February 2005 - PPL-devel - BUGSENG Mailman

[Fwd: Re: mpz_get_d precision]
by Roberto Bagnara 19 Feb '05

19 Feb '05

-------- Original Message -------- Subject: Re: mpz_get_d precision Date: 18 Feb 2005 22:41:49 +0100 From: Torbjorn Granlund <tege(a)swox.com> To: Roberto Bagnara <bagnara(a)cs.unipr.it> CC: gmp-devel(a)swox.com References: <20040430135004.GB31761(a)papillon.inria.fr> <87fzaluq5j.fsf(a)zip.com.au> <87u0yubm1p.fsf(a)zip.com.au> <420F26AF.5040907(a)cs.unipr.it> Roberto Bagnara <bagnara(a)cs.unipr.it> writes: Kevin Ryde wrote: > Updated words on the get_d functions will be as follows. > The bits about hardware traps are because I don't want to try to > guarantee they will or won't occur. I'm fairly sure in the past some > cases trapped and some not, so this should be a no-change. > -- Function: double mpz_get_d (mpz_t OP) > Convert OP to a `double', truncating if necessary (ie. rounding > towards zero). > If the exponent from the conversion is too big, the result is > system dependent. An infinity is returned where available. A > hardware overflow trap may or may not occur. > -- Function: double mpz_get_d_2exp (signed long int *EXP, mpz_t OP) > Convert OP to a `double', truncating if necessary (ie. rounding > towards zero), and returning the exponent separately. > The return value is in the range 0.5<=abs(D)<1 and the exponent is > stored to `*EXP'. D * 2^EXP is the (truncated) OP value. If OP > is zero, the return is 0.0 and 0 is stored to `*EXP'. > This is similar to the standard C `frexp' function (*note > Normalization Functions: (libc)Normalization Functions.). > -- Function: double mpq_get_d (mpq_t OP) > Convert OP to a `double', truncating if necessary (ie. rounding > towards zero). > If the exponent from the conversion is too big or too small to fit > a `double' then the result is system dependent. For too big an > infinity is returned when available. For too small 0.0 is > returned. Hardware overflow, underflow and denorm traps may or > may not occur. > -- Function: double mpf_get_d (mpf_t OP) > Convert OP to a `double', truncating if necessary (ie. rounding > towards zero). > If the exponent in OP is too big or too small to fit a `double' > then the result is system dependent. For too big an infinity is > returned when available. For too small 0.0 is returned. Hardware > overflow, underflow and denorm traps may or may not occur. > -- Function: double mpf_get_d_2exp (signed long int *EXP, mpf_t OP) > Convert OP to a `double', truncating if necessary (ie. rounding > towards zero), and with an exponent returned separately. > The return value is in the range 0.5<=abs(D)<1 and the exponent is > stored to `*EXP'. D * 2^EXP is the (truncated) OP value. If OP > is zero, the return is 0.0 and 0 is stored to `*EXP'. > This is similar to the standard C `frexp' function (*note > Normalization Functions: (libc)Normalization Functions.). I see this extra documentation is not present in the GMP 4.1.4 distribution. Since I am very interested about these guarantees (in particular for what concerns mpz_get_d and mpq_get_d), I would like to ask: 1) Do these words apply to GMP 4.1.4? I don't know. Probably not. 2) (In any case) Will they apply to GMP 4.2? Yes. -- Torbjörn _______________________________________________ gmp-devel mailing list gmp-devel(a)swox.com http://swox.com/mailman/listinfo/gmp-devel -- Prof. Roberto Bagnara Computer Science Group Department of Mathematics, University of Parma, Italy http://www.cs.unipr.it/~bagnara/ mailto:bagnara@cs.unipr.it

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ppl/src Float.inlines.hh
by Roberto Bagnara 18 Feb '05

18 Feb '05

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2005-02-18 23:30:53 Modified files: src : Float.inlines.hh Log message: Include <climits>. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/Float.inlines.hh.diff?cvs…

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ppl/src checked_numeric_limits.hh
by Roberto Bagnara 18 Feb '05

18 Feb '05

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2005-02-18 21:03:17 Modified files: src : checked_numeric_limits.hh Log message: Added more attributes to the specializations of std::numeric_limits for "checked" integer types. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/checked_numeric_limits.hh…

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ppl/src Float.inlines.hh checked_int.inlines.hh
by Abramo Bagnara 18 Feb '05

18 Feb '05

CVSROOT: /cvs/ppl Module name: ppl Changes by: abramo(a)cs.unipr.it 2005-02-18 18:55:29 Modified files: src : Float.inlines.hh checked_int.inlines.hh Log message: Added U to make explicit unsignedness for constants. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/Float.inlines.hh.diff?cvs… http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/checked_int.inlines.hh.di…

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ppl/interfaces/C ppl_c.cc
by Roberto Bagnara 18 Feb '05

18 Feb '05

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2005-02-18 18:28:38 Modified files: interfaces/C : ppl_c.cc Log message: Useless type qualifiers removed. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/interfaces/C/ppl_c.cc.diff?cv…

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ppl/src Saturation_Matrix.cc Saturation_Row.cc ...
by Roberto Bagnara 18 Feb '05

18 Feb '05

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2005-02-18 15:19:02 Modified files: src : Saturation_Matrix.cc Saturation_Row.cc Saturation_Row.defs.hh Saturation_Row.inlines.hh conversion.cc Log message: Several methods speeded up. Now bit positions are represented by means of unsigned longs and the invalid position is represented by ULONG_MAX. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/Saturation_Matrix.cc.diff… http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/Saturation_Row.cc.diff?cv… http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/Saturation_Row.defs.hh.di… http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/Saturation_Row.inlines.hh… http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/conversion.cc.diff?cvsroo…

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ppl/src Makefile.am
by Roberto Bagnara 18 Feb '05

18 Feb '05

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2005-02-18 15:13:55 Modified files: src : Makefile.am Log message: Added checked_numeric_limits.hh to INCLUDE_FILES. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/Makefile.am.diff?cvsroot=…

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ppl/tests/BD_Shape empty5.cc
by Roberto Bagnara 18 Feb '05

18 Feb '05

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2005-02-18 13:43:34 Modified files: tests/BD_Shape : empty5.cc Log message: Allow for every definition of Coefficient. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/tests/BD_Shape/empty5.cc.diff…

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ppl/src checked_numeric_limits.hh
by Roberto Bagnara 18 Feb '05

18 Feb '05

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2005-02-18 13:42:50 Added files: src : checked_numeric_limits.hh Log message: Specializations of std::numeric_limits for "checked" types (still incomplete as far as `round_style' is concerned). Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/checked_numeric_limits.hh…

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ppl/src BD_Shape.inlines.hh
by Roberto Bagnara 17 Feb '05

17 Feb '05

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2005-02-17 19:24:21 Modified files: src : BD_Shape.inlines.hh Log message: BD_Shape<T>::contains() improved. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/BD_Shape.inlines.hh.diff?…

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