At 1:38 PM +0100 10/18/02, Simon Cozens wrote:
Yep, that's definitely a good way to do that. In many cases I think it'll be the right way[EMAIL PROTECTED] (Rhys Weatherley) writes:int x = ...; int y = (short)x;The value of x is truncated to 16 bits, and then sign-extended to int. I'm looking for something like the "conv.i2" instruction in IL, or "i2s" in JVM.One concievable way to do that is basically have the hypothetical CSInt and CSShort PMC classes know and care how many bits they're supposed to be, and handle overflow internally.
Alternately, we can have ops that act on I regs as 8, 16, 32 or, maybe, 64 bit quantities. Dealing with I regs as 64 bit quantities on a 32 bit system is somewhat problematic, as there are interesting architectural issues. (Do you double up registers? If so, what about systems that don't need it? Or do you keep a second set of half-registers squirrelled away somewhere? Which is an interesting problem in cache coherency, not to mention a hack)If need an op to do it, you can always provide a custom one. I think.
--
Dan
--------------------------------------"it's like this"-------------------
Dan Sugalski even samurai
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