2009-03-18 Yaakov Selkowitz <yselkowitz@users.sourceforge.net>

        * libm/common/s_log2.c: New file.
        * libm/common/sf_log2.c: Ditto.
        * libm/common/Makefile.am: Add s_log2.c and sf_log2.c.
        * libm/common/Makefile.in: Regenerated.
        * libc/include/math.h: Add log2 and log2f function prototypes.

4 files changed, 166 insertions, 25 deletions

diff --git a/newlib/libm/common/Makefile.am b/newlib/libm/common/Makefile.am
index f79a67c55..1369c25bf 100644
--- a/newlib/libm/common/Makefile.am
+++ b/newlib/libm/common/Makefile.am
@@ -8,7 +8,7 @@ src = 	s_finite.c s_copysign.c s_modf.c s_scalbn.c \
 	s_cbrt.c s_exp10.c s_expm1.c s_ilogb.c s_infconst.c \
 	s_infinity.c s_isinf.c s_isinfd.c s_isnan.c s_isnand.c \
 	s_log1p.c s_nan.c s_nextafter.c s_pow10.c \
-	s_rint.c s_logb.c s_matherr.c s_lib_ver.c \
+	s_rint.c s_logb.c s_log2.c s_matherr.c s_lib_ver.c \
 	s_fdim.c s_fma.c s_fmax.c s_fmin.c s_fpclassify.c s_lrint.c \
 	s_lround.c s_nearbyint.c s_remquo.c s_round.c s_scalbln.c \
 	s_signbit.c s_trunc.c
@@ -17,7 +17,7 @@ fsrc =	sf_finite.c sf_copysign.c sf_modf.c sf_scalbn.c \
 	sf_cbrt.c sf_exp10.c sf_expm1.c sf_ilogb.c \
 	sf_infinity.c sf_isinf.c sf_isinff.c sf_isnan.c sf_isnanf.c \
 	sf_log1p.c sf_nan.c sf_nextafter.c sf_pow10.c \
-	sf_rint.c sf_logb.c \
+	sf_rint.c sf_logb.c sf_log2.c \
 	sf_fdim.c sf_fma.c sf_fmax.c sf_fmin.c sf_fpclassify.c sf_lrint.c \
 	sf_lround.c sf_nearbyint.c sf_remquo.c sf_round.c \
 	sf_scalbln.c sf_trunc.c
@@ -94,6 +94,10 @@ slog1p.def: s_log1p.c
 	$(CHEW) < $(srcdir)/s_log1p.c >$@ 2>/dev/null
 	touch stmp-def
 
