Hi, X10 ver 2.4.0 claims that arrays are now Long-based so that we can exploit large memory. I often use large arrays so I'm really happy to see this change.
http://x10-lang.org/software/download-x10/latest-release.html > Taken together these two changes enable natural exploitation > of large memories via 64-bit addressing and Long-based indexing > of arrays and similar data structures. However, I wonder if it holds true for the Java backend. Below is a small example to illustrate the problem. ===start here import x10.util.Random; public class RandomFill { static N = 1000 * 1000 * 1000 * 8; public static def main(args: Rail[String]) { val arr = new Rail[Long](N); val r = new Random(); Console.OUT.println("Filling"); for(i in 0..(N - 1)) arr(i) = r.nextLong(); // Access to the large array (*) } } ===end here Here, N is 8G, so could not be represented in 32 bits. It worked fine with the C++ backend. Also I checked the compiled code and everything seemed as expected. However, with Java backend, the compiled code looked like this (note: I edited it for readability): final long[] arr$value137 = ((long[])arr.value); (snip) final long i128 = i131; final long t127 = r.nextLong$O(); arr$value137[(int)i128]=t127; Here we see that the index of the array is int. I know that JVM does not allow large arrays so it could not be fixed without significant engineering, but I believe it should be indicated somewhere. -- Masahiro KASAHARA <mk...@cb.k.u-tokyo.ac.jp> Department of Computational Biology, Graduate School of Frontier Sciences, University of Tokyo CB09, 5-1-5, Kashiwanoha, Kashiwa City, Chiba Pref. 277-8583, JAPAN TEL : +81-4-7136-4110 FAX : +81-4-7136-4500 ------------------------------------------------------------------------------ Android is increasing in popularity, but the open development platform that developers love is also attractive to malware creators. Download this white paper to learn more about secure code signing practices that can help keep Android apps secure. http://pubads.g.doubleclick.net/gampad/clk?id=65839951&iu=/4140/ostg.clktrk _______________________________________________ X10-users mailing list X10-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/x10-users