On Mon, 4 Apr 2011 11:09:29 -0400, O'Brien, David W. (NIH/CIT) [C] <[email protected]> wrote:
>A colleague asked that the following query be posted: > >Are there any tutorials/samples for writing floating point assembler code. We need to work with the z/VM Performance data and it is stored in short floating point. Been playing in the Principles of Operation but have a bit of a time wrapping my head around floating point manipulation. > Dave, The floating point instructions in some ways are easier to use than the integer instructions because you don't have to worry about scaling and implied decimal points and all of that. The biggest problem with floating point is converting numbers to floating point and from floating point (any of the 3 formats). Until the conversion instructions came along to assist in the effort, doing the conversions was pretty arcane. Now its easier, but still work. The book "IBM Assembler Language Programming" by Sharon Tuggle (long out of print I imagine) does discuss the hexadecimal floating instructions and does provide sample programs for converting into and out of hexadecimal floating point. I was the reviewer for the floating point section. I still find TSO TEST useful for testing short segments of Assembler code, and one of my frustrations is that it only formats the original 4 floating point registers (0, 2, 4 and 6). It hasn't a clue that there are now 16 floating point registers or that there are now 3 floating point formats. In general, most testing environments give "lip service" to floating point. W. Kevin Kelley -- IBM POK Lab -- z/OS Core Technical Development ---------------------------------------------------------------------- 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
