Re: [Tinycc-devel] RE :Re: New test 73_arm64 hangs if ran on RPi

[Michael Matz]

Hi,

On Mon, 9 Mar 2015, Edmund Grimley Evans wrote:

> Michael Matz <address@hidden>:
>
> > And some more fixes for more tests in 73_arm64, namely stdarg
> > passing of structs passed in purely integer registers.  structs
> > passed in fp regs or mixed int/fp regs are unfortunately not
> > consecutive in the reg_save_area, and hence need temporary memory,
> > but this requires some more involved changes in libtcc1.
>
> On arm64 a struct is sometimes not consecutive in memory. Code is
> generated in gen_va_arg() in arm64-gen.c to rearrange the data. I get
> more stack space using the global variable "loc".

Yes, I know.  I just wanted to avoid having to open-code a va_arg in 
x86-64, it currently uses a C implementation from libtcc1.  With that 
approach I can't allocate stack in the calling routine, of course, and 
would have to resort to a static buffer, which in turn would break 
multi-threaded use, or use malloc which would create a leak, or use malloc 
with reuse, which requires a global list, again creating multi-threaded 
problems :-/  Over that set of stones and hard places I went to bed.  (I 
now think the only realistic option is indeed to generate va_arg from the 
backend).


Ciao,
Michael.