better debug print for inverse interpolate

MANIFEST

@@ -218,6 +218,7 @@ t/26-isfundamental.t
 t/26-isgaussianprime.t
 t/26-isodd.t
 t/26-isomegaprime.t
+t/26-isperfectnumber.t
 t/26-ispower.t
 t/26-issemiprime.t
 t/26-issquarefree.t

inverse_interpolate.c

@@ -130,6 +130,7 @@ static UV _inverse_interpolate(UV lo, UV hi, UV n,
     UV x0 = lo,  x1 = lo + ((hi-lo)>>1);   /* x2 = hi */
     UV rx1 = CALLBACK(x1);
     IV fx0 = rlo-n,  fx1 = rx1-n,  fx2=rhi-n+1;
+    if(_dbgprint)printf("  2s lo %lu  mid %lu  hi %lu  (%lu)\n", lo, x1, hi, (rx1>n) ? rx1-n : n-rx1);
 
     double pos = ((double)(x1-x0) * (double)fx1)
                / sqrtl((double)fx1 * (double)fx1 - (double)fx0 * (double)fx2);
@@ -141,14 +142,14 @@ static UV _inverse_interpolate(UV lo, UV hi, UV n,
       else          { lo = x1; rlo = rx1; }
     } else {
       UV rx3 = CALLBACK(x3);
+      if(_dbgprint)printf("  2S lo %lu  mid %lu  hi %lu  (%lu)\n", lo, x3, hi, (rx3>n) ? rx3-n : n-rx3);
       /* Swap if needed to have:   [lo  x1  x3  hi]  */
       if (rx1 > rx3) { UV t=x1; x1=x3; x3=t;  t=rx1; fx1=rx3; rx3=t; }
       if      (rx1 >= n) {                      hi = x1; rhi = rx1; }
       else if (rx3 >= n) { lo = x1; rlo = rx1;  hi = x3; rhi = rx3; }
       else               { lo = x3; rlo = rx3; }
     }
     MPUassert(rlo < n && rhi >= n, "interpolation: Ridder step error");
-    if(_dbgprint)printf("  2s lo %lu  mid %lu  hi %lu  (%lu)\n", lo, mid, hi, rhi-n);
   }
 
   /* Step 3.  Binary search. */

t/26-isperfectnumber.t

@@ -0,0 +1,22 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+
+use Test::More;
+use Math::Prime::Util qw/is_perfect_number/;
+
+#my $extra = defined $ENV{EXTENDED_TESTING} && $ENV{EXTENDED_TESTING};
+#my $usexs  = Math::Prime::Util::prime_get_config->{'xs'};
+#my $usegmp = Math::Prime::Util::prime_get_config->{'gmp'};
+
+my @true  = (qw/8128 33550336 8589869056 137438691328 2305843008139952128 2658455991569831744654692615953842176/);
+my @false = (qw/8505 12285 19845 28665 31185 198585576189 8 32 2096128 35184367894528 144115187807420416 9444732965670570950656/);
+
+
+plan tests => 1 + 2;
+            ;
+
+is_deeply([grep { is_perfect_number($_) } -10 .. 500], [6,28,496], "is_perfect_number(-10 .. 500)");
+
+is_deeply([map { is_perfect_number($_) } @true], [map { 1 } @true], "perfect: [@true]");
+is_deeply([map { is_perfect_number($_) } @false], [map { 0 } @false], "not perfect: [@false]");