
Vladimir Ivanov

On 5/23/15 7:49 AM, Dean Long wrote:
> Isn't this what you want:
>
> 5656 // Load Unsigned Byte (8 bit UNsigned) with 32-bit mask into Long
> Register
> 5657 instruct loadUB2L_immI(iRegL dst, memory mem, immI mask) %{
> 5658   match(Set dst (ConvI2L (AndI (LoadUB mem) mask)));
> 5659   ins_cost(MEMORY_REF_COST + DEFAULT_COST);
> 5660
> 5661   size(2*4);
> 5662   format %{ "LDUB   $mem,$dst\t# ubyte & 32-bit mask -> long\n\t"
> 5663             "AND    $dst,right_n_bits($mask, 8),$dst" %}
> 5664   ins_encode %{
> 5665     __ ldub($mem$$Address, $dst$$Register);
> 5666     __ and3($dst$$Register, right_n_bits($mask$$constant, 8),
> $dst$$Register);
> 5667   %}
> 5668   ins_pipe(iload_mem);
> 5669 %}
>
> dl
>
> On 5/22/2015 8:38 AM, Vladimir Ivanov wrote:
>> Updated webrev:
>>   http://cr.openjdk.java.net/~vlivanov/8001622/webrev.01
>>
>> Introduced immU8/immU16 operands on sparc.
>>
>> As a cleanup, sorted immI/immU operand declarations.
>>
>> Best regards,
>> Vladimir Ivanov
>>
>> On 5/22/15 6:14 PM, Vladimir Ivanov wrote:
>>> Thanks for looking into the fix, Roland.
>>>
>>> On 5/22/15 5:57 PM, Roland Westrelin wrote:
>>>>> http://cr.openjdk.java.net/~vlivanov/8001622/webrev.00
>>>>> https://bugs.openjdk.java.net/browse/JDK-8001622
>>>>>
>>>>> Mask in loadUB2L_immI8 & loadUS2L_immI16 can be relaxed from
>>>>> immI8/immI16 to immI, since zero-extending move is used.
>>>>
>>>> The change on sparc doesn’t look good:
>>>> __ and3($dst$$Register, $mask$$constant, $dst$$Register);
>>>>
>>>> the and instruction cannot encode arbitrary large integer constants.
>>> Good catch. I missed that it is and3.
>>>
>>>> Isn’t the root of the problem that we want an unsigned 8 bit integer
>>>> and not a signed one?
>>> Yes, unsigned 8-bit integer work fine, but it can be generalized to
>>> arbitrary masks as well.
>>>
>>> I experimented with new operand types (immU8, immU16), but it was more
>>> code for no particular benefit. I can use them on sparc.
>>>
>>> Best regards,
>>> Vladimir Ivanov
>