[src/trunk]: src/sys/sys Add __MASK(3)

[skrll <skrll%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f0839c56c178
branches:  trunk
changeset: 359773:f0839c56c178
user:      skrll <skrll%NetBSD.org@localhost>
date:      Sat Jan 22 08:58:48 2022 +0000

description:
Add __MASK(3)

__MASK(n): first n bits all set, where __MASK(4) == 0b1111.

diffstat:

 distrib/sets/lists/comp/mi |   5 ++++-
 share/man/man3/Makefile    |   3 ++-
 share/man/man3/bits.3      |  18 ++++++++++++++----
 sys/sys/cdefs.h            |   5 ++++-
 4 files changed, 24 insertions(+), 7 deletions(-)

diffs (128 lines):

diff -r 7f40f5adee5f -r f0839c56c178 distrib/sets/lists/comp/mi
--- a/distrib/sets/lists/comp/mi        Sat Jan 22 08:09:39 2022 +0000
+++ b/distrib/sets/lists/comp/mi        Sat Jan 22 08:58:48 2022 +0000
@@ -1,4 +1,4 @@
-#      $NetBSD: mi,v 1.2409 2022/01/22 08:09:39 pho Exp $
+#      $NetBSD: mi,v 1.2410 2022/01/22 08:58:48 skrll Exp $
 #
 # Note: don't delete entries from here - mark them as "obsolete" instead.
 ./etc/mtree/set.comp                           comp-sys-root
@@ -5851,6 +5851,7 @@
 ./usr/share/man/cat3/__CONCAT.0                        comp-c-catman           .cat
 ./usr/share/man/cat3/__FPTRCAST.0              comp-c-catman           .cat
 ./usr/share/man/cat3/__KERNEL_RCSID.0          comp-c-catman           .cat
+./usr/share/man/cat3/__MASK.0                  comp-c-catman           .cat
 ./usr/share/man/cat3/__RCSID.0                 comp-c-catman           .cat
 ./usr/share/man/cat3/__SHIFTIN.0               comp-c-catman           .cat
 ./usr/share/man/cat3/__SHIFTOUT.0              comp-c-catman           .cat
@@ -14198,6 +14199,7 @@
 ./usr/share/man/html3/__CONCAT.html            comp-c-htmlman          html
 ./usr/share/man/html3/__FPTRCAST.html          comp-c-htmlman          html
 ./usr/share/man/html3/__KERNEL_RCSID.html      comp-c-htmlman          html
+./usr/share/man/html3/__MASK.html              comp-c-htmlman          html
 ./usr/share/man/html3/__RCSID.html             comp-c-htmlman          html
 ./usr/share/man/html3/__SHIFTIN.html           comp-c-htmlman          html
 ./usr/share/man/html3/__SHIFTOUT.html          comp-c-htmlman          html
@@ -22382,6 +22384,7 @@
 ./usr/share/man/man3/__CONCAT.3                        comp-c-man              .man
 ./usr/share/man/man3/__FPTRCAST.3              comp-c-man              .man
 ./usr/share/man/man3/__KERNEL_RCSID.3          comp-c-man              .man
+./usr/share/man/man3/__MASK.3                  comp-c-man              .man
 ./usr/share/man/man3/__RCSID.3                 comp-c-man              .man
 ./usr/share/man/man3/__SHIFTIN.3               comp-c-man              .man
 ./usr/share/man/man3/__SHIFTOUT.3              comp-c-man              .man
diff -r 7f40f5adee5f -r f0839c56c178 share/man/man3/Makefile
--- a/share/man/man3/Makefile   Sat Jan 22 08:09:39 2022 +0000
+++ b/share/man/man3/Makefile   Sat Jan 22 08:58:48 2022 +0000
@@ -1,4 +1,4 @@
-#      $NetBSD: Makefile,v 1.90 2020/01/13 08:25:02 kamil Exp $
+#      $NetBSD: Makefile,v 1.91 2022/01/22 08:58:48 skrll Exp $
 #      @(#)Makefile    8.2 (Berkeley) 12/13/93
 
