diff --git a/CHANGES b/CHANGES
index 3baf397..cb93ce0 100644
--- a/CHANGES
+++ b/CHANGES
@@ -140,6 +140,13 @@
   * fixed a leak in _div() (Thanx Tassilo v. Parsival!)
   * put _div() into XS, making division slightly faster for small numbers
   * put leak.pl and leaktest into MANIFEST for later checking
+2005-01-01 v1.17 Tels 5182 tests
+  * use XSLoader instead of DynaLoader to save a tiny amount of memory
+  * take over tests from Math::BigInt v1.74
+  * require Math::BigInt v1.74
+  * simplify sub code in XS (left-over artifact from v1.16)
+  * fix a leak in _zeros()
+  * _zeros() is now much faster for odd numbers (O(1) vs. O(N*N))
 
 Please send me test-reports, your experiences with this and your ideas - I love
 to hear about my work!
diff --git a/GMP.xs b/GMP.xs
index 2f96c52..9916c91 100644
--- a/GMP.xs
+++ b/GMP.xs
@@ -151,6 +151,10 @@ _num(Class, n)
 
 ##############################################################################
 # _zeros() - return number of trailing zeros (in decimal form)
+# This is costly, since it needs O(N*N) to convert the number to decimal,
+# even though for most cases the number does not have many trailing zeros.
+# For numbers longer than X digits (10?) we could divide repeatable by 1e5
+# or something and see if we get zeros.
 
 int
 _zeros(Class,n)
@@ -163,30 +167,37 @@ _zeros(Class,n)
     char *buf_end;
 
   CODE:
-    /* len is always >= 1, and might be off (greater) by one than real len */
-    len = mpz_sizeinbase(*n, 10);
-    TEMP = newSV(len);			/* alloc len +1 bytes */
-    SvPOK_on(TEMP);			/* make an PV */
-    buf = SvPVX(TEMP);			/* get ptr to storage */ 
-    buf_end = buf + len - 1;		/* end of storage (-1)*/
-    mpz_get_str(buf, 10, *n);		/* convert to decimal string */
-    RETVAL = 0;
-    if (*buf_end == 0)
-      {
-      buf_end--;			/* ptr to last real digit */
-      len --;				/* got one shorter than expected */
-      }
-    if (len > 1)			/* '0' has not trailing zeross! */
+    /* odd numbers can not have trailing zeros */
+    RETVAL = 1 - mpz_tstbit(*n,0);
+
+    if (RETVAL != 0)			/* was even */
       {
-      while (len-- > 0)
+      /* len is always >= 1, and might be off (greater) by one than real len */
+      len = mpz_sizeinbase(*n, 10);
+      TEMP = newSV(len);		/* alloc len +1 bytes */
+      SvPOK_on(TEMP);			/* make an PV */
+      buf = SvPVX(TEMP);		/* get ptr to storage */ 
+      buf_end = buf + len - 1;		/* end of storage (-1)*/
+      mpz_get_str(buf, 10, *n);		/* convert to decimal string */
+      RETVAL = 0;
+      if (*buf_end == 0)		/* points to terminating zero? */
         {
-        if (*buf_end-- != '0')
-  	  {
-          break;
-	  }
-        RETVAL++;
+        buf_end--;			/* ptr to last real digit */
+        len --;				/* got one shorter than expected */
         }
-      }
+      if (len > 1)			/* '0' has not trailing zeross! */
+        {
+        while (len-- > 0)		/* actually, we should hit a nonzero */
+          {				/* before the end */
+          if (*buf_end-- != '0')
+	    {
+	    break;
+	    }
+          RETVAL++;
+          }
+        }
+       SvREFCNT_dec(TEMP);		/* Bumpersticker: Free Temp! */
+     } /* end if n was even */
   OUTPUT:
     RETVAL
 
