Math::BigInt v1.67 released

Message-Id: <200312121847.49039@bloodgate.com>

p4raw-id: //depot/perl@21882

7 files changed, 56 insertions, 16 deletions

diff --git a/lib/Math/BigInt/Calc.pm b/lib/Math/BigInt/Calc.pm
index 6db1a62bd0..02770e22e1 100644
--- a/lib/Math/BigInt/Calc.pm
+++ b/lib/Math/BigInt/Calc.pm
@@ -1351,38 +1351,48 @@ sub _log_int
   if ($cmp == 0)
     {
     splice (@$x,1); $x->[0] = 1;
-    return $x;
+    return ($x,1)
     }
   # X < BASE
   if ($cmp < 0)
     {
     splice (@$x,1); $x->[0] = 0;
-    return $x;
+    return ($x,undef);
     }
 
   # this trial multiplication is very fast, even for large counts (like for
   # 2 ** 1024, since this still requires only 1024 very fast steps
   # (multiplication of a large number by a very small number is very fast))
   my $x_org = _copy($c,$x);		# preserve x
-  splice(@$x,1); $x->[0] = 0;		# keep ref to $x
+  splice(@$x,1); $x->[0] = 1;		# keep ref to $x
+
+  # simple loop that increments $x by two in each step, possible overstepping
+  # the real result by one
 
   # use a loop that keeps $x as scalar as long as possible (this is faster)
-  my $trial = _copy($c,$base); my $count = 0; my $a;
-  while (($a = _acmp($x,$trial,$x_org) <= 0) && $count < $BASE)
+  my $trial = _copy($c,$base); my $a;
+  my $base_mul = _mul($c, _copy($c,$base), $base);
+
+  while (($a = _acmp($x,$trial,$x_org)) < 0)
     {
-    _mul($c,$trial,$base); $count++;
+    _mul($c,$trial,$base_mul); _add($c, $x, [2]);
     }
-  if ($a <= 0)
+
+  my $exact = 1;
+  if ($a > 0)
     {
-    # not done yet?
-    $x->[0] = $count;
-    while (_acmp($x,$trial,$x_org) <= 0)
+    # overstepped the result
+    _dec($c, $x);
+    _div($c,$trial,$base);
+    $a = _acmp($x,$trial,$x_org);
+    if ($a > 0)
       {
-      _mul($c,$trial,$base); _inc($c,$x);
+      _dec($c, $x);
       }
+    $exact = 0 if $a != 0;
     }
   
-  $x;				# return result
+  ($x,$exact);				# return result
   }
 
 # for debugging:
@@ -1978,6 +1988,10 @@ slow) fallback routines to emulate these:
 	_modpow		return modulus of power ($x ** $y) % $z
 	_log_int(X,N)	calculate integer log() of X in base N
 			X >= 0, N >= 0 (return undef for NaN)
+			returns (RESULT, EXACT) where EXACT is:
+			 1     : result is exactly RESULT
+			 0     : result was truncated to RESULT
+			 undef : unknown whether result is exactly RESULT
 
 Input strings come in as unsigned but with prefix (i.e. as '123', '0xabc'
 or '0b1101').
diff --git a/lib/Math/BigInt/t/bare_mbi.t b/lib/Math/BigInt/t/bare_mbi.t
index 6bcc6bd266..0af4c42742 100644
--- a/lib/Math/BigInt/t/bare_mbi.t
+++ b/lib/Math/BigInt/t/bare_mbi.t
@@ -26,7 +26,7 @@ BEGIN
     }
   print "# INC = @INC\n";
 
