Re: lib/60635: humanize_number(3): exa/exbi issues

To: lib-bug-people%netbsd.org@localhost,gnats-admin%netbsd.org@localhost,netbsd-bugs%netbsd.org@localhost,campbell+netbsd%mumble.net@localhost
Subject: Re: lib/60635: humanize_number(3): exa/exbi issues
From: "Taylor R Campbell via gnats" <gnats-admin%NetBSD.org@localhost>
Date: Sun, 23 Aug 2026 17:40:02 +0000 (UTC)

The following reply was made to PR lib/60635; it has been noted by GNATS.

From: Taylor R Campbell <riastradh%NetBSD.org@localhost>
To: gnats-bugs%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Cc: 
Subject: Re: lib/60635: humanize_number(3): exa/exbi issues
Date: Sun, 23 Aug 2026 17:39:25 +0000

 This is a multi-part message in MIME format.
 --=_aD0stfJJ+WVg8+9bTfy4bTTT5i9m1xYu
 
 
 --=_aD0stfJJ+WVg8+9bTfy4bTTT5i9m1xYu
 Content-Type: text/plain; charset="ISO-8859-1"; name="pr60635-humanizeiec"
 Content-Transfer-Encoding: quoted-printable
 Content-Disposition: attachment; filename="pr60635-humanizeiec.patch"
 
 # HG changeset patch
 # User Taylor R Campbell <riastradh%NetBSD.org@localhost>
 # Date 1787506011 0
 #      Sun Aug 23 17:26:51 2026 +0000
 # Branch trunk
 # Node ID cc8c7b6b7bd389ee5f3db6fdd197869e8577a0cd
 # Parent  6f8d3c18f5e5266c57e1b8b3736224c0146f1726
 # EXP-Topic riastradh-pr59411-prgrowingnowaitcleanup
 humanize_number(3): New option HN_IEC for IEC prefixes.
 