@@ -359,19 +370,13 @@ _sub(Class,x,y, ...)
   PREINIT:
         mpz_t* TEMP;
         mpz_t* TEMP_1;
-        mpz_t* TEMP_2;
   PPCODE:
     GMP_GET_ARGS_0_1;	/* (TEMP, TEMP_1) = (x,y)  */
     if ( items == 4 && SvTRUE(ST(3)) ) 
       {
-      /* return new(y - x) */ 
-      /* need to create TEMP_2 or it will ssegfault */
-      TEMP_2 = malloc (sizeof(mpz_t)); mpz_init(*TEMP_2);
-
-      mpz_sub(*TEMP_2, *TEMP, *TEMP_1);
-
-      PUSHs(sv_setref_pv(sv_newmortal(), "Math::BigInt::GMP", (void*)TEMP_2)); 
-      /*PUSHs(sv_setref_pv(y, "Math::BigInt::GMP", (void*)TEMP_2)); */ 
+      /* y -= x */ 
+      mpz_sub(*TEMP_1, *TEMP, *TEMP_1);
+      PUSHs( y );
       }
     else
       {
diff --git a/META.yml b/META.yml
index 3b6394b..ae72393 100644
--- a/META.yml
+++ b/META.yml
@@ -1,11 +1,11 @@
 --- #YAML:1.0
 name: Math-BigInt-GMP
-version: 1.16
+version: 1.17
 version_from: lib/Math/BigInt/GMP.pm
 license: perl
 distribution_type: module
-generated_by: Math-BigInt-GMP version 1.16
+generated_by: Math-BigInt-GMP version 1.17
 installdirs: site
 requires:
-  Math::BigFloat: 1.47
-  Math::BigInt: 1.73
+  Math::BigInt: 1.74
+  XSLoader: 0.02
diff --git a/Makefile.PL b/Makefile.PL
index 0b0f51d..5ac308b 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -31,8 +31,8 @@ WriteMakefile(
     'NAME'		=> 'Math::BigInt::GMP',
     'VERSION_FROM'	=> 'lib/Math/BigInt/GMP.pm', # finds $VERSION
     'PREREQ_PM'		=> {
-				Math::BigInt => 1.73,
-				Math::BigFloat => 1.47,
+				Math::BigInt => 1.74,
+				XSLoader => 0.02,
 			   }, 
     'LIBS'		=> ['-lgmp'], # e.g., '-lm'
     'DEFINE'		=> '', # e.g., '-DHAVE_SOMETHING'
diff --git a/NEW b/NEW
index 052da82..b6d57fc 100644
--- a/NEW
+++ b/NEW
@@ -1,18 +1,27 @@
 
 Changes between the last and this version:
 
-v1.16:
-  * fixed a leak in _div() and simplified it (Thanx Tassilo v. Parseval)
-  * moved the _div() code to XS to make it a bit faster
-  * put leak.pl and leaktest into MANIFEST for later checking
+v1.17:
+  * use XSLoader instead of DynaLoader to save a tiny amount of memory
+  * take over tests from Math::BigInt v1.74
+  * require Math::BigInt v1.74
+  * simplify sub code in XS (left-over artifact from v1.16)
+  * fix a leak in _zeros()
+  * _zeros() is now much faster for odd numbers (O(1) vs. O(N*N))
 
 #############################################################################
 
-v1.15:
- 221 / 444:  5 wallclock secs ( 5.20 usr +  0.01 sys =  5.21 CPU) @ 18940/s (n=98679)
- 444 / 221:  6 wallclock secs ( 5.20 usr +  0.01 sys =  5.21 CPU) @ 19108/s (n=99555)
-
 v1.16:
- 221 / 444:  6 wallclock secs ( 5.24 usr +  0.01 sys =  5.25 CPU) @ 20957/s (n=110026)
- 444 / 221:  5 wallclock secs ( 5.28 usr +  0.00 sys =  5.28 CPU) @ 21231/s (n=112102)
+
+Benchmark: running zeros(1.0x1000), zeros(123), zeros(1x1000) for at least 5 CPU seconds...
+zeros(1.0x1000):  5s (5.02 usr +  0.15 sys =  5.17 CPU) @  14179/s (n=73309)
+zeros(123):  	  5s (5.19 usr +  0.11 sys =  5.30 CPU) @ 253584/s (n=1344000)
+zeros(1x1000):    5s (5.06 usr +  0.17 sys =  5.23 CPU) @  14106/s (n=73777)
+
+
+v1.17:
+Benchmark: running zeros(1.0x1000), zeros(123), zeros(1x1000) for at least 5 CPU seconds...
+zeros(1.0x1000):  5s (5.06 usr +  0.15 sys =  5.21 CPU) @  14160/s (n=73777)
+zeros(123):  	  5s (5.27 usr +  0.01 sys =  5.28 CPU) @ 299044/s (n=1578957)
+zeros(1x1000):    5s (5.21 usr +  0.01 sys =  5.22 CPU) @ 302482/s (n=1578957)
 
diff --git a/SIGNATURE b/SIGNATURE
index 52a2237..c1fc9cf 100644
--- a/SIGNATURE
+++ b/SIGNATURE
@@ -1,12 +1,12 @@
 This file contains message digests of all files listed in MANIFEST,
-signed via the Module::Signature module, version 0.41.
+signed via the Module::Signature module, version 0.42.
 
