Crystal: Force 64-bit maths

[EddieRingle]

As you pointed out in the last PR, the Crystal version was using 32-bit integers. This patch fixes that.

New benchmark against Clang:

ganglion:genprime eddie$ ./genprime-crystal 250000 1000000
Found   250000 primes in    1.65555 seconds (last was    3497861)
Found   500000 primes in    4.67614 seconds (last was    7368787)
Found   750000 primes in    8.79405 seconds (last was   11381621)
Found  1000000 primes in   13.79081 seconds (last was   15485863)

ganglion:genprime eddie$ ./genprime-c-clang 250000 1000000
Found   250000 primes in    1.75610 seconds (last was    3497861)
Found   500000 primes in    5.02919 seconds (last was    7368787)
Found   750000 primes in    9.30910 seconds (last was   11381621)
Found  1000000 primes in   15.12655 seconds (last was   15485863)

[EddieRingle]

lim was already 64-bit, y was not, however.

New commit forces 64-bit maths, verified the LLVM IR to be equivalent to the Clang version.

[tycho]

Also it would be ideal if it used the native integer width like the C
version does (instead of explicitly 64-bit)
On May 4, 2015 11:16 AM, "Eddie Ringle" notifications@github.com wrote:

lim was already 64-bit, y was not, however.

New commit forces 64-bit maths, verified the LLVM IR to be equivalent to
the Clang version.

—
Reply to this email directly or view it on GitHub
#5 (comment).

[EddieRingle]

I'm not sure just using the native integer width types is so easy, as per:
http://crystal-lang.org/docs/builtin_types/integer_types.html

There are also to_i and to_u, which are just synonims [sic] of to_i32 and to_u32 respectively.

So it's 32-bit by default, I guess.