From: Gabriel Ravier <gabravier@gmail.com>
To: musl@lists.openwall.com
Subject: [musl] fcvt(99.99, 1, ...) appears to be broken because of varying rounding
Date: Tue, 6 Sep 2022 23:13:26 +0200 [thread overview]
Message-ID: <a0c7cfdc-8d8a-0561-dd35-af569dd9ba9c@gmail.com> (raw)
fcvt(99.99, 1, &decpt, &sign) results in musl returning "9999". I am
pretty sure the standard ensures that regardless of how the rounding is
done, only "999" and "1000" are supposed to be valid results for fcvt in
this situation.
I'd like to add that this seems to occur because of a difference in
rounding that occurs between the calls to sprintf in fcvt and ecvt, with
fcvt's call of it returning "100.0" and ecvt's call returning
"9.999e+01" (i.e. fcvt asked ecvt for 4 significant digits assuming it
would return "1000" but it ended up getting a contradicting result from
its call to printf)
reply other threads:[~2022-09-06 21:13 UTC|newest]
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