[cfe-dev] Figuring out if parameter types are passed in same register
Nat! via cfe-dev
cfe-dev at lists.llvm.org
Mon Sep 14 03:19:20 PDT 2015
mats petersson wrote:
> I'm assuming you are looking to "not reload edi", but that's not going
> to work if f1 or f2 makes any call that takes an argument [or edi is
> used for something else in the function!].
Actually no. In my case [^1] there is a trampoline function hidden
between g and f and I would like to figure out, which kind of types I
can pass transparently on the ABI/architecture.
So it would be more akin to
void f1( int x)
void call( void (*f)( void *), void *arg)
call( (void (*)( void *)) f1, (void *) 1848);
This would work on x86_64, but fail on 680x0 AFAIK.
To elaborate a bit more, if the parameters are passed on the stack, then
trivially types of different size are bound to fail, thats why I am
looking at registers only.
Thanks for the response.
[^1] For the big picture view :)
I am currently doing "A more formal definition of the mulle-objc meta
call convention" point 2.
More information about the cfe-dev