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-rw-r--r--ChangeLog15
-rw-r--r--doc/posix-functions/sqrtl.texi3
-rw-r--r--lib/math.in.h15
-rw-r--r--m4/math_h.m43
-rw-r--r--m4/sqrtl.m466
-rw-r--r--modules/math1
-rw-r--r--modules/sqrtl12
-rw-r--r--tests/test-sqrtl.c24
8 files changed, 128 insertions, 11 deletions
diff --git a/ChangeLog b/ChangeLog
index e3a0355826..2555d9ed12 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+2012-03-13 Bruno Haible <bruno@clisp.org>
+
+ sqrtl: Bypass broken implementation in OpenBSD 5.1/SPARC.
+ * lib/math.in.h (sqrtl): Replace it if REPLACE_SQRTL is 1.
+ * m4/sqrtl.m4 (gl_FUNC_SQRTL_WORKS): New macro.
+ (gl_FUNC_SQRTL): Invoke it. Set REPLACE_SQRTL to 1 if sqrtl() produces
+ too big rounding errors.
+ * m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize REPLACE_SQRTL.
+ * modules/math (Makefile.am): Substitute REPLACE_SQRTL.
+ * modules/sqrtl (configure.ac): Consider REPLACE_SQRTL.
+ (Depends-on): Update conditions.
+ * tests/test-sqrtl.c (my_ldexpl): New function.
+ (main): Add test of a particular value.
+ * doc/posix-functions/sqrtl.texi: Mention the OpenBSD 5.1/SPARC bug.
+
2012-03-13 Pádraig Brady <P@draigBrady.com>
doc: Update timer_* platform portability notes.
diff --git a/doc/posix-functions/sqrtl.texi b/doc/posix-functions/sqrtl.texi
index 28f4dd063d..738b922e13 100644
--- a/doc/posix-functions/sqrtl.texi
+++ b/doc/posix-functions/sqrtl.texi
@@ -17,6 +17,9 @@ MSVC 9.
@item
This function is not declared on some platforms:
MacOS X 10.3.
+@item
+This function produces very imprecise results on some platforms:
+OpenBSD 5.1/SPARC.
@end itemize
Portability problems not fixed by Gnulib:
diff --git a/lib/math.in.h b/lib/math.in.h
index b530044494..4b2ce87ac2 100644
--- a/lib/math.in.h
+++ b/lib/math.in.h
@@ -1698,11 +1698,20 @@ _GL_WARN_ON_USE (sqrtf, "sqrtf is unportable - "
#endif
#if @GNULIB_SQRTL@
-# if !@HAVE_SQRTL@ || !@HAVE_DECL_SQRTL@
-# undef sqrtl
+# if @REPLACE_SQRTL@
+# if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+# undef sqrtl
+# define sqrtl rpl_sqrtl
+# endif
+_GL_FUNCDECL_RPL (sqrtl, long double, (long double x));
+_GL_CXXALIAS_RPL (sqrtl, long double, (long double x));
+# else
+# if !@HAVE_SQRTL@ || !@HAVE_DECL_SQRTL@
+# undef sqrtl
_GL_FUNCDECL_SYS (sqrtl, long double, (long double x));
-# endif
+# endif
_GL_CXXALIAS_SYS (sqrtl, long double, (long double x));
+# endif
_GL_CXXALIASWARN (sqrtl);
#elif defined GNULIB_POSIXCHECK
# undef sqrtl
diff --git a/m4/math_h.m4 b/m4/math_h.m4
index d48fd97355..ff1654ec7f 100644
--- a/m4/math_h.m4
+++ b/m4/math_h.m4
@@ -1,4 +1,4 @@
-# math_h.m4 serial 103
+# math_h.m4 serial 104
dnl Copyright (C) 2007-2012 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -295,6 +295,7 @@ AC_DEFUN([gl_MATH_H_DEFAULTS],
REPLACE_ROUNDL=0; AC_SUBST([REPLACE_ROUNDL])
REPLACE_SIGNBIT=0; AC_SUBST([REPLACE_SIGNBIT])
REPLACE_SIGNBIT_USING_GCC=0; AC_SUBST([REPLACE_SIGNBIT_USING_GCC])
+ REPLACE_SQRTL=0; AC_SUBST([REPLACE_SQRTL])
REPLACE_TRUNC=0; AC_SUBST([REPLACE_TRUNC])
REPLACE_TRUNCF=0; AC_SUBST([REPLACE_TRUNCF])
REPLACE_TRUNCL=0; AC_SUBST([REPLACE_TRUNCL])
diff --git a/m4/sqrtl.m4 b/m4/sqrtl.m4
index 70de8240b8..9f65c2432a 100644
--- a/m4/sqrtl.m4
+++ b/m4/sqrtl.m4
@@ -1,4 +1,4 @@
-# sqrtl.m4 serial 7
+# sqrtl.m4 serial 8
dnl Copyright (C) 2010-2012 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -58,9 +58,20 @@ AC_DEFUN([gl_FUNC_SQRTL],
dnl Also check whether it's declared.
dnl MacOS X 10.3 has sqrtl() in libc but doesn't declare it in <math.h>.
