Re: Performance problem with table.move

[Andrew Gierth <andrew@...>]

>>>>> "Ranier" == Ranier Vilela <ranier.vf@gmail.com> writes:

 Ranier> For loops, the quickest option, are variables with the natural
 Ranier> size of the machine.
 
 >> No.
 
 Ranier> No what?

I mean: No, that is a false statement.

For a concrete example: on 64-bit intel, there is an explicit
optimization guideline (from Intel's own optimization reference manual):

  Assembly/Compiler Coding Rule 63. (H impact, M generality) Use the
  32-bit versions of instructions in 64-bit mode to reduce code size
  unless the 64-bit version is necessary to access 64-bit data or
  additional registers.

("H impact" = high impact, "M generality" = medium generality)

Other 64-bit architectures typically have equal performance for 32-bit
and 64-bit operations.

If you want to prove me wrong, show an example of _actual code_ where
either 64-bit values or unsigned 32-bit are an improvement over signed
32-bit.

-- 
Andrew.