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Re: [PATCH] Adjust _Unwind_Word in unwind.h to version in libgcc.


On Fri, Jul 31, 2015 at 09:18:46AM -0400, Carlos O'Donell wrote:
> 
> Does this mean s390 has 2 supported ABIs for 32-bit?
> 
> If so, we should adjust:
> 
> https://sourceware.org/glibc/wiki/ABIList?highlight=%28ABI%29#s390

No, there is only one ABI for s390-32.  s390-32 ESA and s390-32 ZARCH
both are supposed to adhere to the 31 bit ABI.  The latter will use 64
bit registers only in non-ABI relevant situations.  In order to
achieve this in GCC we had to increase the register size to 64 bit
even when compiling with -m31. Unfortunately the register size was
exposed to outside GCC in some places (e.g. mode(__word__)).  That's
why something like __unwind_word__ was invented (there are others).
mode("__unwind_word__") changes only with ABI switches (-m31/-m64)
while mode("__word__") does change with -mesa/-mzarch.

What Stefan just fixed was a problem where the libgcc and Glibc unwind
code was out of sync.

Bye,

-Andreas-


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