John, >> more overhead: consistent use of the compare and trap (or compare >> plus branch, 2 instructions, or compare-and-branch instruction on >> the z196)
Consistent use of compare and trap is not something you want. POP warns of cases when trap springs (this warning plus the extra overhead of operating system of choice for program-check handling). So I would expect a C-compiler to make heavy use of C+B but rarely use C+T (I am not a C-programmer: are there constructs that signal: likely outcome of a compare- or circumstances when condition is met). -- Martin Pi_cap_CPU - all you ever need around MWLC/SCRT/CMT in z/VSE more at http://www.picapcpu.de
