1 files changed, 19 insertions, 2 deletions
diff --git a/configure.ac b/configure.ac
index ffbcfbc..375dd69 100644
--- a/configure.ac
+++ b/configure.ac
@@ -122,18 +122,35 @@ esac
 # Checks for header files.
 AC_HEADER_STDC
 AC_CHECK_HEADERS([complex.h locale.h inttypes.h stdint.h limits.h unistd.h sys/time.h])
+AC_HEADER_TIME
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
 AC_TYPE_SIZE_T
-AC_HEADER_TIME
 
 # Checks for libraries.
-AC_CHECK_LIB([m], [creal])
+AC_CHECK_HEADERS(
+   [complex.h],
+   [
+   AC_MSG_CHECKING(whether creal and cimag can be used without libm)
+   AC_LINK_IFELSE(
+      [AC_LANG_PROGRAM(
+         [[#include <complex.h>]],
+         [[complex double x = 1.0 + 2.0 * I; return (creal (x) + cimag (x));]]
+      )],
+      [AC_MSG_RESULT([yes])],
+      [
+         AC_MSG_RESULT([no])
+         AC_CHECK_LIB([m], [creal])
+      ]
+      )
+   ]
+   )
 
 AC_CHECK_LIB([gmp], [__gmpz_init],
              [LIBS="-lgmp $LIBS"],
              [AC_MSG_ERROR([libgmp not found or uses a different ABI.])])
+
 AC_MSG_CHECKING(for MPFR)
 LIBS="-lmpfr $LIBS"
 AC_LINK_IFELSE(