Path: utzoo!attcan!uunet!husc6!bloom-beacon!bu-cs!mirror!necntc!ima!compilers-sender From: sco!seanf@uunet.uu.net (Sean Fagan) Newsgroups: comp.compilers Subject: Re: Compilers for Decoupled Architectures. Message-ID: <1955@scolex> Date: 20 Dec 88 18:19:56 GMT References: <3058@ima.ima.isc.com> Sender: compilers-sender@ima.ima.isc.com Reply-To: sco!seanf@uunet.uu.net (Sean Fagan) Organization: The Santa Cruz Operation, Inc. Lines: 29 Approved: compilers@ima.UUCP In article <3058@ima.ima.isc.com> Theodore Stevens Norvell writes: >I am interested in references on compilers for decoupled architectures and >machines with a similar register structure (such as the CDC 170 and the Crays). [my favorite word 8-)] [brief description of splitting of registers given] Well, I worked on a Cyber 170 for quite a while, and looked a bit into what GCC would need to get it to work (you've always wanted 60-bit char's right?). Basicly, there isn't a big problem for compiler written for that machine. FTN5, for the Cyber, would put index registers and DO loop variables into the 18-bit B registers (unless you told it you wanted "big" DO loops, in which case it used a 60-bit X register). Making gcc work, on the other hand, would not do such a thing (because a B register is a register of class Pointer, for which it has at least some basic hooks), unless the person describing the cyber to gcc were really clever (which I'm not 8-)). Also, in your example, if N is a constant, and less than 2**17, than it would be best to put it into an index register. A[i], B[i], and z should go into data registers, as you said. However, on a Cray, you could probably vectorize it, splitting it up (at run time?) to do it in chunks of 64 A's and B's. -- Sean Eric Fagan | "Merry Christmas, drive carefully and have some great sex." seanf@sco.UUCP | -- Art Hoppe (408) 458-1422 | Any opinions expressed are my own, not my employers'. -- Send compilers articles to ima!compilers or, in a pinch, to Levine@YALE.EDU Plausible paths are { decvax | harvard | yale | bbn}!ima Please send responses to the originator of the message -- I cannot forward mail accidentally sent back to compilers. Meta-mail to ima!compilers-request