AC_CHECK_DECL([sqrtl], , [HAVE_DECL_SQRTL=0], [[#include <math.h>]])
+
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $SQRTL_LIBM"
+ gl_FUNC_SQRTL_WORKS
+ LIBS="$save_LIBS"
+ case "$gl_cv_func_sqrtl_works" in
+ *yes) ;;
+ *) REPLACE_SQRTL=1 ;;
+ esac
else
HAVE_DECL_SQRTL=0
HAVE_SQRTL=0
+ fi
+ if test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; then
dnl Find libraries needed to link lib/sqrtl.c.
if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
AC_REQUIRE([gl_FUNC_SQRT])
@@ -94,3 +105,56 @@ AC_DEFUN([gl_FUNC_SQRTL],
fi
AC_SUBST([SQRTL_LIBM])
])
+
+dnl Test whether sqrtl() works.
+dnl On OpenBSD 5.1/SPARC, sqrtl(8.1974099812331540680810141969554806865L) has
+dnl rounding errors that eat up the last 8 to 9 decimal digits.
+AC_DEFUN([gl_FUNC_SQRTL_WORKS],
+[
+ AC_REQUIRE([AC_PROG_CC])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether sqrtl works], [gl_cv_func_sqrtl_works],
+ [
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#include <float.h>
+#include <math.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+long double sqrtl (long double);
+static long double
+my_ldexpl (long double x, int d)
+{
+ for (; d > 0; d--)
+ x *= 2.0L;
+ for (; d < 0; d++)
+ x *= 0.5L;
+ return x;
+}
+volatile long double x;
+volatile long double y;
+long double z;
+int main ()
+{
+ x = 8.1974099812331540680810141969554806865L;
+ y = sqrtl (x);
+ z = y * y - x;
+ z = my_ldexpl (z, LDBL_MANT_DIG);
+ if (z < 0)
+ z = - z;
+ if (z > 100.0L)
+ return 1;
+ return 0;
+}
+]])],
+ [gl_cv_func_sqrtl_works=yes],
+ [gl_cv_func_sqrtl_works=no],
+ [case "$host_os" in
+ osf*) gl_cv_func_sqrtl_works="guessing no";;
+ *) gl_cv_func_sqrtl_works="guessing yes";;
+ esac
+ ])
+ ])
+])
diff --git a/modules/math b/modules/math
index 46d0455a59..51db89e0a6 100644
--- a/modules/math
+++ b/modules/math
@@ -262,6 +262,7 @@ math.h: math.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(
-e 's|@''REPLACE_ROUNDL''@|$(REPLACE_ROUNDL)|g' \
-e 's|@''REPLACE_SIGNBIT''@|$(REPLACE_SIGNBIT)|g' \
-e 's|@''REPLACE_SIGNBIT_USING_GCC''@|$(REPLACE_SIGNBIT_USING_GCC)|g' \
+ -e 's|@''REPLACE_SQRTL''@|$(REPLACE_SQRTL)|g' \
-e 's|@''REPLACE_TRUNC''@|$(REPLACE_TRUNC)|g' \
-e 's|@''REPLACE_TRUNCF''@|$(REPLACE_TRUNCF)|g' \
-e 's|@''REPLACE_TRUNCL''@|$(REPLACE_TRUNCL)|g' \
diff --git a/modules/sqrtl b/modules/sqrtl
index 9bfa38181e..65a91d7c98 100644
--- a/modules/sqrtl
+++ b/modules/sqrtl
@@ -8,15 +8,15 @@ m4/sqrtl.m4
Depends-on:
math
extensions
-sqrt [test $HAVE_SQRTL = 0]
-float [test $HAVE_SQRTL = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0]
-isnanl [test $HAVE_SQRTL = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0]
-frexpl [test $HAVE_SQRTL = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0]
-ldexpl [test $HAVE_SQRTL = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0]
+sqrt [{ test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; }]
+float [{ test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0]
+isnanl [{ test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0]
+frexpl [{ test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0]
+ldexpl [{ test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0]
configure.ac:
gl_FUNC_SQRTL
-if test $HAVE_SQRTL = 0; then
+if test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; then
AC_LIBOBJ([sqrtl])
fi
gl_MATH_MODULE_INDICATOR([sqrtl])
diff --git a/tests/test-sqrtl.c b/tests/test-sqrtl.c
index 23dcfe43ae..c4404f9895 100644
--- a/tests/test-sqrtl.c
+++ b/tests/test-sqrtl.c
@@ -35,6 +35,16 @@ SIGNATURE_CHECK (sqrtl, long double, (long double));
#define RANDOM randoml
#include "test-sqrt.h"
+static long double
+my_ldexpl (long double x, int d)
+{
+ for (; d > 0; d--)
+ x *= 2.0L;
+ for (; d < 0; d++)
+ x *= 0.5L;
+ return x;
+}
+
int
main ()
{
@@ -47,6 +57,20 @@ main ()
y = sqrtl (x);
ASSERT (y >= 0.7745966692L && y <= 0.7745966693L);
+ /* Another particular value. */
+ {
+ long double z;
+ long double err;
+
+ x = 8.1974099812331540680810141969554806865L;
+ y = sqrtl (x);
+ z = y * y - x;
+ err = my_ldexpl (z, LDBL_MANT_DIG);
+ if (err < 0)
+ err = - err;
+ ASSERT (err <= 100.0L);
+ }
+
test_function ();
return 0;
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