I never tried it before but Math::BigInt can be used to see these numbers in full precision.

use strict;
use warnings;
use Math::BigInt;

my $x = Math::BigInt->new('0x1fffffffffffff');
$x->blsft(1023 - 52);
print '0x1fffffffffffff: ' .  $x->bstr() . "\n\n";

my $y = Math::BigInt->new('0x1ffffffffffffe');
$y->blsft(1023 - 52);
print '0x1ffffffffffffe: ' .  $y->bstr() . "\n\n";

my $z = $x - $y;
print 'difference      : ' . $z->bstr() . "\n\n";

my $n = Math::BigInt->new(2);
$n->bpow(971);
print '2**971          : ' . $n->bstr() . "\n\n";


print "length of largest double precision value in base 10            
+ : " . length($x->bstr()) . " digits\n";
print "length of 2**971 (least significant bit of mantissa) in base 10
+ : " . length($n->bstr()) . " digits\n";

__END__

0x1fffffffffffff: 1797693134862315708145274237317043567980705675258449
+965989174768031572607800285387605895586327668781715404589535143824642
+343213268894641827684675467035375169860499105765512820762454900903893
+289440758685084551339423045832369032229481658085593321233482747978262
+04144723168738177180919299881250404026184124858368

0x1ffffffffffffe: 1797693134862315508561243283845062402343434371574593
+359244048724485818457545561143884706399431262203219608040271573715708
+098528849645117430440876627676009095943319277282370788761887605795325
+637686986540648252621157710157914639830148577040081234194593862451417
+23703148097529108423358883457665451722744025579520

difference      : 1995840309534719811656372713036838566067451260435457
+541502547242437211891868964065784957965492635701089342446844192495243
+972437988393593660739171798284831420320005672951085676517537721444362
+987182653356744543923993330810455120870388888855268448044157507120906
+8757560416423584952303440099278848

2**971          : 1995840309534719811656372713036838566067451260435457
+541502547242437211891868964065784957965492635701089342446844192495243
+972437988393593660739171798284831420320005672951085676517537721444362
+987182653356744543923993330810455120870388888855268448044157507120906
+8757560416423584952303440099278848

length of largest double precision value in base 10             : 309 
+digits
length of 2**971 (least significant bit of mantissa) in base 10 : 293 
+digits

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In reply to Re^4: Large floating point literals by ig
in thread Large floating point literals by ig

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