Import new gnulib.

m4/float_h.m4

@@ -1,5 +1,5 @@
-# float_h.m4 serial 4
-dnl Copyright (C) 2007, 2009, 2010 Free Software Foundation, Inc.
+# float_h.m4 serial 9
+dnl Copyright (C) 2007, 2009-2013 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.
@@ -9,11 +9,90 @@ AC_DEFUN([gl_FLOAT_H],
   AC_REQUIRE([AC_PROG_CC])
   AC_REQUIRE([AC_CANONICAL_HOST])
   FLOAT_H=
+  REPLACE_FLOAT_LDBL=0
   case "$host_os" in
-    beos* | openbsd* | mirbsd*)
+    aix* | beos* | openbsd* | mirbsd* | irix*)
       FLOAT_H=float.h
-      gl_CHECK_NEXT_HEADERS([float.h])
+      ;;
+    freebsd*)
+      case "$host_cpu" in
+changequote(,)dnl
+        i[34567]86 )
+changequote([,])dnl
+          FLOAT_H=float.h
+          ;;
+        x86_64 )
+          # On x86_64 systems, the C compiler may still be generating
+          # 32-bit code.
+          AC_EGREP_CPP([yes],
+            [#if defined __LP64__ || defined __x86_64__ || defined __amd64__
+             yes
+             #endif],
+            [],
+            [FLOAT_H=float.h])
+          ;;
+      esac
+      ;;
+    linux*)
+      case "$host_cpu" in
+        powerpc*)
+          FLOAT_H=float.h
+          ;;
+      esac
       ;;
   esac
+  case "$host_os" in
+    aix* | freebsd* | linux*)
+      if test -n "$FLOAT_H"; then
+        REPLACE_FLOAT_LDBL=1
+      fi
+      ;;
+  esac
+
+  dnl Test against glibc-2.7 Linux/SPARC64 bug.
+  REPLACE_ITOLD=0
+  AC_CACHE_CHECK([whether conversion from 'int' to 'long double' works],
+    [gl_cv_func_itold_works],
+    [
+      AC_RUN_IFELSE(
+        [AC_LANG_SOURCE([[
+int i = -1;
+volatile long double ld;
+int main ()
+{
+  ld += i * 1.0L;
+  if (ld > 0)
+    return 1;
+  return 0;
+}]])],
+        [gl_cv_func_itold_works=yes],
+        [gl_cv_func_itold_works=no],
+        [case "$host" in
+           sparc*-*-linux*)
+             AC_EGREP_CPP([yes],
+               [#if defined __LP64__ || defined __arch64__
+                yes
+                #endif],
+               [gl_cv_func_itold_works="guessing no"],
+               [gl_cv_func_itold_works="guessing yes"])
+             ;;
+           *) gl_cv_func_itold_works="guessing yes" ;;
+         esac
+        ])
+    ])
+  case "$gl_cv_func_itold_works" in
+    *no)
+      REPLACE_ITOLD=1
+      dnl We add the workaround to <float.h> but also to <math.h>,
+      dnl to increase the chances that the fix function gets pulled in.
+      FLOAT_H=float.h
+      ;;
+  esac
+
+  if test -n "$FLOAT_H"; then
+    gl_NEXT_HEADERS([float.h])
+  fi
   AC_SUBST([FLOAT_H])
+  AM_CONDITIONAL([GL_GENERATE_FLOAT_H], [test -n "$FLOAT_H"])
+  AC_SUBST([REPLACE_ITOLD])
 ])