Number to string conversion is inaccurate

[p5pRT]

Migrated from rt.perl.org#982 (status was 'resolved')

Searchable as RT982$

[p5pRT]

From [email protected]

The following program​:

  $_ = 9007199254740991; # 2**52-1
  print "$_";

produces the output

  9.00719925474099e+15

I think it should produce the output

  9007199254740991

since 2**52-1 is accurately represented.

Perl Info

Site configuration information for perl 5.00502:

Configured by abw at Thu Nov 19 10:50:08 GMT 1998.

Summary of my perl5 (5.0 patchlevel 5 subversion 2) configuration:
  Platform:
    osname=solaris, osvers=2.6, archname=sun4-solaris
    uname='sunos bandanna 5.6 generic_105181-03 sun4u sparc sunw,ultra-1 '
    hint=previous, useposix=true, d_sigaction=define
    usethreads=undef useperlio=undef d_sfio=undef
  Compiler:
    cc='gcc', optimize='-O', gccversion=2.8.0
    cppflags='-I/opt/gnu/include -I/user/perl/build/include'
    ccflags ='-I/opt/gnu/include -I/user/perl/build/include'
    stdchar='unsigned char', d_stdstdio=define, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    alignbytes=8, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='gcc', ldflags ='-L/opt/gnu/lib -L/user/perl/build/lib'
    libpth=/opt/gnu/lib /lib /usr/lib /usr/ccs/lib /user/perl/build/lib
    libs=-lsocket -lnsl -lgdbm -ldl -lm -lc -lcrypt -ldb
    libc=/lib/libc.so, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags=' '
    cccdlflags='-fPIC', lddlflags='-G -L/opt/gnu/lib -L/user/perl/build/lib'

Locally applied patches:
    


@INC for perl 5.00502:
    /apps/perl5/lib/5.00502/sun4-solaris
    /apps/perl5/lib/5.00502
    /apps/perl5/lib/site_perl/5.005/sun4-solaris
    /apps/perl5/lib/site_perl/5.005
    .


Environment for perl 5.00502:
    HOME=/user/garethr
    LANG=C
    LD_LIBRARY_PATH=/usr/dt/lib:/usr/openwin/lib:/apps/X11R5/lib:/usr/lib
    LOGDIR (unset)
    PATH=/usr/dt/bin:/usr/openwin/bin:/bin:/usr/bin:/usr/ucb:/bin:/usr/bin:/cre/bin:/apps/gcc-2.8.0/bin:/apps/frame5/bin:/apps/emacs/bin:/apps/tex/bin:/apps/perl5/bin:/user/web/bin/scripts:/user/web/bin/SunOS-5.6:/apps/gnu/bin:/apps/mysql/bin:/usr/ccs/bin:/apps/X11R5/bin:/usr/openwin/bin
    PERL_BADLANG (unset)
    SHELL=/cre/bin/bash