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Re: SH5 compact register numbering in gcc -> gdb interface


ac131313@cygnus.com wrote:
> Humor me here.
> 
> How do you use dwarf2 cfi to unwind a compact register (saved on the
> stack) back to a media register?  In addition to the address of the
> saved register you'll need to know that only part of the register was
> saved. Does CFI describe this?

With the proposed numbering change (2nd revision), we get different
numbers to describe compact an media registers.  So when only the lower
32 bits are saved, gcc can use the SHcompact register number to describe
this.

N.B., the upper 32 bits of the register are actually overwritten in the
process.  The restore from the stack sign-extends from bit 31.  The caller
is responsible to make sure that no 64 bit value is live in the register.	

-- 
--------------------------
SuperH
2430 Aztec West / Almondsbury / BRISTOL / BS32 4AQ
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