+slog2.def: s_log2.c
+	$(CHEW) < $(srcdir)/s_log2.c >$@ 2>/dev/null
+	touch stmp-def
+
 smodf.def: s_modf.c
 	$(CHEW) < $(srcdir)/s_modf.c >$@ 2>/dev/null
 	touch stmp-def
diff --git a/newlib/libm/common/Makefile.in b/newlib/libm/common/Makefile.in
index 498b3f3f1..f84166cfb 100644
--- a/newlib/libm/common/Makefile.in
+++ b/newlib/libm/common/Makefile.in
@@ -67,14 +67,14 @@ am__objects_1 = lib_a-s_finite.$(OBJEXT) lib_a-s_copysign.$(OBJEXT) \
 	lib_a-s_log1p.$(OBJEXT) lib_a-s_nan.$(OBJEXT) \
 	lib_a-s_nextafter.$(OBJEXT) lib_a-s_pow10.$(OBJEXT) \
 	lib_a-s_rint.$(OBJEXT) lib_a-s_logb.$(OBJEXT) \
-	lib_a-s_matherr.$(OBJEXT) lib_a-s_lib_ver.$(OBJEXT) \
-	lib_a-s_fdim.$(OBJEXT) lib_a-s_fma.$(OBJEXT) \
-	lib_a-s_fmax.$(OBJEXT) lib_a-s_fmin.$(OBJEXT) \
-	lib_a-s_fpclassify.$(OBJEXT) lib_a-s_lrint.$(OBJEXT) \
-	lib_a-s_lround.$(OBJEXT) lib_a-s_nearbyint.$(OBJEXT) \
-	lib_a-s_remquo.$(OBJEXT) lib_a-s_round.$(OBJEXT) \
-	lib_a-s_scalbln.$(OBJEXT) lib_a-s_signbit.$(OBJEXT) \
-	lib_a-s_trunc.$(OBJEXT)
+	lib_a-s_log2.$(OBJEXT) lib_a-s_matherr.$(OBJEXT) \
+	lib_a-s_lib_ver.$(OBJEXT) lib_a-s_fdim.$(OBJEXT) \
+	lib_a-s_fma.$(OBJEXT) lib_a-s_fmax.$(OBJEXT) \
+	lib_a-s_fmin.$(OBJEXT) lib_a-s_fpclassify.$(OBJEXT) \
+	lib_a-s_lrint.$(OBJEXT) lib_a-s_lround.$(OBJEXT) \
+	lib_a-s_nearbyint.$(OBJEXT) lib_a-s_remquo.$(OBJEXT) \
+	lib_a-s_round.$(OBJEXT) lib_a-s_scalbln.$(OBJEXT) \
+	lib_a-s_signbit.$(OBJEXT) lib_a-s_trunc.$(OBJEXT)
 am__objects_2 = lib_a-sf_finite.$(OBJEXT) lib_a-sf_copysign.$(OBJEXT) \
 	lib_a-sf_modf.$(OBJEXT) lib_a-sf_scalbn.$(OBJEXT) \
 	lib_a-sf_cbrt.$(OBJEXT) lib_a-sf_exp10.$(OBJEXT) \
@@ -84,13 +84,13 @@ am__objects_2 = lib_a-sf_finite.$(OBJEXT) lib_a-sf_copysign.$(OBJEXT) \
 	lib_a-sf_isnanf.$(OBJEXT) lib_a-sf_log1p.$(OBJEXT) \
 	lib_a-sf_nan.$(OBJEXT) lib_a-sf_nextafter.$(OBJEXT) \
 	lib_a-sf_pow10.$(OBJEXT) lib_a-sf_rint.$(OBJEXT) \
-	lib_a-sf_logb.$(OBJEXT) lib_a-sf_fdim.$(OBJEXT) \
-	lib_a-sf_fma.$(OBJEXT) lib_a-sf_fmax.$(OBJEXT) \
-	lib_a-sf_fmin.$(OBJEXT) lib_a-sf_fpclassify.$(OBJEXT) \
-	lib_a-sf_lrint.$(OBJEXT) lib_a-sf_lround.$(OBJEXT) \
-	lib_a-sf_nearbyint.$(OBJEXT) lib_a-sf_remquo.$(OBJEXT) \
-	lib_a-sf_round.$(OBJEXT) lib_a-sf_scalbln.$(OBJEXT) \
-	lib_a-sf_trunc.$(OBJEXT)
+	lib_a-sf_logb.$(OBJEXT) lib_a-sf_log2.$(OBJEXT) \
+	lib_a-sf_fdim.$(OBJEXT) lib_a-sf_fma.$(OBJEXT) \
+	lib_a-sf_fmax.$(OBJEXT) lib_a-sf_fmin.$(OBJEXT) \
+	lib_a-sf_fpclassify.$(OBJEXT) lib_a-sf_lrint.$(OBJEXT) \
+	lib_a-sf_lround.$(OBJEXT) lib_a-sf_nearbyint.$(OBJEXT) \
+	lib_a-sf_remquo.$(OBJEXT) lib_a-sf_round.$(OBJEXT) \
+	lib_a-sf_scalbln.$(OBJEXT) lib_a-sf_trunc.$(OBJEXT)
 @USE_LIBTOOL_FALSE@am_lib_a_OBJECTS = $(am__objects_1) \
