From: Jakub Wilk <jwilk@jwilk.net>
To: Rohit Saily <rohit@rohitsaily.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>, <linux-man@vger.kernel.org>
Subject: Re: PRINTF(3) Miswriting
Date: Mon, 18 May 2020 17:38:41 +0200 [thread overview]
Message-ID: <20200518153841.5urnrimzrqadvpvy@jwilk.net> (raw)
In-Reply-To: <CAEYDfj7TDMwUy08DiHRde6D8Qam79tALL0u=Bf2tVghKn8jeMw@mail.gmail.com>
Hi Rohit!
* Rohit Saily <rohit@rohitsaily.com>, 2020-05-16, 18:04:
>I am having difficulty understanding a sentence in the PRINTF(3) man
>page's explanation of the 'a' and 'A' conversion specifiers, more
>specifically it is the following sentence:
>
>>The digit before the decimal point is unspecified for nonnormalized
>>numbers, and nonzero but other‐wise unspecified for normalized
>>numbers.
>
>My confusion arises due to the fact that the two posible cases are
>described with the same outcome,
I believe the wording is correct. The outcome is not always the same:
the leading digit zero is allowed only for non-normalized numbers.
For example, printf("%a", 1.0) could produce any of these outputs:
0x8.0p-3
0x4.0p-2
0x2.0p-1
0x1.0p+0
but not:
0x0.8p+1
On the other hand, assuming the IEEE 754 binary64 format,
printf("%a\n", 0x0.8p-1022) could produce any of these:
0x8.0p-1026
0x4.0p-1025
0x2.0p-1024
0x1.0p-1023
0x0.8p-1022
--
Jakub Wilk
next prev parent reply other threads:[~2020-05-18 15:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-16 22:04 PRINTF(3) Miswriting Rohit Saily
2020-05-18 15:38 ` Jakub Wilk [this message]
[not found] ` <CAEYDfj4TK2Maoaxudhfxkx9NJGJa4CNL30Rhud-eBUnHVpFvzw@mail.gmail.com>
2020-05-18 19:01 ` Rohit Saily
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