 MAN=   _DIAGASSERT.3 __CONCAT.3 __FPTRCAST.3 __UNCONST.3 __USE.3 CMSG_DATA.3 \
@@ -47,6 +47,7 @@
        bitstring.3 bit_test.3
 MLINKS+=bits.3 __BIT.3 \
        bits.3 __BITS.3 \
+       bits.3 __MASK.3 \
        bits.3 __SHIFTIN.3 \
        bits.3 __SHIFTOUT.3 \
        bits.3 __SHIFTOUT_MASK.3
diff -r 7f40f5adee5f -r f0839c56c178 share/man/man3/bits.3
--- a/share/man/man3/bits.3     Sat Jan 22 08:09:39 2022 +0000
+++ b/share/man/man3/bits.3     Sat Jan 22 08:58:48 2022 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: bits.3,v 1.20 2022/01/20 07:30:25 skrll Exp $
+.\"    $NetBSD: bits.3,v 1.21 2022/01/22 08:58:48 skrll Exp $
 .\"
 .\" Copyright (c) 2006, 2010 David Young.  All rights reserved.
 .\"
@@ -25,12 +25,13 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd January 20, 2022
+.Dd January 22, 2022
 .Dt BITS 3
 .Os
 .Sh NAME
 .Nm __BIT ,
 .Nm __BITS ,
+.Nm __MASK ,
 .Nm __SHIFTIN ,
 .Nm __SHIFTOUT ,
 .Nm __SHIFTOUT_MASK
@@ -43,6 +44,8 @@
 .Ft uintmax_t
 .Fn __BITS "m" "n"
 .Ft uintmax_t
+.Fn __MASK "n"
+.Ft uintmax_t
 .Fn __SHIFTIN "v" "mask"
 .Ft uintmax_t
 .Fn __SHIFTOUT "v" "mask"
@@ -57,9 +60,10 @@
 the bits in the bitfield.
 .Pp
 Use
-.Fn __BIT
+.Fn __BIT ,
+.Fn __BITS ,
 and
-.Fn __BITS
+.Fn __MASK
 to define bitmasks:
 .Bl -tag -width __BITS -offset indent
 .It Fn __BIT "n"
@@ -77,6 +81,12 @@
 or
 .Fa m No <= Fa n .
 The least significant bit is bit 0.
+.It Fn __MASK "n"
+Return a bitmask with the first
+.Fa n
+bits set. That is, bits 0 through
+.Fa n
+- 1, inclusive, set.
 .El
 .Pp
 .Fn __SHIFTIN ,
diff -r 7f40f5adee5f -r f0839c56c178 sys/sys/cdefs.h
--- a/sys/sys/cdefs.h   Sat Jan 22 08:09:39 2022 +0000
+++ b/sys/sys/cdefs.h   Sat Jan 22 08:58:48 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cdefs.h,v 1.158 2021/12/14 20:12:48 christos Exp $     */
+/*     $NetBSD: cdefs.h,v 1.159 2022/01/22 08:58:48 skrll Exp $        */
 
 /* * Copyright (c) 1991, 1993
  *     The Regents of the University of California.  All rights reserved.
@@ -649,6 +649,9 @@
     (((uintmax_t)(__n) >= NBBY * sizeof(uintmax_t)) ? 0 : \
     ((uintmax_t)1 << (uintmax_t)((__n) & (NBBY * sizeof(uintmax_t) - 1))))
 
+/* __MASK(n): first n bits all set, where __MASK(4) == 0b1111. */
+#define        __MASK(__n)     (__BIT(__n) - 1)
+
 /* Macros for min/max. */
 #define        __MIN(a,b)      ((/*CONSTCOND*/(a)<=(b))?(a):(b))
 #define        __MAX(a,b)      ((/*CONSTCOND*/(a)>(b))?(a):(b))