Re: Calling conventions (particularly 32-bit ARM)

On Tue, 7 Jan 2025 23:35:31 +0000, Scott Lurndal wrote:

mitchalsup@aol.com (MitchAlsup1) writes:

My 66000 ABI passes structs up to 8 doublewords in size as
arguments and as results.

>
What is a doubleword in your architecture?   In intel vernacular
it's  32-bits, but that's not universal.

Intel is wrong, IBM defined the tern before Intel was existent
(1963 or earlier).
Byte    8-bits
Half   16-bits
word   32-bits
DW     64-bits
QW    128-bits
OW    256-bits
Line  512-bits
Oh, and BTW:: DEI stands for Dale Earnhardt Incorporated...

Both x86_64 and ARM64 support passing eight 64-bit quantities
as arguments and as results architecturally without using
the SIMD registers.
>
Now, ABI conventions may be otherwise, but they're important
for interoperability, not basic functionality.

Done wrong (or weak) they add overhead.