diff options
Diffstat (limited to 'm4/truncf.m4')
| -rw-r--r-- | m4/truncf.m4 | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/m4/truncf.m4 b/m4/truncf.m4 new file mode 100644 index 0000000000..7de15fe2a4 --- /dev/null +++ b/m4/truncf.m4 @@ -0,0 +1,48 @@ +# truncf.m4 serial 1 +dnl Copyright (C) 2007 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_TRUNCF], +[ + AC_REQUIRE([gl_MATH_H_DEFAULTS]) + dnl Persuade glibc <math.h> to declare truncf(). + AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) + dnl Test whether truncf() is declared. + AC_CHECK_DECLS([truncf], , , [#include <math.h>]) + if test "$ac_cv_have_decl_truncf" = yes; then + dnl Test whether truncf() can be used without libm. + TRUNCF_LIBM=? + AC_TRY_LINK([ + #ifndef __NO_MATH_INLINES + # define __NO_MATH_INLINES 1 /* for glibc */ + #endif + #include <math.h> + float x;], + [x = truncf(x);], + [TRUNCF_LIBM=]) + if test "$TRUNCF_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> + float x;], + [x = truncf(x);], + [TRUNCF_LIBM="-lm"]) + LIBS="$save_LIBS" + fi + if test "$TRUNCF_LIBM" = "?"; then + TRUNCF_LIBM= + fi + else + HAVE_DECL_TRUNCF=0 + AC_LIBOBJ([truncf]) + TRUNCF_LIBM= + fi + AC_SUBST([HAVE_DECL_TRUNCF]) + AC_SUBST([TRUNCF_LIBM]) +]) |