 @USE_LIBTOOL_FALSE@	$(am__objects_2)
 lib_a_OBJECTS = $(am_lib_a_OBJECTS)
@@ -100,17 +100,17 @@ am__objects_3 = s_finite.lo s_copysign.lo s_modf.lo s_scalbn.lo \
 	s_cbrt.lo s_exp10.lo s_expm1.lo s_ilogb.lo s_infconst.lo \
 	s_infinity.lo s_isinf.lo s_isinfd.lo s_isnan.lo s_isnand.lo \
 	s_log1p.lo s_nan.lo s_nextafter.lo s_pow10.lo s_rint.lo \
-	s_logb.lo s_matherr.lo s_lib_ver.lo s_fdim.lo s_fma.lo \
-	s_fmax.lo s_fmin.lo s_fpclassify.lo s_lrint.lo s_lround.lo \
-	s_nearbyint.lo s_remquo.lo s_round.lo s_scalbln.lo \
+	s_logb.lo s_log2.lo s_matherr.lo s_lib_ver.lo s_fdim.lo \
+	s_fma.lo s_fmax.lo s_fmin.lo s_fpclassify.lo s_lrint.lo \
+	s_lround.lo s_nearbyint.lo s_remquo.lo s_round.lo s_scalbln.lo \
 	s_signbit.lo s_trunc.lo
 am__objects_4 = sf_finite.lo sf_copysign.lo sf_modf.lo sf_scalbn.lo \
 	sf_cbrt.lo sf_exp10.lo sf_expm1.lo sf_ilogb.lo sf_infinity.lo \
 	sf_isinf.lo sf_isinff.lo sf_isnan.lo sf_isnanf.lo sf_log1p.lo \
 	sf_nan.lo sf_nextafter.lo sf_pow10.lo sf_rint.lo sf_logb.lo \
-	sf_fdim.lo sf_fma.lo sf_fmax.lo sf_fmin.lo sf_fpclassify.lo \
-	sf_lrint.lo sf_lround.lo sf_nearbyint.lo sf_remquo.lo \
-	sf_round.lo sf_scalbln.lo sf_trunc.lo
+	sf_log2.lo sf_fdim.lo sf_fma.lo sf_fmax.lo sf_fmin.lo \
+	sf_fpclassify.lo sf_lrint.lo sf_lround.lo sf_nearbyint.lo \
+	sf_remquo.lo sf_round.lo sf_scalbln.lo sf_trunc.lo
 @USE_LIBTOOL_TRUE@am_libcommon_la_OBJECTS = $(am__objects_3) \
 @USE_LIBTOOL_TRUE@	$(am__objects_4)
 libcommon_la_OBJECTS = $(am_libcommon_la_OBJECTS)
@@ -278,7 +278,7 @@ src = s_finite.c s_copysign.c s_modf.c s_scalbn.c \
 	s_cbrt.c s_exp10.c s_expm1.c s_ilogb.c s_infconst.c \
 	s_infinity.c s_isinf.c s_isinfd.c s_isnan.c s_isnand.c \
 	s_log1p.c s_nan.c s_nextafter.c s_pow10.c \
-	s_rint.c s_logb.c s_matherr.c s_lib_ver.c \
+	s_rint.c s_logb.c s_log2.c s_matherr.c s_lib_ver.c \
 	s_fdim.c s_fma.c s_fmax.c s_fmin.c s_fpclassify.c s_lrint.c \
 	s_lround.c s_nearbyint.c s_remquo.c s_round.c s_scalbln.c \
 	s_signbit.c s_trunc.c
@@ -287,7 +287,7 @@ fsrc = sf_finite.c sf_copysign.c sf_modf.c sf_scalbn.c \
 	sf_cbrt.c sf_exp10.c sf_expm1.c sf_ilogb.c \
 	sf_infinity.c sf_isinf.c sf_isinff.c sf_isnan.c sf_isnanf.c \
 	sf_log1p.c sf_nan.c sf_nextafter.c sf_pow10.c \
-	sf_rint.c sf_logb.c \
+	sf_rint.c sf_logb.c sf_log2.c \
 	sf_fdim.c sf_fma.c sf_fmax.c sf_fmin.c sf_fpclassify.c sf_lrint.c \
 	sf_lround.c sf_nearbyint.c sf_remquo.c sf_round.c \
 	sf_scalbln.c sf_trunc.c
@@ -495,6 +495,12 @@ lib_a-s_logb.o: s_logb.c
 lib_a-s_logb.obj: s_logb.c
 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-s_logb.obj `if test -f 's_logb.c'; then $(CYGPATH_W) 's_logb.c'; else $(CYGPATH_W) '$(srcdir)/s_logb.c'; fi`
 
