14 May
2017
14 May
'17
7:14 p.m.
On Sat, May 13, 2017 at 03:05:24PM -0400, Random832 wrote:
On Sat, May 13, 2017, at 08:20, Michael Kjörling
wrote:
I recall reading a proposed ABI for C on MIPS which would have done
something similar for passing structs by value, namely pass a pointer
but allocate local storage space in the callee. If the callee ever
assigned to the passed struct, it was to copy the actual values,
then update its pointer. I don't think that ABI was ever implemented.
DF
Correct me if I am wrong, but _pass by value_ as
opposed to _pass by
reference_ requires making a copy, no? That's the whole point, to
allow the callee to poke at the value it is given at will.
If that were the issue, the callee could simply automatically make the
copy if-and-only-if it needs it.