-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Karthik Parashar wrote: > --- Stephen Williams <[EMAIL PROTECTED]> wrote: > >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> Karthik Parashar wrote: >>> Hi, >>> >>> I have one interesting observation when it comes >> to >>> iverilog's vvp assembly instructions. Which is as >>> follows: >>> >>> "Between the thread activities, there is no >> dependecy >>> on the threads 2^16 bit-wise registers." >> I think what you are saying is that the thread >> bit-wise >> registers are not accessible to other threads. That >> is >> a true statement. Threads only interact through >> variables >> and events. >> >> For example, it would be completely reasonable to >> swap out >> all the thread bits/registers when switching to >> another >> thread. > > I'm sorry for the confusion! > > What i want to know is, when a "%delay" is encountered > in the vvp assembly, the thread's bit-wise registers > dont seem to be having any dependency. > > Which means, in case, i try to save the thread context > when a delay occurs, i dont have to keep a backup of > these thread wise registers. Is this true?
Maybe it depends on what you consider the "thread's bit-wise registers". I am assuming you mean the things in the thread structure, and *not* the .net and .var declared variables. The machine does preserve all thread bit (and word) registers even across %delay statements, so a switched machine needs to save/restore the thread registers. In may not quite look like that in the code you are seeing, because the code generator knows that while a thread %delays (or %waits) other threads may change the variables external to the thread; and since most of the contents of the thread bits are copies of shared variables or expressions of the shared variables, they mostly get reloaded when returning from %delay. That's not a requirement, though, and I may well add optimizations where I detect that is not necessary and will skip the reload. - -- Steve Williams "The woods are lovely, dark and deep. steve at icarus.com But I have promises to keep, http://www.icarus.com and lines to code before I sleep, http://www.picturel.com And lines to code before I sleep." -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFEdc+ZrPt1Sc2b3ikRAn78AJ9IkHGDLcbwLX5m7WA9MUmvFYUkVACdGEZW RBoEvDFiFWmI2eUsE1Du1Ns= =f2XT -----END PGP SIGNATURE-----
