Move the gcd function to lib/.

6 files changed, 128 insertions, 67 deletions

diff --git a/lib/ChangeLog b/lib/ChangeLog
index 56a9552..03e041a 100644
--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,5 +1,12 @@
 2001-09-02  Bruno Haible  <haible@clisp.cons.org>
 
+	* gcd.h: New file.
+	* gcd.c: New file.
+	* Makefile.am (libnlsut_a_SOURCES): Add gcd.c.
+	(noinst_HEADERS): Add gcd.h.
+
+2001-09-02  Bruno Haible  <haible@clisp.cons.org>
+
 	* pipe.h: Ensure pid_t gets declared.
 	* pipe-bidi.c: Include pipe.h.
 	* pipe-in.c: Likewise.
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 86ea5cc..488ac0a 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -28,13 +28,13 @@ stdbool.h.in \
 gen-lbrkprop.c 3level.h
 
 libnlsut_a_SOURCES = basename.c c-ctype.c concatpath.c findprog.c fstrcmp.c \
-full-write.c getopt.c getopt1.c hash.c linebreak.c localcharset.c mbswidth.c \
-obstack.c pipe-bidi.c pipe-in.c pipe-out.c progname.c safe-read.c \
+full-write.c gcd.c getopt.c getopt1.c hash.c linebreak.c localcharset.c \
+mbswidth.c obstack.c pipe-bidi.c pipe-in.c pipe-out.c progname.c safe-read.c \
 wait-process.c xerror.c xgetcwd.c xmalloc.c xstrdup.c
 
 libnlsut_a_LIBADD = @ALLOCA@ @LIBOBJS@
 
-noinst_HEADERS = c-ctype.h error.h findprog.h fstrcmp.h full-write.h \
+noinst_HEADERS = c-ctype.h error.h findprog.h fstrcmp.h full-write.h gcd.h \
 getline.h getopt.h hash.h lbrkprop.h linebreak.h mbswidth.h obstack.h \
 pathmax.h pipe.h progname.h safe-read.h system.h utf8-ucs4.h utf16-ucs4.h \
 wait-process.h xerror.h
diff --git a/lib/gcd.c b/lib/gcd.c
new file mode 100644
index 0000000..a2dfc52
--- /dev/null
+++ b/lib/gcd.c
@@ -0,0 +1,80 @@
+/* Arithmetic.
+   Copyright (C) 2001 Free Software Foundation, Inc.
+   Written by Bruno Haible <haible@clisp.cons.org>, 2001.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* Specification.  */
+#include "gcd.h"
+
+/* Return the greatest common divisor of a > 0 and b > 0.  */
+unsigned int
+gcd (a, b)
+     unsigned int a;
+     unsigned int b;
+{
+  /* Why no division, as in Euclid's algorithm? Because in Euclid's algorithm
+     the division result floor(a/b) or floor(b/a) is very often = 1 or = 2,
+     and nearly always < 8.  A sequence of a few subtractions and tests is
+     faster than a division.  */
+  /* Why not Euclid's algorithm? Because the two integers can be shifted by 1
+     bit in a single instruction, and the algorithm uses fewer variables than
+     Euclid's algorithm.  */
+
+  unsigned int c = a | b;
+  c = c ^ (c - 1);
+  /* c = largest power of 2 that divides a and b.  */
+
+  if (a & c)
+    {
+      if (b & c)
+	goto odd_odd;
+      else
+	goto odd_even;
+    }
+  else
+    {
+      if (b & c)
+	goto even_odd;
+      else
+	abort ();
+    }
+
+  for (;;)
+    {
+    odd_odd: /* a/c and b/c both odd */
+      if (a == b)
+	break;
+      if (a > b)
+	{
+	  a = a - b;
+	even_odd: /* a/c even, b/c odd */
+	  do
+	    a = a >> 1;
+	  while ((a & c) == 0);
+	}
+      else
+	{
+	  b = b - a;
+	odd_even: /* a/c odd, b/c even */
+	  do
+	    b = b >> 1;
+	  while ((b & c) == 0);
+	}
+    }
+
+  /* a = b */
+  return a;
+}
diff --git a/lib/gcd.h b/lib/gcd.h
new file mode 100644
index 0000000..8fadde2
--- /dev/null
+++ b/lib/gcd.h
@@ -0,0 +1,33 @@
+/* Arithmetic.
+   Copyright (C) 2001 Free Software Foundation, Inc.
+   Written by Bruno Haible <haible@clisp.cons.org>, 2001.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#ifndef _GCD_H
+#define _GCD_H
+
+#ifndef PARAMS
+# if defined (__GNUC__) || __STDC__
+#  define PARAMS(args) args
+# else
+#  define PARAMS(args) ()
+# endif
+#endif
+
+/* Return the greatest common divisor of a > 0 and b > 0.  */
+extern unsigned int gcd PARAMS ((unsigned int a, unsigned int b));
+
+#endif /* _GCD_H */
diff --git a/src/ChangeLog b/src/ChangeLog
index 4c26d42..27c8a5b 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2001-09-02  Bruno Haible  <haible@clisp.cons.org>
+
+	* format-lisp.c (gcd): Remove function. Include "gcd.h" instead.
+
 2001-09-03  Bruno Haible  <haible@clisp.cons.org>
 
