#!/usr/bin/perl -w
# We want to generate a stream of characters such that differences between
# character pairs cover all the ranges between [-255, 255].
#
# Naively, we could generate the cartesian product of [0,255] x [0,255],
# resulting in a 128K input file, and the output C code from that causes
# both GCC and Clang to use more than ~2G of memory to compile, even with
# optimizations disabled.
# 
# We can do a lot better by generating all byte pairs 0 x [0,255] instead.
# Each byte pair covers the deltas in the range of [0,255], and overlap with
# the starting byte of the next pair covers [-254,0].  We need one extra
# zero byte at the end to cover the -255 case.  This results in a 513 byte
# file, which costs GCC only ~300MB of RAM to compile.

use strict;

die "$0 <output.bin>\n" unless $#ARGV == 0;

open my $output, ">$ARGV[0]" or die $!;
foreach my $i (0..255)
{
   print $output chr(0), chr($i);
}
print $output chr(0);
close $output;