8 Jun
2017
8 Jun
'17
7:49 p.m.
On Wed, Jun 7, 2017, at 15:15, Arthur Krewat wrote:
On 6/7/2017 3:03 PM, Ron Natalie wrote:
In the days when memory and clock cycles were costly, an extra decrement
or subtract was not something to be taken lightly :)
You wouldn't need a decrement per access, because the base itself could
still be stored as the address of the "0th" element (i.e. what would be
the "-1th" in a 0-based system). It might add some extra complexity to
the relocator, if it's not currently possible to have a reference
outside the bounds of an object and/or with a negative offset, but
statically linked programs (the only kind on V7 and earlier) did not do
any runtime relocation.
Why go to
the trouble of decrementing the index to retreive the first entry?
What makes you
think that you have to decrement the index. Don't get sucked up in the idiotic C
implementation of an array. Arrays can be efficiently implemented no matter where the
index starts.