Request for review: 6896617: Optimize sun.nio.cs.ISO_8859_1$Encode.encodeArrayLoop() on x86

[Vladimir Kozlov]

 From JIT compiler view current code is better since it has only one 
compare. Your code has two compares: one to calculate "overflow" and an 
other (depended on first) to calculate "len".

Thanks,
Vladimir

On 1/9/13 3:57 PM, Ulf Zibis wrote:
> Another little simplification:
>    179             boolean overflow = sr > dr;
>    180             sr = overflow ? dr : sr;
> or in your existing logic:
>   178             int len = sl - sp;
>   179             boolean overflow = len > (dl - dp);
>   180             len = overflow ? dl - dp : len;
> (len is equivalent to sr)
>
> -Ulf
>
> Am 09.01.2013 19:03, schrieb Vladimir Kozlov:
>> Ulf,
>>
>> Thank you for this suggestion but I would like to keep surrounding
>> code intact. I will rename "overflowflag" to "overflow". It is used to
>> indicate that we should return CoderResult.OVERFLOW result.
>>
>> Thanks,
>> Vladimir
>>
>> On 1/9/13 3:58 AM, Ulf Zibis wrote:
>>> Am 09.01.2013 01:10, schrieb Vitaly Davidovich:
>>>> On Jan 8, 2013 6:18 PM, "Vladimir Kozlov" <vladimir.kozlov at oracle.com>
>>>> wrote:
>>>>
>>>>> http://cr.openjdk.java.net/~**kvn/6896617_jdk/webrev<http://cr.openjdk.java.net/~kvn/6896617_jdk/webrev>
>>>>>
>>>>>
>>>
>>> Another tweak:
>>>   168             char[] sa = src.array();
>>>   169             int sp = src.arrayOffset() + src.position();
>>>   170             int sr = src.remaining();
>>>   171             int sl = sp + sr;
>>>   172             assert (sp <= sl); // superfluous, sr is always >= 0
>>>   173             sp = (sp <= sl ? sp : sl); // superfluous "
>>>   174             byte[] da = dst.array();
>>>   175             int dp = dst.arrayOffset() + dst.position();
>>>   170             int dr = dst.remaining();
>>>   176             int dl = dp + dr;
>>>   177             assert (dp <= dl); // superfluous   "
>>>   178             dp = (dp <= dl ? dp : dl); // superfluous "
>>>   179             boolean overflow = false;
>>>   180             if (sr > dr) {
>>>   181                 sr = dr;
>>>   182                 overflow = true;
>>>   183             }
>>>
>>> Why you called it "overflowflag", in that way, you could name each
>>> variable "myvaluevariable" or "myvaluefield" ;-)
>>>
>>>
>>> -Ulf
>>>
>>
>