On 01/04/2012 12:09 AM, Manu wrote:
Does returning a tuple give any ABI guarantees? How can I be sure multiple return values will return in consecutive
registers?
* 1, 2 and 4 byte structs are returned in EAX.
* 8 byte structs are returned in EDX,EAX, where EDX gets the most
significant half.
* For other struct sizes, the return value is stored through a hidden
pointer passed as an argument to the function.
What if the return types are of different types, a float and an int...
can I expect each to return in their own register types respectively?
No.
This needs to be defined and loosely guaranteed (within reason) so
people can expect multiple return values to behave as expected on any
architecture.
A possibility would be to allow TypeTuple return types.
On 4 January 2012 01:02, Sean Kelly <s...@invisibleduck.org
<mailto:s...@invisibleduck.org>> wrote:
It's easy enough with Tuple, though better language support would be
nice.
Sent from my iPhone
On Jan 3, 2012, at 2:40 PM, Manu <turkey...@gmail.com
<mailto:turkey...@gmail.com>> wrote:
> Why doesn't D support multiple return values like many other
modern languages?
>
> Clearly the same syntax as Go wouldn't work, but I'm sure a neat
and tidy syntax could be invented?
> I constantly want to be able to return x,y from a function, or
retVal,errorCode and I want the language to make some rough ABI
guarantees, like multiple return values will be returned in
consecutive registers, rather than a single return value register
like C/C++, avoiding the need to pass output addresses through ref
function parameters (slow!).
