Optimal for loop on the 68020.

Jef Poskanzer pokey at well.UUCP
Wed Jun 7 09:13:32 AEST 1989


In the referenced message, edler at cmcl2.UUCP (Jan Edler) wrote:
}However, the compiler shouldn't do either of these when d0 is initialized
}to a value < 65536.

Not good enough, since the loop body might modify the index variable.
If the compiler is smart enough to do a global semantic check for this
sort of thing, then you can do this optimization; but we've already
established that cc and gcc aren't that smart.
---
Jef

   Jef Poskanzer   {ucbvax, lll-crg, sun!pacbell, apple, hplabs}!well!pokey
 "A banker is a fellow who lends you his umbrella when the sun is shining and
          wants it back the minute it begins to rain." -- Mark Twain



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