 	* xgettext.c (usage): Mention ObjectiveC and Java.
diff --git a/src/format-lisp.c b/src/format-lisp.c
index 482e082..b8fc090 100644
--- a/src/format-lisp.c
+++ b/src/format-lisp.c
@@ -25,6 +25,7 @@
 
 #include "format.h"
 #include "c-ctype.h"
+#include "gcd.h"
 #include "system.h"
 #include "error.h"
 #include "progname.h"
@@ -127,7 +128,6 @@ struct param
 /* Prototypes for local functions.  Needed to ensure compiler checking of
    function argument counts despite of K&R C function definition syntax.  */
 #define union make_union
-static unsigned int gcd PARAMS ((unsigned int a, unsigned int b));
 static void verify_element PARAMS ((const struct format_arg * e));
 static void verify_list PARAMS ((const struct format_arg_list *list));
 static inline void free_element PARAMS ((struct format_arg *element));
@@ -232,69 +232,6 @@ static bool format_check PARAMS ((const lex_pos_ty *pos,
 				  void *msgid_descr, void *msgstr_descr));
 
 
-/* ============================== Arithmetic ============================== */
-
-/* Return the greatest common divisor of a > 0 and b > 0.  */
-static unsigned int
-gcd (a, b)
-     unsigned int a;
-     unsigned int b;
-{
-  /* Why no division, as in Euclid's algorithm? Because in Euclid's algorithm
-     the division result floor(a/b) or floor(b/a) is very often = 1 or = 2,
-     and nearly always < 8.  A sequence of a few subtractions and tests is
-     faster than a division.  */
-  /* Why not Euclid's algorithm? Because the two integers can be shifted by 1
-     bit in a single instruction, and the algorithm uses fewer variables than
-     Euclid's algorithm.  */
-
-  unsigned int c = a | b;
-  c = c ^ (c - 1);
-  /* c = largest power of 2 that divides a and b.  */
-
-  if (a & c)
-    {
-      if (b & c)
-	goto odd_odd;
-      else
-	goto odd_even;
-    }
-  else
-    {
-      if (b & c)
-	goto even_odd;
-      else
-	abort ();
-    }
-
-  for (;;)
-    {
-    odd_odd: /* a/c and b/c both odd */
-      if (a == b)
-	break;
-      if (a > b)
-	{
-	  a = a - b;
-	even_odd: /* a/c even, b/c odd */
-	  do
-	    a = a >> 1;
-	  while ((a & c) == 0);
-	}
-      else
-	{
-	  b = b - a;
-	odd_even: /* a/c odd, b/c even */
-	  do
-	    b = b >> 1;
-	  while ((b & c) == 0);
-	}
-    }
-
-  /* a = b */
-  return a;
-}
-
-
 /* ======================= Verify a format_arg_list ======================= */
 
 /* Verify some invariants.  */