 PR lib/60635: humanize_number(3): exa/exbi issues
 
 diff -r 6f8d3c18f5e5 -r cc8c7b6b7bd3 lib/libc/gen/humanize_number.3
 --- a/lib/libc/gen/humanize_number.3	Sun Aug 23 16:54:15 2026 +0000
 +++ b/lib/libc/gen/humanize_number.3	Sun Aug 23 17:26:51 2026 +0000
 @@ -61,20 +61,52 @@ would be too long to fit into
  .Fa buffer ,
  then repeatedly divide
  .Fa number
 -by 1024 until it will fit.
 +by a base, either 1024 (default) or 1000 (decimal, with
 +.Dv HN_DIVISOR_1000 ) ,
 +until it will fit.
  In this case, prefix
  .Fa suffix
 -with the appropriate SI designator.
 +with the corresponding scale designator.
 +.Pp
 +For the default binary base (1024), the prefixes are:
 +.Bl -column "Prefix" "IEC" "Name" "Multiplier" -offset indent
 +.It Sy "Prefix" Ta Sy "IEC" Ta Sy "Name" Ta Sy "Multiplier"
 +.It K	Ki	kibi	1,024
 +.It M	Mi	mebi	1,048,576
 +.It G	Gi	gibi	1,073,741,824
 +.It T	Ti	tebi	1,099,511,627,776
 +.It P	Pi	pebi	1,125,899,906,842,624
 +.It E	Ei	exbi	1,152,921,504,606,846,976
 +.El
  .Pp
 -The prefixes are:
 -.Bl -column "Prefix" "Description" "Multiplier" -offset indent
 -.It Sy "Prefix" Ta Sy "Description" Ta Sy "Multiplier"
 -.It k	kilo	1024
 -.It M	mega	1048576
 -.It G	giga	1073741824
 -.It T	tera	1099511627776
 -.It P	peta	1125899906842624
 -.It E	exa	1152921504606846976
 +The nonstandard
 +.Dq Tn SI
 +or
 +.Tn JEDEC Ns No - Ns style
 +prefixes
 +.Dq K ,
 +.Dq M ,
 +etc., are chosen by default.
 +The
 +.Tn IEC
 +prefixes
 +.Dq Ki ,
 +.Dq Mi ,
 +etc., are chosen by the
 +.Dv HN_IEC
 +option.
 +.Pp
 +For the decimal base (1000, chosen by
 +.Dv HN_DIVISOR_1000 ) ,
 +the SI prefixes are:
 +.Bl -column "Prefix" "Name" "Multiplier" -offset indent
 +.It Sy "Prefix" Ta Sy "Name" Ta Sy "Multiplier"
 +.It k	kilo	1,000
 +.It M	mega	1,000,000
 +.It G	giga	1,000,000,000
 +.It T	tera	1,000,000,000,000
 +.It P	peta	1,000,000,000,000,000
 +.It E	exa	1,000,000,000,000,000,000
  .El
  .Pp
  .Fa len
 @@ -123,6 +155,17 @@ Divide
  .Fa number
  with 1000 instead of 1024.
  That is, use decimal scaling instead of binary.
 +.Pp
 +Exclusive with
 +.Dv HN_IEC .
 +.It Dv HN_IEC
 +Use IEC prefixes
 +.Dq Ki ,
 +.Dq Mi ,
 +etc.
 +.Pp
 +Exclusive with
 +.Dv HN_DIVISOR_1000 .
  .El
  .Pp
  To generate the shortest meaningful value,
 diff -r 6f8d3c18f5e5 -r cc8c7b6b7bd3 lib/libc/gen/humanize_number.c
 --- a/lib/libc/gen/humanize_number.c	Sun Aug 23 16:54:15 2026 +0000
 +++ b/lib/libc/gen/humanize_number.c	Sun Aug 23 17:26:51 2026 +0000
 @@ -52,9 +52,12 @@ humanize_number(char *buf, size_t len, i
  	int64_t	divisor, max, post =3D 1;
  	size_t	baselen;
  	int	maxscale;
 +	int	prefixbytes =3D 1;
 =20
  	_DIAGASSERT(buf !=3D NULL);
  	_DIAGASSERT(scale >=3D 0);
 +	_DIAGASSERT((flags & (HN_DIVISOR_1000|HN_IEC)) !=3D
 +	    (HN_DIVISOR_1000|HN_IEC));
 =20
  	if (suffix =3D=3D NULL)
  		suffix =3D "";
 @@ -68,17 +71,31 @@ humanize_number(char *buf, size_t len, i
  			prefixes =3D "\0\0k\0M\0G\0T\0P\0E";
  	} else {
  		/*
 -		 * binary multiplies
 -		 * XXX IEC 60027-2 recommends Ki, Mi, Gi...
 +		 * binary multiplies with `SI'/JEDEC-style or IEC
 +		 * prefixes
  		 */
  		divisor =3D 1024;
 -		if (flags & HN_B)
 +		switch (flags & (HN_B|HN_IEC)) {
 +		case HN_B:
  			prefixes =3D "B\0K\0M\0G\0T\0P\0E";
 -		else
 +			break;
 +		case 0:
  			prefixes =3D "\0\0K\0M\0G\0T\0P\0E";
 +			break;
 +		case HN_B|HN_IEC:
 +			prefixes =3D "B\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei";
 +			prefixbytes =3D 2;
 +			break;
 +		case HN_IEC:
 +			prefixes =3D "\0\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei";
 +			prefixbytes =3D 2;
 +			break;
 +		default:
 +			__unreachable();
 +		}
  	}
 =20
 -#define	SCALE2PREFIX(scale)	(&prefixes[(scale) << 1])
 +#define	SCALE2PREFIX(scale)	(&prefixes[(scale) * (prefixbytes + 1)])
  	maxscale =3D 6;
 =20
  	if (scale < 0 || (scale > maxscale &&
 diff -r 6f8d3c18f5e5 -r cc8c7b6b7bd3 tests/lib/libc/gen/t_humanize_number.c
 --- a/tests/lib/libc/gen/t_humanize_number.c	Sun Aug 23 16:54:15 2026 +0000
 +++ b/tests/lib/libc/gen/t_humanize_number.c	Sun Aug 23 17:26:51 2026 +0000
 @@ -112,6 +112,32 @@ const struct hnopts {
  	  NULL },
  	{ 4, 1024LL*1024*1024*1024*1024*1024, "", HN_AUTOSCALE, HN_B, 3, "1 E",
  	  "PR lib/60635: humanize_number(3): exa/exbi issues" },
 +
 +	{ 5, 1, "", HN_AUTOSCALE, HN_IEC, 2, "1 ", NULL },
 +	{ 5, 1024LL, "", HN_AUTOSCALE, HN_IEC, 4, "1 Ki", NULL },
 +	{ 5, 1024LL*1024, "", HN_AUTOSCALE, HN_IEC, 4, "1 Mi", NULL },
 +	{ 5, 1024LL*1024*1024, "", HN_AUTOSCALE, HN_IEC, 4, "1 Gi", NULL },
 +	{ 5, 1024LL*1024*1024*1024, "", HN_AUTOSCALE, HN_IEC, 4, "1 Ti",
 +	  NULL },
 +	{ 5, 1024LL*1024*1024*1024*1024, "", HN_AUTOSCALE, HN_IEC, 4, "1 Pi",
 +	  NULL },
 +	{ 5, 1024LL*1024*1024*1024*1024*1024, "", HN_AUTOSCALE,HN_IEC, 4,
 +	  "1 Ei",
 +	  "PR lib/60635: humanize_number(3): exa/exbi issues" },
 +
 +	{ 5, 1, "", HN_AUTOSCALE, HN_IEC|HN_B, 3, "1 B", NULL },
 +	{ 5, 1024LL, "", HN_AUTOSCALE, HN_IEC|HN_B, 4, "1 Ki", NULL },
 +	{ 5, 1024LL*1024, "", HN_AUTOSCALE, HN_IEC|HN_B, 4, "1 Mi", NULL },
 +	{ 5, 1024LL*1024*1024, "", HN_AUTOSCALE, HN_IEC|HN_B, 4, "1 Gi",
 +	  NULL },
 +	{ 5, 1024LL*1024*1024*1024, "", HN_AUTOSCALE, HN_IEC|HN_B, 4, "1 Ti",
 +	  NULL },
 +	{ 5, 1024LL*1024*1024*1024*1024, "", HN_AUTOSCALE, HN_IEC|HN_B, 4,
 +	  "1 Pi",
 +	  NULL },
 +	{ 5, 1024LL*1024*1024*1024*1024*1024, "", HN_AUTOSCALE, HN_IEC|HN_B, 4,
 +	  "1 Ei",
 +	  "PR lib/60635: humanize_number(3): exa/exbi issues" },
  };
 =20
  struct hnflags {
 
 --=_aD0stfJJ+WVg8+9bTfy4bTTT5i9m1xYu--

Prev by Date: Re: lib/60635: humanize_number(3): exa/exbi issues
Next by Date: PR/59411 CVS commit: src/sys
Previous by Thread: Re: lib/60635: humanize_number(3): exa/exbi issues
Next by Thread: PR/59411 CVS commit: src/sys
Indexes:

Home | Main Index | Thread Index | Old Index