As Corion pointed out, the switch from !$_ to /0/ is overpowering the other differences and invalidating your test.

But other improvements can be made.

There's no reason to use an intermediate array in the latter snippet. This avoids the creation of 5 million scalars. 

my @e =
   grep !$_,
      map $_ % 2,
         @c;

[download]

You could even eliminate the grep. 

my @e =
   map $_ % 2 ? () : 0,
      @c;

[download]

Similar improvements can be made for the foreach version. 

my @e;
for my $c ( @c ) {
   my $d = $c % 2;
   push @e, $d if !$d;
}

[download]
my @e;
for my $c ( @c ) {
   push @e, 0 if !( $c % 2 );
}

[download]

Finally, I'm curious how these compare: 

my @e = ( 0 ) x grep !( $_ % 2 ), @c;

[download]
my @e; push @e, 0 for 1 .. grep !( $_ % 2 ), @c;

[download]

In reply to Re: Speed comparison of foreach vs grep + map by ikegami
in thread Speed comparison of foreach vs grep + map by mldvx4

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