Merge commit 'a39d4083cab589d7cd6a13e8a4b8db8875261d75'

[gnulib.git] / m4 / fmodl.m4

diff --git a/m4/fmodl.m4 b/m4/fmodl.m4
index 3207215..e223ae6 100644 (file)
--- a/m4/fmodl.m4
+++ b/m4/fmodl.m4
@@ -1,15 +1,19 @@
-# fmodl.m4 serial 1
-dnl Copyright (C) 2011-2012 Free Software Foundation, Inc.
+# fmodl.m4 serial 5
+dnl Copyright (C) 2011-2014 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_FMODL],
 [
+  m4_divert_text([DEFAULTS], [gl_fmodl_required=plain])
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
   AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
   AC_REQUIRE([gl_FUNC_FMOD])
 
+  dnl Persuade glibc <math.h> to declare fmodl().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Test whether fmodl() is declared.
   dnl AIX 5.1 has fmodl() in libc but doesn't declare it in <math.h>, and the
   dnl function produces NaN results for finite values.
@@ -24,30 +28,100 @@ AC_DEFUN([gl_FUNC_FMODL],
   AC_CHECK_FUNCS([fmodl])
   LIBS="$save_LIBS"
   if test $ac_cv_func_fmodl = yes; then
-    if test $ac_cv_have_decl_fmodl = yes; then
-      FMODL_LIBM="$FMOD_LIBM"
-    else
+    FMODL_LIBM="$FMOD_LIBM"
+    if test $ac_cv_have_decl_fmodl = no; then
       REPLACE_FMODL=1
     fi
+    m4_ifdef([gl_FUNC_FMODL_IEEE], [
+      if test $gl_fmodl_required = ieee && test $REPLACE_FMODL = 0; then
+        AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+        AC_CACHE_CHECK([whether fmodl works according to ISO C 99 with IEC 60559],
+          [gl_cv_func_fmodl_ieee],
+          [
+            save_LIBS="$LIBS"
+            LIBS="$LIBS $FMODL_LIBM"
+            AC_RUN_IFELSE(
+              [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+/* Compare two numbers with ==.
+   This is a separate function because IRIX 6.5 "cc -O" miscompiles an
+   'x == x' test.  */
+static int
+numeric_equal (long double x, long double y)
+{
+  return x == y;
+}
+static long double dummy (long double x, long double y) { return 0; }
+int main (int argc, char *argv[])
+{
+  long double (*my_fmodl) (long double, long double) = argc ? fmodl : dummy;
+  long double f;
+  /* Test fmodl(...,0.0L).
+     This test fails on OSF/1 5.1.  */
+  f = my_fmodl (2.0L, 0.0L);
+  if (numeric_equal (f, f))
+    return 1;
+  return 0;
+}
+              ]])],
+              [gl_cv_func_fmodl_ieee=yes],
+              [gl_cv_func_fmodl_ieee=no],
+              [case "$host_os" in
+                         # Guess yes on glibc systems.
+                 *-gnu*) gl_cv_func_fmodl_ieee="guessing yes" ;;
+                         # If we don't know, assume the worst.
+                 *)      gl_cv_func_fmodl_ieee="guessing no" ;;
+               esac
+              ])
+            LIBS="$save_LIBS"
+          ])
+        case "$gl_cv_func_fmodl_ieee" in
+          *yes) ;;
+          *) REPLACE_FMODL=1 ;;
+        esac
+      fi
+    ])
   else
     HAVE_FMODL=0
   fi
   if test $HAVE_FMODL = 0 || test $REPLACE_FMODL = 1; then
+    dnl Find libraries needed to link lib/fmodl.c.
     if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
       FMODL_LIBM="$FMOD_LIBM"
     else
+      AC_REQUIRE([gl_FUNC_FABSL])
+      AC_REQUIRE([gl_FUNC_FREXPL])
       AC_REQUIRE([gl_FUNC_TRUNCL])
-      AC_REQUIRE([gl_FUNC_FMAL])
+      AC_REQUIRE([gl_FUNC_LDEXPL])
+      AC_REQUIRE([gl_FUNC_ISNANL])
       FMODL_LIBM=
+      dnl Append $FABSL_LIBM to FMODL_LIBM, avoiding gratuitous duplicates.
+      case " $FMODL_LIBM " in
+        *" $FABSL_LIBM "*) ;;
+        *) FMODL_LIBM="$FMODL_LIBM $FABSL_LIBM" ;;
+      esac
+      dnl Append $FREXPL_LIBM to FMODL_LIBM, avoiding gratuitous duplicates.
+      case " $FMODL_LIBM " in
+        *" $FREXPL_LIBM "*) ;;
+        *) FMODL_LIBM="$FMODL_LIBM $FREXPL_LIBM" ;;
+      esac
       dnl Append $TRUNCL_LIBM to FMODL_LIBM, avoiding gratuitous duplicates.
       case " $FMODL_LIBM " in
         *" $TRUNCL_LIBM "*) ;;
         *) FMODL_LIBM="$FMODL_LIBM $TRUNCL_LIBM" ;;
       esac
-      dnl Append $FMAL_LIBM to FMODL_LIBM, avoiding gratuitous duplicates.
+      dnl Append $LDEXPL_LIBM to FMODL_LIBM, avoiding gratuitous duplicates.
+      case " $FMODL_LIBM " in
+        *" $LDEXPL_LIBM "*) ;;
+        *) FMODL_LIBM="$FMODL_LIBM $LDEXPL_LIBM" ;;
+      esac
+      dnl Append $ISNANL_LIBM to FMODL_LIBM, avoiding gratuitous duplicates.
       case " $FMODL_LIBM " in
-        *" $FMAL_LIBM "*) ;;
-        *) FMODL_LIBM="$FMODL_LIBM $FMAL_LIBM" ;;
+        *" $ISNANL_LIBM "*) ;;
+        *) FMODL_LIBM="$FMODL_LIBM $ISNANL_LIBM" ;;
       esac
     fi
   fi