 To verify the content in this distribution, first make sure you have
 Module::Signature installed, then type:
 
     % cpansign -v
 
-It would check each file's integrity, as well as the signature's
+It will check each file's integrity, as well as the signature's
 validity.  If "==> Signature verified OK! <==" is not displayed,
 the distribution may already have been compromised, and you should
 not run its Makefile.PL or Build.PL.
@@ -14,35 +14,35 @@ not run its Makefile.PL or Build.PL.
 -----BEGIN PGP SIGNED MESSAGE-----
 
 SHA1 70d6187d0152848c922dc4360fa6dd3a3dc35c62 BUGS
-SHA1 3743ce85e7e98c882bd05ec9eebcfb31ff453815 CHANGES
+SHA1 10ba246d1dbff89a3905428d6f76f42aef36579a CHANGES
 SHA1 dda5ca4f413031e9efcaa1600461d5e2adaa3a40 CREDITS
-SHA1 636480140c61a18f193b0178dc9809c295d9456a GMP.xs
+SHA1 c6b4374d7e911bd399534af9fa5ceb8c90dc6485 GMP.xs
 SHA1 1c219a49ee07891ca39de3f89ce4bbe02549af82 INSTALL
 SHA1 d6a6c30ee6d9ba6b9afab8bbf6a25e1b23c744e0 LICENSE
 SHA1 6cd50151e6eab24927bce91ec062e6d71724ce63 MANIFEST
-SHA1 9c0c8cf77b1ce503893fba602c9ea48cb1d996b9 META.yml
-SHA1 185af48c59491c5e3351c6d9950c3565de74005a Makefile.PL
-SHA1 704f02fad759cc0d99558352f5a7cfb7d8c11b1e NEW
+SHA1 8b0a5a75c4530c61658e4af1cd76420270023e19 META.yml
+SHA1 83262bb7cc34f4016ed89005e3b0d93438963f31 Makefile.PL
+SHA1 2be04f1ccd8a14a7e00e99ce661a47e579f9f02f NEW
 SHA1 e9de29b6e5e9a5e446231b5b12b644f6ed2caafc README
-SHA1 e4fd0b099ed6ef332c72cbf85719a7cf1bd2dc6a TODO
+SHA1 200ade10e14449652ac59d0c8a9569cf29645cbd TODO
 SHA1 fd48d0d8750eb949e485d8136b5b424fe73e9775 build/README
-SHA1 c93694211f8ba09c49ae69b5f3fd4d957bd26f62 build/leak.pl
+SHA1 7bcc4113830721ad6e37a1ea79df94a6987c836d build/leak.pl
 SHA1 ac25bda8a6eb9058a9e42a8943c3e11b9fed88dc build/leaktest
-SHA1 bed207cfb72446fcb746c8d438538b6801a181fd lib/Math/BigInt/GMP.pm
-SHA1 7704eb924e8a297edafa95c5075df502bbc2f14a t/bigfltpm.inc
-SHA1 3287807111be40445e3f8ed5cb1f738996e2b18d t/bigfltpm.t
-SHA1 b0f41f0025528cfea909c9a212c2e377ee3d9243 t/bigintg.t
-SHA1 43b2f324aa16df6865272c192bcab9f25bf7008e t/bigintpm.inc
+SHA1 103f5b902922eba6550271837d8d64d6c40d73d7 lib/Math/BigInt/GMP.pm
+SHA1 57a416650fede5f54aa295e5cd133022a0b9efdd t/bigfltpm.inc
+SHA1 ba0b4085ef17b06a733d7ee26cb5b54ecf4c6094 t/bigfltpm.t
+SHA1 d552991e5df86d3f04b6928c97efe2653fc776d2 t/bigintg.t
+SHA1 aaaea1e9f34d1dfe090911863e5289f85f83ed46 t/bigintpm.inc
 SHA1 6dfbf7bc6601b23073204e9c104d3b68213c93ab t/bigintpm.t
 SHA1 f7aad87c0a30330d474f4fb45f6d1953d6701d2f typemap
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.2.4 (GNU/Linux)
 
