On 17 January 2012 13:01, John Gilmore <[email protected]> wrote:
> The cross-platform emphasis in PL/X discourages and was intended to > discourage this sort of thing; but optimizing machinery, less > important in PL/S because resort to assemb ly language was possible, > does not appear to be much used by PL/X. (Even such obvious things > as moving common subexpressions out of loops and suppressing redundant > subscript arithmetic don't seem to happen.) > > IBM knows and has always known how to fix this problem; what has been|is > lacking is the will to do it. IBM almost a decade ago fixed the problem where it really counts - in its millicode. That is generated by the GCC suite, with a private-to-IBM PL8 language front end, and a published(?) middle-end optimizer and back end code generator. One bumps into the odd non-millicode module compiled by PL8's CMS-hosted predecessor implementation, PL.8, but porting of the whole GCC and Linuxy infrastructure, including ELF object format and other baggage, into the likes of z/OS would presumably be required before the current PL/X could be replaced and its code optimized. An outsider can only imagine the internal geopolitical goings on with regard to all this. Tony H.
