# use strict;
-print "1..32\n";
+print "1..54\n";
my $test = 1;
{
no warnings 'uninitialized';
- my $x, $y;
+ my ($x, $y);
eval {
$y ="$x\n";
++$x;
ok($x == 1, $x);
ok($@ eq '', $@);
- my $p, $q;
+ my ($p, $q);
eval {
$q ="$p\n";
--$p;
$a = 2147483648;
$c=$a--;
ok ($a == 2147483647, $a);
+
+{
+ use integer;
+ my $x = 0;
+ $x++;
+ ok ($x == 1, "(void) i_postinc");
+ $x--;
+ ok ($x == 0, "(void) i_postdec");
+}
+
+# I'm sure that there's an IBM format with a 48 bit mantissa
+# IEEE doubles have a 53 bit mantissa
+# 80 bit long doubles have a 64 bit mantissa
+# sparcs have a 112 bit mantissa for their long doubles. Just to be awkward :-)
+
+sub check_some_code {
+ my ($start, $warn, $action, $description) = @_;
+ my $warn_line = ($warn ? 'use' : 'no') . " warnings 'imprecision';";
+ my @warnings;
+ local $SIG{__WARN__} = sub {push @warnings, "@_"};
+
+ print "# checking $action under $warn_line\n";
+ my $code = <<"EOC";
+$warn_line
+my \$i = \$start;
+for(0 .. 3) {
+ my \$a = $action;
+}
+1;
+EOC
+ eval $code or die "# $@\n$code";
+
+ if ($warn) {
+ unless (ok (scalar @warnings == 2, scalar @warnings)) {
+ print STDERR "# $_" foreach @warnings;
+ }
+ foreach (@warnings) {
+ unless (ok (/Lost precision when incrementing \d+/, $_)) {
+ print STDERR "# $_"
+ }
+ }
+ } else {
+ unless (ok (scalar @warnings == 0)) {
+ print STDERR "# @$_" foreach @warnings;
+ }
+ }
+}
+
+my $h_uv_max = 1 + (~0 >> 1);
+my $found;
+for my $n (47..113) {
+ my $power_of_2 = 2**$n;
+ my $plus_1 = $power_of_2 + 1;
+ next if $plus_1 != $power_of_2;
+ my ($start_p, $start_n);
+ if ($h_uv_max > $power_of_2 / 2) {
+ my $uv_max = 1 + 2 * (~0 >> 1);
+ # UV_MAX is 2**$something - 1, so subtract 1 to get the start value
+ $start_p = $uv_max - 1;
+ # whereas IV_MIN is -(2**$something), so subtract 2
+ $start_n = -$h_uv_max + 2;
+ print "# Mantissa overflows at 2**$n ($power_of_2)\n";
+ print "# But max UV ($uv_max) is greater so testing that\n";
+ } else {
+ print "# Testing 2**$n ($power_of_2) which overflows the mantissa\n";
+ $start_p = int($power_of_2 - 2);
+ $start_n = -$start_p;
+ my $check = $power_of_2 - 2;
+ die "Something wrong with our rounding assumptions: $check vs $start_p"
+ unless $start_p == $check;
+ }
+
+ foreach my $warn (0, 1) {
+ foreach (['++$i', 'pre-inc'], ['$i++', 'post-inc']) {
+ check_some_code($start_p, $warn, @$_);
+ }
+ foreach (['--$i', 'pre-dec'], ['$i--', 'post-dec']) {
+ check_some_code($start_n, $warn, @$_);
+ }
+ }
+
+ $found = 1;
+ last;
+}
+die "Could not find a value which overflows the mantissa" unless $found;
+
+# these will segfault if they fail
+
+sub PVBM () { 'foo' }
+{ my $dummy = index 'foo', PVBM }
+
+ok (scalar eval { my $pvbm = PVBM; $pvbm++ });
+ok (scalar eval { my $pvbm = PVBM; $pvbm-- });
+ok (scalar eval { my $pvbm = PVBM; ++$pvbm });
+ok (scalar eval { my $pvbm = PVBM; --$pvbm });
+