-iQEVAwUBQboC9XcLPEOTuEwVAQFPLQf+Olfms17l/g4dhwcRpRLtaAm525xWEtiV
-ARQnCf/xIYfhmDR4deih71aDX6PXjRjihukU+OtPIMdE6MyHUUbzvNqGa0waPIor
-O+eOqZlZnyjJLvFGKZXJJtFF39M0ZSzmrMh9wuYvRzQhdKNXgqCju20Ni9puw6IA
-tD+V7Y0I5FkXJOCewy8NECoXnQjlcSAiWHZRsByDkJSLA6pBtoQUXuzN73D8I1P/
-JEOuQTQ0ZlF+kFs9wSShOoYYc16OS/EGcBWHw8F8jdzENErmUZ/RP7E9E4fMewey
-0MnJ9V2gRHu5Qe8oaoQs8UcaqrWOE5QG/bhW7rcXCVRL4RxNXv0iTw==
-=GgRM
+iQEVAwUBQdbBZXcLPEOTuEwVAQGaAwf8DE9+TD70VMuSB8qPkutFHacs2Z1ztUGf
+pqNMNtKi/Y6W7gY0zyQbp7nqwX8oR2Dcx5ULi1UuIM3MzIaDlB/se0ThEqsd+No4
+a9pjBxqnQ3zDisFCqtsEWsEmvBYu7JUH2y4ZSe46p2qfm/UYGFBXzjm9PXXpVQyn
+JU/0GxsQrhfZBnEIKT4KbPzDKp1oPLw0gf41+Zmh6clix4hp5i0zUNycwSX9nUWV
+KNVpO41KgMDjZURTRazFbZgz+DgIymvdgp8yCTNv5DGLTfhNpS0c0hj6EyVmXnTQ
+iiX+YLRUkwr2yLfKwLN4p2kk4KO7rL9oA9M9AHS/y8/cqvidUiXuCQ==
+=bjyF
 -----END PGP SIGNATURE-----
diff --git a/TODO b/TODO
index f9f41d9..9f7c8f4 100644
--- a/TODO
+++ b/TODO
@@ -1,7 +1,6 @@
 
 * _lsft() and _rsft() could probably be a bit more optimized
 * move _log_int() to XS
-* move sub() and div() completely to XS ?
 * _digit() and _len() could be more optimized
 * _zeros() could be more optimized (divide by 1e5, check for == 0?)
 * replace all malloc() with New() and all free() with Savefree()?
diff --git a/build/leak.pl b/build/leak.pl
index 275e44d..1cbe60c 100644
--- a/build/leak.pl
+++ b/build/leak.pl
@@ -29,11 +29,12 @@
   [ sub { my $z = $x; $z %= $y; 1; }, '%=' ],
   [ sub { my $z = $x; $z /= $y; 1; }, '/=' ],
   [ sub { my ($q,$r) = $x->copy()->bdiv($y); 1; }, '(q,r) = x / y' ],
+  [ sub { $x->_trailing_zeros(); }, '_zeros(x)' ],			# needs an even number!
  )
   {
   my $handle;
   my $count = Devel::Leak::NoteSV($handle);
-  for (1..10) { &{$do->[0]}; }
+  for (1..13) { &{$do->[0]}; }
   print "$do->[1] leaked ", Devel::Leak::CheckSV($handle) - $count, " things\n";
   }
 
diff --git a/lib/Math/BigInt/GMP.pm b/lib/Math/BigInt/GMP.pm
index af67c6a..3a3f414 100644
--- a/lib/Math/BigInt/GMP.pm
+++ b/lib/Math/BigInt/GMP.pm
@@ -7,14 +7,12 @@ use strict;
 use 5.005;
 # use warnings; # dont use warnings for older Perls
 
-require Exporter;
-require DynaLoader;
+use vars qw/$VERSION/;
 
-use vars qw/@ISA $VERSION/;
-@ISA = qw(Exporter DynaLoader);
-$VERSION = '1.16';
+$VERSION = '1.17';
 
-bootstrap Math::BigInt::GMP $VERSION;
+use XSLoader;
+XSLoader::load "Math::BigInt::GMP", $VERSION;
 
 sub import { }			# catch and throw away
 sub api_version() { 1; }	# we are compatible with MBI v1.70 and up
diff --git a/t/bigfltpm.inc b/t/bigfltpm.inc
index 131e453..5f27a8b 100644
--- a/t/bigfltpm.inc
+++ b/t/bigfltpm.inc
@@ -4,6 +4,8 @@ ok ($class->config()->{lib},$CL);
 
 use strict;
 
