if ($SIRtrue && !($_ =~ /SPECint_base/)){
    $SIR{$_}=$_;
    }
    if ($SFRtrue && !($_ =~ /SPECfp_base/)){
    $SFR{$_}=$_;
    }
##</code><code>##

use strict;
use warnings;

use Data::Dumper;

my $str = <<END;
SPECint_base
1
2
3
SPECfp_base
4
5
6
END

open my $fh, '<', \$str or die "Could not open for read:$!\n";

my $SIRtrue;
my $SFRtrue;
my %SIR = ();
my %SFR = ();

while (<$fh>){
    chomp;
    if (/SPECint_base/){
        $SIRtrue = 1;
        $SFRtrue = 0;
        next;
    }
    elsif (/SPECfp_base/){
        $SIRtrue = 0;
        $SFRtrue = 1;
        next;
    }
    if ($SIRtrue)){
        push( @{$SIR{SPECint_base}}, $_ );
    }
    elsif ($SFRtrue){
        push( @{$SFR{SPECfp_base}}, $_ );
    }
}

print Dumper(\%SIR);
print Dumper(\%SFR);
##</code><code>##

$VAR1 = {
          'SPECint_base' => [
                              '1',
                              '2',
                              '3'
                            ]
        };
$VAR1 = {
          'SPECfp_base' => [
                             '4',
                             '5',
                             '6'
                           ]
        };