Re: Calling conventions (particularly 32-bit ARM)

On Tue, 14 Jan 2025 19:18:27 +0100
Terje Mathisen <terje.mathisen@tmsw.no> wrote:

Stephen Fuld wrote:

On 1/12/2025 5:20 PM, Waldek Hebisch wrote: 

You are implicitely assuming that passing large number of
arguments is expensive.  

 
I guess.  I am actually assuming that passing arguments in memory
is more expensive than passing them in registers.  I don't think
that is controversial. 

 
Usually true, except for recursive functions where you have to store
most stuff on the stack anyway, so going directly there can sometimes
generate more compact code.
 
Terje
 

I would think that for Fortran (==everything passed by reference)
memory would beat registers most of the time. May be, except for
functions with 0-4 parameters.
Do common Fortarn compilers even bother with passing in register?
It would require replacement of natural by-reference "pointer in
register points to value in memory" calling sequence to something like
copy-in/copy-out, right?