+my $z;
+
 while (<DATA>)
   {
   chomp;
@@ -87,7 +89,27 @@ while (<DATA>)
     else
       {
       $try .= "\$y = $class->new(\"$args[1]\");";
-      if ($f eq "fcmp") {
+      
+      if ($f eq "bgcd")
+        {
+        if (defined $args[2])
+          {
+          $try .= " \$z = $class->new(\"$args[2]\"); ";
+          }
+        $try .= "$class\::bgcd(\$x, \$y";
+        $try .= ", \$z" if (defined $args[2]);
+        $try .= " );";
+        }
+      elsif ($f eq "blcm")
+        {
+        if (defined $args[2])
+          {
+          $try .= " \$z = $class->new(\"$args[2]\"); ";
+          }
+        $try .= "$class\::blcm(\$x, \$y";
+        $try .= ", \$z" if (defined $args[2]);
+        $try .= " );";
+      } elsif ($f eq "fcmp") {
         $try .= '$x <=> $y;';
       } elsif ($f eq "facmp") {
         $try .= '$x->facmp($y);';
@@ -115,6 +137,7 @@ while (<DATA>)
     }
     # print "# Trying: '$try'\n";
     $ans1 = eval $try;
+    print "# Error: $@\n" if $@;
     if ($ans =~ m|^/(.*)$|)
       {
       my $pat = $1;
@@ -337,6 +360,42 @@ sub ok_undef
   }
 
 __DATA__
+&bgcd
+inf:12:NaN
+-inf:12:NaN
+12:inf:NaN
+12:-inf:NaN
+inf:inf:NaN
+inf:-inf:NaN
+-inf:-inf:NaN
+abc:abc:NaN
+abc:+0:NaN
++0:abc:NaN
++0:+0:0
++0:+1:1
++1:+0:1
++1:+1:1
++2:+3:1
++3:+2:1
+-3:+2:1
+-3:-2:1
+-144:-60:12
+144:-60:12
+144:60:12
+100:625:25
+4096:81:1
+1034:804:2
+27:90:56:1
+27:90:54:9
+&blcm
+abc:abc:NaN
+abc:+0:NaN
++0:abc:NaN
++0:+0:NaN
++1:+0:0
++0:+1:0
++27:+90:270
++1034:+804:415668
 $div_scale = 40;
 &flog
 0::NaN
@@ -1479,7 +1538,7 @@ abc:0
 1200:1
 -1200:1
 &is_positive
-0:1
+0:0
 1:1
 -1:0
 -123:0
diff --git a/t/bigfltpm.t b/t/bigfltpm.t
index 60926bc..c32a12e 100755
--- a/t/bigfltpm.t
+++ b/t/bigfltpm.t
@@ -9,7 +9,7 @@ BEGIN
   unshift @INC, '../lib'; 	# for running manually
   unshift @INC, '../blib/arch';
   chdir 't' if -d 't';
-  plan tests => 1924;
+  plan tests => 1992;
   }
 
 use Math::BigInt lib => 'GMP';
diff --git a/t/bigintg.t b/t/bigintg.t
index 5ca2055..c403964 100755
--- a/t/bigintg.t
+++ b/t/bigintg.t
@@ -9,7 +9,7 @@ BEGIN
   chdir 't' if -d 't';
   unshift @INC, '../lib';		# for running manually
   unshift @INC, '../blib/arch';		# for running manually
-  plan tests => 286;
+  plan tests => 288;
   }
 
 use Math::BigInt::GMP;
@@ -154,6 +154,8 @@ foreach (qw/ 1 12 123 1234 12345 123456 1234567 12345678 123456789/)
 $x = $C->_new("1256000000"); ok ($C->_zeros($x),6);
 $x = $C->_new("152"); ok ($C->_zeros($x),0);
 $x = $C->_new("123000"); ok ($C->_zeros($x),3); 
+$x = $C->_new("123001"); ok ($C->_zeros($x),0); 
+$x = $C->_new("1"); ok ($C->_zeros($x),0); 
 $x = $C->_new("0"); ok ($C->_zeros($x),0); 
 
 # _lsft, _rsft
diff --git a/t/bigintpm.inc b/t/bigintpm.inc
index 6453879..4a8a663 100644
--- a/t/bigintpm.inc
+++ b/t/bigintpm.inc
@@ -778,7 +778,7 @@ inf:inf:NaN
 -inf:1
 NaNneg:0
 &is_positive
-0:1
+0:0
 -1:0
 1:1
 +inf:1