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Groups > comp.lang.java.programmer > #31858
| From | Eric Sosman <esosman@comcast-dot-net.invalid> |
|---|---|
| Newsgroups | comp.lang.java.programmer |
| Subject | Re: elementary loops |
| Date | 2015-06-26 08:26 -0400 |
| Organization | A noiseless patient Spider |
| Message-ID | <mmjgbb$him$1@dont-email.me> (permalink) |
| References | <loops-20150622181350@ram.dialup.fu-berlin.de> <mmiu9s$pa$1@gwaiyur.mb-net.net> <slrnmoq6pg.uoi.avl@login.logic.tuwien.ac.at> <mmjdme$543$1@gwaiyur.mb-net.net> |
On 6/26/2015 7:39 AM, Marcel Mueller wrote:
> On 26.06.15 11.26, Andreas Leitgeb wrote:
>>>> { public static void main( final java.lang.String[] args )
>>>> { short i = -1;
>>>> int j = -1;
>>>> for( int k = 0; k < 65; ++k ){ i >>>= 1; j <<= 32; }
>>
>> The short i is promoted to int, then the MSB ("sign"-bit) zeroed,
>> then converted back to short, where it's still -1
>
> In this case the >>> operator is meaningless for short int and there is
> no option to perform this operation except for emulating the behavior by
> other bit functions or types. The same applies to byte as well.
> Of course, this is only another side effect of the missing unsigned types.
> Is this guaranteed by the language or just implementation defined?
The former. The relevant bits of the Java Language Specification
<http://docs.oracle.com/javase/specs/jls/se8/html/index.html> are
- 15.26.2 "Compound Assignment Operators"
- 15.19 "Shift Operators"
- 5.6.1 "Unary Numeric Promotion"
- 5.1.2 "Widening Primitive Conversion"
- 15.16 "Cast Expressions" (implied by 15.26.2)
- 5.1.3 "Narrowing Primitive Conversion"
--
esosman@comcast-dot-net.invalid
"Don't be afraid of work. Make work afraid of you." -- TLM
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Re: elementary loops Marcel Mueller <news.5.maazl@spamgourmet.org> - 2015-06-26 09:17 +0200
Re: elementary loops Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2015-06-26 09:26 +0000
Re: elementary loops Marcel Mueller <news.5.maazl@spamgourmet.org> - 2015-06-26 13:39 +0200
Re: elementary loops Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-06-26 08:26 -0400
Re: elementary loops Arne Vajhøj <arne@vajhoej.dk> - 2015-06-28 20:12 -0400
Re: elementary loops Marcel Mueller <news.5.maazl@spamgourmet.org> - 2015-06-29 19:50 +0200
Re: elementary loops Arne Vajhøj <arne@vajhoej.dk> - 2015-06-29 13:58 -0400
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