verify: new macro 'assume'

[gnulib.git] / m4 / ceill.m4

diff --git a/m4/ceill.m4 b/m4/ceill.m4
index 4bf9caa..e26c1b0 100644 (file)
--- a/m4/ceill.m4
+++ b/m4/ceill.m4
@@ -1,16 +1,20 @@
-# ceill.m4 serial 3
-dnl Copyright (C) 2007 Free Software Foundation, Inc.
+# ceill.m4 serial 14
+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.
 
 AC_DEFUN([gl_FUNC_CEILL],
 [
+  m4_divert_text([DEFAULTS], [gl_ceill_required=plain])
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
+  AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
+
   dnl Persuade glibc <math.h> to declare ceill().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Test whether ceill() is declared.
-  AC_CHECK_DECLS([ceill], , , [#include <math.h>])
+  AC_CHECK_DECLS([ceill], , , [[#include <math.h>]])
   if test "$ac_cv_have_decl_ceill" = yes; then
     dnl Test whether ceill() can be used without libm.
     gl_FUNC_CEILL_LIBS
@@ -19,14 +23,61 @@ AC_DEFUN([gl_FUNC_CEILL],
       dnl libm.so, but not in the libm.so that the compiler uses.
       REPLACE_CEILL=1
     fi
+    m4_ifdef([gl_FUNC_CEILL_IEEE], [
+      if test $gl_ceill_required = ieee && test $REPLACE_CEILL = 0; then
+        AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+        AC_CACHE_CHECK([whether ceill works according to ISO C 99 with IEC 60559],
+          [gl_cv_func_ceill_ieee],
+          [
+            save_LIBS="$LIBS"
+            LIBS="$LIBS $CEILL_LIBM"
+            AC_RUN_IFELSE(
+              [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+]gl_LONG_DOUBLE_MINUS_ZERO_CODE[
+]gl_LONG_DOUBLE_SIGNBIT_CODE[
+static long double dummy (long double f) { return 0; }
+int main (int argc, char *argv[])
+{
+  long double (*my_ceill) (long double) = argc ? ceill : dummy;
+  /* Test whether ceill (-0.3L) is -0.0L.  */
+  if (signbitl (minus_zerol) && !signbitl (my_ceill (-0.3L)))
+    return 1;
+  return 0;
+}
+              ]])],
+              [gl_cv_func_ceill_ieee=yes],
+              [gl_cv_func_ceill_ieee=no],
+              [case "$host_os" in
+                         # Guess yes on glibc systems.
+                 *-gnu*) gl_cv_func_ceill_ieee="guessing yes" ;;
+                         # If we don't know, assume the worst.
+                 *)      gl_cv_func_ceill_ieee="guessing no" ;;
+               esac
+              ])
+            LIBS="$save_LIBS"
+          ])
+        case "$gl_cv_func_ceill_ieee" in
+          *yes) ;;
+          *) REPLACE_CEILL=1 ;;
+        esac
+      fi
+    ])
   else
-    REPLACE_CEILL=1
+    HAVE_DECL_CEILL=0
   fi
-  if test $REPLACE_CEILL = 1; then
-    AC_LIBOBJ([ceill])
-    CEILL_LIBM=
+  if test $HAVE_DECL_CEILL = 0 || test $REPLACE_CEILL = 1; then
+    dnl Find libraries needed to link lib/ceill.c.
+    if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
+      AC_REQUIRE([gl_FUNC_CEIL])
+      CEILL_LIBM="$CEIL_LIBM"
+    else
+      CEILL_LIBM=
+    fi
   fi
-  AC_SUBST([REPLACE_CEILL])
   AC_SUBST([CEILL_LIBM])
 ])
 
@@ -34,29 +85,33 @@ AC_DEFUN([gl_FUNC_CEILL],
 # Sets CEILL_LIBM.
 AC_DEFUN([gl_FUNC_CEILL_LIBS],
 [
-  AC_CACHE_VAL([gl_func_ceill_libm], [
-    gl_func_ceill_libm=?
-    AC_TRY_LINK([
-       #ifndef __NO_MATH_INLINES
-       # define __NO_MATH_INLINES 1 /* for glibc */
-       #endif
-       #include <math.h>
-       long double x;],
-      [x = ceill(x);],
-      [gl_func_ceill_libm=])
-    if test "$gl_func_ceill_libm" = "?"; then
+  gl_CACHE_VAL_SILENT([gl_cv_func_ceill_libm], [
+    gl_cv_func_ceill_libm=?
+    AC_LINK_IFELSE(
+      [AC_LANG_PROGRAM(
+         [[#ifndef __NO_MATH_INLINES
+           # define __NO_MATH_INLINES 1 /* for glibc */
+           #endif
+           #include <math.h>
+           long double (*funcptr) (long double) = ceill;
+           long double x;]],
+         [[x = funcptr(x) + ceill(x);]])],
+      [gl_cv_func_ceill_libm=])
+    if test "$gl_cv_func_ceill_libm" = "?"; then
       save_LIBS="$LIBS"
       LIBS="$LIBS -lm"
-      AC_TRY_LINK([
-         #ifndef __NO_MATH_INLINES
-         # define __NO_MATH_INLINES 1 /* for glibc */
-         #endif
-         #include <math.h>
-         long double x;],
-        [x = ceill(x);],
-        [gl_func_ceill_libm="-lm"])
+      AC_LINK_IFELSE(
+        [AC_LANG_PROGRAM(
+           [[#ifndef __NO_MATH_INLINES
+             # define __NO_MATH_INLINES 1 /* for glibc */
+             #endif
+             #include <math.h>
+             long double (*funcptr) (long double) = ceill;
+             long double x;]],
+           [[x = funcptr(x) + ceill(x);]])],
+        [gl_cv_func_ceill_libm="-lm"])
       LIBS="$save_LIBS"
     fi
   ])
-  CEILL_LIBM="$gl_func_ceill_libm"
+  CEILL_LIBM="$gl_cv_func_ceill_libm"
 ])