configure: don't bother to run checks which can be done at the compile time.

Don't check for sizeof of various types, this can be done at the compile time.
GCC optimizes away these checks, so the actual code is the same.

diff --git a/configure.ac b/configure.ac
index 75a644bef1862e4d27c7af386ef234e6463ea045..576a72bb46cf364fc0adb85f4543ce2bf74871dd 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -71,12 +71,6 @@ AM_PROG_LIBTOOL
 AM_PROG_LEX
 AC_PROG_YACC
 
-dnl Check for data types which are needed by the hash function 
-dnl (golden_ratio_hash).
-AC_CHECK_SIZEOF(int)
-AC_CHECK_SIZEOF(long)
-AC_CHECK_SIZEOF(long long)
-AC_CHECK_SIZEOF(void *)
 
 dnl Switch to C++ language mode for the following libraries and headers.
 AC_LANG([C++])
@@ -84,6 +78,10 @@ AC_LANG([C++])
 dnl Make sure all the necessary standard headers are installed on the system.
 GINAC_STD_CXX_HEADERS
 
+dnl Check for data types which are needed by the hash function 
+dnl (golden_ratio_hash).
+AC_CHECK_TYPE(long long)
+
 dnl Check for stuff needed for building the GiNaC interactive shell (ginsh).
 AC_CHECK_HEADERS(unistd.h)
 GINAC_HAVE_RUSAGE

diff --git a/ginac/utils.h b/ginac/utils.h
index eaa9a723ac0a6d5db1533954976f5958a19bbabc..3c293ea8c5e2e3f7b42391e701f780d3e064acdd 100644 (file)
--- a/ginac/utils.h
+++ b/ginac/utils.h
@@ -81,24 +81,26 @@ inline unsigned golden_ratio_hash(p_int n)
 {
        // This function works much better when fast arithmetic with at
        // least 64 significant bits is available.
-#if SIZEOF_LONG >= 8
+       if (sizeof(long) >= 8) {
        // So 'long' has 64 bits.  Excellent!  We prefer it because it might be
        // more efficient than 'long long'.
        unsigned long l = n * 0x4f1bbcddUL;
        return (unsigned)l;
-#elif SIZEOF_LONG_LONG >= 8
+       }
+#ifdef HAVE_LONG_LONG
+       else if (sizeof(long long) >= 8) {
        // This requires 'long long' (or an equivalent 64 bit type)---which is,
        // unfortunately, not ANSI-C++-compliant.
        // (Yet C99 demands it, which is reason for hope.)
        unsigned long long l = n * 0x4f1bbcddULL;
        return (unsigned)l;
-#else
+       }
+#endif
        // Without a type with 64 significant bits do the multiplication manually
        // by splitting n up into the lower and upper two bytes.
        const unsigned n0 = (n & 0x0000ffffU);
        const unsigned n1 = (n & 0xffff0000U) >> 16;
        return (n0 * 0x0000bcddU) + ((n1 * 0x0000bcddU + n0 * 0x00004f1bU) << 16);
-#endif
 }
 
 /* Compute the sign of a permutation of a container, with and without an