+lib_a-s_log2.o: s_log2.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-s_log2.o `test -f 's_log2.c' || echo '$(srcdir)/'`s_log2.c
+
+lib_a-s_log2.obj: s_log2.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-s_log2.obj `if test -f 's_log2.c'; then $(CYGPATH_W) 's_log2.c'; else $(CYGPATH_W) '$(srcdir)/s_log2.c'; fi`
+
 lib_a-s_matherr.o: s_matherr.c
 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-s_matherr.o `test -f 's_matherr.c' || echo '$(srcdir)/'`s_matherr.c
 
@@ -699,6 +705,12 @@ lib_a-sf_logb.o: sf_logb.c
 lib_a-sf_logb.obj: sf_logb.c
 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-sf_logb.obj `if test -f 'sf_logb.c'; then $(CYGPATH_W) 'sf_logb.c'; else $(CYGPATH_W) '$(srcdir)/sf_logb.c'; fi`
 
+lib_a-sf_log2.o: sf_log2.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-sf_log2.o `test -f 'sf_log2.c' || echo '$(srcdir)/'`sf_log2.c
+
+lib_a-sf_log2.obj: sf_log2.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-sf_log2.obj `if test -f 'sf_log2.c'; then $(CYGPATH_W) 'sf_log2.c'; else $(CYGPATH_W) '$(srcdir)/sf_log2.c'; fi`
+
 lib_a-sf_fdim.o: sf_fdim.c
 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-sf_fdim.o `test -f 'sf_fdim.c' || echo '$(srcdir)/'`sf_fdim.c
 
@@ -970,6 +982,10 @@ slog1p.def: s_log1p.c
 	$(CHEW) < $(srcdir)/s_log1p.c >$@ 2>/dev/null
 	touch stmp-def
 
+slog2.def: s_log2.c
+	$(CHEW) < $(srcdir)/s_log2.c >$@ 2>/dev/null
+	touch stmp-def
+
 smodf.def: s_modf.c
 	$(CHEW) < $(srcdir)/s_modf.c >$@ 2>/dev/null
 	touch stmp-def
diff --git a/newlib/libm/common/s_log2.c b/newlib/libm/common/s_log2.c
new file mode 100644
index 000000000..4683960eb
--- /dev/null
+++ b/newlib/libm/common/s_log2.c
@@ -0,0 +1,73 @@
+/* @(#)s_log2.c 5.1 93/09/24 */
+/* Modification from s_exp10.c Yaakov Selkowitz 2009.  */
+
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+/*
+FUNCTION
+	<<log2>>, <<log2f>>---base 2 logarithm
+INDEX
+	log2
+INDEX
+	log2f
+
+ANSI_SYNOPSIS
+	#include <math.h>
+	double log2(double <[x]>);
+	float log2f(float <[x]>);
+
+TRAD_SYNOPSIS
+	#include <math.h>
+	double log2(<[x]>);
+	double <[x]>;
+
+	float log2f(<[x]>);
+	float <[x]>;
+
+DESCRIPTION
+	<<log2>> returns the base 2 logarithm of <[x]>.
+
+	<<log2f>> is identical, save that it takes and returns <<float>> values.
+
+RETURNS
+	On success, <<log2>> and <<log2f>> return the calculated value.
+	If the result underflows, the returned value is <<0>>.  If the
+	result overflows, the returned value is <<HUGE_VAL>>.  In
+	either case, <<errno>> is set to <<ERANGE>>.
+
+PORTABILITY
+	<<log2>> and <<log2f>> are required by ISO/IEC 9899:1999 and the
+	System V Interface Definition (Issue 6).
+*/
+
+/*
+ * wrapper log2(x)
+ */
+
+#include "fdlibm.h"
+#include <errno.h>
+#include <math.h>
+#undef log2
+
+#ifndef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+	double log2(double x)		/* wrapper log2 */
+#else
+	double log2(x)			/* wrapper log2 */
+	double x;
+#endif
+{
+  return (log(x) / M_LOG2_E);
+}
+
+#endif /* defined(_DOUBLE_IS_32BITS) */
diff --git a/newlib/libm/common/sf_log2.c b/newlib/libm/common/sf_log2.c
new file mode 100644
index 000000000..eb8863c9f
--- /dev/null
+++ b/newlib/libm/common/sf_log2.c
@@ -0,0 +1,48 @@
+/* sf_log2.c -- float version of s_log2.c.
+ * Modification of sf_exp10.c by Yaakov Selkowitz 2009.
+ */
+
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice 
+ * is preserved.
+ * ====================================================
+ */
+
+/* 
+ * wrapper log2f(x)
+ */
+
+#include "fdlibm.h"
+#include <errno.h>
+#include <math.h>
+#undef log2
+#undef log2f
+
+#ifdef __STDC__
+	float log2f(float x)		/* wrapper log2f */
+#else
+	float log2f(x)			/* wrapper log2f */
+	float x;
+#endif
+{
+  return (logf(x) / (float) M_LOG2_E);
+}
+
+#ifdef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+	double log2(double x)
+#else
+	double log2(x)
+	double x;
+#endif
+{
+	return (double) log2f((float) x);
+}
+
+#endif /* defined(_DOUBLE_IS_32BITS) */