Import Gnulib's `log1p' and `round' modules.

[bpt/guile.git] / m4 / floor.m4

diff --git a/m4/floor.m4 b/m4/floor.m4
new file mode 100644 (file)
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--- /dev/null
+++ b/m4/floor.m4
@@ -0,0 +1,88 @@
+# floor.m4 serial 5
+dnl Copyright (C) 2007, 2009-2011 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_FLOOR],
+[
+  m4_divert_text([DEFAULTS], [gl_floor_required=plain])
+  AC_REQUIRE([gl_MATH_H_DEFAULTS])
+  dnl Test whether floor() can be used without libm.
+  gl_FUNC_FLOOR_LIBS
+  if test "$FLOOR_LIBM" = "?"; then
+    FLOOR_LIBM=
+  fi
+  m4_ifdef([gl_FUNC_FLOOR_IEEE], [
+    if test $gl_floor_required = ieee && test $REPLACE_FLOOR = 0; then
+      AC_CACHE_CHECK([whether floor works according to ISO C 99 with IEC 60559],
+        [gl_cv_func_floor_ieee],
+        [
+          save_LIBS="$LIBS"
+          LIBS="$LIBS $FLOOR_LIBM"
+          AC_RUN_IFELSE(
+            [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+]gl_DOUBLE_MINUS_ZERO_CODE[
+]gl_DOUBLE_SIGNBIT_CODE[
+int main()
+{
+  /* Test whether floor (-0.0) is -0.0.  */
+  if (signbitd (minus_zerod) && !signbitd (floor (minus_zerod)))
+    return 1;
+  return 0;
+}
+            ]])],
+            [gl_cv_func_floor_ieee=yes],
+            [gl_cv_func_floor_ieee=no],
+            [gl_cv_func_floor_ieee="guessing no"])
+          LIBS="$save_LIBS"
+        ])
+      case "$gl_cv_func_floor_ieee" in
+        *yes) ;;
+        *) REPLACE_FLOOR=1 ;;
+      esac
+    fi
+  ])
+  if test $REPLACE_FLOOR = 1; then
+    AC_LIBOBJ([floor])
+    FLOOR_LIBM=
+  fi
+  AC_SUBST([FLOOR_LIBM])
+])
+
+# Determines the libraries needed to get the floor() function.
+# Sets FLOOR_LIBM.
+AC_DEFUN([gl_FUNC_FLOOR_LIBS],
+[
+  gl_CACHE_VAL_SILENT([gl_cv_func_floor_libm], [
+    gl_cv_func_floor_libm=?
+    AC_LINK_IFELSE(
+      [AC_LANG_PROGRAM(
+         [[#ifndef __NO_MATH_INLINES
+           # define __NO_MATH_INLINES 1 /* for glibc */
+           #endif
+           #include <math.h>
+           double x;]],
+         [[x = floor(x);]])],
+      [gl_cv_func_floor_libm=])
+    if test "$gl_cv_func_floor_libm" = "?"; then
+      save_LIBS="$LIBS"
+      LIBS="$LIBS -lm"
+      AC_LINK_IFELSE(
+        [AC_LANG_PROGRAM(
+           [[#ifndef __NO_MATH_INLINES
+             # define __NO_MATH_INLINES 1 /* for glibc */
+             #endif
+             #include <math.h>
+             double x;]],
+           [[x = floor(x);]])],
+        [gl_cv_func_floor_libm="-lm"])
+      LIBS="$save_LIBS"
+    fi
+  ])
+  FLOOR_LIBM="$gl_cv_func_floor_libm"
+])