1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
Open jobs for finishing GNU libc:
---------------------------------
Status: January 1997
If you have time and talent to take over any of the jobs below please
contact <bug-glibc@prep.ai.mit.edu>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[ 1] Port to new platforms or test current version on formerly supported
platforms.
**** See http://www.gnu.org/software/libc/porting.html for more details.
[ 2] Test compliance with standards. If you have access to recent
standards (IEEE, ISO, ANSI, X/Open, ...) and/or test suites you
could do some checks as the goal is to be compliant with all
standards if they do not contradict each other.
[ 3] The IMHO opinion most important task is to write a more complete
test suite. We cannot get too many people working on this. It is
not difficult to write a test, find a definition of the function
which I normally can provide, if necessary, and start writing tests
to test for compliance. Beside this, take a look at the sources
and write tests which in total test as many paths of execution as
possible.
[ 4] Write translations for the GNU libc message for the so far
unsupported languages. GNU libc is fully internationalized and
users can immediately benefit from this.
Take a look at the matrix in
ftp://prep.ai.mit.edu/pub/gnu/ABOUT-NLS
for the current status (of course better use a mirror of prep).
[ 5] Write wordexp() function; this is described in POSIX.2, the
header <wordexp.h> already exists.
Implementation idea: use some functions from bash.
**** Somebody is working on this. Help may or may not be appreciated.
[ 6] Write `long double' versions of the math functions. This should be
done in collaboration with the NetBSD and FreeBSD people.
The libm is in fact fdlibm (not the same as in Linux libc).
**** Partly done. But we need someone with numerical experiences for
the rest.
[ 7] Several math functions have to be written:
- exp2
- log2
each with float, double, and long double arguments. Writing these
functions should be possible when following the implementation of
the existing exp/log functions for other bases.
Beside this most of the complex math functions which are new in
ISO C 9X. gcc already has support for numbers of complex type so the
implementation should be possible today. I mention here the names
and the way to write them (argument is z = x + iy):
- cexp(z) = e^x (cos y + i sin y)
- sin(z) = 1/(2i) (e^(iz) - e^-(iz)) = sin(x) cosh(y) + i cos(x) sinh(y)
- cos(z) = 1/2 (e^(iz) + e^-(iz)) = cos(x) cosh(y) - i sin(x) sinh(y)
- tan(z) = 1/i (e^(iz) - e^-(iz))/(e^(iz) + e^-(iz))
- cot(z) = i (e^(iz) + e^-(iz))/(e^(iz) - e^-(iz))
- asin(z) = -i ln(iz + sqrt(1-z^2))
- acos(z) = -i ln(z + sqrt(z^2-1))
- atan(z) = 1/(2i) ln((1+iz)/(1-iz))
- acot(z) = -1/(2i) ln((iz+1)/(iz-1))
- sinh(z) = 1/2 (e^z - e^-z)
- cosh(z) = 1/2 (e^z + e^-z)
- tanh(z) = (e^z - e^-z)/(e^z + e^-z)
- coth(z) = (e^z + e^-z)/(e^z - e^-z)
All functions should we written with all the parallelism in mind.
And assembler versions are highly expreciated since, e.g., the ix87
FPU provides an `fsincos' instructions which is certainly useful for
the `sin' function. The implementations for the normal math functions
shows other optimization techniques.
[ 8] If you enjoy assembler programming (as I do --drepper :-) you might
be interested in writing optimized versions for some functions.
Especially the string handling functions can be optimized a lot.
Take a look at
Faster String Functions
Henry Spencer, University of Toronto
Usenix Winter '92, pp. 419--428
or just ask. Currently mostly i?86 and Alpha optimized versions
exist. Please ask before working on this to avoid duplicate
work.
[ 9] Write nftw() function. Perhaps it might be good to reimplement the
ftw() function as well to share most of the code.
**** Almost done!
[10] Write AVL-tree based tsearch() et.al. functions. Currently only
a very simple algorithm is used.
There is a public domain version but using this would cause problems
with the assignment.
[11] Extend regex and/or rx to work with wide characters and complete
implementation of character class and collation class handling.
It is planed to do a complete rewrite.
[12] Write access function for netmasks, bootparams, and automount
databases for nss_files and nss_db module.
The functions should be embedded in the nss scheme. This is not
hard and not all services must be supported at once.
[13] Rewrite utmp/wtmp functions to use database functions. This is much
better than the normal flat file format.
**** There are plans for a new approach to this problem. Please contact
bug-glibc@prep.ai.mit.edu before starting to work.)
[14] Several more or less small functions have to be written:
+ tcgetid() and waitid() from XPG4.2
+ grantpt(), ptsname(), unlockpt() from XPG4.2
+ getdate() from XPG4.2
+ fmtmsg() from SVID
More information are available on request.
[15] We need to write a library for on-the-fly transformation of streams
of text. In fact, this would be a recode-library (you know, GNU recode).
This is needed in several places in the GNU libc and I already have
rather concrete plans but so far no possibility to start this.
|
