Merge commit 'a39d4083cab589d7cd6a13e8a4b8db8875261d75'

[gnulib.git] / m4 / remainder.m4

diff --git a/m4/remainder.m4 b/m4/remainder.m4
index 6cc0001..8a9fee7 100644 (file)
--- a/m4/remainder.m4
+++ b/m4/remainder.m4
@@ -1,11 +1,12 @@
-# remainder.m4 serial 1
-dnl Copyright (C) 2012 Free Software Foundation, Inc.
+# remainder.m4 serial 4
+dnl Copyright (C) 2012-2014 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_REMAINDER],
 [
+  m4_divert_text([DEFAULTS], [gl_remainder_required=plain])
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
 
   dnl Test whether remainder() is declared. On IRIX 5.3 it is not declared.
@@ -50,22 +51,84 @@ AC_DEFUN([gl_FUNC_REMAINDER],
       REMAINDER_LIBM=-lm
     fi
   fi
-  if test $gl_cv_func_remainder_no_libm = no \
-     && test $gl_cv_func_remainder_in_libm = no; then
+  if test $gl_cv_func_remainder_no_libm = yes \
+     || test $gl_cv_func_remainder_in_libm = yes; then
+    :
+    m4_ifdef([gl_FUNC_REMAINDER_IEEE], [
+      if test $gl_remainder_required = ieee && test $REPLACE_REMAINDER = 0; then
+        AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+        AC_CACHE_CHECK([whether remainder works according to ISO C 99 with IEC 60559],
+          [gl_cv_func_remainder_ieee],
+          [
+            save_LIBS="$LIBS"
+            LIBS="$LIBS $REMAINDER_LIBM"
+            AC_RUN_IFELSE(
+              [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+/* Compare two numbers with ==.
+   This is a separate function because IRIX 6.5 "cc -O" miscompiles an
+   'x == x' test.  */
+static int
+numeric_equal (double x, double y)
+{
+  return x == y;
+}
+static double dummy (double x, double y) { return 0; }
+int main (int argc, char *argv[])
+{
+  double (*my_remainder) (double, double) = argc ? remainder : dummy;
+  double f;
+  /* Test remainder(...,0.0).
+     This test fails on OSF/1 5.1.  */
+  f = my_remainder (2.0, 0.0);
+  if (numeric_equal (f, f))
+    return 1;
+  return 0;
+}
+              ]])],
+              [gl_cv_func_remainder_ieee=yes],
+              [gl_cv_func_remainder_ieee=no],
+              [case "$host_os" in
+                         # Guess yes on glibc systems.
+                 *-gnu*) gl_cv_func_remainder_ieee="guessing yes" ;;
+                         # If we don't know, assume the worst.
+                 *)      gl_cv_func_remainder_ieee="guessing no" ;;
+               esac
+              ])
+            LIBS="$save_LIBS"
+          ])
+        case "$gl_cv_func_remainder_ieee" in
+          *yes) ;;
+          *) REPLACE_REMAINDER=1 ;;
+        esac
+      fi
+    ])
+  else
     HAVE_REMAINDER=0
+  fi
+  if test $HAVE_REMAINDER = 0 || test $REPLACE_REMAINDER = 1; then
     dnl Find libraries needed to link lib/remainder.c.
-    AC_REQUIRE([gl_FUNC_ROUND])
-    AC_REQUIRE([gl_FUNC_FMA])
+    AC_REQUIRE([gl_FUNC_FABS])
+    AC_REQUIRE([gl_FUNC_FMOD])
+    AC_REQUIRE([gl_FUNC_ISNAND])
     REMAINDER_LIBM=
-    dnl Append $ROUND_LIBM to REMAINDER_LIBM, avoiding gratuitous duplicates.
+    dnl Append $FABS_LIBM to REMAINDER_LIBM, avoiding gratuitous duplicates.
+    case " $REMAINDER_LIBM " in
+      *" $FABS_LIBM "*) ;;
+      *) REMAINDER_LIBM="$REMAINDER_LIBM $FABS_LIBM" ;;
+    esac
+    dnl Append $FMOD_LIBM to REMAINDER_LIBM, avoiding gratuitous duplicates.
     case " $REMAINDER_LIBM " in
-      *" $ROUND_LIBM "*) ;;
-      *) REMAINDER_LIBM="$REMAINDER_LIBM $ROUND_LIBM" ;;
+      *" $FMOD_LIBM "*) ;;
+      *) REMAINDER_LIBM="$REMAINDER_LIBM $FMOD_LIBM" ;;
     esac
-    dnl Append $FMA_LIBM to REMAINDER_LIBM, avoiding gratuitous duplicates.
+    dnl Append $ISNAND_LIBM to REMAINDER_LIBM, avoiding gratuitous duplicates.
     case " $REMAINDER_LIBM " in
-      *" $FMA_LIBM "*) ;;
-      *) REMAINDER_LIBM="$REMAINDER_LIBM $FMA_LIBM" ;;
+      *" $ISNAND_LIBM "*) ;;
+      *) REMAINDER_LIBM="$REMAINDER_LIBM $ISNAND_LIBM" ;;
     esac
   fi
   AC_SUBST([REMAINDER_LIBM])