In a scientific application, that exact floating point representation could be the literal you gave it, but it could also be the result of math that has been rounded to fit in the 53 bit mantissa. For example perl -MPOSIX -e “printf ‘%.0f’, POSIX::DBL_MAX - 10000000000000000;” Now the very precise answer from gcc is wrong. If you actually care about the digits beyond the first 17 then you need to use a BigFloat.

Anyway, but no I don’t know if there’s a way to ask ms libc for a different implementation.

In reply to Re^3: [XS] C printf() and Microsoft compilers. by NERDVANA
in thread [XS] C printf() and Microsoft compilers. by syphilis

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.