One Assembler trick I have seen in speeding up scanning loops was to use a CLI instruction to check the first byte of a string and then only doing the CLC/CLCL if the CLI matches. This trick even works if doing a binary search.
-----Original Message----- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Tom Marchant Sent: Monday, January 16, 2012 6:35 AM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: How bad is the EX instruction? On Fri, 13 Jan 2012 18:29:55 -0800, glen herrmannsfeldt wrote: >> The EX CLC is in fact in loop scanning a linked list for the right >> entry among 100-200 elements. > >You could also do binary search, which will find the right entry with >about log(n) comparisons. How do you do a binary search on a linked list? -- Tom Marchant
