On 1 October 2013 20:06, Bernd Oppolzer <bernd.oppol...@t-online.de> wrote: > Stanford PASCAL also generates P-Code in the first step, > which in the second step is translated to 370 machine code.
Interesting; I had thought that P-code was only interpreted. > BTW: The P-Code of the 1982 variant of the Stanford compiler > had been extended compared to the 1979 variant, and because > I found only a description of the 1979 variant, it was a little bit > complicated to find out what the "new" P-Code instructions do. > There is not "one" P-Code, but many variants of P-Code. > > And: it turned out, that the P-Code is not so machine-independant > as it should be. There will be some difficulties regarding character > sets etc., when I try to port the compiler to an ASCII based platform, > for example (which I would like to do in the future). You could instead generate JVM bytecodes... It's almost machine-independent. I haven't looked at P-code (is there an accessible overview?), but had heard of it long ago. When Java came out I looked at the JVM reference book, and thought - Oh, this isn't too complicated, I could write an interpreter for it in a week or so and have my own JVM. But it turns out that the hard part of a JVM isn't the bytecode interpreter at all; it's all the class loading stuff. I imagine the P-code system doesn't have such heavy baggage. Tony H. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
