{print STDERR "1"; "x" x 2**20}
{print STDERR "2"; "x" x 2**20}
{print STDERR "3"; "x" x 2**20}

##</code><code>##

$ strace -e mmap,munmap,write ./903114.pl
...
write(2, "1", 11)                        = 1
mmap(NULL, 1052672, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe6d7315000
write(2, "2", 12)                        = 1
mmap(NULL, 1052672, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe6d5e0f000
write(2, "3", 13)                        = 1
mmap(NULL, 1052672, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe6d5d0e000
munmap(0x7fe6d5d0e000, 1052672)         = 0
munmap(0x7fe6d5e0f000, 1052672)         = 0
munmap(0x7fe6d7315000, 1052672)         = 0

##</code><code>##

$ perl -MO=Concise,-exec ./903114.pl
...
11 <$> const[PV "x"] s
12 <$> const[IV 1048576] s
13 <2> repeat[t9] vK/2          <---
...