X-Git-Url: https://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fcbrtl.m4;h=dea67e4768c049eb1d1f5d787efe67ae419bf163;hb=da8054d48dc22e1c051db54049e005d51a006e69;hp=3f02abcc30642165f0789aaaedec3d4fb288e6dc;hpb=7eb9ec92d98cf8a79c6bb977d7ba29686bf03be0;p=gnulib.git

diff --git a/m4/cbrtl.m4 b/m4/cbrtl.m4
index 3f02abcc3..dea67e476 100644
--- a/m4/cbrtl.m4
+++ b/m4/cbrtl.m4
@@ -1,15 +1,19 @@
-# cbrtl.m4 serial 1
-dnl Copyright (C) 2012 Free Software Foundation, Inc.
+# cbrtl.m4 serial 5
+dnl Copyright (C) 2012-2013 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_CBRTL],
 [
+  m4_divert_text([DEFAULTS], [gl_cbrtl_required=plain])
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
   AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
   AC_REQUIRE([gl_FUNC_CBRT])
 
+  dnl Persuade glibc <math.h> to declare cbrtl().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Test whether cbrtl() exists. Assume that cbrtl(), if it exists, is
   dnl defined in the same library as cbrt().
   save_LIBS="$LIBS"
@@ -21,9 +25,72 @@ AC_DEFUN([gl_FUNC_CBRTL],
     dnl Also check whether it's declared.
     dnl IRIX 6.5 has cbrtl() in libm but doesn't declare it in <math.h>.
     AC_CHECK_DECL([cbrtl], , [HAVE_DECL_CBRTL=0], [[#include <math.h>]])
+
+    save_LIBS="$LIBS"
+    LIBS="$LIBS $CBRTL_LIBM"
+    gl_FUNC_CBRTL_WORKS
+    LIBS="$save_LIBS"
+    case "$gl_cv_func_cbrtl_works" in
+      *yes) ;;
+      *) REPLACE_CBRTL=1 ;;
+    esac
+
+    m4_ifdef([gl_FUNC_CBRTL_IEEE], [
+      if test $gl_cbrtl_required = ieee && test $REPLACE_CBRTL = 0; then
+        AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+        AC_CACHE_CHECK([whether cbrtl works according to ISO C 99 with IEC 60559],
+          [gl_cv_func_cbrtl_ieee],
+          [
+            save_LIBS="$LIBS"
+            LIBS="$LIBS $CBRTL_LIBM"
+            AC_RUN_IFELSE(
+              [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+]gl_LONG_DOUBLE_MINUS_ZERO_CODE[
+]gl_LONG_DOUBLE_SIGNBIT_CODE[
+static long double dummy (long double x) { return 0; }
+int main (int argc, char *argv[])
+{
+  extern
+  #ifdef __cplusplus
+  "C"
+  #endif
+  long double cbrtl (long double);
+  long double (*my_cbrtl) (long double) = argc ? cbrtl : dummy;
+  long double f;
+  /* Test cbrtl(-0.0).
+     This test fails on IRIX 6.5.  */
+  f = my_cbrtl (minus_zerol);
+  if (!(f == 0.0L) || (signbitl (minus_zerol) && !signbitl (f)))
+    return 1;
+  return 0;
+}
+              ]])],
+              [gl_cv_func_cbrtl_ieee=yes],
+              [gl_cv_func_cbrtl_ieee=no],
+              [case "$host_os" in
+                         # Guess yes on glibc systems.
+                 *-gnu*) gl_cv_func_cbrtl_ieee="guessing yes" ;;
+                         # If we don't know, assume the worst.
+                 *)      gl_cv_func_cbrtl_ieee="guessing no" ;;
+               esac
+              ])
+            LIBS="$save_LIBS"
+          ])
+        case "$gl_cv_func_cbrtl_ieee" in
+          *yes) ;;
+          *) REPLACE_CBRTL=1 ;;
+        esac
+      fi
+    ])
   else
     HAVE_CBRTL=0
     HAVE_DECL_CBRTL=0
+  fi
+  if test $HAVE_CBRTL = 0 || test $REPLACE_CBRTL = 1; then
     dnl Find libraries needed to link lib/cbrtl.c.
     if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
       CBRTL_LIBM="$CBRT_LIBM"
@@ -45,3 +112,40 @@ AC_DEFUN([gl_FUNC_CBRTL],
   fi
   AC_SUBST([CBRTL_LIBM])
 ])
+
+dnl Test whether cbrtl() works.
+dnl On OpenBSD 5.1/SPARC, cbrtl(16.0L) is = 1.2599...
+AC_DEFUN([gl_FUNC_CBRTL_WORKS],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether cbrtl works], [gl_cv_func_cbrtl_works],
+    [
+      AC_RUN_IFELSE(
+        [AC_LANG_SOURCE([[
+#include <math.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+long double cbrtl (long double);
+volatile long double x;
+long double y;
+int main ()
+{
+  x = 16.0L;
+  y = cbrtl (x);
+  if (y < 2.0L)
+    return 1;
+  return 0;
+}
+]])],
+        [gl_cv_func_cbrtl_works=yes],
+        [gl_cv_func_cbrtl_works=no],
+        [case "$host_os" in
+           openbsd*) gl_cv_func_cbrtl_works="guessing no";;
+           *)        gl_cv_func_cbrtl_works="guessing yes";;
+         esac
+        ])
+    ])
+])