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Re: SH atomic asms in glibc and the stack pointer

"Joseph S. Myers" <> wrote:
> This asm doesn't tell the compiler that r15 is temporarily saved and 
> restored, and marking it as clobbering the stack pointer is unlikely to 
> work.  It might be possible to avoid problems by marking all the inputs 
> that are used while the stack pointer has its special value as being 
> read/write operands, so they do not get assigned to the stack pointer, or 
> by clobbering additional fixed registers that are used to load the input 
> values at the start of the asm.  But both of these seem inefficient 
> (requiring extra registers to be allocated) when what's actually required 
> is simply to allocate the inputs to any register other than r15.  So in my 
> view the best fix is to add a new constraint that means "any 
> general-purpose register other than r15" and to use it in glibc when the 
> compiler version is new enough.  That is what these GCC and glibc patches 
> do.  Comments?  OK?

OK.  Thanks for fixing this!

Uli, could you please approve the libc patch?


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