-  plan tests => 2728;
+  plan tests => 2760;
   }
 
 use Math::BigInt lib => 'BareCalc';
diff --git a/lib/Math/BigInt/t/bigintpm.inc b/lib/Math/BigInt/t/bigintpm.inc
index 332f575211..db52553c92 100644
--- a/lib/Math/BigInt/t/bigintpm.inc
+++ b/lib/Math/BigInt/t/bigintpm.inc
@@ -718,6 +718,22 @@ inf:inf:NaN
 15625:5:6
 15626:5:6
 15624:5:5
+1000:10:3
+10000:10:4
+100000:10:5
+1000000:10:6
+10000000:10:7
+100000000:10:8
+8916100448256:12:12
+8916100448257:12:12
+8916100448255:12:11
+2251799813685248:8:17
+72057594037927936:2:56
+144115188075855872:2:57
+288230376151711744:2:58
+576460752303423488:2:59
+4096:2:12
+1329227995784915872903807060280344576:2:120
 # $x == $base => result 1
 3:3:1
 # $x < $base => result 0 ($base ** 0 <= $x)
diff --git a/lib/Math/BigInt/t/bigintpm.t b/lib/Math/BigInt/t/bigintpm.t
index b541aae606..d4e0772d7d 100755
--- a/lib/Math/BigInt/t/bigintpm.t
+++ b/lib/Math/BigInt/t/bigintpm.t
@@ -10,7 +10,7 @@ BEGIN
   my $location = $0; $location =~ s/bigintpm.t//;
   unshift @INC, $location; # to locate the testing files
   chdir 't' if -d 't';
-  plan tests => 2728;
+  plan tests => 2760;
   }
 
 use Math::BigInt;
diff --git a/lib/Math/BigInt/t/downgrade.t b/lib/Math/BigInt/t/downgrade.t
index 0208a56bc3..25d672c50f 100644
--- a/lib/Math/BigInt/t/downgrade.t
+++ b/lib/Math/BigInt/t/downgrade.t
@@ -10,7 +10,7 @@ BEGIN
   my $location = $0; $location =~ s/downgrade.t//;
   unshift @INC, $location; # to locate the testing files
   chdir 't' if -d 't';
-  plan tests => 12;
+  plan tests => 15;
   }
 
 use Math::BigInt upgrade => 'Math::BigFloat';
@@ -36,6 +36,12 @@ ok (ref(Math::BigFloat->new('10')),'Math::BigInt');
 ok (ref(Math::BigFloat->new('-10')),'Math::BigInt');
 ok (ref(Math::BigFloat->new('-10.0E1')),'Math::BigInt');
 
+# bug until v1.67:
+ok (Math::BigFloat->new('0.2E0'), '0.2');
+ok (Math::BigFloat->new('0.2E1'), '2');
+# until v1.67 resulted in 200:
+ok (Math::BigFloat->new('0.2E2'), '20');
+
 # disable, otherwise it screws calculations
 Math::BigFloat->upgrade(undef);
 ok (Math::BigFloat->upgrade()||'','');
diff --git a/lib/Math/BigInt/t/fallback.t b/lib/Math/BigInt/t/fallback.t
index c09a201a5c..e348d9240d 100644
--- a/lib/Math/BigInt/t/fallback.t
+++ b/lib/Math/BigInt/t/fallback.t
@@ -31,6 +31,10 @@ BEGIN
   plan tests => 8;
   }
 
+# The tests below test that cos(BigInt) = cos(Scalar) which is DWIM, but not
+# exactly right, ideally cos(BigInt) should truncate to int() and cos(BigFLoat)
+# should calculate the result to X digits accuracy. For now, this is better
+# than die()ing...
 
 use Math::BigInt;
 use Math::BigFloat;
diff --git a/lib/Math/BigInt/t/sub_mbi.t b/lib/Math/BigInt/t/sub_mbi.t
index 65c6d0b25f..3b3c6e645e 100755
--- a/lib/Math/BigInt/t/sub_mbi.t
+++ b/lib/Math/BigInt/t/sub_mbi.t
@@ -26,7 +26,7 @@ BEGIN
     }
   print "# INC = @INC\n";
 
-  plan tests => 2728
+  plan tests => 2760
     + 5;	# +5 own tests
   }