Thank you for looking into this, dave_the_m. But there's still performance issue if integer, or float that appears to be integer, is not the first, but last element of array. Then there's just one expensive-to-free element in derived array?

use strict;
use warnings;
use Devel::Peek;
use Benchmark qw/ cmpthese timeit /;

our @a = map log, 2..1e6; 
push @a, 0/1;
print "************   a   ************\n";
Dump $a[-2];
Dump $a[-1];
my @b = map $_ * 4, @a;
print "************   b   ************\n";
Dump $b[-2];
Dump $b[-1];
 
cmpthese( -2, {
    1 => 'my @c = map $_ * 4, @a',
    2 => 'my @c = map $_ / (1/4), @a',
});

__END__

************   a   ************
SV = NV(0x55f0580) at 0x55f0598
  REFCNT = 1
  FLAGS = (NOK,pNOK)
  NV = 13.8155105579643
SV = NV(0x102a388) at 0x102a3a0
  REFCNT = 1
  FLAGS = (NOK,pNOK)
  NV = 0
************   b   ************
SV = NV(0xae879c8) at 0xae879e0
  REFCNT = 1
  FLAGS = (NOK,pNOK)
  NV = 55.2620422318571
SV = PVNV(0x714ec8) at 0xae879f8
  REFCNT = 1
  FLAGS = (IOK,pIOK)
  IV = 0
  NV = 0
  PV = 0
    Rate    1    2
1 10.3/s   -- -20%
2 12.8/s  25%   --

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In reply to Re^5: Should multiplication by integer be avoided in favour of division for performance reasons? (benchmark pitfalls) by vr
in thread Should multiplication by integer be avoided in favour of division for performance reasons? by vr

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