Groups > comp.lang.java.programmer > #38426

Re: Has Android different floats?

Path	csiph.com!news.bbs.nz!.POSTED.184-155-113-241.cpe.cableone.net!not-for-mail
From	"bursejan" <bursejan@1:261/38.remove-i5b-this>
Newsgroups	comp.lang.java.programmer
Subject	Re: Has Android different floats?
Date	Sun, 24 Jun 2018 13:35:42 -0500
Organization	Agency News - Dunedin, New Zealand
Message-ID	<5B329ADB.1165.ucljprogr@castlerockbbs.com> (permalink)
References	<5B329ADB.1164.ucljprogr@castlerockbbs.com>
Content-Type	text/plain; charset=IBM437
Content-Transfer-Encoding	8bit
Injection-Info	news.bbs.nz; posting-host="OzrHixpCILyhgWpD0JEChpw8GfzwXVr5j8UB2bSv2xw"; logging-data="16453"; mail-complaints-to="abuse@news.bbs.nz"
To	bursejan
X-FTN-REPLY	1:261/38.0 de900e19
X-FTN-AREA	COMP.LANG.JAVA.PROGRAMMER
X-FTN-Kludge	CHARSET: LATIN-1
In-Reply-To	<5B329ADB.1164.ucljprogr@castlerockbbs.com>
X-Gateway	castlerockbbs.com [Synchronet 3.17a-Linux NewsLink 1.108]
X-Comment-To	bursejan
X-FTN-MSGID	1:261/38.0 86a26328
Xref	csiph.com comp.lang.java.programmer:38426

Show key headers only | View raw

  To: bursejan
From: "bursejan" <bursejan@1:261/38.remove-101j-this>

  To: bursejan
From: bursejan@gmail.com

The test code would be:

        for (int i=22; i<25; i++) {
           System.out.println("Math.pow(10,"+i+")="+Math.pow(10,i));
        }

The result (without strictfp modifier to main()) is:

   Math.pow(10,22)=1.0E22
   Math.pow(10,23)=1.0000000000000001E23
   Math.pow(10,24)=1.0E24

The result (with strictfp modifier to main()) is:

   Math.pow(10,22)=1.0E22
   Math.pow(10,23)=1.0000000000000001E23
   Math.pow(10,24)=1.0E24

Because invoking Math.pow() is not a basic operator +, *, /, etc..

Am Sonntag, 24. Juni 2018 22:31:44 UTC+2 schrieb burs...@gmail.com:
> You cannot use the strictfp keyword in front
> of Math.pow(). Thats only for the basic operations.
>
> Math.pow() itself is implemented in JDK 1.8 as follows:
>
>     public static double pow(double a, double b) {
>         return StrictMath.pow(a, b); // default impl. delegates to StrictMath
>     }
>
> Am Sonntag, 24. Juni 2018 21:21:57 UTC+2 schrieb Arne VajhÄ,j:
> > On 6/24/2018 2:41 PM, j4n bur53 wrote:
> > > Running a simple test.
> > > ** is Math.pow(),
> > > ^ is BigInteger.pow() and then BigInteger.doubleValue().
> > >
> > > On Java:
> > >
> > >  ā  ?- between(15,30,N), X is 10**N-10^N, write(N-X), nl, fail; true.
> > >  ā  15-0.0
> >
> > >  ā  23-1.6777216E7
> >
> > >  ā  29-0.0
> > >  ā  30-0.0
> > >
> > > On Adroid:
> > >
> > >  ā  ?- between(15,30,N), X is 10**N-10^N, write(N-X), nl, fail; true.
> > >  ā  15-0.0
> >
> > >  ā  23-0.0
> >
> > >  ā  29-1.7592186044416E13
> > >  ā  30-0.0
> > >
> > > Has Android different floats?
> > > Tested jdk1.8.0_152 against Android 8.0.0
> >
> > ARM supposedly use standard IEEE 754 FP.
> >
> > But I wonder if usage of strictfp would change your results.
> >
> > Arne

-+- BBBS/Li6 v4.10 Toy-3
 + Origin: Prism bbs (1:261/38)

--- BBBS/Li6 v4.10 Toy-3
 * Origin: Prism bbs (1:261/38)

Thread

Re: Has Android different floats? "Arne Vajhøj" <arne vajhøj@1:261/38.remove-i5b-this> - 2018-06-24 15:21 -0500
  Re: Has Android different floats? "bursejan" <bursejan@1:261/38.remove-i5b-this> - 2018-06-24 13:31 -0500
    Re: Has Android different floats? "bursejan" <bursejan@1:261/38.remove-i5b-this> - 2018-06-24 13:35 -0500
      Re: Has Android different floats? "bursejan" <bursejan@1:261/38.remove-i5b-this> - 2018-06-24 13:44 -0500
      Re: Has Android different floats? "Eric Sosman" <eric.sosman@1:261/38.remove-i5b-this> - 2018-06-24 17:28 -0500
        Re: Has Android different floats? "bursejan" <bursejan@1:261/38.remove-i5b-this> - 2018-06-24 16:08 -0500

csiph-web