RFR: 8075443: AARCH64: Missed L2I optimizations in C2

[Vladimir Kozlov]

Looks good to me.

Thanks,
Vladimir

On 3/19/15 9:26 AM, Andrew Haley wrote:
> I think I need another reviewer for this.
>
> Thanks,
> Andrew.
>
>
> On 03/18/2015 02:54 PM, Andrew Haley wrote:
>> We use iRegIOrL2I erratically in aarch64.ad.  We can use it whenever
>> we have a 32-bit input operand, and doing so improves code quality in
>> many cases. We should use iRegIOrL2I instead of iRegI whenever it can
>> be used as an input operand and the patterns allow us to do so.
>>
>> I also took the opportunity to do a little technical debt reduction.
>> In a few places we were doing int-mode operations in 64-bit-wide
>> instructions.  This doesn't really matter, but it's a lot easier to
>> reason about code generation if you have a rule that instructions must
>> always use the correct mode.
>>
>> This is an example of a pattern which has both changes.
>>
>> @@ -8274,14 +8274,14 @@
>>   %}
>>
>>   instruct XorI_reg_not_reg(iRegINoSp dst,
>> -                         iRegI src1, iRegI src2, immI_M1 m1,
>> +                         iRegIorL2I src1, iRegIorL2I src2, immI_M1 m1,
>>                            rFlagsReg cr) %{
>>     match(Set dst (XorI m1 (XorI src2 src1)));
>>     ins_cost(INSN_COST);
>> -  format %{ "eon  $dst, $src1, $src2" %}
>> -
>> -  ins_encode %{
>> -    __ eon(as_Register($dst$$reg),
>> +  format %{ "eonw  $dst, $src1, $src2" %}
>> +
>> +  ins_encode %{
>> +    __ eonw(as_Register($dst$$reg),
>>                 as_Register($src1$$reg),
>>                 as_Register($src2$$reg),
>>                 Assembler::LSL, 0);
>>
>> http://cr.openjdk.java.net/~aph/8075443/
>>
>> Andrew.
>>
>