I don't think so... my test program:

#!/usr/bin/perl -w
use strict;
my @a;
push @a,{x=>1,y=>1};
push @a,{x=>2,y=>1};
push @a,{x=>1,y=>2};
push @a,{x=>2,y=>3};
push @a,{x=>2,y=>2};
foreach(sort {$a->{x} <=> $b->{x} or $a->{y} <=> $b->{y}} @a){
  print " $_->{x}  $_->{y}\n";
}
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prints the correct results:

$ ./sort.pl 
 1  1
 1  2
 2  1
 2  2
 2  3
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