remainder: Support for MSVC.

* lib/math.in.h (remainder): New declaration.
* lib/remainder.c: New file.
* m4/remainder.m4: New file.
* modules/remainder (Files): Add lib/remainder.c, m4/remainder.m4.
(Depends-on): Add math, round, fma.
(configure.ac): Use results of gl_FUNC_REMAINDER.
* m4/math_h.m4 (gl_MATH_H): Test whether remainder is declared.
(gl_MATH_H_DEFAULTS): Initialize GNULIB_REMAINDER, HAVE_REMAINDER,
HAVE_DECL_REMAINDER.
* modules/math (Makefile.am): Substitute GNULIB_REMAINDER,
HAVE_REMAINDER, HAVE_DECL_REMAINDER.
* tests/test-math-c++.cc: Check the declaration of remainder.
* doc/posix-functions/remainder.texi: Mention that the MSVC and IRIX 5
problems are fixed.

1 files changed, 72 insertions, 0 deletions

diff --git a/m4/remainder.m4 b/m4/remainder.m4
new file mode 100644
index 0000000000..6cc0001b5f
--- /dev/null
+++ b/m4/remainder.m4
@@ -0,0 +1,72 @@
+# remainder.m4 serial 1
+dnl Copyright (C) 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,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_REMAINDER],
+[
+  AC_REQUIRE([gl_MATH_H_DEFAULTS])
+
+  dnl Test whether remainder() is declared. On IRIX 5.3 it is not declared.
+  AC_CHECK_DECL([remainder], , [HAVE_DECL_REMAINDER=0], [[#include <math.h>]])
+
+  REMAINDER_LIBM=
+  AC_CACHE_CHECK([whether remainder() can be used without linking with libm],
+    [gl_cv_func_remainder_no_libm],
+    [
+      AC_LINK_IFELSE(
+        [AC_LANG_PROGRAM(
+           [[#ifndef __NO_MATH_INLINES
+             # define __NO_MATH_INLINES 1 /* for glibc */
+             #endif
+             #include <math.h>
+             double x;
+             double y;]],
+           [[return remainder (x, y) > 1;]])],
+        [gl_cv_func_remainder_no_libm=yes],
+        [gl_cv_func_remainder_no_libm=no])
+    ])
+  if test $gl_cv_func_remainder_no_libm = no; then
+    AC_CACHE_CHECK([whether remainder() can be used with libm],
+      [gl_cv_func_remainder_in_libm],
+      [
+        save_LIBS="$LIBS"
+        LIBS="$LIBS -lm"
+        AC_LINK_IFELSE(
+          [AC_LANG_PROGRAM(
+             [[#ifndef __NO_MATH_INLINES
+               # define __NO_MATH_INLINES 1 /* for glibc */
+               #endif
+               #include <math.h>
+               double x;
+               double y;]],
+             [[return remainder (x, y) > 1;]])],
+          [gl_cv_func_remainder_in_libm=yes],
+          [gl_cv_func_remainder_in_libm=no])
+        LIBS="$save_LIBS"
+      ])
+    if test $gl_cv_func_remainder_in_libm = yes; then
+      REMAINDER_LIBM=-lm
+    fi
+  fi
+  if test $gl_cv_func_remainder_no_libm = no \
+     && test $gl_cv_func_remainder_in_libm = no; then
+    HAVE_REMAINDER=0
+    dnl Find libraries needed to link lib/remainder.c.
+    AC_REQUIRE([gl_FUNC_ROUND])
+    AC_REQUIRE([gl_FUNC_FMA])
+    REMAINDER_LIBM=
+    dnl Append $ROUND_LIBM to REMAINDER_LIBM, avoiding gratuitous duplicates.
+    case " $REMAINDER_LIBM " in
+      *" $ROUND_LIBM "*) ;;
+      *) REMAINDER_LIBM="$REMAINDER_LIBM $ROUND_LIBM" ;;
+    esac
+    dnl Append $FMA_LIBM to REMAINDER_LIBM, avoiding gratuitous duplicates.
+    case " $REMAINDER_LIBM " in
+      *" $FMA_LIBM "*) ;;
+      *) REMAINDER_LIBM="$REMAINDER_LIBM $FMA_LIBM" ;;
+    esac
+  fi
+  AC_SUBST([REMAINDER_LIBM])
+])