On Tue, 16 Feb 2010 12:09:48 -0600 "McKown, John" <[email protected]> wrote:
:>I know "it's the one not taken!". But of the B, J, or BR, can they be ordered? I am 99.9% certain that having the branch address in a register is the fastest. But is it significant enough that I should dedicate a register for it? I'm asking because I'm reoptimizing some code which is very heavily used. So heavy, that a 1% improvement is worth while. I am currenly holding 4 different addresses in registers to speed up branch processing in my main loop. This loop is basically compressing blanks using a primitive RLE algorithm. Probably J, as it is relative. :>Two ancillary questions: :>What is the fastest way to find a blank starting at an address in a register and not going past the address in another register. Right now, I'm just doing a loop like: :>LOOP DS 0H :> CLI 0(R8),C' ' :> BER Rx PRELOADED WITH THE RIGHT ADDRESS :> LA R8,1(,R8) :> CR R8,R9 :> BLR Ry PRELOADED WITH A(LOOP) :> B NOMORE :>Would an EX of a TRT be worth while? Use SRST. :>Second: once I have found the blank, what is the fastest way to find the next non-blank, again not going past the end of the buffer, which is in R9. I'm currently using CLCL. Where the registers are set up so that the "source" address is zeros, the length is the length of the remaining buffer, and the "pad" character is 0x40. This makes it scan for a blank without accessing the second memory address. :>This is on a z9BC, which is now purchased. So we ain't gonna be upgrading anytime soon. -- Binyamin Dissen <[email protected]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
